N LIBRARY UNIVERS'TY OF I CALIFORNIA^/ an fyt rfouti) tte at '. , . Faringdon . ... Feme Ferns Feversham . . v . Flexley . Ford Fountains .... Frethelstoke . <"{ . Furness Garendon . . i .' Glastonbury . . . Glenluce Grace- Dieu .... Great Corrall . i ; . Haddington . '. . Haghman .... Hagneby . . I ' . Hales Owen . ] . Hasledon .... Hayles Hertland .... Hexham Hilton Holme-Cultram . . Holy- Cross . . Holy-Hood . . ..'.} . Home Lacy . . i f > Horton Hulme Humberstayn . . . ABB ABBEYS. ABB NAME. Hurnston .... Hyde . . ORDER. Benedictine Cluniac Cistercian Augustine Do. Cistercian Augustine Cistercian Do. Tyrone Augustine Do. Cistercian Tyrone Cistercian Do. Do. Do. Do. Do. Premonstrant Do. Augustine Premonstrant Do. Premonstrant Tyrone Augustine Tyrone Cistercian Augustine Cistercian Do. Benedictine Cistercian Do. Do. Do. Do. Do. Do. Benedictine Do. Augustine Cistercian Do. Do. Premonstrant Cistercian Do. Premonstrant Cistercian DATE. temp. H. II. 1110 1180 1200 1200 1180 temp.Dav.I. 1156 1145 1128 1122 1170 1200 1140 1200 1139 1209 1152 1139 1150 1192 1198 1136 temp. Hen. II. 1143 1182 1140 1178 1178 1145 1139 temp. Dav. I. 675 1147 1283 1150 1200 1142 1136 1148 939 933 1133 temp. Hen. I 1138 1239 1198 1140 1246 1143 1150 COUNTY. Lincolnshire Hampshire Argyleshire Kilkenny Perthshire Do. Down Roxburghshire Yorkshire Do. Roxburghshire Warwickshire Somersetshire Tipperary Ayrshire Merionethshire Wiltshire Merionethshire Yorkshire Lincolnshire Moray Kent Norfolk Gloucestershire Buckinghamshire Leicestershire Suffolk Lanarkshire Gloucestershire Perthshire Monmouthshire Shropshire Lincolnshire Avrshire Wiltshire Glamorganshire Denbighshire Yorkshire Buckinghamshire Louth Roxburghshire Warwickshire Somersetshire Dorsetshire Buckinghamshire Glamorganshire Northumberland Hampshire Lincolnshire Edinburghshire Devonshire Lincolnshire Down Icolmkill .... lespoint Inchaffray .... Inchmahome . . . Inys . . . Jedburgh .... Jerval Joneval Kelso Kenilworth .... Keynsham .... Kilcooly Kilwinning .... Kimmer or Cymmer . Kingswood .... Kinner ..... Kirkstall .... Kirkstead .... Kynloss Langdon (West) . . Lanulev Lanthony .... Lavenden .... Leicester .... Leiston Lesmahagow . . . Lesnes Lindores Llantarnam .... Lolleshull .... Louth Park .... Machline .... Malmsbiiry .... Margan Maynan ..... Meaux . Medmenham . . . Mellifont .... Melrose Mereval Michelney .... Milton Missenden .... Neath Nerminster .... Netley Newbo Newbottle .... Newenham .... Newhouse .... Newry ABB ABBEYS. ABB NAME. Northampton . . . Nutley ORDER. Augustine Do. Augustine Do. Do. Cistercian Templars Cluniac Benedictine Cistercian Do. Do. Benedictine Do. Cistercian Do. Do. Do. Do. Augustine Cistercian Do. Do. Benedictine Cistercian Do. Do. Augustine Benedictine Do. Premonstrant Benedictine Do. Cistercian Benedictine Cistercian Do. Do. Premonstrant Benedictine Do. Do. Augustine Benedictine Cistercian Augustine Cistercian Augustine Cistercian Premonstrant Cistercian DATE. 1112 1162 St. Columba 1129 1175 1205 temp. Hen. II. 1164 984 1143 1132 1140 969 1121 1142 1280 1131 1176 1147 1146 1148 1098 1136 1146 1146 1164 1114 1069 888 temp. Hen. II. 705 1083 1149 1052 1172 1151 1154 1151 793 605 1020 1112 1096 1139 temp. Ed. III. 1349 1143 temp. Ed. III. 1191 1294 COUNTY. Northamptonshire Buckinghamshire Argyleshire Oxfordshire Leicestershire Limerick Leicestershire Renfrewshire Worcestershire Northamptonshire Hampshire Staffordshire Huntingdonshire Berkshire Lincolnshire Oxfordshire Yorkshire Sussex Yorkshire Staffordshire Ireland Nottinghamshire Isle of Man Essex Yorkshire Huntingdonshire Argyleshire Perthshire Yorkshire Dorsetshire Westmoreland Dorsetshire Shropshire Suffolk Lincolnshire Cheshire Wiltshire Warwickshire Yorkshire Hertfordshire Kent Norfolk Northampton Essex Dublin Drogheda Middlesex Leicestershire Ireland Kent Cardiganshire Oransey .... Osney Osulveston .... Owney Owrston Paisley Pershore Pipwell . . . 4 :. Quarre . . . - Radmore .... Ramsey Reading Revesby Rewley Rivaux Robertsbridge . . . Roche Roncester .... Rosglas Rufford Russen . . . M Saffron Walden 'v . Salley . . . Y . Saltry . . . V . Scone Selby . *}(?ftiiMJ Shaftesbury . *-'' Shireburn .... Shrewsbury . . . Sibton Spalding .... Stanlaw . . . . . Stanley Stoneley St. Agatha .... St. Alban's . . . St. Augustine . St. Bennet of Hulme St. James .... St. John's, Colchester St. Mary 4 . , ; ^ St. Maiy . . i' > St. Mary de Grace St. Mary de Pre . . St. Mary de Valle 1 Salutis . . . J St. Radegund . . Strada Florida, or "1 Stratfleur . . J ABB ABBEYS. ABB NAME. Stratford Longthorne Stratmargel, or Stra- 1 ta Marcella . . J Sulby Sweetheart, or New . Swine ORDER. Cistercian Do. Premonstrant Cistercian Do. Do. Premonstrant Cistercian Benedictine Do. Augustine Benedictine Cistercian Do. Do. Premonstrant Do. Do. Do. Cistercian Do. Do. Augustine Cistercian Do. Benedictine Premonstrant Augustine Premonstrant Do. Cistercian Benedictine Augustine Cistercian Benedictine Cistercian Augustine Benedictine Do. Cistercian DATE. 1134 1170 1155 1296 temp. Steph. 1134 1197 1137 961 1102 1139 972 1152 1131 1308 1231 1196 1160 temp. H. II. 1266 1200 1147 1062 1135 1128 1153 temp. Hen. I. temp. H. III. 1188 1135 1049 1178 1296 Wm. Conq. 1143 1179 985 1107 1145 COUNTY. Essex Montgomeryshire Northamptonshire Kirkcudbright Yorkshire Lincolnshire Carmarthenshire Oxfordshire Devonshire Gloucestershire Yorkshire Cambridgeshire Essex Monmouthshire Wexford Hampshire Devonshire Kirkcudbright Lincolnshire Cheshire Denbighshire Lincolnshire Essex Bedfordshire Surrey Durham Nottinghamshire Lincolnshire Norfolk Do. Essex Middlesex Kent Lancashire Yorkshire Herefordshire Gloucestershire Norfolk Bedfordshire Swineshead . . . Talley Tame Tavistock .... Tewkesbury . . . Thorneton .... Thorney Tiltey Tintern Tintern Titchfield .... Torr Tungland .... Tupholm .... Vale Royal .... Valle Crucis . . . Vaudey Waltham Abbey . . Wardon Waverley .... Wearmouth . . . Welbeck Wellow .... Wendling .... West Dereham . . West Ham .... Westminster . . . Westwood .... Whalley Whitby Whiteland .... Wigmore .... Winchcombe . . . Windham .... Woburn Abbey gate-house, a lodge or porters at the enti abbey edifice Abbot, the superior of a r monks erected into a priory : there are vario abbots, as mitred, crc dinal, regular, and coi abbots Abbot's lodgings, in the e< English ecclesiastical for warders ance of an oonastery of n abbey or us classes of siered, car- nmendatory irly times of irchitecture, a complete house, with hall, chapel, and every convenience for the resi- dence of a spiritual baron Abbreviate, to contract a word in writing or printing Abbreviations, characters or marks over letters to signify either a word or syllable Abele-tree, a species of white poplar Aberration, in astronomy, an apparent motion of the celestial bodies oc- ABE ABUSES. ABU casioned by the progressive motion of light and the earth's annual motion in its orbit Aberration, in optics, the deviation or dispersion of the rays of light when reflected by a lens, by which they are prevented from meeting or uniting in the same point, called the geometrical focus; but spread over a small span, they produce a confusion of images Ablactation, in gardening, the method of grafting Ablaqueation, the opening of the ground around the roots of trees, for the admission of the air Aboard, a nautical term, the inside of a ship, or to go on board About-ship, the situation of a ship after she has tacked About-sledge, the largest hammer em- ployed by smiths ; it is slung round near the extremity of the handle, and generally used by under work- men, called hammer-men Abrasion, the effect produced by at- trition or rubbing Abreast, as when two ships have their sides parallel Abreuvoir, a watering-place Abreuvoir, in masonry, the interstice or joint between two stones to be filled up with mortar or cement Abscissa, a geometrical term for a seg- ment cut off from the straight line by an ordinate to a curve Absorbents, in chemistry, those earthy substances capable of uniting, by capillary attraction, a large pro- portion of water: such are mag- nesia, lime, and clay, when dry and porous Absorption, in chemistry, takes place when, by the combination of gases with other substances, a very con- siderable diminution of volume is experienced: it differs from con- densation Abstract (To}, a term used by arti- ficers and surveyors in arranging and apportioning their work, to explain and price it Abstract mathematics, otherwise de- nominated pure mathematics, that branch of the science which treats of simple properties, magnitude, figure, or quantity, absolutely and generally considered Absurd, a term used in demonstrating converse propositions Abundant number, a number whose aliquot parts, added together, make a sum which is greater than the number itself Abuses. "Architecture," says Palladio, " being an imitatrix of Nature, de- lights in that which is most conso- nant with her prototype." Ancient edifices were built with wood, trees forming the columns ; and when architects began to build with stone, theymadethe columns to imitate the trunks of trees, tapering from their bases. Being thus originally of wood, and therefore liable to split when much loaded, they bound them with rings at top and bottom. Thus the bases and capitals in the different orders seem originally de- rived from these bandages, though they are now become essential ornaments. Thus also in entabla- tures, the triglyphs, modillions, and dentils represent the ends of those beams and timbers which are em- ployed for the support of the floors and roofs. If, therefore, all these conditions be duly considered, those practices in building are highly to be reprobated which are in oppo- sition to that analogy which should exist between the original and its imitation, or which depart from Na- ture and the simplicity observable in all her works. Consoles or cartouches, which are of a scroll-like form, should never be employed for the appa- rent support of great weights, in place of columns or pilasters ; nor should they ever project from, or spring out of, cornices. Pediments and frontispieces over doors and windows, or elsewhere, should on no account be broken or disconnected in the middle; for the intention of these is to shelter the parts below from the rain, and ABU ABUTMENTS. ACC this result is completely obviated by such a practice. The projecture of cornices, though for the purpose of shelter- ing buildings, should not be more than in due proportion to their height, whether or not accompanied by columns ; for if too heavy, they seem to threaten with danger those who are under them; and if too small in projection, they do not properly perform their office. Again, those columns which are feigned to be composed of several pieces, by being jointed together with rings, should be carefully avoided, because the more solid and strong the columns appear, the better they seem to answer the purpose for which they were erect- ed, which is securely to receive the superincumbent loading. There are many other abuses which the authority of great mas- ters may sanction, but not justify ; and such will readily occur to the student, and themselves point out that they ought to be avoided Abutment, the solid part of a pier from which the arch springs Abutments, the extremities of a bridge, by which it joins upon the banks or sides of a river, &c. : in carpentry and joinery, the junctions or meetings of two pieces of timber, of which the fibres of the one run perpendicular to the joint, and those of the other parallel to it Abuttals, the buttings or boundaries of land Abyss, in heraldry, the centre of an escutcheon Acacio, a heavy, durable wood of the red mahogany character, but darker and plainer ; it is highly esteemed in ship-building Academia, in antiquity, a villa or pleasure-house in one of the sub- urbs of Athens, where Plato and other philosophers assembled Academician, a member of a society or academy instituted for the cul- tivation of the arts and sciences Acanthus, the plant branca ursina, in English bear's breech, the leaves of which are imitated in decorating the Corinthian and Composite ca- pitals of columns Accelerated motion, a force acting in- cessantly upon a body; called also a constant or uniformly accelerating force when the velocity increases equally in equal times : the force of gravity near the earth's surface is of this kind; it generates a ve- locity of 32 feet in each second of time ; that is, a body, after falling one second, acquires a velocity of 32^ feet ; after falling two seconds, it will acquire a velocity of 2 x 32^- feet ; after three seconds, a velocity of 3 x 32^ feet, and so on Accelerating force, in physics, the force which accelerates the motion or velocity of bodies; it is equal to, or expressed by, the quotient arising from the motion or absolute force, divided by the mass or the weight of the body moved Accelerative or retardative force, is commonly understood to be that which affects the velocity only, or that by which the velocity is ac- celerated or retarded; it is equal or proportional to the motive force directly, and to the mass or body moved inversely Accesses, approaches or passages of communication between the various apartments of a building, as corri- dors Accessible, in surveying, a place which admits of having a distance or length of ground measured from it; or such a height or depth as can be measured by the application of a proper instrument Accessories, or accompaniments, in painting, secondary objects to the principal one in a picture, intro- duced as explanatory and illus- trative of the scene: sometimes they are considered as solely con- tributing to the general effect and harmony of the piece Accidental point, in perspective, the point in which a right line drawn from the eye, parallel to another ACC ACROTERIA. ACT right line, cuts the picture or per- spective plane Acclivity, the slope or steepness of a line or plane inclined to the hori- zon, taken upwards ; in contra- distinction to declivity, which is taken downwards Accouplement, in carpentry, a tie or brace, or the entire work when framed Accretion, in physics, the growth or increase of an organized body Accroche, in heraldry, denotes the hanging of one thing upon another Accubilus, a room annexed to large churches, in which the clergy oc- casionally reposed Aceric acid, in chemistry, an acid formed from the juice of the maple- tree Acerra, in antiquity, an altar erected, among the Romans, near the bed of a person deceased, on which his friends daily offered incense until his burial Acetate of lead, sugar of lead, a compound of acetic acid and lead Acetate of potash, a compound of acetic acid and potash, produced by dissolving carbonate of potash in distilled vinegar Acetates, crystallizable salts, formed by the combination of any base with acetic acid, named also radical or pure vinegar Achromatic, a term expressing ab- sence of colour : in optics, applied to telescopes invented to remedy aberrations and colours Acids, in chemistry, are sour to the taste, and convert vegetable blues to a red colour; they combine with alkalies, earths, and metallic oxides, and form, with them, the well- known compounds named salts Acinose, a term applied to iron ore found in masses, and of several co- lours A-cocJc-bill, in navigation, the situ- ation of the yards when they are topped up at an angle with the deck ; the situation of an anchor when it hangs to the cat-head by the ring only Acolyte, in the ancient church, a person who trimmed the lamps, prepared for the sacrament, &c. Acoustics, the doctrine or theory of sounds, consisting of diacoustics, or direct sounds, and catacoustics, or reflecting sounds Acre, a measure of land, containing, by the ordinance for measuring land in the time of Edward I., 160 perches or square poles of land; and as the statute length of a pole is 5.j yards or 16 feet, the acre contains 4840 square yards, or 43560 square feet. The chain with which land is now commonly measured, invented by Gunter, is 4 poles, or 22 yards, in length ; and the acre is therefore just 10 square chains; and as a mile contains 1760 yards, or 80 chains, in length, the square mile is equal to 640 acres. The acre, in surveying, is divided into 4 roods, and the rood into 4 perches Acrolithes, in sculpture, statues, the extremities of which are formed of stone Acropolis, a building strictly appli- cable to a Greek city, and usually erected upon a hill, rock, or some natural elevation, and devoted to a magnificent temple ; also a tower, castle, or citadel Acrostolion, in ancient naval archi- tecture, an ornament of the prow or forecastle of a ship, chiefly of war, most frequently circular or spiral Acroteria, small pedestals at the angles and vertex of a pediment : the gate of the Agora at Athens is the only instance in which they appear in Grecian buildings Actinometer : Sir John Herschel, at the third meeting of the British Association, submitted an instru- ment for measuring at any instant the direct heating power of the solar ray: it affords a dynamical measure of the solar radiation, by receiving a quantity of heat per second, or any short space of time, on a surface exposed to the sun. ACT ACTINOMETER. AER In making observations with this instrument, it should be freely ex- posed in the shade for one minute, and the variation read ; afterwards expose it for the same time to the solar action, and again note it ; and lastly, repeat the experiment in the shade : the mean of the two varia- tions in the shade being subducted from the variation in the sun, the excess gives the dilatation per minute due to the sun's rays ; the quantity subducted being the effect of the other causes at the time Actus, a Roman measure of length, equal to 120 Roman feet Acute angle, in geometry, less than a right angle, and measured by less than 90, or a quadrant of a circle Acute-angled cone, that in which the opposite sides make an acute at the vertex, or whose axis, in a right cone, makes less than half a right angle with the side Acute-angled section of a cone, an el- lipsis made by a plane cutting both sides of an acute-angled cone Acute -angled triangle, that in which the three angles are all acute Adamant, a very hard stone, used by the ancients for cutting and polish- ing other hard stones and glass Adeling, a title of honour given to the children of princes among the An- glo-Saxons Adhesion, the force with which differ- ent bodies remain attached to each other when brought into contact Adit, the passage or approach to a house; applied also to the hori- zontal shaft of a mine, driven for the purposes of ventilating, water- ing, or draining Adit level, in mining, a horizontal excavation through which the water is drawn by the engine Adjacent angle, in geometry, an angle immediately contiguous to another, so that one side is common to both Adjutage (Ajutage), or jet d'eau, a tube fitted to the aperture of a ves- sel through which water is to be played Adonia, a festival celebrated in ho- 10 nour of Aphrodite and Adonis in most of the Grecian cities Adrift, the condition of a vessel broken from her moorings Adumbration, in heraldry, a figure painted of the same colour as the ground of the field, but darker Adytum, the most sacred place in the heathen temples ; the Holy of Ho- lies ; in Christian architecture, the chancel or altar-end of a church Adze, an edged tool used to chip sur- faces in a horizontal direction ; the axe being employed to chop mate- rials in vertical positions JEcclesiolo, in Domesday Book, a cha- pel subordinate to the mother church Mdes, an inferior kind of temple ; in Christian architecture, a chapel ; also sometimes applied to a house JEdicula, a small chapel, house, or building of any kind; not unfre- quently applied to the niches of tabernacles in a wall which held statues of the lares or penates ^Egricanes, a name given to rams' heads when sculptured on friezes, altars, &c. SEolipile, in hydraulics, an instrument consisting of a hollow metallic ball with a slender neck or pipe pro- ceeding from it, which, being filled with water, produces a violent blast of wind JEolus, a small portable machine for refreshing and changing the air of apartments JErarium, a treasury among the Ro- mans ; the place where public mo- ney was deposited Aerial perspective, the relative appa- rent recession of objects from the foreground, owing to the quantity of air interposed between them and the spectator Aerology, the doctrine or science of the air Aerometer, an instrument contrived to ascertain the mean bulk of gases Aerometry, the science of measuring the air, its powers and proper- ties Aeronautics, the art of sailing or float- ing in the air AER AIR-PUMP. AIR Aerostatics, the doctrine of the weight, pressure, and balance of the air and atmosphere dErugo, rust, more especially that of copper; verdigris ^Esthetics, the power of perception hy means of the senses : the word im- plies the perception and the study of those qualities which constitute the beautiful and artistic, and form the finer essence of all productions of fine art. It carries with it, there- fore, a more exact and philosophic meaning than the word ' taste.' In its adjective form, in which it more frequently occurs, it is particularly useful, as no adequate epithet can be substituted for it. Thus we speak of the ' aesthetic sense,' of ' aesthetic feeling,' or ' study,' or ' principles,' &c.; but we cannot correctly say the ' tasteful sense,' or ' tasteful study' Aetoma, a pediment, or the tympanum of a pediment Affinity, in chemistry, the power by which the ultimate particles of matter are made to unite, and kept united Afflux, a flow of electric matter to a globe and conductor, in opposition to efflux, from them After, in ship-building, implies a con- nexion, as belonging to the after- body, after-timber, &c. Agalma, a sculptural ornament or image Ager, a Roman acre of land Agger, a heap or mound of any kind, formed of stone, wood, or earth Agglutination, the cohesion of bodies Aggregation, in chemistry, the collec- tion of bodies, solid, fluid, or gaseous Agora, a place of public assembly in a Greek city for the transaction of all public business ; a market- place Aguilla, an obelisk, or the spire of a church tower A-hull, the condition of a vessel when she has all her sails furled, and her helm lashed a-lee Air -casing, the sheet-iron casing which surrounds the base of the 11 chimney of a steam vessel, to pre- vent too great a transmission of heat to the deck Air-drains, cavities between the ex- ternal walls of a building, protected by a wall towards the earth, which is thus prevented from causing dampness Air-escape, a contrivance for letting off the air from water-pipes Air-holes, those made for admitting air to ventilate apartments Air-machine, in mining, the apparatus used for forcing purer air into or withdrawing foul air from parts badly ventilated Air-pipes, in mining, tubes or pipes of iron or wood, for ventilating under ground, or for the convey- j ance of fresh air into levels having but one communication with the atmosphere, and no current of air : also used for clearing foul air from the holds of ships or other close places Air-pump, a pneumatic instrument, by means of which the air is ex- hausted out of the proper vessels : its effects are produced by the elas- ticity of the air; and as at each stroke of the pump only a part of the remaining air is withdrawn, an absolute vacuum cannot be obtain- ed, although so near an approxi- mation to it may be had as to remove the general effects of the atmosphere. The proportion of the air-pump, as given by Watt, is usually about two-thirds of the diameter of the cylinder, when the length of the stroke of the air- bucket is half the length of the stroke of the steam piston. The area of the passages between the condenser and the air-pump should never be less than one-fourth of the area of the air-pump. The apertures through the air-bucket should have the same proportion ; and, if convenient, the discharging flap or valve should be made larger. The capacity of the condenser should at least be equal to that of the air-pump ; but, when conveni- AIR AIR-VESSEL. ALG ence will admit of it, the larger it is the better Air-pump bucket, an open piston, with valves on the upper surface, opening upwards, so as to admit the air and water in the down- stroke, and lift it with the up- stroke of the pump Air-pump rod, the rod for connecting the bucket to the beam Air-tint, in painting, the tint by which the distant parts of a land- scape are rendered more distinct, or sometimes giving a misty appear- ance to the whole : it is generally compounded of a blue-grey, occa- sionally approaching to purple Air-trap, a trap immersed in water, to prevent foul air arising from sewers or drains Air-valve, applied to steam boilers for the purpose of preventing the formation of a vacuum when the steam is condensing in the boiler Air-vessel, the closed cylinder con- nected to the discharge-pipe of a force-pump, and by the action of which the water ejected by the pis- ton or plunger of the pump enters the cylinder and compresses the air within ; it acts as a spring during the return stroke, and thiis renders the stream constant : also a cham- ber containing air, attached to pumps and other water engines, for thepurpose of making thedischarge constant when the supply is inter- mittent Aisle, the side passage or division of a church, partially separated from the nave and choir by columns or piers Aitre, a hearth or chimney Alabaster, a species of gypsum, a mi- neral substance, chemically termed sulphate of lime: also a box or vase for holding perfumes and oint- ments ; so called because originally made of alabaster, and for which the variety called onyx-alabaster was usually employed Alba, a beacon or light-house Albarium, white-wash ; according to Pliny and Vitruvius, a white stucco 12 or plaster, made of a pure kind of lime burned from marble, and used to spread over the roofs of houses Albarium opus, according to Vitru- vius, a species of stucco-work Alcahest, in ancient chemistry, a universal dissolvent Alcha, a cellar, pantry, or an apart- ment for the reception of drinking vessels Alchemist, one skilled in the art of alchemy or chemistry Alchemy, that branch of chemistry which presumes the transmutation of metals : Lord Bacon calls it the art of distilling or drawing quin- tessences out of metals by fire Alcohol, in chemistry, a pure spirit Alcoholometer, an instrument for as- certaining the strength of spirits Alcorans, in oriental architecture, high slender towers attached to mosques, in which the Koran is read Alcove, a recess in a chamber, or a recess separated from other parts of the room by columns, antse, and balusters Alder, a wood formerly much used. The common alder seldom exceeds 40 feet in height, is very durable under water, and was used for the piles of the Rialto at Venice, the buildings at Ravenna, &c.: it was formerly much used for pipes pumps, and sluices Aleaceria, a palace, castle, or other large edifice Aleatorium, an apartment in a Roman house appropriated to the use of persons playing with dice A-lee, a term used to denote the posi- tion of the helm when it is put in the opposite direction from that in which the wind blows Alembic, in chemistry, a vessel used in distillation Aieois, loopholes in the walls of a castle or fortification, through which ar- rows may be discharged Algaroth, in chemistry, a white pow- der obtained from muriate of anti- mony Algebra, literal arithmetic, or the ALH ALIEN PRIORIES. ALI science by which quantity, and the houses erected in different coun- operations of quantity, are ex- tries, and distinguished as alien pressed by conventional symbols from their dependence on large Alhambra, in Saracenic architecture, foreign monasteries. The following the royal palace of the kings of is a list of those established in Granada England, with the dates of their Alien Priories, cells or small religious foundation : NAME. Ailey ORDER. Benedictine Do. Do. Do. Do. Do. Do. Do. Do. Augustine Benedictine Do. Do. Do. Do. Premonstrant Benedictine Premonstrant Benedictine Do. Black Monks Benedictine Do. Do. Do. Do. Do. Do. Do. Cistercian Black Monks Benedictine Do. Cluniac Benedictine Cistercian Benedictine Do. Do. Do. Do. Black Monks Benedictine DATE. 1160 Henry I. 1364 Win. Conq. Henry III. -1160 Wm. Conq. Henry II. Henry III. 1115 Wm, Rufus 1200 1318 Richard II. 1071 1187 1081 1090 Wm. Conq. 1103 King Steph. 1082 Henry II. King John 1169 Henry I. 1163 Henry II. King Steph. 1113 King John Richard II. 1164 1173 Wm. Conq. 1096 1274 1004 Edw. Conf. Wm. Conq. COUNTY. Herefordshire Shropshire Yorkshire Hampshire Do. Isle of Wight Worcestershire Wiltshire Devonshire Gloucestershire Yorkshire Do. Suffolk Gloucestershire Kent Lincolnshire Do. Isle of Wight Wiltshire Oxfordshire Suffolk Wiltshire Oxfordshire Wiltshire Lincolnshire Devonshire Herefordshire Bedfordshire Yorkshire Rutlandshire Hampshire Norfolk Dorsetshire Monmouthshire Yorkshire Lincolnshire Do. Hampshire Leicestershire Gloucestershire Sussex Devonshire Lancaster Staffordshire Sussex Alberbury .... Allerton Mallever . . Andewell . . ; . . Andover Appledercomb . . . Astley Avebury . . Axmouth .... Beccanford .... Birstall Blakenham .... Brimsfield . . Burne (College of) . Burwell . Cameringham . . . Carisbrook .... Charleton .... Charltonupon Otmoor Clare Clatford . . . Coo^es Cevenham .... Cowike ... Cresswell .... De la Grave . . . Ecclesfield .... Edith Weston . . . Elingham .... Fieldallying . . . Frampton .... Goldcliff Grosmont .... Hagham . . Hao-he . . ' ^ Hamele . . . . 3 Hinckley . . . . Horkeslegh . . * . Hou '. 5 . Ipilpen .... ^ Lancaster .... Lappele .... Lavenestre .... 13 ALI ALIEN PRIORIES. ALI NAME. Lesingham .... Lewisham .... Limburgh Magna . . Llangewith .... Llangkywan . . . ORDER. Benedictine Cistercian Benedictine Black Monks Benedictine Do. Benedictine Do. Do. Do. Do. Do. Do. Do. Benedictine Do. Do. Do. Do. Cistercian Benedictine Carthusian Black Monks Black Monks Benedictine Do. Cluniac Do. Benedictine Do. Cell of Monks Benedictine Black Monks Benedictine Do. Do. Do. Do. DATE. Wm. Rufus before Conq. Richard II. King Steph. 1183 Henry I. 1175 1255 Edw. Conf. 1259 1129 1275 Richard II. 1077 1149 Wm. Conq. 1217 Henry I. Wm. Conq. King Steph. Wm. Rufus 800 King John Wm. Conq. Henry I. 1256 Sax. period Henry I. Henry II. 1170 1153 1155 1085 Wm. Conq. Edward I. Henry I. Wm. Conq. 1267 Wm. Rufus King Steph. 1081 Henry I. Henry I. Wm. Conq. Henry I. Wm. Conq. COUNTY. Norfolk Kent Lincolnshire Glamorganshire Monmouthshire Dorsetshire Lincolnshire Cambridgeshire Essex Oxfordshire Lincolnshire Devonshire Herefordshire Warwickshire Wiltshire Devonshire Northamptonshire Buckinghamshire Kent Gloucestershire Essex Dorsetshire Middlesex Sussex Yorkshire Devonshire Dorsetshire Norfolk Sussex Berkshire Somersetshire Berkshire Carmarthenshire Isle of Wight Do. Cornwall Sussex Cambridgeshire Essex Cornwall Kent Norfolk Surrey Cornwall Buckinghamshire Wiltshire Hertfordshire Dorsetshire Warwickshire Northamptonshire Do. Norfolk Buckinghamshire Long Bengton . . . Lynton Minster Lovel . . . Minting Modbury .... Monkenlane . . . Monks Kirby . . . Okerington .... Overdon .... Newington Longeville New Romney . . . Noent Paunsfield .... Povington .... Riselipp Rotherfield .... Scardeburgh Sidmouth .... Spedtesbury . . . Sporle Stayning .... Steventon .... Stoke Curcy . . . Stratfieldsay . . . St. Clare .... St. Cross .... St. Helen's .... St. Michael's Mount . Sumpting .... Swavesey .... Takeley .... Talcarr Thurlegh .... Tofte Tregony Tykeford .... Uphaven .... Ware "Wareham .... Warmington . . . Wedon on the Street . Wedon Pinkney . . Welles Wenire 14 ALI ALIEN PRIORIES. ALT NAME. Wenghale .... West Ravendale . . West Shirburne . . Westwood .... Willesford .... Wilmington . . . Winterbury Wast . . Wirhara .... ORDER. Premonstrant Benedictine Do. Do. Do. Do. Do. DATE. Henry III. 1202 Henry I. Henry II. King Steph. Wm. Rufus 1214 Richard I. COUNTY. Lincolnshire Do. Hampshire Worcestershire Lincolnshire Sussex Dorsetshire Norfolk Wolfricheston . . . Wolton Wawra . . Black Monks Benedictine Wm. Conq. Henry I. Warwickshire Do. Alipterion, in ancient Rome, a room wherein bathers anointed themselves Aliquot part, such part of a number as will exactly divide it without a remainder ; a part as, being taken or repeated a certain number of times, exactly makes up or is equal to the whole : thus 1 is an aliquot part of 6 or any other whole number Alkalescent, a chemical term applied to such animal and vegetable sub- stances as have a tendency to pro- duce muriate of ammonia, or vola- tile alkali Alkali, in chemistry: potash and soda were usually termed fixed, and am- monia volatile, alkalies : alkalies combine with and neutralize acids, thereby producing salts ; they also change vegetable blues to green Alkalimeter, an instrument for mea- suring and determining the quantity and strength of alkalies Allette, used to express a small wing of a building; also applied to a pilas- ter or buttress Alley, a passage from one part of a building to another ; a passage or court with houses Alligation, one of the rules of arith- metic, by which are resolved ques- tions which relate to the compound- ing or mixing together of divers simples or ingredients Allorium, a piazza, corridor, or co- vered way in the flank of a building Alloy, baser metal, commonly mixed with the precious metals Alluvium, the debris occasioned by causes still in operation, as deposits left by the action of rivers, floods, and torrents 15 Almacantar, lines parallel to the ho- rizon, and conceived to pass through every degree of the meridian Almehrab, a niche in the mosques of the Arabs, for praying Almond-tree, a hard, heavy, oily or resinous kind of wood, somewhat pliable Almonry, a room or place where alms were formerly distributed to the poor Almshouse, a house for the reception and support of the poor Aloof, in navigation, to keep the ship near the wind when sailing upon a quarter wind Alquifore, lead ore found in Cornwall, and used by potters to green var- nish their wares Alrunae, small images carved out of roots of trees, and anciently held in much veneration by the northern nations Altar, an elevated table of either stone, marble, or wood, dedicated to the ceremonies of religious wor- ship. " And Noah builded an altar unto the Lord ; and took of every clean beast, and of every clean fowl, and offered burnt offerings on the altar." Gen. viii. 20. Altar-piece, the ornamental sculpture or painting behind the altar in a Christian church Altar-screen, the back of an altar, or the partition by which the choir is separated from the presbytery and lady-chapel Altars, among the Greeks, according to Wilkins's ' Vitruvius/ faced the east, and were placed lower than the statues arranged about the cella, ALT ALTAR. AMY in order that those who offered up prayers and sacrifices might know, from their different heights, to what particular deities the several altars were consecrated Altare chori, a reading desk in a church Altare f arum, the lustre, chandelier, or cresset, suspended over an altar Altimetry, the art of taking or mea- suring altitudes or heights Altitude, of a figure, the length of a line drawn perpendicularly from the vertex to the hase Alto-rilievo, highly relieved sculpture representing figures either entirely or nearly detached from the hack- ground Alum, a salt extracted from various minerals called alum ores ; of great use to chemists, dyers, and artists ; acid and sharp to the taste Aluminum, in chemistry, the metallic hase of the earth alumina, which is found in nature along with some oxides, and acting as an acid : these combinations are termed alumin- ates, and are insoluble in acids Alveus, in hydrography, the channel or belly of a river Amalgam, a mixture of mercury with any other metal, tin, lead, &c. Ambitus, an enclosure, more particu- larly applied to the space around a building, as a church-yard or a castle-yard Ambo, Ambone, a rostrum or raised platform Ambulatio, walks, or places of exer- cise, according to Vitruvius, adja- cent to theatres Ambulatory, a cloister, gallery, or alley Ammonia, in chemistry, a compound of hydrogen and azote, which can only be exhibited pure in a state of gas ; with carbonic acid, it forms volatile alkali or hartshorn. Am- monia is found in the urine of animals, in the earth, and also in the atmosphere: it w T as formerly obtained by distilling horn, from which it acquired the name of hartshorn. It is generally prepared from chloride of ammonium or sal- 16 ammoniac, from which it receives its name Ammoniac, a gum used for metallic vessels Amphiprostyle, a term applied to a temple with a portico in front and also behind Amphitheatre, an edifice formed by the junction of two theatres at the proscenium, so as to admit of seats all round the periphery Amphitheatre, in Roman antiquity, a large edifice of an elliptic form, with a series of rising seats or benches disposed around a spacious area, called the arena, in which the combats of gladiators and wild beasts, and other sports, were ex- hibited. It consisted exteriorly of a wall pierced in its circumference by two or more ranges of arcades, and interiorly of vaulted passages radiating from the exterior arcades towards the arena, and several transverse vaulted corridors which opened a free communication to the stairs at the ends of the passage and to every other part of the building ; the corridors and ranges of seats forming elliptical figures parallel to the boundary wall Amphithura, in the Greek Church, the veil or curtain opening to the folding doors, and dividing the chancel from the rest of the church Amphora (pi. amphorae), an earthen vase or jar, with a handle on each side of the neck ; among the an- cients, the usual receptacles of olives, grapes, oil, and wine. Hence, in decoration, amphoral means, shaped like an amphora or vase Amulet, in decoration, a figure or cha- racter to which miraculous powers were supposed to be attached, and which particularly distinguished the buildings of Egypt Amussium., anciently a carpenter's and mason's instrument, the use of which was to obtain a true plane surface ; but the statements of the ancient writers render its construc- tion extremely difficult Amylum, in chemistry, starch ANA ANGLES. ANG Anabathra, steps to any elevated situ- ation, as the anabathra of theatres, pulpits, &c. Anacampteria, the lodgings of per- sons who fled for sanctuary to pri- vileged religious houses Anacamptics, the doctrine of reflected light Anachorita, the cell of a hermit Anaclastics, the doctrine of refracted light Anaglyph, an engraved, embossed, or chased ornament Anaglypha, chased or embossed ves- sels made of bronze or the precious metals, which derived their name from the work on them being in relief, and not engraved Anaglyphic work, a species of sculp- ture wherein figures are made pro- minent by embossing Analemma, a projection of the meri- dian; used also to designate a wall, pier, or buttress Analogium, a tomb over the bodies of saints; also a term formerly applied to pulpits wherein the gospels and epistles were read Anamorphosis, a distorted piece of per- spective, occasioned by too near a point of view, and from the injudi- cious attitude or situation of the object, but perfectly true accord- ing to the laws of perspective Anchor, an instrument used for the mooring of ships ; in architecture, a decorative moulding used in the orders, and applied to the echinus ; also an ornament in the form of the fluke of an anchor, frequently cut in the ovolo of Ionic capitals, and in the bed-mouldings of Ionic and Corinthian cornices Anchor-stock, in ship-building, a me- thod of working planks, by which the abutments are to be disposed near the middle of those planks which are above or below them Ancon, in decoration, a carved drink- ing-cup or horn ; an elbow or angle, or corner-stone. The An- cona foot measure is 1*282 of an English foot 17 Ancone, a console or ornament cut on the key-stone of an arch Ancones, trusses or consoles employed in the dressings of apertures ; also used to signify the corners or quoins of walls, cross-beams, or rafters, &c. Andirons, iron bars with legs to sup- port logs of wood in fire-places Android, in mechanics, an automaton Andron, an apartment, cloister, or gallery, assigned to the male part of a monastic establishment ; ap- plied also to the space in a church by which the men were separated from the women Anemography, a description of the winds Anemometer, an instrument for mea- suring the force of the wind Anemoscope, a machine to denote the changes of the wind or weather Angiportum, among the ancients, a narrow lane between two rows of houses Angle, in geometry, the mutual in- clination of two lines meeting in a point Angle-bar, in joinery, the upright bar at the angle of a polygonal window Angle-bead, a vertical bead, commonly of wood, fixed to an exterior angle, and flush with the surface of the plaster, &c. of rooms, arches, &c. Angle-brace, in carpentry, timber fixed to the two extremities of a piece of quadrangular framing, making it to partake of the form of an octagon Angle-bracket, a bracket placed in the vertex of an angle, and not at right angles with the sides Angle-capital, used in Ionic capitals to the flank columns which have their volutes placed at an angle of 45 with the planes of the front and returning friezes Angle-float, in plastering, a float made to any internal angle to the planes of both sides of a room Angle-modillion, a modillion placed in a direction parallel to a diagonal drawn through a cornice at its mitreing Angle of application, the angle which ANG ANNULAR ENGINE. ANT the line of direction of a power gives the lever it acts upon Angle of inclination, the angle an in- clined plane makes with the hori- zon Angle of traction, the angle which the direction of a power makes with the inclined plane Angular perspective, a term applied to the horizontal lines, both of the front and end of a building, con- verging to vanishing points, and terminating in the horizon ; it is sometimes called oblique perspec- tive Anhydrous sulphuric acid, pure sul- phuric acid, in the form of a crys- talline solid Annealing, the process of softening and restoring the malleability of metals, by heating and allowing them to cool very slowly ; and by which means glass, cast iron, and steel may be united to other sub- stances Annotto, in chemistry, a reddish-yel- low vegetable dye, obtained from the seeds of the bixa orellana, and used for colouring cheese Annular engine, a direct-action ma- rine engine, having two concentric cylinders ; the annular space is fitted with a piston which is at- tached to a T-shaped cross-head by two piston-rods : the cross-head is formed by two plates with a space between for the connecting-rod to vibrate, and the lower end slides within the inner cylinder, and is connected to the crank. This ar- rangement has been patented by Messrs. Maudslay Annular vault, a vaulted roof sup- ported on circular walls Annulated columns, ihose clustered to- gether or joined by rings or bands Annulet, in architecture, a small square member in the Doric capi- tal ; also the name of a small flat moulding Antce, square pilasters terminating the walls of a temple : when a temple had no portico in front, two columns were made to intervene 18 between the antae, and the aspect of the temple was said to be in antis Ante-chamber, a room or passage to an inner chamber, for the accom- modation of servants and persons in waiting Ante-capitulum, part of a cloister be- j fore the door of a chapter -house Antefixce (by some called Greek tiles), j upright ornamental blocks placed j at intervals on the cornice along the side of a roof, to conceal or rather terminate the ridges formed by the overlapping of the roof tiles ; also heads of lions, &c., for water spouts, below the eaves of temples Antemural, a term applied to the outward wall of a castle ; or that which separates a presbytery from a choir; also to a barbican entrance before a castle Antepagmenta, or Antepagmentum, the jamb of a door-case Ante -parallels, in geometry, lines which make equal angles with two other lines, but in a contrary direc- tion Ante-portico, a term sometimes used to denote an outer porch or vesti- bule ; the propylcBum in classic architecture Anterides, buttresses for strengthen- ing walls Ante-solarium, a balcony facing the sun Ante-venna, an awning or projecting roof of wood-work ; a wooden or pent-house before a shop Anthepsa, a Grecian vessel used for boiling water or keeping it hot ; a cooking utensil Anthracite, a coal not bituminous, found principally in South Wales and in the United States Antics, in architecture, figures of men, beasts, &c., placed as ornaments to buildings Anticum, a porch before a door Antilia, an ancient machine similar to the modern pump Antimensium, a portable altar or con- secrated table, used as a substitute for a proper altar ANT APOSTLES. APP Antimeter, an optical instrument for measuring angles Antimony, a metal usually found in a crude state combined with sulphur, of a bluish-white colour, crystal- line texture, brittle, and easily pul- verized. It does not oxidate at ordinary temperatures in the air, but, when heated, it burns with a light flame, producing the oxide ; it fuses at 800, and volatilizes at a white heat Antimony yellow, a preparation of antimony, of a deeper colour than Naples yellow, and similar in its properties : it is principally used in enamel and porcelain painting, and is very various in tint; that of a bright colour is not affected by foul air, although blackened by sugar of lead Antipagments, ornaments in carved work on the architrave, jambs, posts, or puncheons of doors Antiquarium, a repository for antique monuments Antrellum, a small cave or grotto; also a small temple Antrum, an early temple for Christian worship Antrum tumbale, a sepulchral cave or grotto Antwerp blue, light - coloured, and somewhat brighter than Prussian blue, or ferro-prussiate of alumine, having more of the terrene basis, but all the other qualities of that pigment, except its extreme depth. Haarlem blue is a similar pigment Antwerp brown, a preparation of asphaltum ground in strong drying oil, by which it becomes less liable to crack Anvil, a large block of iron with a very hard smooth horizontal sur- face on the top, in which there is a hole at one end, for the purpose of inserting various tools, and a strong steel chisel, on which a piece of iron may be laid, and cut through by a blow with a hammer A-peek, a nautical term implying that the cable is hove taut, so as to bring the vessel nearly over her anchor : 19 the yards are a-peek when they are topped up by contrary lifts Aperture, an opening in a wall, door- way, or window Apex, the top or highest point of a cone, mountain, pyramid, spire, roof, &c. Apiary, a place where bees are kept Aplome, a mineral of a deep orange colour Aplustre, in early naval architecture, a carved tablet fixed on the ex- tremity of a ship's head Apodyterium, a dressing-room or ante- room to a bath in Roman villas, con- tiguous to the laconicum Apophyge, in architecture, that part of a column between the upper fillet of the base and the cylindrical shaft, which is usually curved into it by a concave sweep or inverted cavetto Apostles (the) of Jesus Christ were his chief disciples, whom he invested with his authority, filled with his spirit, and instructed particularly in his doctrines and services : they were chosen to raise the edifice of his church; and, after his resurrec- tion, sent into all the world, com- missioned to preach, to baptize, and to work miracles. The names of the twelve were, 1. Peter. 2. An- drew. 3. John. 4. Philip. 5. James, major. G.Bartholomew. 7. Thomas. 8. Matthew. 9. Simon. 10. Jude. 11. James, minor. 12. Judas Is- cariot. The last betrayed his mas- ter, and having hanged himself, Matthias was chosen in his place Apotheca, a place in the upper part of the house, in which the Romans frequently placed their wines in earthen amphorae ; also an apothe- cary's shop, a cabinet, storehouse, &c. Apothesis, a recess on the south side of the chancel of a church, fitted up with shelves for books, vest- ments, &c. Apparatus, a term denoting a com- plete set of instruments belonging to an artist or a mechanist Appaumee, in heraldry, to extend the APP APPIAN WAY. ARC palm of the hand and the thumb and fingers at full length Appian way, a celebrated road lead- ing from Rome to Brundusium : so named from Appius Claudius Appii forum, the forum built by Ap- pius, the Roman consul, about 50 miles distant from Rome, near the modern town of Piperno, on the way to Naples. The uses to which the Romans applied the forum were so various, that it is not easy to as- certain the nature of the building. It might have been a place for the dis- tribution of justice, or for holding a market. The 'Three Taverns' were nearer to Rome than the Appii forum, as Cicero intimates, who, in going from Rome, a little before he came to the forum of Appius, arrived at the Three Taverns; so that probably the chief number of Christians waited for the Apostle Paul at a place of refreshment, while some of their number went forward to meethim and to acquaint him with their expectation of seeing him among them, and for which they respectfully waited his coming. Calmet. Apple-tree, a wood generally hard and close, and of reddish-brown tints, used commonly in Tunbridge turnery, &c. Apricot-tree, a native wood of Ar- menia, used by the French in turnery Apron, the sill or lower part of a win- dow ; a platform or flooring of plank raised at the entrance of a dock : in naval architecture, a piece of curved timber fixed behind the lower part of the stern of a ship Apsis, the east end of a church or chancel; sometimes applied to a canopy over an altar ; also to a circle about a star or planet Apsis gradata, a bishop's throne in cathedral churches Apyrous, a chemical term applied to refractory bodies which resist heat Aquafortis, in chemistry, nitric acid diluted ; the more concentrated is named spirit of nitre 20 Aqua-male, a holy-water basin Aqua regia, nitro- muriatic acid; a compound of two parts nitric acid and one part muriatic acid Aquatinta, in the arts, engraving which resembles drawings in Indian ink Aqua tofano, a poisonous liquor Aqueduct, a conduit for water : a con- struction of stone or timber, built on uneven ground, to preserve the level of water, and convey it by a canal from one place to another Aquemola, a water-mill Aquila, a reading-desk, so called from its shape being that of an eagle with extended wings, supported by a pedestal Arabesque, generally applied to a style of ornament for pilasters, friezes, &c., as those painted by Rafaelle in the Vatican Arabo-tedesco, a term applied to the Moorish style of buildings in Spain, &c. Ara dignitatis, an altar at which none but the highest ecclesiastics perform divine riies Ar&ostyle, in architecture, the great- est interval or distance which can be made between columns, that is, eight modules or four diameters ; also a species of temple which has its columns placed widely asunder Arbor, a spindle or axis upon which a ring or wheel is turned in a lathe Arbor Diance, in chemistry, crystals formed by the combination of sil- ver and mercury Arbores, brass branches for lights sus- pended from ceilings Arboretum, a grove of trees in a park, pleasure-ground, or garden Arbor vit&, a tree which attains to a height of from 40 to 50 feet ; its wood is of a reddish colour, very light, soft, and fine-grained, and is much used in house carpentry Arc, in geometry, part of the circum- ference of a circle, or any curve lying between two points ; a bow, vault, or arch Area, a place in a vaulted chamber for sepulchral purposes ; an exca- ARC ARCADE. ARC vation before the basement story of a house ; an enclosed space ; a chest in which the Romans depo- sited their money: the word is also used to signify a beam of wood which has a groove or channel hol- lowed in it from one end to the other Arcade, a series of recesses with arched ceilings or soffits ; a covered passage ; in modern appliances, a vaulted avenue, now much in vogue, more particularly in Paris. Arcades, though less magnificent than colon- nades, are of extraordinary beauty when well contrived, affording shade from the sun and shelter from the rain. Though not so magnificent as colonnades, they are stronger, more solid, and less expensive. They are proper for triumphal en- trances, gates of cities, of palaces, of gardens, and of parks; for public squares, markets, or large courts in general, and for all apertures that require an extraordinary width. THEIR ORNAMENTS. The piers of arcades may be decorated with columns, pilasters, niches, and aper- tures of different forms. The arch itself may be turned either with rock-worked or plain rustic arch stones or voussoirs, or with an archivolt properly moulded. The keystone is generally carved in the form of a console, or sculptured with some head, or the like. The archivolt springs from an impost or plat-band, or sometimes from co- lumns ; but this is not to be prac- tised except in cases of the most urgent nature, for it makes neither substantial nor beautiful work. In arches that are of large dimen- sions, the keystone should never be omitted ; its carving, however, may be dispensed with, if expense be an object. When the piers are deco- rated with disengaged columns, the entablature must break round over the columns; and the columns, whether engaged cr not, should stand either on a pedestal or high plinth, by which means they will 21 not only be kept dry, but their bases will likewise be protected from accidental damage. Arches must always rise from an impost or a plat-band; and if there be no keystone to the archivolt, its sum- mit should be kept down from the under side of the architrave of the accompanying order, at least half the distance that it would be, were a keystone employed, in order that the disagreeable appearance of the acute angle which it would otherwise form with the architrave may be avoided. THEIR PROPORTIONS. The height of arches to the under side of their crowns should not exceed twice their clear width, nor should it be much less ; the piers not less than one-third the breadth of the arch, nor more than two-thirds; but the piers at the angles should be wider than the other piers by one-half or one-fourth at least Area, in Roman architecture, the gutters of the cavedium Arc-boutant, a kind of arched but- tress formed of a flat arch, or part of an arch, and abutting against the feet or sides of another arch or vault, to support them, and prevent them from bursting or giving way Arcella, in mediaeval architecture, a cheese-room Arch, the curved part of a building, supported at its extremities only, and concave towards the earth ; a vaulted roof, or dome, constructed either with bricks, stone, or other materials : the arch of a bridge is formed of segments of a circle, elliptical or catenarian ; in Christian architecture, arches display twenty- two varieties of form. Arches are used in large intercolumni- ations of spacious buildings ; in porticoes, both within and without temples; in public halls, as ceil- ings, the courts of palaces, cloisters, theatres, and amphitheatres : they also are used to cover the cellars in the foundations of houses and pow- der-magazines ; also as buttresses ARC and counterforts, to support large walls laid deep in the earth ; for triumphal arches, gates, win- dows, &c. ; and, above all, for the foundations of bridges and aque- ducts : they are supported by piers, abutments, imposts, &c. Arches are of several kinds, circular, ellip- tical, cycloidal, catenarian, &c., ac- cording as their curve is in the form of a circle, ellipse, cycloid, cate- nary, &c. Arches are to be found in the Greek theatres, stadia, and gymnasia, some of them erected probably 400 years before Christ. The most ancient arches of which we have correct data are those of the cloacae at Rome. The emperor Hadrian threw a bridge over the Cephisus, between the territories of Attica and Eleusis, on the most frequented road of Greece. Arch (the theory of). This important subject has exercised the talents and ingenuity of some of the great- est mathematicians in modern times, and many different solutions have been given to the various pro- blems connected with it ; but, as the greater part of them are founded on suppositions that have no exist- ence whatever either in nature or practice, they have had a tendency rather to mislead than direct those who are engaged in the operations of bridge-building. Dr. Olinthus Gregory, in the preface to his ex- cellent work on Mechanics, states, that " theoretical and practical men will most effectually promote their mutual interests, not by affecting to despise each other, but by blend- ing their efforts ; and further, that an essential service will be done to mechanical science, by endeavour- ing to make all the scattered rays of light they have separately thrown upon this region of human know- ledge converge to one point." Gauthey, speaking of the theory of La Hire, observes that such analy- tical researches are founded on hy- potheses which every day's experi- ence contradicts. The following are 22 ARCH. ARC the principal writers on the equilib- rium of the arch. In 1691, the ce- lebrated mathematicians, Leibnitz, Huygens*, James and John Ber- nouilli, solved the problem of the catenary curve: it was soon perceiv- ed that this was precisely the curve of that should be given to an arch which the materials were infinitely small and of equal weight, in order that all its parts may be in equili- brium. In the ' Philosophical Transactions' for the year 1697, it is stated that David Gregoiy first noticed this identity; but his mode of argument, though sufficiently rigorous, appears not to be so per- spicuous as could be desired. In one of the posthumous works of James Bernouilli, two direct solu- tions of this problem are given, founded on the different modes of viewing the action of the voussoirs : the first is clear, simple, and precise, and easily leads to the equation of the curve, which he shows to be the catenary inverted ; the second requires a little correction, which Cramer, the editor of his works, has pointed out. In 1695, La Hire, in his ' Treatise on Mecha- nics,' laid down, from the theory of the wedge, the proportion accord- ing to which the absolute weight of the materials of masonry ought to be increased from the keystone to the springing in a semicircular arch. The historian of the Acade- my of Sciences relates, in the vo- lume for the year 1704, that Parent determined on the same principle, but only by points, the figure of the extrados of an arch, the intrados being a semicircle, and found the force or thrust of a similar arch against the piers. In the ' Memoirs of the Academy of Sciences' for the year 1712, La Hire gave an inves- tigation of the thrusts in arches under a point of view suggested by his own experiments : he supposed that arches, the piers of which had not solidity enough to resist the thrust, split towards the haunches ARC ARCH. ARC at an elevation of about 45 degrees above the springings or impost; he consequently regarded the upper part of the arch as a wedge that tends to separate or overturn the abutments, and determined, on the theory of the wedge and the lever, the dimensions which they ought to have to resist this single effort. Couplet, in a memoir composed of two parts, the first of which was printed in the volume of the Aca- demy for 1729, treats of the thrusts of arches and the thickness of the voussoirs, by considering the mate- rials infinitely small, and capable of sliding over each other without any pressure or friction. But, as this hypothesis is not exactly conform- able to experiment, the 2nd part of the memoir, printed in the volume for 1730, resumes the question by supposing that the materials have not the power of sliding over each other, but that they can raise them- selves and separate by minute rota- tory motions. It cannot, however, be said that Couplet has added materially to the theories of La Hire and Parent, and none of them treated the subject, either in theory and practice, in such a satisfactory manner as was afterwards done by Coulomb. S ubsequently a memoir was published by Bouguer on the curve lines that are most proper for the formation of the arches of domes. He considers that there may be an infinite number of curve lines employed for this purpose, and points out the mode of select- ing them. He lays it down uni- formly that the voussoirs have their surfaces infinitely smooth, and es- tablishes, on this hypothesis, the conditions of equilibrium in each horizontal course of the dome, but has not given any method of inves- tigating the thrusts of arches of this kind, nor of the forces that act upon the masonry when the generating curve is subjected to given conditions. In 1770, Bossut gave investigations of arches of the 23 different kinds, in two memoirs, which were printed among those of the Academy of Sciences for the years 1774 and 1776: he appears to have been engaged in this in consequence of some disputes con- cerning the dome of the French Pantheon, begun by the celebrated architect Soufflot, and finished from his designs. In 1772, Dr. Hutton published his principles of bridges, in which he investigated the form of curves for the intrados of an arch, the extrados being given, and vice versa. He set out by develop- ing the properties of the equili- brated polygon, which is extremely useful in the equilibrium of struc- tures. Mr. Attwood has written a dissertation on the construction of arches on the same principles as La Hire. Arch, in architecture, a concave struc- ture raised or turned upon a mould, called the centering, in form of the arc of a curve, and serving as the inward support of some superstruc- ture. Sir Henry Wotton says, " An arch is nothing but a narrow or contracted vault ; and a vault is a dilated arch." Arch, in geometry, a part of any curved line, as of a circle or ellipsis Arch, in masonry, a part of a building suspended over a hollow, and con- cave towards the area of the hollow : the top of the wall or walls which receives the first arch-stones is technically called the abutment or springing Arch, in mining, a piece of ground left unworked Arch-buttress, a piece of insulated masonry usually named a flying- buttress, extending from the cleres- tory of a church and over the roof of its aisle, where it rests on the buttress of the outer wall Arch of equilibration, that which is in equilibrium in all its parts, having no tendency to break in one part more than in another Arch, triumphal, a building of which an arch is the principal feature, ARC ARCHITECTURE. ARC usually raised to commemorate some great achievement Archaeology, the study of ancient art, but more particularly that of the middle ages Arched, in mining : the roads in a mine, when built with stones or bricks, are generally arched level drifts Archeion, a recess in a Grecian tem- ple, for the reception of the trea- sures of the deity to whom the temple was dedicated Archeion, in Athens, the office in which the decrees of the people and other state documents were preserved Archetus, a saw for cutting stones : Muratori used the term for a crane or pulley for raising stones to the upper part of a building Archimedean screw, a machine in- vented by Archimedes for raising water ; also now applied to propel vessels through water Architect, a person skilled in the art of building; one who forms, plans, and designs for edifices, conducts the work, and directs the secondary artificers employed ; and whose emoluments are generally 5 per cent, on the amount of money ex- pended Architecture, a science applicable to the art of constructing domestic, ecclesiastical, municipal, palatial, or other buildings, and the adorn- ment of the same according to the rules of the several orders, Doric, Ionic, and Corinthian, also the Tus- can, and Composite, from Roman models, or other styles, each for its purpose, such as is usually called Gothic architecture, and modes subservient to climate and fashion, or caprice. " Architecture," says Palladio, " being grounded upon rules taken from the imitation of Nature, admits of nothing that is contrary or foreign to that order which Nature has prescribed to all things. An architect is not re- strained from departing sometimes from common methods or usage, 24 provided such variation be agree- able and natural." The public at large has a claim over the architecture of a coun- try. It is common property, in- asmuch as it involves the national taste and character; and no man has a right to pass off his own barbarous inventions as the na- tional taste, and to hand down to posterity his own ignorance and dis- grace to become a satire and a libel on the knowledge and taste of his age. There is perhaps no subject on which persons are more apt to differ in their opinions than on the beauty of a building. In archi- tecture the creative power of Nature herself is the model imitated. It is an art which appeals directly to the understanding, and has not the means of flattering the senses in the same way as the sister arts : hence its productions are not uni- versally appreciated. The beautiful models of Nature, however, are the index and guide of the painter and sculptor : a successful imitation of these models, even without an ad- vance on the part of the artist towards those higher intellectual beauties which distinguish the his- torical painter, is capable of affecting us with very agreeable sensations. The object of an artist's inquiry is not so much to investigate meta- physically the cause of beauty in the productions of his art, as to study the effects that flow from those which by the common con- sent of ages are esteemed beautiful, and thus shorten his road by an a priori method. It is in this way that he will more readily obtain information on those qualities which act on the understanding and ex- cite our affections by means of the beautiful result they exhibit. These qualities may be classed as fol- lows: MAGNITUDE AND SOLIDITY, as qualities which affect the eye. ORDER AND HARMONY, as quali- ties which affect the understanding. ARC ARCHITECTURE. ARC RICHNESS AND SIMPLICITY, as qualities which excite the affec- tions, in which taste is the prin- cipal guide. These qualities answer to the three divisions which those who have written on architecture have usually adopted, namely CONSTRUCTION, in which the chief requisites are solidity and strength. DESIGN OR DISPOSITION, in which the principal requisites are order and harmony. DECORATION, whose requisites are richness or simplicity, according to the nature of the composition. That there are, however, many other circumstances which tend to the production of an agreeable and beautiful result, is sufficiently ob- vious: one of them should be more particularly noticed, because there can be no doubt of its influence in the excitement of our admiration of the splendid monuments of Gre- cian art ; it is an association with the times and countries which are most hallowed in our imagination. It is difficult for us to see them, even in their modern copies, with- out feeling them operate upon our minds, as relics of those polished nations where they first arose, and of that great people by whom they were afterwards borrowed. The business of an architect re- quires him rather to be a learned judge than a skilful operator ; and when he knows how to direct and instruct others with precision, to examine, judge, and value their performances with masterly accu- racy, he may truly be said to have acquired all that most men can ac- quire : there are but few instances of such prodigies as Michael An- gelo Buonarotti, who was at once the first architect, painter, geome- trician, anatomist, and sculptor of his time. Vitruvius furthermore observes, that an art enriched with such variety of knowledge is only to be 25 learned by long and constant appli- cation ; and advises his contempo- raries never to assume the title of architects till they are perfect mas- ters of their own profession, and of the arts and sciences with which it is connected ; a caution that even in the present times may perhaps not be unnecessary. Architecture (the application of the orders of). Among the ancients, the use of the orders was very fre- quent; many parts of their cities were provided with spacious porti- coes, their temples were surround- ed with colonnades, and their the- atres, baths, basilicse, triumphal arches, mausolea, bridges, and other public buildings were profusely enriched with columns; as were likewise the courts, vestibules, and halls of their private villas and houses. In pure architecture, says A. W. Pugin , the smallest detail should have a meaning or serve a purpose ; and even the construction itself should vary with the material employed, and thedesigns should be adapted to the material in which they are executed. Strange as it may appear at first sight, it is in pointed architecture alone that these great principles have been carried out : we may be enabled to illustrate them from the vast cathedral to the simplest erec- tion. Moreover, the architects of the middle ages were the first who turned the natural properties of the various materials to their full account, and made their mechanism a vehicle for their art. The won- derful strength and solidity of their buildings are the result, not of quan- tity or size of the stones employed, but of the art of their disposition. On the following page is a synopsis of the proportions of the orders, and of the various examples of each, compiled expressly by Mr. W. H. Leeds for Pugin's edition of Normand's 'Parallel of the Or- ders.' ARC ARCHITECTURE. AR( Names of the Orders. Base. Column. Capital. Archi- trave. Frieze. TUSCAN. Palladio ll, T3 g P. 1 1 1 1 Jl ft 7oo 7 i o 600 700 5 1 5 1 4 15 5 25 6 20 8 10 5 1 600 7 1 18 7 1 800 800 8 1 800 800 800 800 910 900 8 1 2| 900 8 1 900 8 1 15 900 7 1 800 10 9 1 15 9 15 9 1 10 6 15 9 1 164 9 1 44 ll * T3 5 ft 1 1 1 1 28 1 1 2f 284 16 25 23 23 2 o 9* o 134 10 29 o 14 1 l| 1 If o o 264 o i 04 1 o i 14 24 27 11 15 6^ 10 o 71 o 124 18 8f 16 6f 9? 94 }4k o 54 11 o o 27 a -a * ~ T3 8 ft 5 o 24 25 o 144 20 o 114 20 9 16 H ^ T3 S ft 26 1 9 1 1 5 o i 194 1 254 o i 24 o i 7 1 14 1 Serlio Vignola . DORIC. Temple of Theseus, do. ... . . . Portico of Philip do. ... Temple at Corinth Propyleeum at Athens .... Theatre of Marcellus, Rome . 1 2 5 25 o 214 1 16 1 15 1 15 1 15 1 15 1 15 1 15 1 15 1 19 1 184 Doric Order at Albano .... Baths of Diocletian . Palladio 1 1 1 1 1 1 25 234 1 Of 1 1 22 22 20 o o 204 o o 224 1 84 21 25 23 20 o o 224 24 234; Viola Delorme IONIC. Temple on the Ilissus .... Temple of Minerva Polias, Athens Temple of Erechtheus, Athens . Temple of Fortuna Virilis . . . Theatre of Marcellus .... Baths of Diocletian . 84 13 4 6 15 o 74 21 11| o 164 o 124 o 134 12 12f 12 14 13 o 144 15 91 o 134 8 12 15 16 15 H4 10 9 15 1 254 283 1 6 28 27 28 1 15 o o 224 1 1 94 27| 1 124 1 10 1 13i 1 13 o i 94 1 12 1 15 o i io| 1 14^ 1 10 1 10 o 1 9i o o 234 1 2 1 15 o i 7 1 1 14 254 1 14 1 1 U 1 15 Palladio Vignola Serlio ... . . Albert! CORINTHIAN. Lantern of Demosthenes, Athens Temple of Jupiter Olympius, do. Incantada at Salonica .... Arch of Theseus, Athens . . . Temple of Jupiter Stator, Rome . Temple of Jupiter Tonans . . . Portico of the Pantheon . . . Interior of the Pantheon . . . Temple of Antoninus and Faustina 24 o o 204 24 9 1 64 10 9 l 7 Temple of Mars the Avenger . . Basilica of Antoninus .... Temple of the Sibyl. Tivoli . . Palladio 23 o o 164 1 1 1 1 010 23 20 22 1 14 1 1 10 llf 9 25 9 1 10 10 900 900 10 6 9 1 10 295 000 9 1 15 000 500 Vignola Albert! COMPOSITE. Arch of Titus . . Arch of Septimius Severus . . Baths of Diocletian . . Palladio Scamozzi Vignola Caryatides of the Temple of-i Pandrosus j 26 ARC ARCHITECTURE. ARC Cornice. Entabla- ture. Interco- lumniation. Diameter of column. Architecture, Naval, the art of con- structing ships and vessels to float on the waters. Naval architecture has suffered more than most other sciences by the arbitrary systems of those interested in its improve- ment. Disregarding the fundamen- tal principles of all floating bodies, and too hastily giving up as hope- less the attainment of a theory combining experiment with esta- blished scientific principles, they have contented themselves with ingeniously inventing mechanical methods of forming the designs of ships' bodies, which they did not even pretend to prove had any connexion with the properties of the machine necessary to insure the qualities conducive to its in- tended use. For instance, some invented methods of forming ships' bodies of arcs of circles ; others, of arcs of ellipses, parabolas, or of whatever curve they might arbi- trarily assume. They did not at- tempt to show that these curves possessed any property which would render a ship a faster sailer, a more weatherly or safer ship, than any other curves which might have been adopted in tiie construction of the ship's body Architholus, a round chamber, the sudatorium of a Roman bath Architrave, the lower of the three principal members of the entabla- ture of an order, being the chief beam resting immediately on the column Architrave cornice, an entablature consisting of an architrave and cor- nice only, without the interposition of a frieze Architrave doors, those which have an architrave on the jambs and over the door Architrave windows, of timber, are usually an ogee raised out of the solid timber, with a roll over it Archivolt, a collection of members in the face of an arch, concentric with the intrados, and supported by imposts Hi 1 134 1 11 1 1 10 26 o o 254 28 o l 74 25 3 ~ 1 1 *. 1 1 14V 1 1 22$ 1 1 1 1 10 200 2 11 1 1 12 2 44 1 1 18 i "' '-8 S P. feet, inches. 2 20 2 1 6 2 10 2 25 3 1 5 2 15 6 1ft 6 1ft 7 0'03 2' 5 : 10* 4 4'05 6J 5 16 8 17 15 10 10 1 2 o l 74 1 1 23| 1 20 203 1 1 23 207 200 1 1 25 1 1 25 2 16 2 174 2 1 15 4 11 . . . . . . . . . 2 15 300 1 1 20 2 1 5 1 9'4 2 9'4 2 3-8 3 2 1 10^ 1 6 16 16 12 224 2 10 20 18 ft* 164 1 93 I6i 24 21i o 254 o 224 o 274 284 2 o 174 2 25 18 19 25 15 244 10 2 204 1 27 2 7i 2 14 2 64 2 11| 2 16* 2 15$ 2 284 2 164 2 26$ 2 234 2 74 . . . 206 300 3 24 1 2 2 11'3 2 5' 9" 1 1 5 1 1 34 2 15 2 24 l' l' 14 1 1 1 284 1 1 10* 2 14 200 200 2 20 4 10^ 4 8& 4 11 3 8& 3 6 4 lOfg 2' 'll'tk 5 ll% 2* '4 2 10& 2 Oft 3 o 174 o 19 1 9 10 1 2 1 84 1 21 1 20 o i 163 1 1 1 1 12$ 1 1 24 203 2 1 1 1 13 1 1 10 2 1 2 2 19 2 194 200 1 1 27 2 1 1 1 254 27 ARC ARK. ARK Archivolt of the arch of a bridge, the curve line formed by the upper sides of the arch-stones in the face of the work ; it is sometimes un- derstood to be the whole set of arch-stones which appear in the face of the work Archivoltum, a cesspool or common sewer Archway, an aperture in a building covered with a vault Arcula, a small coffer or box Arcus, an area in the form of an an- cient basilica : Arcus, an arch. A true arch is formed of a series of wedge-like stones or of bricks, supporting each other, and all bound together by their mutual pressure Arcus-toralis, in mediaeval architec- ture, the lattice separating the choir from the nave in a basilica Ardesia, a slate used in Italy for co- vering roofs Area, in geometry, the superficial content of any figure Areas, in computing the superficial content of land, are generally ex- pressed in statute acres, roods, and perches. The acre is equal to 10 square chains of 66 jfeet, or 22 yards in length Arena, the area or floor of an amphi- theatre Arenarium, an amphitheatre, ceme- tery, crypt, or sepulchre Areometer, an instrument for mea- suring the density or gravity of fluids Areopagus, the court in which the areopagites, or supreme judges of Athens, assembled Areostylos, intercolumniations, when their distance from each other is four diameters Arerde, reared, built, or raised up Argand lamp, a lamp with a circular wick, through which a current of air passes Argent, in heraldry, in the blazoning of arms, signifies also white or silver Argyrocopeion, the mint at Athens Ark, a shelter, a place of protec- tion from floods : in the time of 28 Moses a coffer or sort of bark, in shape and appearance like a chest or trunk; also described by Moses as a little wicker basket in which he was exposed on the Nile. The ancients inform us that the Egyptians used on the Nile barks made of bulrushes. Noah's Ark was, in all probability, in form like these Egyptian boats, but much larger. If we reckon the Hebrew cubit at 21 inches, the ark of Noah was 512 feet long, 87 wide, and 52 high ; and the internal capacity of it was 357,600 cubical cubits. If we suppose the cubit to be only 18 inches, its length was 450 feet, its width 75, and its height 45. Its figure was an oblong square ; the covering had a declivity to carry off water. Its length ex- ceeded that of most churches in Europe. The wood used for the ark was called gopher-wood, square pieces of wood, cedar or box, or woods that do not easily perish; some supposed it to have been con- structed of Cyprus wood ArJe : " And this is the fashion which thou shalt make it of; the length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits." Gen. vi. 15. Ark (Noah's), supposed by some authors to be a mere variation from the customary construction of houses for residence, and to change its character from that of a house for standing, to that of a house for floating. Niebuhr compares it with ordinary houses of the east, that the sides are constructed of upright supports of timber, which are plas- tered over with clay. The appli- cation of canes, split and laid across these quarterings, is very like the usage of laths, which are common every where. The same may be said of the coating of bitumen : the substance was employed on account of its property of resisting water ; the mode of its application might be similar to our plastering. ARM ASPHALTUM. ASP Armarium, a niche or cupboard near the side of an altar Armiger, in heraldry, an armour- bearer, an esquire Armilla, an ornament worn by Greek men and women as a bracelet or an armlet Armour, a defensive clothing of metal Armoury, a storehouse or room in which armour is preserved Arnotta (colour), the name of a vege- table substance from the West Indies, of an orange-red colour, soluble in water and spirit of wine, but very fugitive and changeable, and not adapted for painting. It is principally used by the dyer, and in colouring cheese. It is also an ingredient in lacquering Aronade, embattled, a junction of several lines forming indentations Arris, in joinery and masonry, the line of concourse, edge, or meeting of two surfaces Arris fillet, a slight piece of timber of a triangular section, used in raising the slates against chimney shafts, &c. Arris gutter, a wooden gutter of the V form, fixed to the eaves of a building Arris-wise, in bricklaying, tiles laid diagonally Arrondee, in heraldry, the carved cross, the arms which terminate in the escutcheon Arschin, a Russian measure of length, equal to 2 feet English Arsenal, a building for naval or mili- tary stores Arsenic, a white metal of a crystal- line appearance, and very brittle. It sublimes out of the air unchanged at 360, but in air it is oxidated, and becomes arsenious acid; it is occasionally found alone, but is ge- nerally combined with nickel, co- balt, and other metals Artesian wells, so called from a mode practised in Artois in boring for water Artificer, one who possesses a supe- rior knowledge as an artist or ma- nufacturer 2'J Asarotum, a kind of chequered pave- ment used by the Romans Ash, a superior woodof British growth, of a brownish white, with a shade of green ; it is tough and elastic, and superior to any other wood exposed to sudden shocks and strains ; used for frames of machines, wheel car- riages, inside work of furniture, &c. Ashlar, a term applied to common or free stones as they come out of the quarry. By ashlar is also meant the facing of squared stones on the front of a building : if the work be so smoothed as to take out the marks of the tools by which the stones were first cut, it is called plane ashlar; if figured, tooled ash- lar, or random tooled, or chiselled, or bousted, or pointed: if the stones project from the joints, it is said to be rusticated Ashlar, or Achelor, hewn stone, used for the facings of walls Ashlering, in carpentry, the fixing of short upright quarterings between the rafters and the floor Ash-pan, in locomotive engines, an iron box, open to the front only, attached to the fire-box to receive the ashes from the fire Asphalt, native bitumen used with pitch as a substitute for pavement Asphaltum, a bituminous substance, used for pavements and as a build- ing material Asphaltum, called also Bitumen, Mineral Pitch, &c.; it is a resinous substance rendered brown by the action of the fire, natural or artifi- cial. The substances employed in painting under this name are the residua of the distillation of various resinous and bituminous matters in preparing their essential oils, and are all black and glossy like common pitch, which differs from them only in having been less acted upon by fire, and in their being softer. Asphaltum is prin- cipally used in oil-painting ; for which purpose it is first dissolved in oil of turpentine, by which it is fitted for glazing and shading. Its ASS ASSURANCE. ASS fine brown colour and perfect transparency are lures to its free use with many artists notwith- standing the certain destruction which awaits the work on which it is much employed, owing to its disposition to contract and crack from changes of temperature and the atmosphere Assay, to examine and prove metals Assay balance, a very accurate ba- lance, used in determining the ex- act weights of very small bodies Assaying, ascertaining the qualities of gold and silver with respect to their purity Assemblage, in carpentry and joinery, framing, dovetailing, &c. Assemblage of the Orders in archi- tecture, the placing of columns upon one another in the several ranges Asserts, small rafters immediately beneath the tiles of a roof Assurance, or Insurance, a contract to make good a loss Assurance Companies, or Societies, af- ford protection to persons from the chances or hazards to which their property or interests may be exposed. Assurance on human life is a contract by which a certain amount or capital is secured at the expira- tion of a stipulated period, either by the payment of a specified sum at the time of effecting the assur- ance, or by the annual payment of a smaller amount, according to the age of a person whose life is assured. A person, with the view of se- curing a certain sum of money to his family after his death, desires to effect an assurance, either for a determinate period, as one, three, five, seven, ten, or more years, or for the whole term of his life. In the first case, if the person whose life is assured, die before the expi- ration of the term specified in the policy, his inheritors receive the amount for which the assurance has been effected; but, if the assured live beyond that period,they receive nothing, and the assurer reaps the advantage of the contingency. In 30 the latter case, that is, by assur- ance for the whole term of life, the inheritors are entitled to re- ceive the amount named in the policy, upon proof of the death of the person whose life has been as- sured. To prevent the forfeiture of the policy, it is in all cases es- sentially important that the con- ditions upon which it has been granted be strictly complied with. The calculation as to the amount of premium should be made ac- cording to mathematical expecta- tion, that is, equitably as to both parties, allowing a fair rate of pro- fit to the party granting the assur- ance. If the terms for assuring 100 be required, for one year, the probability must depend on the age of the person whose life is pro- posed to be assured ; and in equity the sum to be paid should be equal to the value of the expectation, multiplied by the probability of its being obtained. Should the age of the person be 40 years, the probabi- lity of death in the course of the year will be, according to the ta- bles of mortality generally adopted, ^timr; and this fraction, multiplied by 100, gives the price of the as- surance, namely, 1-74 nearly. The result, according to the tables of mortality used in France, is T89. This is the rate charged by the ' Genei'al Assurance Company ' es- tablished at Brussels ; but the ' Bel- gic and Strangers' Union Society' charges at the rate of 1-87. Both societies adopt Dubillard's table of of mortality, which is deposited in the Bureau of Longitude in Paris. The profit to the assurer thus appears to be reduced to the in- terest on the sum paid by the as- sured; but persons in health being alone accepted, the chance of pro- fit thereby becomes considerable. For a longer term than one year, the calculations are made on an estimate of the probable amount of interest derivable from the pre- mium paid by the assurer. AST ATMOSPHERIC RAILWAY. ATM Astel, in mining, a board or plank, an arch or ceiling of boards, over the men's heads in a mine, to pro- tect them Astragal, a small moulding, whose contour is circular, at the neck of the shafts of columns, next the apo- physes : it also occurs in the base of Ionic columns, and below the fasciae of the Corinthian epistylium Astronomy, a mixed mathematical science, which treats of the hea- venly bodies, their motions, periods, eclipses, magnitudes, &c., and of the causes on which they depend : the knowledge of astronomy is essential in navigation and in measuring the earth's surface ; the diameter of this, the third planet in the system, is 7924 miles and 7 furlongs Astylar, a term which expresses the absence of columns or pilasters, where they might otherwise be supposed to occur Astyilen, in mining, a small ward or stoppage in an adit or mine, to prevent the free and full passage of water, by damming up Asylum, in the Greek states, the tem- ples, altars, sacred groves, and statues of the gods ; a place pro- vided for the protection of debtors and criminals \vho fled for refuge Aticamite, prismatoidal green mala- chite, a native muriate of copper Athanor, an ancient term for a metal furnaces Athen&um, a school founded by the Emperor Hadrian at Rome for the promotion of literary and scientific studies Athwart-hawse, the situation of a ship when driven by the wind or tide across the fore-part of another Atlantes, in architecture, male figures, used similarly to the female Carya- tides, in place of columns Atmosphere, the invisible elastic fluid which surrounds the earth to an unknown exact height, and par- takes of all its motions ; the con- stituent parts are air, water, car- bonic acid gas, and unknown bodies. The atmosphere is measured by a co- 31 lumn of mercury of 29'922 inches, which has been adopted in France as the mean height of the barome- ter at the surface of the sea Atmospheric currents, in high lati- tudes, when undisturbed, are west- erly, particularly in the winter sea- son. If storms and gales revolve by a fixed law, and we are able, by studying these disturbing causes of the usual atmospheric currents, to distinguish revolving gales, it is likely that voyages may be short- ened. The indications of a revolv- ing gale are, a descending barome- ter, and a regularly veering wind Atmospheric engine, an engine in which the steam is admitted only to the under side of the piston for the up-stroke ; it is then con- densed, and the top of the-cylinder being open, the down-stroke is caused by the pressure of the at- mosphere. Marine engines on this principle have three cylinders con- nected to one crank-shaft, to obtain uniformity of motion Atmospheric railway. The con elusions drawn by Mr. R. Stephenson are as follows : 1st, That the atmo- spheric system is not an economical mode of transmitting power, and inferior in this respect both to loco- motive engines and stationary en- gines with ropes. 2ndly, That it is not calculated practically to ac- quire and maintain higher veloci- ties than are comprised in the pre- sent working of locomotive engines. Srdly, That it would not in the ma- jority of instances produce economy in the original construction of rail- ways, and in many would most ma- terially augment their cost. 4thly, That on some short railways, where the traffic is large, admitting of trains of moderate weight, but re- quiring high velocities and frequent departures, and where the face of the country is such as to preclude the use of gradients suitable for locomotive engines,theatmospheric system would prove the most eli- gible. 5thly, That on short lines ATM AUDITORIUM. AUD of railway, say four or five miles in length, in the vicinity of large towns, where frequent and rapid communi- cation is required between the ter- mini alone, the atmospheric system might be advantageously applied. 6thly, That on short lines, such as the Blackwall Railway, where the traffic is chiefly derived from inter- mediate points, requiring frequent stoppages between the termini, the atmospheric system is inapplicable, being much inferior to the plan of disconnecting the carriages from a rope, for the accommodation of the intermediate traffic. 7thly, That on long lines of railway, the requisites of a large traffic cannot be attained by so inflexible a system as the atmospheric, in which the efficient operation of the whole depends so completely upon the perfect per- formance of each individual section of the machinery. Atmospheric vapour. Deluc proves the amount offeree and vapour in a vacuum of any given dimensions is equal to its force and quantity in an equal volume of air at the same temperature, or that the tem- perature of the air will determine the force and quantity of vapour held in it. M. Le Roi, however, first observed the temperature at which dew commences to be de- posited as a rule of ascertaining the moistnre of the atmosphere. Dr. Dalton investigated the force of vapour of every temperature, from Zero to the boiling point of water, Fahrenheit, and expressed this force by the weight of the mercurial column it could support in the tube of the barometer. Dalton and Le Roi find the clear point by pouring cold water into a glass, and marking the temperature at which it just ceases to deposit dew on the sides of the glass in the open air. The temperature here observed is the point at which dew would begin to be formed. From this Dalton infers not only the force exerted by the vapour, but 32 also its amount in a perpendicular column of the whole atmosphere, and likewise the force of evapora- tion at the time of observation Atramentum, a dye made of soot mixed with burnt resin or pitch, used by the ancients, particularly by painters ; and also as a varnish Atrium, a term applied by the Romans to a particular part of a private house ; the court or hall of a Greek or Roman house entered imme- diately from the fauces of the ves- tibilium Attal, Attle, Adall, Addle, in mining, corrupt, impure off-casts in the working of mines Attic base, the base of a column of upper and lower torus, a scotia, and fillets between them Attic Order, a low order of architec- ture, used over a principal order, never with columns, but with antes or small pilasters Attics should not be less than one- quarter nor more than one-third of the order they surmount : they are frequently decorated with small short pilasters, whose breadth ought to be equal to the upper diameter of the column underneath them, and their projection usually not more than one-quarter of their breadth At tic story, the upper story of a house when the ceiling is square with the sides, by which it is distinguished from a common garret Atticuryus, a term applied by Vitru- vius to the base of a column, which he describes as divided by a scotia or trochilus, with a fillet above and below, and beneath all a plinth Attle, in mining, rubbish, deads, re- fuse, or stony matter Attributes, in architecture, symbols given to figures, or disposed as ornaments on a building, to indicate a distinguished character Attrition, the rubbing of bodies one against another, so as to destroy their surfaces Auditorium, an apartment in monas- teries for the reception of strangers ; AUG AXIS. AXL also a place where the Roman ora- tors and poets recited their compo- sitions Auger, a tool for boring large holes ; it consists of a wooden handle, ter- minated at the bottom with steel Aula,a,n area or open place ; in ancient Roman architecture, a court or hall Auleolum, a small church or chapel Aureola, a crown of glory, given by statuaries, &c. to saints, &c. to de- note the victory they have obtained Aiirificina, a place for melting and re- fining gold, &c. Aurum, anciently, gold Automaton, an apparently self-acting machine, constructed of weights, levers, pulleys, andsprings.by means of which it continues in motion for a definite period Autometer, an instrument to mea- sure the quantity of moisture Avenue, a passage from one part of a building to another Aviary, an apartment or building for the keeping of birds Avolta, a place vaulted or arched over A-weather, the situation of the helm of a ship when it is put in the di- rection from which the wind blows Awning, a covering of canvass over the deck of a vessel, or over a boat, as shelter from the sun or rain Aval section, a section through the axis of a body Axes, the timbers of a roof which form two sides of a triangle, the tignum being the base : more gene- rally termed Principals Axiom, a self-evident truth Axis, in architecture, an imaginary line through the centre of a column, &c., or its geometrical representa- tion : where different members are placed over each other, so that the same vertical line, on the elevation, divides them equally, they are said to be on the same axis, although they may be on different planes : thus, triglyphs and modillions are so arranged, that one coincides with the axis or line of axis of each co- lumn : in like manner, the windows or other openings in the several stories of a fa9ade must all be in the same respective axis, whether they are all of the same breadth or not Axis, in geometry, the straight line in a plane figure, about which it re- volves to produce or generate a solid Axis, in mechanics : the axis of a balance is the line upon which it moves or turns Axis, in turning, an imaginary line passing longitudinally through the middle of the body to be turned, from one point to the other of the two cones, by which the work is suspended, or between the back centre and the centre of the collar of the puppet which supports the end of the mandril at the chuck Axis of a circle or sphere, any line drawn through the centre, and ter- minated at the circumference on both sides Axis of a cone, the line from the vertex to the centre of the base Axis of a cylinder, the line from the centre of the one end to that of the other Axis in peritrochio, a wheel and axle, one of the five mechanical powers, or simple machines ; contrived chiefly for the raising of weights to a considerable height, as water from a well, &c. Axis of rotation, of any solid, the line about which the body really re- volves when it is put in motion Axle bearing, in locomotive engines, the gun-metal, or other metal bear- ing, under which the axle journal revolves : it is nicely fitted to the journal, and lubricated by a syphon, to reduce, as far as practicable, the friction on the journal Axle, in locomotive engines, journal or neck, the part of the axle turned and polished for revolving in the axle-box bearing Axle, leading, in locomotive engines, the front axle of the engine : eight- wheeled engines have two axles in front of the driving wheel axle, and they are often called leading axles Axle, trailing, the last axle of the en- gine, usually placed under the foot- B 5 AXL BABYLONIAN ARCHITECTURE. AZU plate : in Stephenson's and Cramp- ton's patent engines, the driving wheel axle is the last axle Axles, in locomotive engines, the iron shafts supporting the engine, and on which the wheels are fixed Axles : driving wheel ; in locomotive engines, with inside cylinders, this is a cranked axle; with outside cylinders, it is a straight axle : it is called the driving axle because the connecting-rods and eccentric- rods connect this axle to the pis- tons, slide-valves, and pumps, and by converting the rectilinear mo- tion of the piston into a rotatory one, it propels or drives the engine in the direction required Axle-box, in locomotive engines, the box (usually cast iron) fitted up with a metal bearing in it, which rests upon the polished part of the axle Axle-box cover,in locomotive engines, the plate of iron (usually lined with leather) fitted to the top of the axle-box to keep the oil clean, and also from shaking out by the motion of the engine Axle-box syphon, in locomotive en- gines, the small tubes fitted into the BAB BABEL, tower of, built by the posterity of Noah, after the Flood ; remark- able for its great height, and for the disappointment of the builders by the confusion of their language. It was erected in the plain of Shi- nar, upon the banks of the great river Euphrates, and near the place where the famous city of Babylon subsequently stood. " Let us build us a city and a tower whose top may reach unto heaven." Gen. xi. 4. * * * The name of it is called Babel, because the Lord did there confound the language of all the earth, and from thence did the Lord scatter them abroad upon the face of all the earth." Ib. xi. 9 Babylonian architecture takes its ap- pellation from the magnificence and extent of the public buildings of 34 top of the axle-box for feeding oil on to the axle journal as it revolves : the oil is fed by a piece of cotton or worsted, having one end intro- duced into these pipes, and the other end lying down amongst the oil in the axle-box Axle-guards, or horn-plates, in loco- motive engines, the parts of the frame in which the axle-box slides up and down, as acted upon by the springs Axle-guard stays, in locomotive en- gines, the iron rods bolted to the frame and to all the ends of the axle-guards, to strengthen them Azimuth compass, an instrument used at sea for finding the sun's magnetic azimuth Azimuth dial, a dial of which the style or gnomon is perpendicular to the plane of the horizon Azote, in chemistry, an important constituent of atmospheric air, &c. ; also a gas called nitrogen, which, when breathed alone, destroys life Azure, in heraldry, the blue colour, in the shields of all persons under the rank of baron : in painting, a light or sky-coloured blue BAB Babylon. This city was founded by Nimrod about 1665 years before Christ : its walls were 50 cubits thick and 200 in height, built of bricks made from the eai'th dug out of the ditch that surrounded the city. In the walls were 100 gates made of brass ; the jambs and lintels were made of the same metal Babylonian engine. The engine that raised water from the Euphrates to supply the hanging gardens of Ba- bylon was constructed and used in this the most ancient and splendid city of the early age, founded by the builders of Babel, and enlarged by Nimrod; extended and beautified by Semiramis. This engine greatly exceeded in the perpendicular the the height to which the water was elevated by it. Extensive terraces BAG BALANCE IN A PICTURE. BAL were formed one above another to the top of the city walls ; and to supply them with the necessary moisture, the engine was erected, of which no account is known at the present time Bac, in navigation, a praam or ferry- boat Bac, in brewing, a cooler Baccalaureus, an ecclesiastical appari- tor or verger, who carries a staff of office Bacca, a light-house, watch-tower, or beacon Baccharis, a ploughman's spikenard Back, the back of a lode is the part of it nearest the surface ; the back of a level is that part of the lode extending above it to within a short distance of the level above Back-board, in turning, that part of the lathe which is sustained by the four legs, and which sustains the pillars that support the puppet-bar ; the back-board is only used in the best constructed lathes Back centre screw, the screw for set- ting up the back centre of a lathe, to the work to be turned, after the puppet-head has been fixed Backed, a sea phrase, to back an an- chor, to carry out a smaller one a- head of the one by which the vessel rides, to take off some of the strain Back-ground, in painting, is the space of ground behind the principal ob- jects of the picture Back-links, the links in a parallel mo- tion which connect the air-pump rod to the beam Back of a hip, in carpentry, is the upper edge of a rafter between two sides of a hipped roof, formed to an angle, so as to range with the raft- ers on each side of it Back of a window, the board or wain- scotingbetween the sash -frames and the floor, uniting with the two elbows in the same plane with the shutters: when framed it is commonly with single panels, with mouldings on the framing corresponding with the doors, shutters, &c., in the apart- ment in which it is fixed Back-painting, the art of painting mezzotinto prints, on plate or crowned glass with oil colours Backs, in carpentry, the principal rafters of a roof Back-staff, an instrument invented by Capt. Davis for a sea quadrant, so named because the back of the ob- server is turned towards the sun when using it Back-stays, long ropes from the top- mast heads to both sides of the ship, where they are extended to the channels Back-stay stool, a short piece of plank fitted for the security of the dead eyes and chains for the back-stays, though sometimes the channels are left long enough at the after end for the back -stays to be fitted thereto Bac-maker a cooper who makes liquor bacs, &c. Baculometry, the art of measuring either accessible or inaccessible lines, by the help of baculi, staves, or rods Badigeon, in statuary, a mixture of plaster and freestone sifted and ground together, used by statuaries to repair defects in their work Baguette, a small moulding, like the astragal : when enriched with foli- age, it is called a chaplet ; when plain, a head Bagnio, a bath Bagpipe. To bagpipe the mizen is to lay it aback by bringing the sheet to the weather-mizen rigging Bailey, an area of ground, a court within the walls of a fortress ; in modern acceptation, frequently used as prison Bakehouse, an apartment with an oven to bake bread Baker's central rule for the construc- tion of equations; is a method of constructing all equations not ex- ceeding the 4th degree Bal, a term used in mining , Balance, or equilibrium, in a picture, is when the forms of objects, the lights, shades, colours, and expres- sions, are happily adapted to each other, and no one figure or colour BAL BALANCE GATES. BAL overpowers or obscures the rest. When a building is seen in one corner of a picture, it is frequently balanced by something in the other; even a large bird will have the effect Balance, one of the six simple powers in mechanics, chiefly used in de- termining the equality or differ- ence in heavy bodies, and conse- quently their masses or quantities of matter Balance, in mechanics, are various; the common balance, the bent lever balance, the Roman balance, and the Swedish or Danish balance, adjustmentof differences in weights, &c. Balance (Hydrostatical), an instru- ment for determining the specific gravity of bodies Balance, of a clock or watch, is that part which, by its motion, regulates and determines the beats Balance gates, in hydraulic engineer- ing, are best described as follows : Balance gates at the Compensation Reservoir of the East London Wa- ter Works. These gates were de- signed for the purpose of discharg- ing the body of water collected in the reservoir during the rise of the tide, in order to supply the mills lower down the river Lea, which might otherwise have been injured by the amount withdrawn from the river by the pumping-engines of the water company. They dif- fer in construction from common flood-gates, being made to work upon a vertical shaft or spindle, as a centre, and having an equal sur- face of gate on each side of that centre, so that whatever pressure of water there may be on one side of the gate tending to force it open, there is as great a pressure on the opposite leaf to keep it shut Balance reef, a reef in a spanker or fore-aft mainsail, which runs from the outer head eaving diagonally to the tack; it is the closest reef, and makes the sail triangular Balcony, a projection in the front of 36 a house or other building, supported by consoles or columns, sometimes applied to the interiors of theatres, and for public convenience in larger buildings Balcony, the projecting gallery in the stern of large ships Baldachin, a canopy supported by columns, and raised over altars, tombs, &c. Baldachino, in architecture, an open building supported by columns and covered with a canopy, frequently placed over an altar Bale. To bale a boat, is to throw water out of her Balistics, used by some for projectiles in the art of throwing heavy bodies Balistraria, a room in fortified build- ings, wherein the crossbows were deposited Ball, is any spherical body, either natural or artificial Ballast, for ships, materials for which consist of gravel, iron, or stone, or any heavy substance, to stow away in the hold, to bring a ship to a proper water-line when unladen, and counterbalance the effect of the wind on the masts, and to give sta- bility Ball-cock, a hollow globe of metal at- tached to the end of a lever, which turns the stopcock of a cistern-pipe by floating on the surface of the water, thereby regulatingthe supply Ball flower, an ornament like a ball, placed in a circular flower, the pe- tals of which form a cap round it, and belongs to the decorated style of the 14th century Ball of a pendulum, is the weight at the bottom of it, and is sometimes called the bob Ball and socket, an instrument made of brass with a perpetual screw, so as to move horizontally, vertically or obliquely, and is used for the managing of surveying and astro- nomical instruments Ballista, in practical geometry, the same as the geometrical cross, called the Jacob's Staff Ballistic Pendulum is an instrument BAL BALUSTRADES. BAN for measuring the velocity of a cannon ball, L e. the force of gun- powder. It consists, in its simplest form, of a beam, which can swing on a fixed axis at one end, while the ball strikes the other end ; and the angle through which that end moves being known, the velocity of the cannon ball may be com- puted Balloon, a spherical hollow body, floating in the air by means of its inflation with gas specifically lighter than the atmosphere Balloon, a globe placed on the top of a pillar or pediment, as an acroter or crowning Balls, in electricity, invented by Mr. Canton, are two pieces of cork or pith of elder-tree, nicely turned in a lathe to the size of a small pea, and suspended by delicate threads Ball valves, the valves in the force- pumps of a locomotive engine : the balls are turned and ground truly spherical, so as to fit water-tight into the valve-seats in every position Balneac, in Greek, signifies a bath or bathing vessel Balteum, a band or girdle, according to Vitruvius : this word is used to denote the moulding on the bolsters or sides of the Ionic capital Baltei, the bands in the flanks of Ionic pulvinated capitals. Balteum and balteus were generally used by the Romans to signify the belt by which the sword or quiver was suspended Baluster, a small column or pillar, used in a balustrade Balusters, placed round the gallery in the stern, and likewise in the quarter gallery of large ships Balustrade, a series or row of balus- ters, joined by a rail, serving for a rest to the arms, or as a fence or inclosure to balconies, altars, stair- cases, &c. Balustrades, when intended for use, as against windows, on flights of steps, terraces, and the like, should not be more than three feet six inches, nor less than three feet in height. When used for ornament, as on the summit of a building, their height may be from two- thirds to four-fifths of the entabla- ture whereon they are employed : and this proportion is to be taken exclusive of their zoccolo or plinth, so that from the proper point of sight the whole balustrade may be exposed to view. There are vari- ous species of balusters ; if single- bellied, the best way is to divide the total height of the space al- lotted for the balustrade into thir- teen equal parts, the height of the baluster to be eight, of the base three, and of the cornice two of those parts ; or divide the total height into fourteen parts, making the baluster eight, the base four, and the cornice two. If double- bellied, the height should be di- vided into fourteen parts, two of which are to be given to the cor- nice, three to the base, and the re- mainder to the baluster. The distance between two ba- lusters should not be more than half the diameter of the baluster in its thickest part, nor less than one- third of it; but on inclined planes the intervals should not be quite so wide. Gwilt. Band, in architecture, denotes any flat low member, or moulding, that is broad and not very deep Banderole, in heraldry, a narrow flag or streamer affixed under the crook of a crosier, and folding over the staff Bandlet, a small fillet, or flat moulding Bandrol, a little flag or streamer affixed to the top of masts Bank, a long piece of timber Bank. To double bank an oar, is to have it pulled by two men Banker, in bricklaying, is a bench from 6 to 12 feet in length ; is used for preparing the bricks for gauged work Banker, a cushion or covering for a seat Banneret, in heraldry, a knight made in the field BAN BAR IRON. BAR Banquet, the raised footway adjoining to the parapet on the sides of a bridge Baptaterium, a hack mill or fulling mill Baptistery, a place or edifice where baptism is performed. A basin, pool, or place for bathing Bar, a barrier, gatehouse: in law, a place where counsellors plead Bar, a bank or shoal at the entrance of a harbour Bar of ground, in mining, any course of vein which runs across a lode, or different from those in its vicinity Barberry wood is of small size, re- sembling alder, and is straight and tenacious Barbican, in the middle ages, the part of a fortress where watch and ward was kept Barcella, a vessel containing incense Barcon, a luggage vessel used in the Mediterranean Bardiglione, a blue variety of anhy- drite, cut and polished for orna- mental purposes Bare poles, the condition of a ship when she has no sail set Barge, a large double-banked boat used by the commander of a vessel in the navy Barge board, the front or facing of the former, to conceal the barge couples, laths, tiles, thatch, &c. Barge boards, or, more properly, verge boards, pendants, pinnacles, and brackets, being the chief deco- rations of houses in early domestic architecture, should always be made of strong oak, and left to acquire by age a grey hue ; and not of slight deal, painted, as is now the too frequent practice Barge couples, in architecture, a beam mortised into another, to strengthen the building Barge course, a part of the tiling or thatching of a roof, projecting over the gable, and filled up with boards, mortar, &c. Bar iron, long prismatic pieces of iron, being rectangular parallelepi- peds, prepared from pig iron, so as 38 to be malleable for the use of black- smiths for the method of joining bars Barium, a metal that exists in the sulphate and carbonate of barytes; found in nature in great abund- ance Barker's mill, an hydraulic machine in much use Barkery, a tan -house; also a sheepcote Barmkyn, the rampart or outer forti- fication of a castle Barn, a covered farm-building for laying up grain, hay, straw, &c. Barnacle, a shell fish often found on a vessel's bottom Barometer and Sympiesometer. The barometer is a measure for the weight of the atmosphere, or its pressure on the surface of the globe. It is well known, that it is owing to the atmospheric pressure that water rises in a common pump, after the air has been drawn from the barrel ; but that the height to w T hich it can be raised by this means is limited, and not much exceeds 30 feet. A little more than 30 feet of water, therefore, balances the at- mosphere. Mercury being about twelve times heavier than water, about 30 inches of mercury will also counterpoise the atmosphere. The principle of the barometer is simple. If a tube, about 3 feet long, closed at one end and open at the other, be filled with mercury, and, with the open end stopped by a finger, this tube be reversed, and placed upright in a cup partly filled with the same liquid, the mercury in the tube, in ordinary states of the weather, will descend to 30 inches, measured from the surface of the fluid in the cup, and not much lower. The mercury is sustained in the tube by the pres- sure of the atmosphere on the sur- face of the fluid in the cup. Such a tube and cup, so filled, would in fact be a barometer ; and if a move- able index were added to it, this simple instrument would indicate the changes which take place in the BAR BAROMETER. BAR atmospheric pressure. The sympie- to be set according to the actual someter is a more delicate instru- temperature, before the atmospheric merit, for measuring the atmospheric pressure can be read off. pressure ; but it is also a more com- Since mercury expands by heat, plicated one than the mercurial a correction for temperature is also barometer, and it would be best un- required for the mercurial barome- derstood by inspection. The upper ter, when exact calculations are to part of the tube contains hydrogen be made; and for this reason ba- gas, which is elastic ; and the lower rometers usually have athermometer part, including the well, contains attached to them, in order that the oil. By this compound construc- temperature may be read off, and tion, whilst the length of the tube recorded at the same time that the is less than that of the mercurial barometer is registered. barometer, the index, or scale for The following is a table for the measuring the pressure, is increased. correction to be applied to the ob- Hydrogen gas being very sensibly served height of the mercury, to affected by all chai iges of tempe- reduce it to the freezing point, at ratnre, the index, by which the at- 32 Fahrenheit, or zero of the cen- mospheric pressure is read, requires tigrade scale. Reduction of the English Barometer to the Freezing Point, or to 32 on Fahrenheit's Scale. Subtractive. PART I. For Mercury only. PART II. Mercury and Brass. Temp. Height of the Barom. in Inches. Height of the Barom. in Inches. \ Fah. Cent. 28 In. 29 In. 30 In. 31 In. 28 In. 29 In. 30 In. 31 In. 3 32 o-oo o-oooo o-oooo o-oooo o-oooo 0-0088 O'OOgi 0-0094 0-0097 2 34 rn 0-0056 0-0058 0-0060 0-0062 0-0138 0-0143 0-0148 0-0152 5 36 2-22 0-0112 0-0116 0-0120 0-0124 0-0188 0-0194 0-0201 0-0208 7 38 3-33 0-0168 0-0174 0-0180 0-0186 0-0238 0-0246 0-0255 0-0263 9 40 4-44 0-0224 0-0232 0-0240 0-0248 0-0288 0-0298 0-0309 0-0319 11 42 5-55 0-0280 0-02QO 0-0300 0-0310 0-0338 0-0350 0-0362 0-0374 12 44 6-66 0-0336 0-0348 0-0360 0-0372 0-0388 0-0402 0-0416 0-0430 14 46 777 0-0392 0-0406 0-0420 0-0434 0-0438 0-0454 0-0470 0-0485 16 48 8-88 0-0448 0-0464 0'0480 0-0496 0-0488 0-0506 0-0523 0-0541 17 50 10-00 0-0504 0-0522 0-0540 0-0558 0-0538 0-0558 0-0577 0-0596 19 52 11-11 0-0559 0-0579 0-0599 0-0619 0-0588 0-0609 0-0630 0-0652 21 54 12-22 0-0615 0-0637 0-0659 0-0681 0-0638 0-0661 0-0684 0-0707 23 56 13-33 0-0671 0-0695 0-0719 0-0/43 0-0688 0-0713 0-0738 0-0762 25 58 14-44 0-0727 0-0753 0-0779 0-0805 0-0/38 0-0765 0-0791 0-0818 26 60 15-55 0-0783 0-0811 0839 0-0867 0-0788 0-0817 0-0845 0-0873 28 62 16-66 0-0838 0-0868 0-0898 0-0928 0-0838 0-0868 0-0898 0-0928 30 64 17'77 0-0894 0-0926 0-0958 0-0990 0-0888 0-0920 0-0951 0-0983 32 66 18-88 0-0950 0-0984 0-1018 0-1051 0-0938 0-0971 O'lOOS 0-1039 34 68 20-00 0-1005 0-1041 0-1077 0-1113 0-0988 0-1023 0-1058 0-1094 36 70 21-11 0-1061 0-1099 0-1137 0-1175 0-1037 0-1075 0-1112 0-1149 38 72 22-22 0-1117 0-1156 0-1196 0-1236 0-1087 0-1126 0-1165 0-1204 40 74 23-33 0-1172 0-1214 0-1256 0-1298 0-1137 0-1178 0-1218 0-1259 42 76 24-44 0-1228 0'1271 0-1315 0-1359 0-1187 0-1229 0-1272 0-1314 44 78 25-55 0-1283 0-1329 0-1375 0-1421 0-1237 0-1281 0-1325 0-1369 45 80 26'66 0-1339 0-1387 0-1434 0-1482 0-1286 0-1332 0-1378 0-1424 47 82 2777 0-1394 10-1444 0-1494 0-1544 0-1336 0-1384 0-1432 0-1479 49 84 28-88 0-1450 0-1502 0-1553 0-1605 0-1386 0-1435 0-1485 0-1534 51 86 30-00 0-1505 0-1559 0-1613 0-1667 0-1435 0-1486 0-1538 1589 53 88 31-11 0-1561 0-l6l6 0-1672 0-1728 0-1485 0-1538 0-1501 0-1644 54 9 32-22 0-1617 0-1674 0-1731 0-1790 0-1535 0-1589 0-1644 0-1699 56 P. P. for 0. 4 0. 8 1 2 1. 6 2. 0. 4 0. 8 1. 2 1. 6 2. Temp. F. + 12 24 35 47 59 10 21 31 42 52 From Galbraith's Tables. BAR BASE COURT. BAS The atmosphere is supposed to extend to about the height of 50 miles ; and its density to diminish from the surface of the globe up- wards, in a geometrical ratio. Thus, when observations are made on land, above the level of the sea, a correction is required for altitude, since the weight of the atmosphere diminishes as we ascend. It is owing to this that we are enabled to determine the height of moun- tains by barometers ; and that aero- nauts compute the altitude to which they ascend in balloons. If any fluid in a cup be put into rapid circular motion, we should have a representation of the form that portion of the atmosphere as- sumes which is within the limits of a storm; the most depressed part of the fluid would represent the centre of the gale where the atmo- spheric pressure is the least. The principle of the barometer should be explained in all works on navigation, and in all schools where navigation is taught Baron, in heraldry, a degree of no- bility next to a viscount Baronet, in heraldry, the lowest de- gree of honour that is hereditary Baroscope, an instrument for proving the weight of the atmosphere Barque, a three-masted vessel having her fore and main masts rigged like a ship's, and her mizen-mast like the main-mast of a schooner, with no sail upon it but a spanker Barra, in the middle ages, a tower or bar at one end of a bridge Barrack, a building for the lodgment of soldiers Barraly, in heraldry, the field divided barwise,intoseveral parts, sideto side Barrel, in machinery, is a term ap- plied generally to any thing hollow and cylindrical Barrow, in mining, a heap of dead attle, rubbish, &c. Barrows, or tumuli, monuments of the greatest antiquity, raised as se- pulchres for the interment of the great ^ 40 Barrulet, in heraldry, the fourth part of the bar, or one-half the closet Barry, in heraldry, is when an escut- cheon is divided barwise, or into any number of compartments Barry-bendy, in heraldry, is when the escutcheon is divided evenly barwise and bendwise Barry-pily, in heraldry, is when a coat is divided by several lines drawn obliquely from side to side, where they form acute angles Bars, straight pieces of timber or metal that run across from one part of a machine to another Bartisan, in architecture, the small overhanging turrets which project from the angles on the top of a tower, or from the parapet or other parts of a building Bartisan, a wooden tower; a turret on the top of a house, castle, or church tower Barton, a manor-house, or out-house Bar Wood, is an African wood, four to five feet long. It is used as red dip wood, used for violin bows, ramrods, and turning Barytes, a heavy mineral substance, found in copper mines, and for- merly named ' ponderous spar' Basalt, a variety of trap rock, usually of a dark green or brownish black colour, composed of augite and fel- spar, with some iron and olivine Basaltes, a heavy, hard stone, chiefly black or greenish, consisting of prismatic crystals, the number of whose sides is uncertain Basanite, a variety of schistose horn- stone, called also Lydian stone Base of a figure, in geometry, denotes the lowest part of its perimeter Base of a conic section, is a right line in the parabola and hyperbola formed by the common intersection of the cutting plane and the base of the cone Base, in architecture, the lower part or member of a column, on which the shaft stands Base-court, the outer or lower yard of a castle, appropriated to stables, offices, &c. BAS BASILICA. BAS Base-line, in perspective, the common section of a picture and the geo- metrical plane Base-line, in surveying, a line, mea- sured with the greatest possible exactness, on which a series of tri- angles are constructed, in order to determine the position of objects and places. The measurement of degrees of the meridian, for the purpose of ascertaining the size of the earth, have been undertaken in various countries, with extreme accuracy. The arc measured by the French extended from Dunkirk to the southernmost point of the Balearic Islands, including 120, 22', 14", having its centre half- way between the equator and the north pole. Another survey of this kind was performed on a part of the shore of Pennsylvania, which happens to be so straight and level as to admit of a line of more than 100 miles being measured directly without triangulation. Very long lines have also been measured (tri- gonometrically) by order of the English government, both at home and in India, the mean result of which makes the earth's axis 7898 miles, 5 furlongs, 16 yards, and the diameter of the equator 7924 miles 7 furlongs Basement, the lower story or floor of a building; the story of a house below the level of the ground Basements. As an alternative for employing orders upon orders, the ground floor is made to assume the appearance of a basement, and the order that decorates the principal story placed thereupon: in such cases the basements should not be higher than the order it supports, nor lower than one-half the height of the order ; but if a basement be introduced merely for the purpose of raising the principal or ground- floor, it may be three, four, five, or six feet high, at pleasure. These basement stories are gene- rally in rock-worked or plain rus- tics ; and in no case should the 41 height of a rustic course be less than one module of the order rest- ing on the basement, nor should it ever much exceed it : their joints, if square, ought not to be broader than one-eighth of the height of the rustic, nor narrower than one- tenth, and their depth should equal their breadth ; if chamfered, the whole joint may be one-quarter to one-third the height of the rustic, the joint being always right-angled. When the basement is high, it is sometimes crowned with a cornice, but a platband is more commonly used. Gwilt. Basenet, a helmet Base-plate, the foundation plate of an engine Basil, that angle the edge of a tool is ground to Basilica, in the time of the Romans, a public hall or court of judicature. After the conversion of the em- peror Constantine to Christianity, these edifices were converted into Christian churches The Basilicce of the Romans were the types from which the early Christian places of worship were taken ; and the ruins of these buildings were the chief materials used. In several instances the columns that divide the centre part of the church from the aisles have been taken from other edifices, either on account of the want of artists capable of executing any thing equal to them, or the haste with which they were erected, The expedient that was adopted tends to show that proportion was not considered ; some columns were reduced from their former height, and others mounted on pedestals to suit the purposes to which they were applied. Besides this total disregard to proportion in the shafts of the columns, capitals and bases were applied without any consider- ation to their fitness. The heathen basilicae, generally situated in the forums, were of rectangular form, and divided into three or five parts by rows of columns parallel to the BAS BASSO-RILIEVO. BAT length of the building; another colonnade at the extremity crossed the former at right angles, and in the middle of the end wall was a semicircular recess, in which was situated the tribune of the judge. These basilica had likewise galle- ries over the aisles, in which com- mercial or other business was trans- acted; but in the Christian churches this was appropriated to the wo- men, who (as in the Jewish syn- agogues) were not allowed to join with the men in the lower parts of the building. These galleries were omitted in the after basilicee, and one of the aisles was retained solely for their use. Six of the principal churches or basilicas at Rome are attributed to the zeal of Constan- tine. The basilicae of St. John de Lateran, St. Peter, St. Laurentius, St. Paul, St. Agnes, and St. Ste- phen were built by him, besides the baptisterium that bears his name Basilicula, a shrine, oratory, or ceno- taph Basins and ewers. In early times, before the cleanly custom of using a fork was practised, the hands were frequently washed during din- ner : a basin and ewer were handed for that purpose by an attendant. At the feast given by Henry VIII. to the French ambassadors, there were three ewry boards ; one for the king, another for the queen, and the third for the princes, &c. Basset. The basset or outcrop means the emergence at the surface of the different mineral strata from be- neath each other Bass-relief or Basso-rilievo, a species of low sculpture, the figures of which do not stand out from the ground in their full proportion Bastard stucco, a three-coated plaster, the first generally roughing in or rendering ; the second floating, as in trowelled stucco ; but the finish- ing coat contains a little hair be- sides the sand: it is not hand- floated, and the trowelling is done 42 with less labour than what is called trowelled stucco Bastard-toothed file, in smithing, that employed after the rubber Bastard-wheel, a flat bevil-wheel, or one which is a near approach to a spur-wheel Bastida, in the twelfth century, a place of defence, a fortress Bastile, a prison ; a castle, tower, fort- ress, or any place of defence Bastion, a rampart, bulwark, or earthen mound Batardean, a coffer-dam, or case of piling without a bottom, for build- ing the piers of a bridge Batch, in mining, a certain quantity of ore sent to the surface by any pair of men Bateau, a light boat, long in propor- tion to its breadth Bath, a receptacle of water, in which to plunge, wash, or bathe the body. Among the Romans, baths were erected both in magnificence of style and purpose, many of them of great architectural beauty. In later times the bath was always used by the Romans before they went to their supper. The rich generally had hot and cold baths in their own houses ; and it was not till the time of Augustus that the baths assumed an air of grandeur and magnificence. The situation chosen for baths ought to be sheltered from the north and north-east. The caldaria and tepidaria should be made to receive their light from the west ; or, should local circumstances not admit of this disposition, they may both be made to face the south, because the ge- neral time of bathing is from mid- day until sunset. One thing neces- sary to be observed is, that the caldaria of that division of the bath which is appropriated to the women should be contiguous to that exclu- sively used by the men, and have the same aspect ; for then the cop- pers of both may be heated from the same furnace. Three brazen vessels are fixed over the furnace, BAT BAY. BAT which are severally called calda- rium, tepidarium, and frigidarium : they are so arranged) that whatever heated water is taken from the first, is replaced by warm water from the second, the deficiency of which is supplied, in a similar man- ner, from the third. The concave coverings of the small tubes of both baths are likewise heated from the same furnace. The insulated stages of the caldaria are thus constructed: the floor is made inclining towards the furnace, so that if a ball were placed upon any part of it, it would not remain at rest, but take a direc- tion towards the mouth ; by which means the flame will more easily pervade the interval between the floors, which is paved with tiles a foot and a half square: upon the floor, earthen props, eight inches each way, are arranged at such in- tervals as to receive upon them square tiles two feet in length : the props are two feet in height; the tiles which form them are cemented with clay and hair mixed together. The square tiles which they sup- port form the substratum of the pavement of the caldaria Bath stone, Bath oolite ; minute glo- bules, cemented together by yel- lowish earthy calcareous matter ; is much used in building, but not a lasting material. It is soft when quarried, but hardens by exposure to the air Batifolium, a moveable wooden tower used by besiegers in attacking a fortress Batten, in carpentry, a scantling of wooden stuff, from two to four inches broad, and about one thick, principally used for wainscot, on which also are bradded,on the plain boards, also batten doors, those which resemble wainscot doors, but are not so ; for in wainscot doors the panels are grooved in the framing Battens, nautical, thin strips of wood put around the hatches to keep the tarpaulin down ; also put upon 43 rigging to keep it from chafing. A large batten widened at the end, and put upon rigging, is called a Scotchman Batter, to displace a portion of the iron of any bar or other piece by the blow of a hammer, so as to flatten or compress it inwardly, and spread it outwardly on all sides around the place of impact Batter, a term applied to walls built out of the upright, or gently sloping inwards; wharf walls and retaining walls built to support embankments Batter, the leaning back of the up- per part of the face of a wall, so as to make the plumb-line fall within the base Battery, in electricity, a combina- tion of coated surfaces of glass, commonly jars, so connected to- gether that they may be charged at once and discharged by a com- mon conductor Battlement, an open or interrupted parapet on the roof of a building ; a parapet with embrasures Bauffium, an out-house or domestic office Baulk, a piece of foreign fir, or deal, from 8 to 16 inches square, being the trunk of a tree of that species of wood; generally brought to a square for the use of building Bawk, a cross beam in the roof of a house which unites and supports the rafters ; a tie-beam Bay, a division of a roof or vaulting of a building, consisting of the space between the beams or arches. A part of a window between the mullions is often called a bay or day Bay, in plastering, the space between the skreeds, prepared for regulating and working the floating-rule Bay of joists, the joisting between two binding joists, or between two girders when binding joists are not used Bay of roofing, the small rafters and their supporting purlins between two principal rafters Bay-salt, salt obtained by evaporating BAY BEAMS. BEA sea-water in shallow ponds by the heat of the sun ; is of a dark grey colour, and contains iodine Bay tree, a native of Italy and Greece ; grows to the height of thirty feet, and is an aromatic wood Bay-window, an oriel window : a win- dow jutting outwards; frequently called bow-window Bazaar, a market-place Beacon, a post or buoy placed over a shoal or bank, to warn vessels off: also a signal-mark on land Beacon, an eminence on which a tower is placed, with a light to de- note the approach of danger Bead, a small globular ornament used in ancient and modern architecture Bead and Butt work, in carpentry, framing in which the pannels are flush, having beads stuck or run upon the two edges, the grain of the wood being in the direction of them Bead and quirk, a bead stuck on the edge of a piece of stuff, flush with its surface Bead-butt and square-work, framing with bead and butt on one side, and square on the other ; is used in doors Bead-house, a dwelling-place for poor religious persons Bead-plane, is a moulding plane of a semi-cylindric contour, and is ge- nerally used in sticking a moulding of the same name on the edge, or on the side close to the arris Beak, the crooked end of a piece of iron, to hold any thing fast Beak, a small pendent fillet, forming a channel behind, to prevent water from running down the lower bed of the cornice Beak-head, a small platform at the forepart of the upper deck in large ships Beak iron, the conic part of the an- vil, with its base attached to the side, and its axis horizontal Beaking -joint, is the joint formed by the meeting of several heading joints in one continued line, which is sometimes the case in folded floors Beam, a horizontal piece of iron or 44 " timber, used to resist a force or weight, as a tie-beam, where it acts as a string, or chain, by its ten- sion; as a collar-beam, where it acts by compression ; as a bres- summer, where it resists a trans- verse insisting weight Beam, in steam-engine, a large lever turning upon a centre, and forming the medium of communication be- tween the piston-rod and the crank shaft Beams. FORMS OF BEAMS. In the construction of beams, it is ne- cessary that their form should be such that they will be equally strong throughout ; or, in other words, that they will offer an equal resistance to fracture in all their parts, and will, therefore, be equally liable to break at one part of their length as at another. If a beam be fixed at one end and loaded at the other, and the breadth uniform throughout its length, then, that the beam may be equally strong throughout, its form must be that of a parabola. This form is generally used in the beams of steam-engines ; and, in double-acting steam-engines, the beam is strained sometimes from one side, and sometimes from the other; therefore, both the sides should be of the same form. Mr. Emerson gives the load that may be safely borne by a square inch rod of each of the following : Ibs. avoird. Iron rod, an inch square! ,-/. , nft will bear . . . / 7MU Brass 35,600 Hempen rope . . . 19,600 Ivory ...... 15,700 Oak, box, yew, plum- ~| tree . . . . J Elm, ash, beech . . 6,070 Walnut, plum . . . 5,3GO Red fir, holly, elder, "1 plane, crab . . J Cherry, hazel . . . 4,760 Alder, asp, birch, willow 4,290 Lead 430 Freestone 914 BEA BEAMS, FORMS OF. BEA He also gives the following prac- tical rule, viz., That a cylinder, the diameter of which is d inches, loaded to one-fourth of its absolute strength, will carry as follows : cwt. Iron 135 x d 2 Good rope .... 22 x d 2 Oak 14 x cP Fir 9 x d* Also he says, that a cylindric rod of good clean fir, of an inch cir- cumference, drawn in length, will bear at its extremity 400 Its. ; and a spear of fir, 2 inches diameter, will bear about 7 tons, but not more. A rod of good iron, of an inch circumference, will bear nearly 3 tons weight. A good hempen rope, of an inch circumference, will bear 1000 frs. being at its extremity. Mr. Barlow gives the following table as a mean derived from his experiments, on the strength of direct cohesion on a square inch of the following : ibs. Box is about .... 20,000 Ash 17,000 Teak 15,000 Fir 12,000 Beech 11,500 Oak 10,000 Pear 9,800 Mahogany .... 8,000 TRANSVERSE STRENGTH OF BEAMS, ETC. The transverse strength of rectangular beams, or the resistance which they offer to fracture, is as the breadth and square of the depth: therefore, if two rectangular beams have the same depth, their strengths are to each other as their breadths ; but if their breadths are the same, then their strengths are to each other as the squares of their depths. The transverse strengths of square beams are as the cubes of the breadths or depths. Also, in cylindrical beams, the transverse 45 strengths are as the cubes of the diameters. Thus, if a beam which is one foot broad and one foot deep support a given weight, then a beam of the same depth, and two feet broad, will support double the weight. But if a beam be one foot broad and two feet deep, it will support four times as much as a beam one foot broad and one foot deep. If a beam one foot square, sup- port a given weight, then a beam two feet square will support eight times as much. Also, a cylinder of two inches in diameter will sup- port eight times as much as a cy- linder one inch in diameter. The following table of data is extracted from tables in Barlow's Essay : Teak 2,462 English oak . . . . 1,672 Canadian do. . . , . 1,766 Dantzic do 1,457 Adriatic do 1,383 Ash 2,026 Beech 1,556 Elm 1,013 Pitch pine 1,632 Red pine 1,341 New England fir ... 1,102 Riga fir 1,108 Mar Forest fir. . . . 1,262 Larch 1,127 Beam-ends. A ship is said to be on her beam-ends when she inclines very much on one side, so that her beams approach to a vertical position Beam engine, generally a land en- gine, which has the top of the pi ton-rod connected to one end of a lever or beam : by a contrivance called a parallel motion, the beam vibrates upon a central axis, and communicates the motion of the piston to the crank by means of a connecting-rod attached to the other end of the beam, and also gives motion to the various parts Beam-filling, the brickwork, or ma- sonry, brought up from the level of the under to the upper sides oJ the beams BEA BED-MOULDINGS. BED Beam gudgeons, the bearings on the centre of the beam, or the central pivot upon which it vibrates Beam of a balance, the horizontal piece of iron from the ends of which the scales are suspended Beams, in naval architecture, strong thick pieces of timber stretching across the ship from side to side, to support the decks : they are sus- tained at each end by thick planks in the ship's side, called clamps, upon which they rest Bearer, any thing used by way of support to another weight Bearer, in turning, that part of the lathe which supports the puppets Bearing, the distance that a beam or rafter is suspended in the clear : thus, if a piece of timber rests upon two opposite walls, the span of the void is called the bearing, and not the whole length of the timber Bearing, that part of a shaft or spindle which is in contact with the supports Bearing, a word for delineating an antique plaster figure. It is gene- rally said, if the drawing of a figure has not the same bearing or angles of inclination as the original pos- sesses, it is out in all its bearings Bearing, in heraldry, the figures on a coat of arms ; a coat of arms in general Bearing, the direction of an object from the person looking. In ship- ping, the bearings of a vessel are the widest part of her below the plank- sheer ; that part of her hull which is on the water line w r hen she is at anchor and in her proper trim Beat away, in mining, to excavate, usually applied to hard ground Beating, in navigation, the operation of making progress at sea against the wind Beaufet, a cupboard or niche Beau ideal, in painting, that beauty which is freed from the deformity and the peculiarity found in nature in all individuals of a species Beauty, in architecture, consists of the following qualities : magnitude 46 and strength, order and harmony, richness and simplicity ; Construc- tion, in which the chief requisites are magnitude and strength, order and harmony; Decoration, whose requisites are richness or simplicity, according to the nature of the com- position Becalm, to intercept the wind by al- ternate tacks BecJcet, a piece of rope placed so as to confine a spar or another rope ; a handle made of rope in the form of a circle Beconage, dues levied for the mainten- ance of beacons Bed of a brick, the horizontal sur- faces as disposed in a wall Bed, a term used in masonry to de- scribe the direction in which the natural strata in stones lie ; it is also applied to the top and bottom surface of stones when worked for building Bed, in mining, a seam or horizontal vein of ore Beds of a stone are the parallel sur- faces which intersect the face of the work in lines parallel to the horizon Beds and Bedding. Feather-beds, bolsters, and pillows filled witb feathers and down, with mattresses and every other comfort of this kind, seem to have been as well known to, and enjoyed by, the su- perior orders of society three cen- turies ago, as they are now. Direc- tions are, however, mentioned as having been given in the reign of Henry VIII. "to examine every night the straw of the king's bed, that no daggers might be con- cealed." Beds (trussing} were beds which packed into chests, for travelling ; and, considering the frequent re- movals, these must havte been the most convenient kind. John of Ghent seems to have always slept in such beds, as by his will it ap- pears that he demised to his wife all the beds made for his body, " called in England trussing-beds ;" and the "best chambers" of both BED BELFRY. BEL Master Fermor and Sir Adrian Fos- kewe had trussing-beds Bed-chambers, in Tudor times. The furniture of these apartments, in great houses, was of the same gor- geous character as that in the chief rooms ; and the paraphernalia of an ancient dressing-table yielded only, in the splendour and costliness of plate, to the cupboard of the great chamber, or the altar of the chapel. Like the hall, the state bed-cham- ber had a high place, on which were placed the ' standing bed' and the ' truckle-bed ' : on the former lay the lord, and on the latter, his at- tendant Beddern, a refectory Bedding-stone, used in bricklaying, a straight piece of marble : its use is to try the rubbed side of the brick ; first, to square, to prove whether the surface of the brick be straight; se- condly , to fit it upon the leading skew- back, or leading end of the arch Bed-mouldings. This may be under- stood as a collective term for all the mouldings beneath the corona or principal projecting member of a cornice, which, without bed- mouldings, would appear too much like a mere shelf Bed-plate, the foundation plate of a marine or a direct action engine Bedsteads, in Tudor times. The posts, head-boards, and canopies, or sper- vers of bedsteads were curiously wrought and carved in oak, walnut, box, and other woods, and variously painted and gilt. Ginger-colour, hatched with gold, was a favourite style, but purple and crimson w r ere also used in their decorations Beech, a species of timber very much used by artificers ; while young, it possesses great toughness, and is of awhitecolour: the cohesive strength is 1 2,225 tbs. weight, which will tear asunder a piece of this timber one square inch Beech wood, common in Buckingham- shire and Sussex as the best ; about fifty feet high and thirty inches in diameter ; white, brown, and black 47 colour : it is used for piles in wet foundations ; is used also, for its uniform texture and closeness, in in-door works, as the frames of machines, bedsteads, and furniture; also for planes, tools, lathe-chucks, keys, cogs of machinery, brushes, handles, &c. Beef wood, red-coloured wood, gene- nerally applied to Botany Bay oak Beer-drawing machines are contriv- ances by means of which beer is drawn up from the ban-el or cask Bees, pieces of plank bolted to the outer end of the bowsprit, to score the fore-top mast stays through Beetle, or Maul, a large mallet to knock the corners of framed work, and to set it in its proper position : the handle is about three feet in length Before the beam, in naval architec- ture, is an arch of the horizon, comprehended between a line which crosses aships'length at right angles, and some object at a distance be- fore it ; or between the line of the beam, and that point of the com- pass which she stems Belay, to make a rope fast by turns round a pin or coil, without hitch- ing or seizing it Belfry, that part of the tower of a church which contains bells Bell, The body of a Corinthian or Com- posite capital, supposing the foliage stripped off, is called the bell ; the same is applied also to the early English and other capitals in Go- thic architecture which in any de- gree partake of this form Bell, a metallic instrument rung in the belfry of a church for the attend- ance of divine w r orship, and upon occasions of rejoicing; composed of three parts of copper and one of tin, called bell-metal Bell-cranJc, a bent lever, used for changing a vertical into a horizon- tal motion Bell-gable, a term applied to the gable of a religious edifice, having a plain or ornamental niche for the recep- tion of one or more bells BEL BELLOWS. BEV Bellows, the instrument for blowing the fire, with an internal cavity so contrived as to be of greater or less capacity by reciprocating motion, and to draw in air at one place while the capacity is upon the increase, and discharge it by another while upon the decrease. " The bellows are placed behind the forge, with a pipe, and are worked by means of a lever, called a rocket. Steam machinery is now much used in the generating of wind for blowing the wind or furnace Bellows, or water-blowing engine, is a machine in which the stream of air is supplied by the flowing of water Belly, the hollow part of a compass timber, the round part of which is called the back Belt, in building, a string-course and blocking-course ; a course of stones projecting from a wall, either mould- ed, plain, fluted, or enriched Belvedere, a turret, lantern, or cupola, raised above the roof of a building. It is sometimes applied in Italy to open galleries or corridors Bema, an ambo, or reading-desk ; a raised structure for the seat or throne of a bishop Bema, the sanctuary, presbytery; or chancel of a church Bema, in Greek, the platform from which the orators spoke in the Athenaeum Ben-alive, Cornish mining Bench, for carpenters and joiners to do their work on, usually 10 or 12 feet in length, and about 2| feet in width Bench planes. The jack-plane, the try- ing-plane, thelong-plane,the jointer, and the smoothing-plane, are called bench planes Bench table, a low stone seat round the interior of the walls of many churches Bend, in mining, indurated clay, a name given by miners to any indu- rated argillaceous substance Bend, the form of the ship from the keel to the top of the side, as the midship bend, &c. 48 Bend, in heraldry, an honourable or- dinary, formed by lines drawn from the dexter-corner to the sinister- base Bends, the strongest part of a vessel's side, to which the beams, knees, and foot-hooks are bolted Bending - straJces, are two strakes wrought near the coverings, worked all fore and aft, about one inch or one inch and a half thicker than the rest of the deck, and let down between the beams and ledges so as the upper side to be even with the rest of the deck Bending of timber. The process of bending wood to any required curve depends on the property of heat, for its pressure increases the elasticity of the wood Bendlet, in heraldry, the sixth part of a shield Bendy, in heraldry, applied to the field when divided into parts dia- gonally, and varying in metal and colour Benefice, a church endowed with a re- venue for the performance of divine service Benetier, a vesselto containholy water; a font, or piscina Ben-heyl, in Cornish mining, rich in tin BenticJc -shrouds, formerly used, and extending from the futtock staves to the opposite channels Benzine, the bi-carburet of hydrogen, procured by heating benzoic acid with lime Berymote, a court held on a hill to decide controversies among mi- ners Berne machine, for rooting up trees, the invention of Peter Sommer, of Berne Berth, the place where a vessel lies ; the place in which a man sleeps Beryl, a pellucid gum, of a bluish green colour, found in the East Indies, Peru, &c., used by artists Betty, in mechanics, an instrument to break open doors Bevel, any angle except one of 90 de- grees Bevel, in bricklaying, is for drawing BEV BILLET MOULDING. BIN the soffit-line on the face of the bricks Bevel, in joinery. One side is said to be bevelled with respect to another, when the angle formed by these two sides is greater or less than a right angle Bevel year, in mechanics, denotes a species of wheel-work where the axis or shaft of the leader or driver forms an angle with the axis or shaft of the follower or the driven. In practice it is requisite to have finite and sensible teeth in bevel gear : these are made similarly to those of spur gear, except that in the latter they are parallel, while in bevel gear they diminish in length and thick- ness in approaching the apex of the cone : the teeth are of any breadth, according to the strength required. Bevel gearing is stronger, works smoother, and has superseded the face-wheel and trundle Bevelling, in ship-building, the wind- ing of a timber, &c., agreeably to directions given from the mould-loft Bevel-wheel, a wheel having teeth formed so as to work at an angle either greater or less than half a right angle Bibbs, in ship-building, pieces of tim- ber bolted to the hounds of a mast, to support the trestle-trees Bibliotheca, in Greek, the place, apart- ment or building where books were kept Bicarbide of hydrogen. This gas is known by the names of light car- buretted hydrogen, marsh-gas, fire- damp, and gas of the acetates. It is discharged from fissures in coal in large quantities, and from the bottoms of the pools in which there is vegetable matter Bice, a blue colour used in painting, prepared from the lapis Armenius Bice or Bise, in painting, a pale blue colour, procured by the reduction of smalt to a fine powder Bicellum, the dwelling of a tradesman, having under it two vaults, for the reception of merchandise Bichoca, a turret or watch-tower 49 Bier-balk, the church road for burials Bifrons, in sculpture, double-fronted or faced, usually applied to Janus Bigelf, an arch or chamber Bigg, to build Bigger, a builder Bight, the double part of a rope when it is folded, in contradistinction from the ends Bilander, a small vessel with two masts, used chiefly in the canals of the Low Countries Bilboes, large bars or bolts of iron, with shackles sliding on them, used for criminals Bilection-mouldings, those surrounding the panels, and projecting before the face of a door, gate, &c. Bilge, that part of the floor of a ship which approaches nearer to an hori- zontal than to a perpendicular di- rection Bilge-pump, the forcing-pump worked by a marine engine, to discharge the bilge-water from the vessel Bilge-pump rod, the plunger-rod, or rod connecting the piston of the bilge-pump to one of the side-levers Bill, the point at the extremity of the fluke of an anchor Billet -moulding, an ornament used in string-courses and the archivolts of windows and doors Billion, in numbers, the sum of a mil- lion of millions Bills, the ends of compass or knee- timber Bimedial line, in geometry, the sum of tw r o medials. When medial lines, equal only in power and containing a rational rectangle, are compound- ed, the whole will be irrational with respect to either of the two : this is called a first bimedial line ; but if two medial lines, commen- surable only in power, and con- taining a medial rectangle, be com- pounded, the whole will be irra- tional, and is then called a second bimedial line Binary, in arithmetic, double Binder, one who undertakes to keep a mine open Binding-joists, those beams in a floor BIN BITUMEN. BIT which support transversely the bridgings above and the ceiling- joists below Bindings, the iron wrought round the dead-eyes Binnacle, a box near the helm, con- taining the compass Binocular telescope, one to which both eyes may be applied Bins, for wine, open subdivisions in a cellar for the reception of bottles Birch wood, a forest tree common to Europe and North America ; an excellent wood for turning, being of light colour, compact, and easily worked Birds, in heraldry, are emblems of expedition, liberty, &c. Bird's-eye perspective is of two kinds, angular and parallel : it is used in the drawings of extensive buildings having spacious courts and gardens, as palaces, colleges, asylums, &c. The observer is supposed to be on an eminence, and looking down on the building, as from a steeple or mountain Bird' 's-mouth, in carpentry, an interior angle or notch cut in the end of a piece of timber for its reception on the edge of a pole or plate. It sig- nifies also the internal angle of a polygon Bireme, a vessel with two banks or tiers of oars Birhomooidal, having a surface of twelve rhombic faces, which, being taken six and six, and prolonged till they intercept each other, would form two different rhombs Birthing, the working a top side, bulk- heads, &c. Bisection, in geometry, the division of any quantity into two equal parts Bishops, prelates holding baronies of the King or of the Pope, and exer- cising ecclesiastical jurisdiction over a certain extent of territory, called their diocese Bismuth. This metal is found native, crystallized in cakes, which gene- rally contain small quantities of silver; it is also combined with oxygen, arsenic, and sulphur 50 Bisjna, a bishopric or episcopal pa- lace Bissextile, or leap-year, a year con- sisting of 366 days, happening once every four years, by the addition of a day in the month of February, to recover the six hours which the sun spends in his course each year, beyond the 365 days usually allow- ed for it Bistre, a brown pigment, extracted by watery solution from the soot of wood fires, when it retains a strong pyroligneous scent. It is of a wax-like texture, and of a ci- trine-brown colour, perfectly dura- ble. It has been much used as a water colour, particularly by the old masters, in tinting drawings and shading sketches, previously to Indian ink coming into general use for such purposes. In oil, it dries with the greatest difficulty Bisturres, small towers placed at in- tervals in the walls of a fortress, forming a barbican Bit, an instrument for boring holes in wood, &c. Bitter end, that part of the cable w r hich is abaft the bitts Bitter Nut wood, a native of America, is a large timber wood, measuring 30 inches when squared ; plain and soft in the grain, like walnut Bitts, in ship-building, perpendicular pieces of timber going through the deck, placed to secure any thing to. The cables are fastened to them, if there is no windlass. There are also bitts to secure the windlass, and each side of the heel of the bowsprit Bitumen, a name for a number of inflammable mineral substances, known under the names of naph- tha, mineral tar, mineral pitch, sea-wax, asphalte, elastic bitumen, or mineral caoutchouc, jet, mineral coal, &c. Bituminous cement, a factitious sub- stance, used for pavements, for roofs, and other useful purposes Bituminous limestone, a limestone of a lamellar structure BLA BLAST-PIPE. BLE Black, the last and the lowest in the series or scale of descending co- lours ; the opposite extreme from white; the maximum of colour. To be perfect, it must be neutral with respect to colours individually, and absolutely transparent, or desti- tute of reflective power in regard to light ; its use in painting being to represent shade or depth, of which it is the element in a picture and in colours, as white is of light Black-band iron-stone, discovered by Mr. David Mushet, in 1801, while engaged in the erection of the Calder iron works. Great prejudice was exerted against him by the iron-masters, in presuming to class the wild coals of the country with iron-stones fit and proper for the blast furnace ; yet that discovery has elevated Scotland to a consi- derable rank amongst the iron- making nations of Europe, and pro- duces an annual average income of 16,500 to Sir W. Alexander, Bart. Black Botany Bay wood is the hardest and most wasteful of all woods : some of the finest, however, if well selected, exceeds all woods for ec- centric turning Black chalk is an indurated black clay, of the texture of white chalk: its principal use is for cutting into the crayons which are employed in sketching and drawing Black dye. The ingredients of black dye are logwood, Aleppo galls, ver- digris, and sulphate of iron, or green vitriol Black iron, malleable iron, in contra- distinction to that which is tinned, called white iron Black Jack, in mining, blende Black lead, plumbago, or graphite, is a native carburet of iron, or oxide of carbon, found principally at Bor- rodale in Cumberland; consumed in large quantities in the formation of crayons and black-lead pencils for writing, sketching, designing, and drawing Black ochre, a variety of the mine- 51 ral black, combined with iron and alluvial clay Black tin, tin ore when dressed, stamped, and washed, ready for melting Black wadd, one of the ores of man- ganese, used as a drying ingredient in paints Blade, in joinery, is expressive of any part of a tool that is broad and thin, as the blade of an axe, of an adze, of a chisel, of a square : the blade of a saw is more frequently called the plate Blades, the principal rafters or breaks of a roof Blanc d* argent, or silver white. This is a false appellation for a white lead, called also French white. It is first produced in the form of drops, is exquisitely white, but is of less body than flake white, and has all the properties of the best white leads; but, being liable to the same changes, is unfit for gene- ral use as a water colour, though good in oil or varnish Blast, the ah* introduced into a fur- nace Blasting of stone, from rocks and beds of stone, for the purpose of quarrying and shaping stones to be used for building purposes. The ordinary implements used are the jumper or cutting-tool, the ham- mer, and scraper. For the process and its effect, see Sir John Bur- goyne's Rudimentary Volume on Blasting, &c. Blast-pipe, the waste steam-pipe of an engine, but more particularly applied to locomotive engines : in the latter it leads from the exhaust passages of the cylinders into the chimney, and is of great use for forming the draught through the fire-tubes, as each jet of steam emitted creates a partial vacuum in the chimney, which is immediately filled by a current of air rushing through the fire-grate Blazonry, in heraldry, deciphering of coats of arms Bleaching,&n art divided into branches, BLE BLOW-OFF PIPE. BLO bleaching of vegetable and animal substances requiring different pro- cesses for whitening them Blende, in mining, one of the ores of zinc, composed of iron, zinc, sul- phur, silex, and water : on being scratched, it emits aphosphoriclight Blending and melting, in colouring or painting, are synonymous terms. They imply the method of laying different tints on buildings, trees, &c., so that they may mingle to- gether while wet, and render it im- possible to discover where one colour begins and another ends. A variety of tints of nearly the same tone, employed on the same object and on the same part, gives a richness and mellowness to the effect ; while the outline, insensibly melting into the back-ground, and artfully disappearing, binds the ob- jects together, and preserves them in unison Bleostaning, Mosaic pavement Block, a lump of wood or stone Blocks, pieces of wood in which the sheaves or pulleys run, and through w r hich the ropes pass Block cornices and entablatures are frequently used to finish plain build- ings, where none of the regular or- ders have been employed. Of this kind there is a very beautiful one composed by Vignola, much used in Italy, and employed by Sir Chris- topher Wren to finish the second design of St. Paul's cathedral Block-house, a building erected by be- siegers for the investment of a cas- tle. Block-houses were erected in the time of Henry VIII. on the south and south-western coast of England Blocking-course, a course of masonry or brick -work, laid on the top of a cornice crowning a wall Blockings, small pieces of wood, fitted in, or glued, or fixed to the interior angle of two boards or other pieces, in order to give strength to the joint Block-machinery, the machinery for manufacturing ships' blocks, invent- 52 ed by the elder Brunei, and ad- justed by the late Dr. Gregory Block- tin, tin cast into blocks or in- gots Blood-red heat, the degree of heat which is only necessary to reduce the protuberances on coarse iron by the hammer, in order to prepare it for the file, the iron being previ- ously brought to its shape. This heat is also used in punching small pieces of iron Bloom, a mass of iron after having un- dergone the first hammering Blower, in mining, a smelter Blowing, the projection of air into a furnace, in a strong and rapid cur- rent, for the purpose of increasing combustion Blow-off cock, the stop-cock in the blow-off pipe Blow-off pipe, the pipe fixed to the bottom of a boiler, for discharging the sediment, which is effected by blowing through a portion of the water from the boiler Blow-pipe. The blow-pipe is a most valuable little instrument to the mineralogist, as its effects are strik- ing, rapid, well characterized, and pass immediately under the eye of the operator. The most efficacious flame is produced by a regular, mo- derate stream of air ; while the act of blowing with more force only has the effect of fatiguing the mus- cles of the cheeks, oppressing the chest, and at the same time renders the flame unsteady. The student should fill his mouth with air, so as to inflate the cheeks moderately, and continue to breathe without letting the air in the mouth escape ; the blow-pipe may then be introduced between the lips, and while the breathing is carried on through the medium of the nose, the cheeks will expel a stream of air through the blow-pipe ; and by replenishing the mouth at each ex- piration, and merely discharging the surplus air through the nostrils, a facility will be acquired of keep- ing up a constant stream of air. BLO BLOW-PIPE. BLU The best flame for the purpose of this instrument is that of a thick wax candle, such as are made for the lamps of carriages, the wick being snuffed to such a length as to occasion a strong combustion : it should be deflected a little to one side, and the current of air directed along its surface towards the point : a well-defined cone will be pro- duced, consisting of an external yellow, and an internal blue flame. At the point of the former, calcina- tion, the oxidation of metals, roast- ing of ores to expel the sulphur and other volatile ingredients, may be accomplished; and by the ex- treme point of the latter (which affords the most intense heat) fu- sion, the deoxidation of metals, and all those operations which require the highest temperature, will be effected. The piece of mineral to be examined must necessarily be supported on some substance ; and for the earths, or any subject not being metallic, or requiring the operation of a flux, a spoon or pair of forceps made of platina will be found useful; but, as the metals and most of the fluxes act on pla- tina, the most serviceable support, for general purposes, will be a piece of sound, well-burnt charcoal, with the bark scraped off, as free as pos- sible from knots or cracks : the piece of mineral to be examined should not in general be larger than a pepper-corn, which should be placed in a hollow made in the charcoal ; and the first impression of the heat should be very gentle, as the sudden application of a high temperature is extremely liable to destroy those effects which it is most material to observe. Many substances decrepitate immediately they become hot; and when that is found to be the case, they should be heated red, under circumstances which will prevent their escape : this may be effected, with the earthy minerals, by wrapping them in a piece of platina foil, and, with 53 the metallic ores, by confining them between two pieces of charcoal, driving the point of the flame through a small groove towards the place where the mineral is fixed, by which means a sort of reverberating furnace may be formed. The prin- cipal phenomena to be noticed are, phosphorescence, ebullition, intu- mescence, the exhalation of vapours having the odour either of sulphur or garlic (the latter arising from the presence of arsenic), decrepita- tion, fusibility; and, amongst the fusible minerals, whether the pro- duce is a transparent glass, an opaque enamel, or a bead of metal. Having first made some observa- tions on a particle of the mineral alone, either the residue or a fresh piece should be examined with the addition of a flux, more particularly in the case of the ores, as the na- ture of the metal may be generally decided by the colour with which it tinges the substance used. The most eligible flux is glass of borax: a piece about half the size of a pea being placed on the charcoal, is to be heated till it melts ; the particle of ore being then taken in a pair of forceps, is to be pressed down in it, and the heat applied; or, should the mineral not be inclined to de- crepitate, it may be laid on the charcoal, and two or three pieces of glass of borax, about the size of a pin's head, placed over it ; and on using the blow-pipe, the whole will form itself into a globular bead. Blow-valve, the ' snifting valve ' of a condensing engine Blue, one of the seven primitive co- lours of the rays of light, into which they are divided when refracted through a glass prism Blue-black is a well-burnt and lavi- gated charcoal, of a cool, neutral colour, and not differing from the common Frankfort black. Blue- black was formerly much employed in painting, &c. Blue carmine is a blue oxide of mo- lybdena, of which little is known BLU BOATS. BOB as a substance or as a pigment. It is said to be of a beautiful blue colour, and durable in a strong light, but is subject to be changed in hue by other substances, and blackened by foul air: we may conjecture, therefore, that it is not of much value in painting Blue dyes, indigo, Prussian blue, log- wood, bilberry, &c. Blueing, the process of heating iron, and some other metals, until they assume a blue colour Blue John, fluor spar, called so by Derbyshire miners Blue ochre is a mineral colour of rare occurrence, found with iron pyrites in Cornwall, and also in North America, and is a subphosphate of iron. What Indian red is to the colour red, and the Oxford ochre to yellow, this is to other blue co- lours. They class in likeness of character: hence it is admirable rather for the modesty and solidity, than for the brilliancy of its colour Blue pigments, found in common, are Prussian blue, mountain blue, Bre- men blue, iron blue, cobalt blue, smalt, charcoal blue, ultramarine, indigo, litmus, and blue cake Blue tint, in colouring, is made of ultramarine and white, mixed to a lightish azure. It is a pleasant working colour, and with it should be blended the gradations in a pic- ture. It follows the yellows, and with them it makes the greens ; and with the red it produces the purples. No colour is so proper for blending down or softening the lights into keeping. In pictures of less value, Antwerp blue may be substituted for ultramarine Blue verditer is a blue oxide of cop- per, or precipitate of the nitrate of copper by lime, and is of a beauti- ful light-blue colour. It is little affected by light ; but time, damp, and impure air turn it green, and ultimately blacken it, changes which ensue even more rapidly in oil than in water : it is, therefore, by no means an eligible pigment in 54 oil, and is principally confined to distemper, painting, and the uses of the paper-stainer, though it has been found to stand well, many years, in water-colour drawings and in crayon paintings, when preserved dry. Blue vitriol, sulphate of copper Bluff : a bluff-bowed or bluff -headed vessel is one which is full and square forward Blunk, heavy cotton cloth : the term used in Scotland Board, a substance of wood contained between two parallel planes ; as when the baulk is divided into se- veral pieces by the pit-saw, the pieces are called boards Board, in nautical language, the line over which a ship runs between tack and tack. To board is to en- ter a ship Boarding -floors are those covered with boards : the operation of boarding floors should commence as soon as the windows are in, and the plaster dry Boar ding -joists, joists in naked floor- ing, to which the boards are fixed Boarding-pike, a pike used by sailors in boarding an enemy's vessel Boasting, in masonry, the paring of a stone with a broad chisel and mal- let Boasting, in sculpture or carving, is the rough cutting of a stone to form the outline of a statue or ornament Boats, small open vessels, impelled on the water by rowing or sailing, having different uses, dimensions, &c., either for river or sea service Boat-hook, an iron hook with a sharp point, fixed on a pole, at the extre- mity Boatswain, a warrant officer in the navy, who has the charge of the rigging, and calls the crew to duty Bob, the miner's engine-beam Bob, of a pendulum, is the metallic weight which is attached to the lower extremity of a pendulum rod Bobst ay -holes, those in the fore-part of the knee of the head, for the se- curity of the bobstay BOB BOILERS. BOI Bob-stays, used to confine the bow- sprit down to the stem or the cut- water Bocatorium, anciently a slaughter- house ' Bodium, a crypt, or subterraneous I chapel I Body, in physics or natural philosophy, I any solid or extended palpable sub- stance Body, or solid, in geometry, has three dimensions; length, breadth, and I thickness. Bodies are either hard, | soft, or elastic Body plan, in naval architectural draw- | ing, sectional parts showing fore and after parts of a vessel Boeria, anciently a manor-house or large country dwelling Bog, soft, marshy, and spongy matter, or quagmire. Railroads have been made across bogs in Lancashire and in America by draining, &c., and in the latter by piling as well as drain- ing Bog-iron ore, an iron ore discoverable in boggy land Boiler, a wrought iron vessel contain- ing water, to which heat is applied for the generation of steam. Boilers are made of various forms, according to the nature of their application, and are constructed so as to obtain the largest heating surface with the least cubical content Boilers. A boiler for 20-horse power is usually 15 feet long and 6 feet wide; therefore 90 feet of surface, or4^feet to 1 horse power; a boiler for a 14-horse power 60 feet of surface, or 4'3 feet to 1 horse power ; but engineers allow 5 feet of surface to 1 horse power, and Mr. Hicks, of Bolton, proportions his boilers at the rate of 5 square feet of hori- zontal surface of water to each horse power : Mr. Watt allows 25 cubic feet of space to each horse power Boilers. Iron cement is far preferable to any other material for making iron joints : it has the excellent property, that it becomes more sound and tight the longer it stands, so that cemented joints which at 55 first may be a little leaky, soon be- come perfectly tight. The follow- ing is the best mode of preparing this iron cement : take 16 parts of iron filings, free from rust ; 3 parts powdered sal-ammoniac [muriate of ammonia] ; and 2 parts of flower of sulphur : mix all together inti- mately, and preserve the compound in a stoppered vessel, kept in a dry place, until it is wanted for use. Then take 1 part of the mixture, add it to 12 parts of clean iron filings, and mix this new compound with so much water as will bring it to the consistence of a paste, hav- ing previously added to the water a few drops of sulphuric acid. In- stead of filings of hammered iron, filings, turnings, or borings of cast iron may be used ; but it must be remarked, that a cement made en- tirely of cast iron is not so tena- cious and firm as if of wrought iron; it sooner crumbles and breaks away. It is better to add a certain quantity, at least one-third, of the latter to the former. There is but little ground to fear for the soundness of a well-riveted iron boiler; for in time the action of rust and deposit will stop almost any crevices. In order, however, to take all precaution, it is to be re- commended that some clammy substance, such as horse-dung, bran, coarse meal, or potatoes, should be boiled in the vessel before it is used. A very small quantity also of the same kind of substance may be put into the boiler whenfirst set to work : this will find its way into the cre- vices by the pressure within, and, gradually hardening, will soon ren- der the vessel perfectly sound. Boilers. Copper is more tough and less liable to crack than iron, and is a most excellent material for high-pressure boilers : it has, how- ever, a less cohesive power; and therefore a greater thickness of me- tal is necessary to produce an equal strength : but since copper boilers never fly in pieces in case of explo- BOI BOND TIMBER. BON sion, it is not necessary to be too scrupulous in regard to this point. Even when the metal is thin, espe- cially if the diameter is not great, the use of copper removes all dan- ger of destructive explosion, since at most only a simple tearing asun- der of the metal will ensue Boiling, or ebullition, the agitation of fluids, arising from the action of fire, &c. Bole, an argillaceous mineral, having a conchoidal fracture, an internal lustre, and a shining streak Bollards, large posts set in the ground at each side of the docks, to lash and secure hawsers for docking and undocking ships Bollard timbers, in a ship, two timbers within the stern, one on each side of the bowsprit, to secure its end Bolognes School, in painting, a Lom- bard school, founded by Caracci Bolognian stone is derived from sul- phate of baryta by calcination and sure to the rays of the sun Bolster, a piece of timber placed upon the upper or lower cheek, worked up about half the depth of the hawse-holes, and cut away for the easement of the cable, and to pre- vent its rubbing the cheek; like- wise the solid piece of timber that is bolted to the ship's side, on which the stantients for the linings of the anchors are placed; or any other small piece fixed under the gunwale, to prevent the main sheet from being rubbed, &c. Bolster, a tool used for punching holes and for making bolts Bolster of a capital ; the flank of the Ionic capital Bolt, a cylindrical pin of iron or other metal, used for various purposes of fastening, planking, &c. Bolt auger, an auger of a larger size, used by ship-builders Bolt rope, the rope to which the edges of sails are sewed, to strengthen them Bolt-screwing machine, a machine for screwing bolts, by fixing the bolt- 56 head to a revolving chuck, and causing the end which it is required to screw to enter a set of dies, which advance as the bolt revolves Bolts, long cylindrical bars of iron or ' copper, used to secure or unite the different parts of a vessel | Bolts, the principal iron-work for fast- < ening and securing the ship Bolts, large iron pins Bomb-vessel, a strong-built vessel car- rying heavy metal for bombardment Bond, in masonry, is that connection of lapping the stones upon one ano- ther in the carrying up of the work so as to form an inseparable mass of building Bond, in bricklaying and masonry, is the arrangement or placing of bricks, &c., so as to form a secure mass of building Bonders, Bond stones, Binding stones, stones which reach a considerable distance into, or entirely through, a wall, for the purpose of binding it together Bond stones, are placed in the thick- ness of a wall, at right angles to its face, to bind securely together Bond timber, pieces of timber used to bind in brick- work especially. The naked flooring being laid, in carry- ing up the second story bond tim- bers must be introduced opposite to all horizontal mouldings, as bases and surfaces. It is also customary to put a row of bond timber in the middle of the story, of greater strength than those for the bases and surfaces Bone-brown and Ivory-brown, pro- duced by torrefying or roasting bone and ivory, till, by partial charring, they become of a brown colour throughout Boning, in carpentry and masonry, the art of making a plane surface by the guidance of the eye : joiners try up their work by boning with two straight-edges, which determine whether it be in or out of winding, that is to say, whether the surface be twisted or a plane Bonnet, in navigation, an additional BON BORING-MACHINE. BOT piece of canvas attached to the foot of a jib, or a schooner's foresail, by lacings, taken off in bad weather Bonnets, the cast-iron plates which cover the openings in the valve- chambers of a pump : the openings are made so that ready access can be had when the valves need re- pairing Boom, in ship-building, a long pole run out from different places in the ship, to extend the bottoms of par- ticular sails, as jib-boom, flying- boom, studding-sails-boom, &c. Boomkin, in ship-building, a beam of timber projecting from each bow of a ship, to extend the clue or lower corner of the foresail to wind- ward Booth, a stall or standing in a fair or market Boot-topping, scraping off the grease, or other matter, which may be on a vessel's bottom, and daubing it over with tallow Borax, in chemistry, a salt in appear- ance like crystals of alum ; an ar- tificial salt used for soldering metals Borcer, an instrument of iron, steel- pointed, to bore holes in large rocks, in order to blow them up with gun- powder Bord, anciently a cottage Bore : in hydrography, a sudden and abrupt influx of the tide into a river or narrow strait Boreas, the north wind Borer, a boring instrument, with a piece of steel at the end, called a boring-bolt Boring, the art of perforating or mak- ing a hole through any solid body; as boring the earth for water; bor- ing water-pipes, either wood, iron, zinc, or lead ; boring cannon, &c. Boring. Modern steam engines depend on the improved method of boring their cylinders. The cylinder to be bored is firmly fixed with its axis parallel to the direction in which the borer is to move : the cutting ap- paratus moves along a bar of iron ac- curately turned to a cylindrical form Boring-bar, a bar of a small horizontal boring machine : it is used for bor- ing the brasses of plummer-blocks, by means of a cutter fixed in it Boring -collar, in turning, a machine having a plate with conical holes of different diameters : the plate is moveable upon a centre, which is equidistant from the centres or axes of the conical holes ; the axes are placed in the circumference of a circle. The use of the boring- collar is to support the end of a long body that is to be turned hol- low, and which would otherwise be too long to be supported by a chuck Boring lathe, a lathe used for boring wheels or short cylinders. The wheel or cylinder is fixed on a large chuck, screwed to the mandril of a lathe Boring machine, a machine for turn- ing the inside of a cylinder Boron, in chemistry, is an olive-green powder, which, heated out of the air, becomes harder, and darker in colour: it burns brilliantly when heated in air or oxygen, forming boracic acid Boss, a sculptured keystone or carved piece of wood, or moulded plaster, placed at intervals of ribs or groins in vaulted and flat roofs of Gothic structures Boss, a short trough for holding mor- tar when tiling a roof: it is hung to the laths Bossage, projecting stones laid rough in building, to be afterwards cut into mouldings or ornaments Botany Bay oak, resembling in colour full red mahogany, is used as veneer for the backs of brushes, turnery, &c. Bottle-glass, a composition of sand and lime, clay, and alkaline ashes of any kind Bottom - captain, a superintendent over the miners in the bottoms Bottom heat, artificial temperature, produced in hot-houses Bottom-lift, in mining, the deepest or bottom tier of pumps Bottom-rail, in joinery, the lowest rail of a door Bottoms, in mining, the deepest work- 57 c 5 EOT BOWER CABLES. BOW ing parts of a mine, wrought either tant is an arch, or buttress, serving by sloping, driving, or otherwise to sustain a vault, and which is it- breaking the lode self sustained by some strong wall Bottoms in fork. In Cornwall, when or massive pile all the bottoms are unwatered, they Bova, anciently a wine-cellar say, 'the bottoms are in fork;' Bovey coal, wood-coal found at Bovey, and to draw out the water from in Devonshire them, or any dippa, or any other particular part of a mine, is said to Bow,the roundpart of the ship forward Bow, anciently an arch or gateway be 'forking the water ;' and when Bow compass, for drawing arches of accomplished, such dippa, &c., is very large aisles; it consists of a ' in fork.' Likewise when an en- beam of wood or brass with three gine has drawn out all the water, long screws that bend a lath of they say, ' the engine is in fork ' wood or steel to any arch . The Bottony; in heraldry, a cross-bottony term also denotes small compasses is terminated at each end in three employed in describing arcs too buds, or knots, or buttons small to be accurately drawn by Boudoir, a small retiring-room the common compasses Bouget, in heraldry, the representa- Bower, anciently a small enriched tion of a vessel for carrying water chamber for ladies; a private room, Boulders, fragments of rocks trans- or parlour, in ancient castles and ported by water, and found on the mansions sea-shore Bower, a working anchor, the cable of Boulder walls, walls built of the above which is bent and veered through Boultine, in architecture, a convex the hawse-hole moulding whose periphery is a Bower, in navigation, two anchors quarter of a circle, next below the thus named from their being car- plinth in theDoricandTuscan orders ried at the bow Bounds, in mining, signifies the right Bower cables, for ships. to tin ore over a given district Table showing the different lands Bourse, a public edifice for the as- of best bower cables at present em- semblage of merchants to consult ployed in the British navy, with the on matters of business or money corresponding iron cables, and the Boutant; in architecture, an arc-bou- proof-strain for each : Best bower hempen Diameter and cables, 100 fathoms. Number weight of the bolt of Breaking of the iron cable Strain Cir- . threads strain by substituted for for the Rates of Ships. cum. Weight. in each. experiment. the preceding. proof. in. cwt. qr. Ib. tons. cwt. qr. tons. First-rate, large . 25 114 2 7 3240 : , v ,; middle 24 105 2 17 2988 small . 23 96 2 27 2/361 2-J inches. J81 Second-rate . . 23 96 2 27 27361 114 218 cwt. J Third, large . . 23 96 2 27 2736 J small . 22 8g 12 2520 \ . ( 2 inches. 1 __ Fourth, CO guns . 21 80 22 2268/ 89 \ 186 cwt. 2qrs. }72 58 do. . 19 66 21 1872 f l|inch. \fiQ 50 do. . 184 62 1 14 1764 1 170 cwt. 2 qrs. )63 Fifth, 48 do. . 18 58 2 6 1656 63 1 .,. , 46 do. 1 42 do. J itt 56 1 1584 1 If inch. J145 cwt. 3 qrs. }55 Sixth, 28 do. . 14i 38 21 1080 40 r 1| inch. \ 87 cwt. 2 qrs. }34 Ship, sloop . . 134 33 10 936 f 1 inch. "Ua Brig, large . . . 134 33 10 936 1 74 cwt. 3 qrs. )28 Ditto, small . . 11 21 2 15 612 ( IJinch. I 6 1 cwt. 1 or. J23 58 BOW BRACKETS. BRA From the preceding Table the im- mense advantage of iron cables will be distinctly seen, and particularly when it is considered that a hempen cable, on a rocky bottom, is de- stroyed in a few months, while the other will sustain no perceptible injury. Boweric, in the East Indies, a well descended by steps Bow-grace, a frame of old rope, or junk, placed round the bows and sides of a vessel, to prevent the ice from injuring her Bow-line, in navigation, a rope leading forward from the leach of a square sail, to keep the leach well out, when sailing close-hauled Bowls of silver were used as drinking- glasses are now, before the intro- duction of glass for such purposes ; they were of small sizes, in 'nests' fitting one within another. Of the larger sized bowl, the most distin- guished are the mazer and the wassail. Mazer is a term applied to large goblets, of every kind of material; but the best authors agree that its derivation is from maeser, which, in Dutch, means maple ; and therefore that a mazer bowl is one formed of maple wood Bow-saw, a saw used for cutting the thin edges of wood into curves Bowse, to pull upon a tackle Bowsprit, in ship-building, a large boom or mast which projects for- ward over the stem to carry sail Bowtel, the shaft of a clustered pillar, or a shaft attached to the jambs of a door or window Box, for mitring, a trough for cutting mitres : it has three sides, and is open at the ends, with cuts in the vertical sides at angles of 45 with them Box-drain, an underground drain built of brick and stone, and of a rectan- gular section Box of a rib-saw, two thin iron plates fixed to a handle, in one of which plates an opening is made for the reception of a wedge, by which it is fixed to the saw 59 Box-haul, to veer a ship in a manner when it is impossible to tack Box the compass, to repeat thirty- two points of the compass in order Boxing-off, throwing the head sails a-back, to force the ship's head ra- pidly off the wind Boxings of a window, the cases oppo- site each other on each side of a window, into which the shutters are folded Box wood is of a yellow colour, in- clining to orange ; is a sound and useful wood, measuring from 2 to 6 feet long, and 2^ to 12 inches in diameter : it is much used by wood engravers ; for clarionets, flutes ; for carpenters' rules, drawing-scales, &c. Much of it comes from Box Hill, in Surrey, and from several districts in Gloucestershire, also from other parts of Europe Boziga, anciently a house or dwelling Brace, a piece of slanting timber, used in truss partitions, or in framed roofs, in order to form a triangle, and thereby rendering the frame immoveable : when a brace is used by way of support to a rafter, it is called a strut : braces in partitions and span roofs are always, or should be, disposed in pairs, and placed in opposite directions Brace, an instrument into which a vernier is fixed ; also part of the press-drill Brace, a rope by which a yard is turned about Braces, that security for the rudder which is fixed to the stern-post and to the bottom of a ship Bracket plummer-block, a support for a shaft to revolve in, formed so that it can be fixed vertically to the frame of a machine, or to a wall Brackets, ornaments : the hair bracket in ship-building is the boundary of the aft-part of the figure of the head, the lower part of which ends with the fore-part of the upper cheek. The console bracket is a light piece of ornament at the fore- part of the quarter-gallery, some- times called a canting-hose BRA BRAMAH'S HYDROSTATIC PRESS. BRA Brackets, the cheeks of the carriage of a mortar; a cramping-iron to stay timher-work ; also stays set under a shelf, to support it Bracket -stairs. " The same method must be observed, with regard to taking the dimensions and laying down the plan and section, as in dogling-stairs. In all stairs what- ever, after having ascertained the number of steps, take a rod the height of the story, from the surface of the lower floor to the surface of the upper floor ; divide the rod into as many equal parts as there are to be risers ; then, if you have a level surface to work upon below the stairs, try each one of the risers as you go on : this will prevent any defect." Brad, a small nail with a projecting head on one edge Brad-awl, the smallest boring tool usedby a carpenter; its handle is the frustrum of a cone tapering down- wards ; the steel part is also coni- cal, but tapering upwards, and the cutting edge is the meeting of two basils, ground equally from each side Brails, in navigation, ropes by which the foot or lower corners of fore and aft sails are hauled up Brake,ihe apparatus used for retarding the motion of a wheel by friction upon its periphery Brake, the handle of a ship's pump Brake, a machine used in dressing flax Brake-wheel, the wheel acted upon by a brake Bramah's hydrostatic press consists in the application of water to engines, so as to cause them to act with im- mense force ; in others,to communi- cate the motion and powers of one part of a machine to some other part of the same machine This press was constructed in Woolwich dockyard for testing iron cables, and the strain is pro- duced by hydrostatic pressure : its amount is estimated by a system of levers balanced on knife edges, which act quite independently of 60 the strain upon the machine, and exhibit sensibly a change of pressure of |th of a ton, even when the total strain amounts to 100 tons. This proving machine was con- structed by Messrs. Bramah, of Pimlico, and is doubtless one of the most perfect of the kind which has been executed. It consists of two cast-iron sides, cast in lengths of 9| feet each, with pro- per flanches for abutting against each other, and for fixing the whole to sleepers resting on a secure stone foundation. The whole length of the frame is 104| feet, equal to th the length of a cable for a first-rate ; so that the cables are tested in that number of detached lengths, which are afterwards united by shackle- bolts. The press is securely bolted down at one end of the frame, and the cylinder is open at both ends. The solid piston is 5 inches in diameter in front and 10| inches behind, so that the surface of press- ure is the difference of the two, viz. '2ll 2 2l] 2 \ 2 ~T j x '7854 =65i inches. The system of levers hung on knife edges is attached to the other end of the frame, and the cable is attached by bolt-links to this and to the end of the piston-rod. The levers being properly balanced, and the cable attached to a short arm rising above the axis, this draws the other arm downwards; and at a dis- tance equal to twelve times the short arm, is a descending pin and ball, acting in a cup placed on the upper part of the arm of the second lever, and this again acts on a third. The first two levers are under the floor, and pass ultimately into an adjacent room,where a scale carryingweights is conveniently placed, andthewhole combination is such that every pound in the scale is the measure of a ton strain : the whole acts with such precision that |-th of a pound, more or less, in the scale, very sensibly BRA BRASSES. BRE affects the balance. At the same place is situated a scale, acted upon by the water pressure from the charge-pipe of the press, and the valve in this pipe is of such dimen- sions that, together with the lever by which it acts, the power is again such that a pound should balance a ton ; but the friction is here so great that it requires several pounds to make a sensible change in the apparent balance, and for this rea- son this scale is never used. The forcing-pumps are in another adja- cent room, and are worked by han- dles, after the manner of a fire en- gine. At first, six pistons are acting, and the operation proceeds quickly; but as the pressure and strains in- crease, the barrels are successively shut off, till at length the whole power of the men is employed on one pair of pumps only, and on this the action is continued till the proof- strain is brought on the cable. A communication is then opened be- tween the cistern and cylinder, and every thing is again restored to equi- librium. Branch, in mining, a leader, string, or rib of ore, that runs in a lode ; or if a lode is divided into several strings, they are called branches, whether they contain ore or not : likewise strings of ore which run transversely into the lode are called branches; and so are all veins that are small, dead or alive, i. e. whe- ther they contain ore or not Branched -work, carved and sculp- tured leaves and branches in mo- numents and friezes Branches, anciently the ribs of groined ceilings Brandishing or Brattishing, a term used for carved work, as a crest, battlement, or other parapet ' Brandrith, a fence or rail round the opening of a well Brass, a factitious metal, made of copper and zinc Brass, in the middle ages, a plate of metal inserted or affixed to a flat gravestone 61 Brasses, se2)ulchral,monMmenia\ plates of brass or mixed metal, anciently called latten, inlaid on large slabs of stone, which usually form part of the pavement of a church, and represent in their outline, or by lines engraved upon them, the figure of the deceased Brattishing, anciently, carved open work Bray, anciently a bank or earthen mound Brazed, in heraldry, three chevrons clasping one another Brazil wood, the wood of the Cfesal- pinia crista, which yields a red dye: it is imported principally from Per- nambuco : the tree is large, crooked, and knotty; and the bark is thick, and equals the third or fourth of its diameter. Its principal use is for dyeing : the best pieces are se- lected for violin-bows and turnery Braziletto wood is of a ruddy orange colour, principally used for dyeing, and for turnery and violin-bows Brazing, the soldering together of edges of iron, copper, brass, &c., with an alloy of brass and zinc called spelter solder Breaching, a strong rope used to se- cure the breech of a gun to the ship's side Breadth is applied to painting when the colours and shadows are broad and massive, such as the lights and shadows of the drapery; and when the eye is not checked and dis- tracted by numerous little cavities, but glides easily over the whole. Breadth of colouring is a promi- nent character in the painting of all great masters Break, in shipping. To break bulk, is to begin to unload Break, a projection or recess from the surface or wall of a building Break joint, constructively, to dis- allow two joints to occur over each other Breaker, a small cask containing water Breaking down, in sawing, is dividing the baulk into boards or planks BRE BRICKS. BRI Breaking joint, in joinery, is not to allow two joints to come together Breakwater, a human contrivance to ward off and diminish the force of waves, to protect harbours, stations, &c., from the viplence of tempes- tuous gales. Some stupendous works have been executed for these purposes, especially that at Ply- mouth, by the great Sir John Rennie Breaming, cleaning a ship's bottom by burning Breast, in mining, the face of coal- workings Breast-fast, a rope used to confine a vessel sideways to a wharf or to some other vessel Breast-hooks, pieces of compass or knee-timber, placed withinside a ship, to keep the bows together. The deck-holes are fayed to the timbers, and placed in the direction of the decks : the rest are placed one between each deck, and as many in the hold as are thought needful; all of which should be placed square with the body of the ship, and fayed on the planks. Breast-hooks are the chief security to keep the ship's bows together ; therefore they require to be very- strong and well- secured Breast-knees, those placed in the forward part of a vessel, across the stem, to unite the bows on each side Breast-plate, that in which the end of the drill opposite the boring end is inserted Breast-rail, the upper rail of the bal- cony or of the breast-work on the quarter-deck Breast-rope, a rope passed round a man in chains, while sounding Breast-wheel, in mill-work, a form of water-wheel in which the water is delivered to the float-boards at a point somewhat between the bot- tom and top. Buckets are seldom employed on breast-wheels Breast-work, the stantients with rails ojti the quarter-deck and forecastle. The breast-work fitted on the up- per deck of such ships as have no 62 quarter-deck serves to distinguish the main deck from the quarter-deck Breech, the angle of knee-timber, the inside of which is called the throat Breeze, small ashes and cinders used instead of coal for the burning of bricks Breort-weall, anciently, a breast-high wall Bressummer, a beam supporting a su- perincumbent part of an exterior wall, and running longitudinally below that part Bretachi(B, anciently, wooden towers, attached to fortified towns Brick. * * * " Let us make brick, and burn them thoroughly. And they had brick for stone, and slime had they for mortar." Gen. xi. 3 Bricks are a kind of factitious stone, composed of argillaceous earth, and frequently a certain portion of sand and cinders of sea coal (called breeze), tempered together with water, dried in the sun, and burnt in a kiln, or in a heap, or stack, called a clamp. For good brick- making, the earth should be of the purest kind, dug in autumn, and exposed during the winter's frost : this allows the air to penetrate, and divide the earth particles, and facilitates the subsequent opera- tions of mixing and tempering The Romans made bricks of va- rious sizes, from 2 feet to 1 foot in length, from 7 inches to 9 inches in breadth, and from 3| inches to 1^ in thickness. Roman bricks found in the old Roman wall at Veru- lam, compared with modern bricks, showed the superiority of the old to the new; the Roman bricks being lighter and better burnt than the modern. The brick remains of the period of the Roman empire are more en- tire than the stone. Bricks were found at Toulouse, quite sharp at the edges, and not altered by time; they measured 14 inches long, 9 inches broad, and 1 thick. These bricks formed the founda- tion all around the building. The BRI BRIDGE. BRI arches were formed of them for entrances ; and round, large, water- worn pebbles of quartz with mor- tar, formed the walls of the circus, resting on the brick arches. Mr. Layard, in his work on Ni- neveh, says ' ' The soil, an alluvial deposit, was rich and tenacious : the builders moistened it with water, and adding a little chopped straw, that it might be more firmly bound together, they formed it into squares, which, when dried by the heat of the sun, served them as bricks. In that climate, the process required but two or three days. Such were the earliest building materials, and as they are used to this day, almost exclusively, in the same country. " The Assyrians appear to have made much less use of bricks baked in the furnace than the Babylonians; no masses of brick- work, such as are every where found in Babylonia Proper, existing to the north of that province. Common clay moistened with water, and mixed with a little stubble, formed, as it does to this day, the mortar used in buildings ; but, however simple the materials, they have successfully resisted the ravages of time, and still mark the stupendous nature of the Assyrian structures. " This mode of brick-making is described by Sanchoniathon : The people of Tyre invented the art of brick-making and of building of huts ; afterthem came two brothers : one of them, Chrysor or Hyphaes- tus, was the first who sailedin boats; his brother invented the way of making walls with bricks. From the generation were born two youths, one called Technites and the other Genius Autochthon, They disco- vered the method of mingling stub- ble with the loam of the bricks, and drying them in the sun ; they also invented tiling." Bricks. Some of Palladio's finest ex- amples are of brick : the cortile of the Carita at Venice is an instance. The interiors of the Redentore and 63 ~~' St. Giorgio, in the same city, have but a coat of plaster on 'them ; the beautiful Palazzo Thiene at Vicenza, at least that part which was exe- cuted, is left with its rock-worked basement in brick-work chipped out. Form alone fastens on the mind in works of art : the rest is meretri- cious, if used as a substitute to su- persede this grand desideratum Brick axe, used for axing off the soffits of bricks to the saw-cut- tings, and the sides to the lines drawn: as the bricks are always rubbed smooth after axing, the more truly they are axed, the less labour there will be in rubbing Brick groins, the intersecting or meet- ing of two circles upon their dia- gonal elevations drawn upon the different sides of a square, whose principal strength lies in the united force of elevation divided by geo- metrical proportions to one certain gravity Bricklaying, the art by which bricks are joined and cemented, so as to adhere a sone body. This art, in London, includes the business of walling, tiling, and paving with bricks or tiles Brick-nogging, brick-work carried up and filled in between timber fram- ing Brick trimmer, a brick arch abutting upon the wooden trimmer under the slab of a fire-place, to prevent the communication of fire Brick-trowel, a tool used for taking up mortar and spreading it on the top of a wall, to cement together the bricks, &c. Bridge, a constructed platform, sup- ported at intervals, or at remote points, for the purpose of a road- way over a strait, an inlet or arm of the sea, a river, or other stream of water, a canal, a valley, or other depression, or over another road: it is distinguished from a cause- way, or embanked or other con- tinuously supported road- way, and from a raft, by being so borne at intervals or at remote points. BRI BRIDGE. BRI Constructions of the nature and general form and arrangement of bridges, such as aqueducts and viaducts ; the former, being to lead or carry streams of \vater or canals, and the latter, to carry roads or railways upon the same, or nearly the same level, over depressions, are in practice considered as bridges, although they are not such in the commonly received sense of the term. Taken, however, in the sense which the most plausible ety- mology that has been suggested of the term would require, the word bridge being formed by prefixing the constructive be to ridge, a bridge is an elevated construction upon, or over a depression, and be- tween depressed points. There are bridges built of the materials, stone, brick, iron, timber, wire, and on the principles of sus- pension; for the explanation of which, see the word Suspension. The bridge across the Zab, at Lizari, is of basket-work. Stakes are firmly fastened together with twigs, forming a long hurdle, reach- ing from one side of the river to the other. The two ends are laid upon beams, resting upon piers on the opposite banks. Both the beams and the basket-work are kept in their places by heavy stones heaped upon them. Animals, as well as men, are able to cross over this frail structure, which swings to and fro, and seems ready to give way at every step. These bridges are of frequent occurrence in the Tiejari mountains. Bridges. The principal object to be observed in forming the plan of a bridge, is to give a suitable and convenient aperture to the arches, so as to afford a free vent to the waters of sudden floods or inunda- tions, and to secure the solidity and duration of the edifice by a skilful construction. The solidity of a bridge depends almost entirely on the manner in which its foun- dations are laid. When these are 64 once properly arranged, the upper part may be erected either with simplicity or elegance, without im- pairing in any degree the durability of the structure. Experience has proved, that many bridges either decay, or are swept away by sud- den floods, by reason of the de- fective mode of fixing their founda- tions, while very few suffer from an unskilful construction of the piles or arches. This latter defect, how- ever, is easy of correction, nor is it difficult to prevent the consequences that might be expected from it. In the projection of a bridge, five principal points are necessary to be considered, first, the choice of its position or locality; secondly, the vent, or egress that must be al- lowed to the river; thirdly, the form of the arches ; fourthly, the size of the arches; fifthly, the breadth of the bridge. Bridge-board, or notch-board, a board on which the ends of the steps of wooden stairs are fastened Bridged gutters are made with boards supported by bearers, and covered above with lead Bridge-stone, a stone laid from the pavement to the entrance-door of a house, over a sunk area, and sup- ported by an arch Bridging -floors, floors in which bridg- ing joists are used Bridging-joists are the smallest beams in naked floorings, for supporting the boarding for walking upon Bridging -pieces, pieces placed between two opposite beams, to prevent their nearer approach, as rafters, braces, struts, &c. Bridle, the spans of rope attached to the leaches of square sails, to which the bow-lines are made fast Bridle-cable, in navigation. When a vessel is moored by laying down a cable upon the ground, with an anchor at each end, then another cable attached to the middle of the ground cable is called bridle-cable Bridle-part, the foremost part, used for stowing the anchors BUI BUCKETS. BUG Brig, a square-rigged vessel with two masts Brine-pump, the pump in a steam- ship, used occasionally for drawing off a sufficient quantity of water, to prevent the salt from depositing in the boiler Brittleness, in iron, is a want of tena- city or strength, so as to be easily broken by pressure or impact: when iron is made too hot, so as to be nearly in a state of fusion, or so hard as to resist the action of the file, this is called the dispo- sition of cast iron Broach, an old English term for a spire ; still in use in some parts of the country to denote a spire spring- ing from the tower without any intermediate parapet Broach-to, to fall off so much, when going free, as to bring the wind round on the other quarter, and take the sails a-back Broadside, the whole side of a vessel Broken back, the state of a vessel when she is so loosened as to droop at each end Bromine, in chemistry, is found com- bined with silver in a few ores, also in sea-water and salt-springs ; as bromide of potassium, sodium, or magnesium Brontern, in Greek architecture, brazen vessels placed under the floor of a theatre, with stones in them, to imitate thunder Bronze, a compound metal, made of from 6 to 12 parts of tin and 100 parts of copper Brood, in mining, any heterogeneous mixture among tin or copper ore, as Mundick, Black Jack, &c. Browning, a process by which the surfaces of articles of iron acquire a shining brown lustre : the mate- rial used to produce this is the chloride of antimony Brown ink. Various compounds were used in sketching by Claude, Rem- brandt, and many of the old mas- ters, the principal of which were solutions of bistre and sepia Brown ochre, Spruce ochre, or Ochre 65 de Rue, a kind of dark-coloured yel- low ochre : it is much employed, and affords useful and permanent tints. This and all natural ochres require grinding and washing over, to se- parate them from extraneous sub- stances ; and they acquire depth and redness by burning Brown-pink, a fine glazing colour having but little strength of body. In the flesh, it should never join or mix with the lights, because this colour and white antipathize and mix of a warm dirty hue; for which reason their joinings should be blended with a cold middle tint Brown-post, a name given by some builders to a beam laid across a building Brown spar, a magnesian carbonate of lime, tinged by oxide of iron and manganese Bruiser, a concave tool used in grind- ing the specula of telescopes Brunswick green, a pigment composed of carbonate of copper with chalk or lime Brush-wheels are used in light ma- chinery, to turn each other by means of bristles or brushes fixed to their circumference Buata, anciently an arch or chamber; a crypt Bucca, anciently an almonry Bucentaur, the name of the once ce- lebrated galley of Venice, used by the Doge on Ascension-day, to ce- lebrate the wedding of the Adriatic, by dropping a ring into that sea Buckers, in mining, bruisers of the ore Buckets, in water-wheels, a series of cavities placed on the circumfer- ence of the wheel, and into which the water is delivered, to set the wheel in motion. By the revolu- tion of the wheel the buckets are alternately placed so as to receive the water, and inverted so as to discharge it ; the loaded side al- ways descending Bucking, in mining, a term applied to a method of breaking the poor foul copper ore smaller by hand, with small flat irons, called bucking- BUG BUILDING. BUI ing-irons, in order to wash and se- parate the pure ore from the use- less waste : the same term is used in the lead-mines ; but Pettus, in his ' Plata Miner,' gives it the sig- nification of washing or wet-stamp- ing ores Bucking-iron, in mining, the tool with which the ore is pulverized Buckle, in heraldry, a token of surety, faith, and service in the bearer Buckler, a shield of armour, anciently used in war Bucklers, in ships, blocks of wood made to fit in the hawse-holes, or holes in the half -ports, when at sea Bucranes, in sculpture, the heads of oxen, flayed and lacerated, some- times represented on friezes Buddie, in mining, a pit dug in the earth near the stamping-mill, 7 feet long, 3 feet wide, and 2^ feet deep, where the stamped tin is curiously washed from its impurities by water constantly running through the bud- die, while a boy, called a buddle- boy, is standing in the body of it, and working both with a shovel and with his feet Budget, a pocket used by tilers for holding the nails in lathing for tiling Buffers, in locomotive engines, rods with enlarged ends or striking blocks projecting from the ends of the frame of a railway carriage, and attached to springs, for deadening the shocks received from the engines Buhl, unburnished gold Buhl-work, ornamental furniture, in which tortoise-shell is inlaid with wood and brass Builder, a term applied to buildings in civil and naval architecture: in the former he is mostly employed under the superintendence of an architect by contract, or at measure and value ; the latter, under the naval architect, mostly by contract Building, the art which comprises all the operations of an architect in building with stone, brick, timber, iron, cement, &c. Buildings. Of the aspects best adapted to convenience and health, for the 66 different kinds of buildings, Vitru- vius writes : " The principles which should be attended to in allotting to each kind of building an appro- priate aspect remain to be explain- ed: the winter eating-rooms and baths ought to face the winter- west, because the use of them re- quires that they should be light at the time of the sun's setting : be- sides which, the western sun, being immediately opposite to them, ren- ders their temperature mild at the close of the day. The sleeping apartments and libraries should be made to front the east, because the morning light is necessary for them; and books are better preserved when the air and light are received from that quarter. When libraries have a southern or western aspect, they admit those winds, which, at the same time that they carry with them moths, instil also damp va- pours into the books, which, in process of time, cause their decay. The vernal and autumnal triclinia should face the east, because the windows being turned from the sun's rays, whose heat increases as the sun advances towards the west, their temperature is cool at the hours they are generally used. The summer triclinia should front the north ; because, having that aspect, they will be least exposed to the sun, and the temperature of the apartments will be grateful, at the same time that it is conducive to health. No other aspect possesses equal advantages; for the sun, dur- ing the solstice, would render the air of all others sultry. This as- pect is necessary for pinacothecae and the apartments in which the pursuits of embroidery and painting are followed, because the colours used in works of this kind retain their brightness longer when ex- posed to an equable and regular light." Wilkins's Vit. p. 220. Buildings Act, an Act of Parliament passed in the 7th and 8th of Vic- toria to regulate the construction of BUI BURDEN. BUR buildings generally, and appurte- nances thereto, and to determine their supervisions by district sur- veyors and referees Building of beams, the joining of two or several pieces of timber together in one thickness, and of several pieces in one length, by means of bolts, so as to form a beam of given dimensions, which it would be im- possible to obtain from a single piece of timber Bulcuteria, among the Greeks, coun- cil-chambers or public halls Bulge, that part of a ship which bulges out at the floor-heads, to assist the ship when taking the ground Bulge-way, a large piece of timber, or pieces bolted together, making one solid piece, placed under the bulge of a ship, to support her launch. The support of the bulge-w r ays to lie on is called ways, which some- times are placed straight and some- times cumber : but if they do cum- ber, it should be truly circular; though sometimes the curve is quicker at the lower part, but this is liable to strain the sheer of the ship. Their extreme distance is generally about one -third the breadth of the ship, but this must depend on the form of the mid-ship bend Bulk, the contents of the hold of a ship Bulk-heads, partitions built up in several parts of a ship, to form and separate the various apartments Bullantic, so-called ornamentalcapital letters, used in apostolic bulls Bullen-nails, such as have round heads with short shanks, turned and lac- quered, used principally for hang- ings of rooms Bullet wood, from the West Indies, is the produce of a large tree with a white sap ; is of a greenish hazel, close and hard; used in the coun- try for building purposes Bullet wood, another species, from Berbice, is of a hazel-brown colour, adapted to general and eccentric turning 67 Bull's-eye, a small circular aperture for the admission of light or air Bull's-eye, a small oval block of hard wood without sheaves, having a groove round the outside, and a hole in the middle Bulwarks, the wood-work round a vessel, above her deck, consisting of boards fastened to stanchions and timber-heads Bumboats, those which lie alongside a vessel in port with provisions for sale Bumpkins, pieces fitted above the main -rail in the head, which ex- tend nearly as far forward as the fore-part of the knee of the head, and are for the use of hauling down the fore-tack Bunch, or Bunchy: a mine that is sometimes rich and at other times poor, is said to be bunchy Bunch, or Squat, in mining, a quan- tity of ore, of small extent, more than a stone and not so much as a course : a mine is said to be bunchy when these are found in place of a regular lode Bundle-pillar, a column or pier, with others of small dimensions attached to it Bunny, in mining, of tin or copper ore ; a sombrero in Alonzo Barba ; a pipe of ore ; a great collection of ore without any vein coming into or going out from it Bunt of a sail, the middle part formed into a bag or cavity, that it may gather more wind Buntine, thin woollen stuff, of which a ship's colours are made Bunt-line cloth, the lining sewed up the sail in the direction of the bunt-line, to prevent the rope from chafing the sail Bunt-lines, ropes fastened to cringles on the bottoms of the square sails, to draw them up to their yards Buoy, a cask, or block of wood, fast- ened by a rope to an anchor, to point out shoals or particular spots Burden, in mining, the tops or heads of stream-work which lie over the stream of tin, and which must be first cleansed BUR BURNERS. BUR Burdon, a pilgrim's staff Bureau, a chamber or office for the transaction of state or business af- fairs Burges, the Persian word for Towers, evidently the same as the Gothic burgh; a fortified dwelling or en- closed town. Gird or gard is in Persian a city or fortress, which approximates to garth, an enclosure, in the Gothic : hence garden. But a castle, comprehending towers and walls, is in Persian calaa Burgundy pitch, a resin collected from the spruce fir Burgus, anciently a number of houses protected by a fortress Burgward, anciently the custody or keeping of a castle Burg-work, anciently applied to a castle or borough Burin, an engraver's instrument ; a graver Burners, for gas-light. Coal-gas has now been used for the purposes of artificial illumination nearly fifty years, and the burners sanctioned by the companies at the present day are of several shapes. Carburetted hydrogen of the spe- cific gravity '390 (which is about the density of gas when arrived at the point where it has to be burnt) requires two volumes of pure oxy- gen for its complete combustion and conversion into carbonic acid and water. Atmospheric air contains, in its pure state, twenty per cent, of oxygen, in populous towns less ; but twenty per cent, may be taken as a fair average : 1 cubic foot of carburetted hydrogen then requires for its proper combustion 10 cubic feet of air; if less be ad- mitted on to the flame, a quantity of free carbon will escape (from its not finding a proper volume of oxy- gen for conversion into carbonic acid), and be deposited in the form of dense black smoke. When the flame from an Argand burner is turned up high, the air which rushes through the interior ring becomes decomposed before it can reach the 68 air on the top of the flame, which consequently burns in one undivided mass, the gas being in part uncon- sumed, the products unconverted, and carbon deposited abundantly. If an excess of air is admitted, it would appear at first to be of no consequence, but it will be found that the quantity of nitrogen ac- companying this excess has a ten- dency to extinguish the flame, while it takes no part in the elective affi- nity constantly going on between the several elementary gases, viz. hydrogen, oxygen, and the vapour of carbon ; and also thatthe quantity of atmospheric air passing through the flame unchanged, tends to re- duce the temperature below that necessary for ignition, and therefore to diminish the quantity of light. For the proper combustion of the gas, neither more nor less air than the exact quantity required for the formation of carbonic acid and water can be admitted through the flame without being injurious. It is not possible practically to regulate the supply of air to such a nicety : it is preferred therefore to diminish the quantity of light by having a slight excess of air rather than to pro- duce smoke by a deficiency, the former being unquestionably the least evil. Burning-glass, a glass lens, which, being exposed directly to the sun, refracts the rays which fall upon it into a focus Burning-house, the furnace in which tin ores are calcined, to sublime the sulphur from pyrites : the latter being thus decomposed, are more readily removed by washing Burnisher, a tool used for smoothing and polishing a rough surface. Agates, polished steel, ivory, &c., are used for burnishing Burnt Carmine is, according to its name, the carmine of cochineal par- tially charred till it resembles in colour the purple of gold, for the uses of which in miniature and water painting it excels BUR BUTTRESS. BY Burnt Sienna earth is, as its name implies, the terra di sienna burnt, and is of an orange-russet colour Burnt Umber, a pigment obtained from a fossil substance, which when burnt assumes a deeper and more russet hue : it contains manganese and iron, and is very drying in oil, in which it is employed as a dryer. It is a fine warm brown, and a good working strong colour, of great use for the hair of the human head, and mixes finely with the warm shade Burnt Verdigris is an olive-coloured oxide of copper deprived of acid. It dries well in oil, and is more durable, and in other respects an improved and more eligible pig- ment than in its original state Burre-stone, a mill-stone which is al- most pure silex : the best kind is of a whitish colour Burrock, a small weir or dam, where wheels are laid in a river for catch- ing fish Burrow, in mining, the heap or heaps of attle, deads, or earth (void of ore), which are raised out of a mine, and commonlylie aroundthe shafts ; any heap or hillock of deads or waste Burr-pump, a bilge-pump worked by a bar of wood pulled up and down by a rope fastened by the middle Bursa, a bag; a purse used in the mid- dle ages for the purposes of a little college or hall for students Bursar, one to whom a stipend is paid out of a fund set apart for poor students; the treasurer of a college Bursary, the treasury of a college Bursery, the exchequer of collegiate and conventual houses, and for paying and receiving monies Burthen, the weight or measure of capacity of a ship. Multiply the length of the keel, the inner mid- ship breadth, and the depth from the main-deck to the plank joining the keelson together ; and the pro- duct, divided by 94, gives the ton- nage or burthen Burton, a manor ; a manor-house Burton, in a ship, a small tackle of 69 two single blocks, named from the inventor Bush, in machinery, a piece of metal fitted into the plummer-block of a shaft in which the journal turns. The guide of a sliding-rod also bears the same name Bush, a circular piece of iron or other metal, let into the sheaves of such blocks as have iron pins, to prevent their wearing Bushel, a dry measure of 8 gallons or 4 pecks Bush-harrow, an implement used in harrowing grass lands Buskin, a high shoe or boot worn an- ciently, in tragedy, on the stage Buss, a small sea-vessel used in the herring-fishery Bust, in sculpture, the head, neck, and breast of a human figure Bustum, anciently a tomb But, the end of a plank where it unites with another But-hinges, those employed in the hanging of doors, shutters, &c. Butmen cheeks, the two solid sides of a mortise varying in thickness Butments, the supports on which the feet of arches stand Butterfly-valve, the double valve of an air-pump bucket, consisting of two clack-valves, having the joints opposite and on each side of the pump-rod Butteris, an instrument of steel set in a wooden handle, used by far- riers for paring the hoof of a horse Buttery, a cellar in which butts of wine are kept; a place for provisions Buttock, the round part of a ship abaft, from the wing transom to the upper water-line, or lower down Buttress, in Gothic architectural struc- tures, a pilaster, pier, or masonry added to and standing out from the exterior of a wall Buttress, a piece of strong wall that stands on the outside of another wall, to support it By, said of a vessel when her head is lower in the water than her stern ; if her stern is lower in the water, she is by the stern BYA BYZANTINE ARCHITECTURE. BYZ Byard, a piece of leather across the breast, used by those who drag the sledges in coal-pits Byzantine Architecture. About the year A. D. 328, Constantine, who had previously resided at Rome, commenced his new capital in the East, which was called after his name, and in May, 330, was so- lemnly dedicated to the Virgin Mary. He adorned it with so many stately edifices that it nearly equalled the ancient capital itself: he here built a cathedral dedicated to Santa Sophia or the Eternal Wis- dom, and a church to the Apostles. This cathedral, having been twice destroyed by fire, was finally rebuilt about 532 A. D., by Justinian, who had invited the celebrated architect Anthemius to Constantinople for that purpose. It was completed in six years from the time of laying the first stone. The emperor, in his admiration of this magnificent edifice, is said to have exclaimed, " I have vanquished thee, Solomon:" and with justice might he glorify himself; for the dome of St. Sophia is the largest in the world, and the more to be ad- mired in its construction from the lowness of the curvature. This church, after twelve centu- ries, remains the same, with the ex- ception of the mode of worship to which it is devoted. It still retains its former name, but the Mahome- tans, instead of the Christians, pos- sess it. This is the earliest Byzantine building extant, totally dissimilar in arrangement to the Christian churches in the empire. The plan of the interior is that of a Greek cross, the four arms of which are of equal length ; the cen- CAB GABBLING. The process in the ma- nufacture of iron, which in Glou- cestershire is called ' scabbling,' or, 70 tral part is square, the sides are about 115 feet in length. At each angle of the square a massive pier has been carried, 86 feet in height from the pavement, and four semi- circular arches stretch across the intervals overthe sides ofthe square, and rest on the piers. The interior angles between the four piers are filled up in a concave form. At 145 feet from the ground is the level of the springing of the dome, which is 115 feet in diameter ; the form is a segment of a circle, and the height is equal to one-sixth of its diameter at the base. On both the eastern and western side of the square is a semicircular recess, with domes that rest against the main arches, and assist in resisting the lateral thrust. On the north and south sides of the square are vestibules forming a square on the plan. Above the vesti- bules are galleries appropriated to women during the performance of worship. The whole church is sur- rounded by cloisters, and enclosed by walls. The total cost of St. Sophia has been reckoned at the lowest com- putation to have exceeded one mil- lion pounds ; as before the building was 4 feet out of the ground, its cost had amounted to a sum equi- valent to 200,000 sterling. Besides this cathedral, Justinian is said to have built, at Constanti- nople, twenty-five churches to the honour of Christ, the Virgin, and the Saints ; he also built a church to St. John at Ephesus, and another to the Virgin at Jerusalem: the bridges, hospitals, and aqueducts erected by this emperor were nu- merously distributed throughout the empire. Byzanteum artificium, Mosaic-work CAB more correctly, ' cabbling,' may be thus described. When the cast or pig iron has been subjected to the CAB CALCULATING MACHINE. CAL influence of a refinery, the product is called ' Finery:' it is then carried to the forge, and smelted in a furnace with charcoal: in a short time, a large ball, about 2 cwt., is formed by working with an iron bar ; this ball is then taken to a large ham- mer, and beaten into a flat oval or oblong shape, from 2 to 4 inches in thickness : this is allowed to cool, when ' cabbling' commences, and which is simply breaking up this flat iron into small pieces. Men are especially allocated for this operation, and are named ' cabblers.' The pieces of iron ob- tained by cabbling are then heated in another furnace almost to fusion, hammered down into shape, and ultimately drawn out into bar-iron Cabin, a room or apartment in a ship where any of the officers usually reside, and also used in passenger vessels for the residence of passen- gers Cabinet pictures, usually denominated so, are small valuable paintings from the old masters, painted on copper, panel, or canvas. Modern subjects, if painted small in size, should equally be called Cabinet Cabinets, in Tudor times, were of massive proportions, carved in oak, ebony, walnut, and other woods, inlaid. Some of them answered the double purpose of depositories and cupboards for plate, from having drawers and recesses, or ambries, enclosed by doors; and broad shelves between the tiers of turned columns were conspicuous objects in these apartments Cable, a thick stout rope, made of hemp, &c., to keep a ship at anchor Cable-moulding, ahead ortorus mould- ing, cut in imitation of the twisting of a rope, much used in the later period of the Norman style Cabling, a round moulding, frequently used in the flutes of columns, pilas- ters, &c. Caduceus, an emblem or attribute of Mercury; a rod entwined by two winged serpents 71 Caslatura (Greek), a branch of the fine arts, under which all sorts of ornamental work in metal, except actual statues, appear to be included Caementicius, built of unhewn stones ; large irregular masses laid together without mortar, having the inter- stices filled in with small chippings Caen stone, a peculiar quality of stone used for building purposes, prin- cipally for Gothic structures ; it is taken from quarries in Normandy Caisson, a wooden frame or box with a flatbottom, made of strong timbers firmly connected together; used for laying the foundations of a bridge in situations where the coffer-dam cannot be adopted Caisson, a name given to the sunk panels of various geometrical forms symmetrically disposed in flat or vaulted ceilings, or in soffits gene- rally Cal, in Cornish mining, a kind of iron Gossan stone found in the bryle and backs of lodes, much of the colour of old iron ; reckoned a poor brood with tin Calcar, a small oven or reverberatory furnace, in which the first calcina- tion of sand and potashes is made for turning them into frit, from which glass is ultimately made Calcareous earth, the same as lime, and of which there are various com- binations, as marble, limestone, marl, gypsum, &c. Calcatorium, among the Romans, a raised platform of masonry in the cellar attached to a vineyard Calcination, the process of subjecting a body to the action of fire, to drive off the volatile parts, whereby it is reduced to a condition that it may be converted into a powder : thus marble is converted into lime by driving off the carbonic acid and water; and gypsum, alum, borax, and other saline bodies are said to be calcined when they are deprived of their water of crystallization Calcium, the metallic basis of lime Calcography, to write, engrave, &c. Calculating machines are of early in- CAL CAMBER SLIP. CAM ventiou ; but recently Mr. Babbage has completed a calculating ma- chine surpassing all previous ones : the machine accomplishes the ad- ditions of numbers by the move- ments of a number of cylinders having on the convex surface of each the series of numbers 1234 567890; and the operations are of two kinds : by the first the additions are made, and by the second there is introduced the 1, which should be carried to the ten's place every time that the sum of the two numbers is greater than 10, &c. Caldarium, the hot bath. The vase which supplied the hot bath was likewise so termed Caldarium, according to Vitruvius, the thermal chamber in a set of baths Calender, a mechanical engine for dressing and finishing cloths Calends, in Roman antiquity, the first day of every month Caliber or Caliper compasses; com- passes made with bowed or arched legs, for the purpose of taking the diameter of any round body Caliber, an instrument used by car- penters, joiners, and bricklayers, to see whether their work be well squared Calico, a cloth made from cotton wool, like linens ; the origin of the name is from Calicut, in India Calico printing, the art of applying coloured patterns on a white or coloured ground of linen or cotton Calk, a Cornish term for lime Callipers, a species of compasses with legs of a circular form, used to take the thickness or diameter of work, either circular or flat; used also to take the interior size of holes Callipers, in turning, compasses with each of the legs bent into the form of a curve, so that when shut the points are united ; and the curves, being equal and opposite, enclose a space. The use of the callipers is to try the work in the act of turn- ing, in order to ascertain the dia- meter orthe diameters of the various 72 parts. As the points stand nearer together at the greatest required diameter than the parts of the legs above, the callipers are well adapted to the use intended Callys ovKillas (Cornish), hard, smart; the most common and agreeable stratum in our mine country, usually called killas Caloric, the matter and cause of heat Calorific, in chemistry, the quality of producing heat Calorimeter, an instrument to measure the heat given out by a body in cooling by the quantity of ice it melts Calquing, the process of copying or transferring a drawing. It is ef- fected by rubbing over the back of the original with a fine powder of red chalk or black lead; the smeared side is then laid on a sheet of paper, and the lines of the drawing are traced by a blunt-pointed needle, which imprints them on the paper under- neath. Another method is to hold the drawing up to a window with a sheet of paper before it: the out- lines will appear through, and may be pencilled off without damage to the original Calyon, flint or pebble stone, used in building walls, &c. Cam, in steam machinery, a plate with curved sides, triangular or other- wise, fixed upon a revolving shaft, for changing the uniform rotatory motion into an irregular rectilineal motion. It is sometimes used for moving the slide-valves Camaieu, a term used in painting when there is only one colour, the light and shades being of gold, or on a golden and azure ground. It is chiefly used to represent basso-rilievo Camber, the convexity of a beam upon the upper surface, in order that it may not become concave by its own weight, or by the binder it may have to sustain, in the course of time Camber-beams are those used in the flats of truncated roofs, and raised in the middle with an obtuse angle, for discharging the rain-water to- wards both sides of the roof CAM CANAL. CAN Camber-slip, a piece of wood, gene- rally about half an inch thick, with at least one curved edge rising about 1 inch in 6 feet, for drawing the soffit-lines of straight arches : when the other edge is curved, it rises only to about one-half of the other, viz. about half an inch in 6 feet, for the purpose of drawing the upper side of the arch so as to prevent it from becoming hol- low by the settling of the bricks. The upper edge of the arch is not always cambered, some persons pre- ferring it to be straight. The brick- layer is always provided with a camber-slip, which being sufficiently long, answers to many different widths of openings : when he has done drawing his arch, he gives the camber-slip to the carpenter, in order to form the centre to the required curve of the soffit Cambering, a sea phrase, used when a deck is higher in the middle than at the ends Camel, the name of a machine used by the Dutch for carrying vessels hea- vily laden over the sand-banks in the Zuyder Zee Camera (Greek), an arched or vaulted roof, covering or ceiling, formed by circular bands or beams of wood, over the intervals of which a coating of lath and plaster was spread: they resembled, in their construc- tion, the hooped awnings now commonly in use Camera-lucida, and Camera-obscura, (the light and dark chamber,) the names given to two methods, simi- lar in principle, of thro wing images of external objects upon plane or curved surfaces, for the purpose of drawing or amusement: in the first contrivance there is no chamber; but as it was the last invented, and as its predecessor had been called the ' camera-obscura,' it was termed the 'camera-lucida' Camerated, a term applied to the roof of a church Games, the slender rods of metal used by glaziers as turned lead; 73 they are usually cast in lengths which measure 12 or 14 inches Caminus, according to Pliny, a smelt- ing furnace Campance or Campanula, or Guttae, the drops of the Doric architrave Campanile, from the Italian, a bell- tower, principally used for church purposes, but now sometimes for domestic edifices Camphor wood is imported from China and the Indies in logs and planks of large size, and used in England for cabinet-work and turnery Campus Martius, a district outside the walls of ancient Rome, between the Quirinal and Pincian Mounts and the Tiber, dedicated to Mars : there public exercises w r ere per- formed, and the consuls and other magistrates elected : it was adorned with statues, columns, arches, &c., and much frequented by the citizens Cam wood, the best and hardest of the red dye-woods : it is brought from Africa, and used in ornamental and eccentric turnery Canal, an artificial water-course for connecting rivers or lakes ; a navi- gable communication Canalis, in Latin, a water-pipe or gutter ; used in architecture for any channel, such as the flutings of co- lumns; the channel between the volutes of an Ionic column Canary wood, from South America, is a sound, light, orange-coloured wood, used for cabinet-work, mus- ketry, and turnery Cancelli, among the Romans, iron gratings and trellis-work ; in mo- dern buildings, latticed windows made with cross-bars of wood, iron, lead, &c. Candela, a candle, made either of wax or tallow ; used generally by the Romans before the invention of lamps Candelabrum, originally a candle- stick, but afterwards used to sup- port lamps Candlemas., the popular name for the feast of the Purification of the Virgin Mary, February 2, derived CAN CAOUTCHOUC. CAO from the lights which were then distributed and carried about in procession Candlestick of gold (The) was made by Moses for the service of the Temple, and consisted wholly of pure gold : it had seven branches, upon the extremities of which were seven golden lamps, which were fed with pure olive oil, and lighted every evening by the priest on duty : it was used in the holy place, and served to illumine the altar of incense and the table of shew-bread, which stood in the same chamber Candlesticks. The magnificence of these articles was at first displayed in chapels and in domestic apart- ments, as banquets in early times were given by daylight. We find them, however, of very costly de- scriptions. In Henry the Eighth's temporary banqueting - room, at Greenwich, "the candlestykes were of antyke worke, which bare little torchetts of white waxe : these candlestykes were polished lyke ambre." Cangica wood, from South America, is of a light and yellow-brown colour, used for cabinet-work and turnery Can-hooks, strings with flat hooks at each end, used for hoisting bar- rels or light casks Canopy, a covering or hood, the en- riched projecting head to a niche or tabernacle. The tablet or drip- stone, whether straight or circular, over the heads of doors or windows, if enriched, is so called Canopy, in Gothic architecture, an ornamental projection over doors, windows, &c.;acoveringoverniches, tombs, &c. Cant, a term used among carpenters to express the cutting off the angle of a square Cantalivcr, a kind of bracket to sup- port eaves, cornices, balconies, &c. Canted, applied to a pillar or turret when the plan is of a polygonal form Canterii, beams of wood in the frame- work of a roof, extending from the ridge to the eaves, corresponding to the rafters of a modern roof. The word canterii was also applied to two inclining reeds fixed in the ground some distance asunder and meeting at the top, for the support of vines Cantharus, a fountain or cistern in the atrium or court-yard before ancient churches, at which persons washed before they entered the sacred buildings Canthus, in Greek and Latin, the tire of a wheel ; a hoop of iron or bronze fastened on to the felloe, to preserve the wood from abrasion Cantilevers are horizontal rows of timbers, projecting at right angles from the naked part of a w r all, for sustaining the eaves or other mould- ings Cant -moulding, abevelled surface, nei- ther perpendicular to the horizon nor to the vertical surface to which it may be attached Cantoned, in architecture, is when the corner of a building is adorned with a pilaster, an angular column, rustic quoins, or any thing that pro- jects beyond the wall Cant-pieces, in ships, pieces of timber fastened to the angles of fishes and side-trees, to supply any part that may prove rotten Cant -timbers, in ship-building, those timbers or ribs of the ship which are situated afore or abaft, or at the two ends, where the ship grows narrower below Cant-timber abaft, the chock upon w r hich the spanker-boom rests when the sail is not set Cantuar. The signature of the Arch- bishop of Canterbury, is thus abbre- viated, the Christian name being usually prefixed Canvas, the cloth of which the sails of ships are made Caoutchouc, a substance produced by the sephonia elastica, the ficus elas- tica, and the urceola elastica, and many other American and Asiatic trees. It is often termed Indian CAP CAPITOL. CAP rubber, from its use in removing pencil traces from paper. There are various chemical properties which render caoutchouc valuable in the arts, but elasticity and impervious- ness to water are those for which it is most prized. It is worked into a great variety of useful things for dress and for domestic purposes Cap, a thick, strong block of wood, with two holesthroughit,one square and the other round, used in ship- building to confine together the head of a mast and the lower part of that next above it Capacity, the same in sense as content or volume in pure mathematics. In physics it generally signifies the power of holding or retaining: thus we speak of the capacity of a body for heat, &c. Capel, in mining, a stone composed of quartz, schorl, andhornblende, usu- ally occurring in one or both walls of a lode, and more frequently ac- companying tin than copper ores Capillary attraction and repulsion. These names have been given to the properties of matter which cause the ascent above or descent below the level of the surrounding fluid which takes place when a tube of small diameter is dipped into water, mercury, &c. Capital, in architecture, the head or uppermost part of a column or pi- laster. The capitals of the columns constitute the principal and most obvious indicial mark of the re- spective orders. For those of each of the three classes or orders a cer- tain character conformable with the rest of the order is to be observed; but that attended to, further re- striction is unnecessary. Between several examples, all decidedly re- ferrible to one and the same order, very great special differences occur, and there might easily be a very great many more. Although the capital itself is indispensable, it is so only aesthetically, and not out of positive necessity. The necessity is only artistic : decoration of the kind 75 there must be,butthe express mode of it is one of those matters which should be left to design, to which it properly belongs. Capitals are just as legitimate subjects for the exercise of taste and invention as any thing else in decorative design. The capital is only an ornamental head to the column, and therefore admits of being as freely designed as any other piece of ornament, on the conditions of itsbeing accordant in character with the rest of the order, and of forming an agreeable transition from the shaft of the co- lumn to the architrave Capitolium, a temple or citadel at Rome, on the Tarpeian rock : it was finished by Tarquinius Superbus, and consecrated by the consul M. Horatius, was burnt in the time of Marius, and rebuilt by Sylla, destroyed a second and third time in the troubles under Vitellius and Vespasian, and lastly raised again by Domitian. Its name was de- rived from the discovery of the head of Tolius, during the excava- tion of the earth for the founda- tion. Q. Catulus consecrated it to Jupiter Capitolinus, and covered it with gilded brass tiles. The steep ascent of the rock was mounted by 100 steps on the side of the forum. In the temple were statues of gold and silver, vessels of those metals and of crystal, and 3000 brass tables on which the Roman laws were engraved Caple (in Cornwall) stone is something like limestone, but will not burn. The walls of most lodes are of this kind, and therefore it is common to call a lode by the name of its caple : those veins which abound with it are termed caples or caple- lodes Capreoli, the pieces of timber on a roof which serve to uphold the axes or principals. A fork inclined so as to afford support to any thing was formerly called a Capreolus Capsa or Capsula, a box for holding books among the Romans : these CAP CARLISLE TABLES. CAR boxes were usually made of beech wood, and were cylindrical in form Capsize, to overturn Capstan,in naval architecture, a strong massive piece of timber let down through the decks of a ship, and resting its foot or axis, which is shod with iron, in an iron socket, called a saucer, fixed on a wooden block or standard, called the step, resting on the beams Captain, in mining, an experienced miner; one who directs and over- sees the workmen and business of a mine Caracol, a term sometimes used for a staircase in a helix or spiral form Caradoc formation, the uppermost of the two great divisions of the lower Silurian strata of Murchison, seen principally in Shropshire, Worces- tershire, Somersetshire, &c., and on the eastern borders of Wales Caravanserai, a building in the East, expressed in our version of the Scripture by the term Inn; in Turkey it is understood to be a place of accommodation for strangers and travellers : they are built at proper distances through the roads of the Turkish dominions, and afford the indigent and weary traveller an asylum from the inclemency of the weather Carbon, a non- metallic elementary solid body, which is widely diffused throughout nature. The purest and at the same time the rarest form in which it occurs is that of the dia- mond ; the more common states in which it is met with are those of anthracite, graphite, and coal : an- other form is that of charcoal Carbonate, a salt composed of car- bonic acid and a base. The chief varieties are described under their alkaline, earthy, and metallic bases Carburet, a compound of carbon with nitrogen, metals, &c. Carcass (The} of a building is the naked walls and the rough timber- work of the flooring and quarter partitions before the building is plastered or the floors laid 76 Carcass-roofing, that which supports the covering by a grated frame of timber-work Career, a prison or gaol. The Roman prisons were divided into three stories, one above the other, each of which w r as appropriated to dis- tinct purposes Card -malting machine, an arrange- ment of wires used in the cotton manufacture, for disentangling the fibres of cotton preparatory to spin- ning Cardo, a pivot and socket, an appa- ratus by means of which the doors of the ancients were fixed in their places, and made to revolve in opening and shutting Careening, the operation of heaving a ship down on one side by the application of a strong purchase to her masts, which are properly supported for the occasion, to prevent their breaking with so great a strain, and by which means one side of the bottom, being elevated above the surface of the water, it may be cleansed or re- paired Carina, according to Cicero, the keel or lowest piece of timber in the frame -work of a ship Car/m<7S,shortpieces of timber ranging fore and aft from one deck-beam to another, into which their ends are mortised : they are used to sustain and fortify the smaller beams of the ship Carlisle Tables, so called from the more recent mode of making calculations of the value of annuities on lives, based on the average duration of human life, as taken at Carlisle, in Cumberland. The value of a life annuity depends upon the manner in which it is presumed a large number of persons,similarly situated with the buyer, would die off suc- cessively. Various tables of these decrements of life, as they are called, have been constructed from observations made among different classes of lives. Some make the mortality greater than others ; and, CAR CARPENTRY. CAR of course, tables which give a large mortality give the value of the an- nuity smaller than those which suppose men to live longer. Those who huy annuities would therefore be glad to be rated according to tables of high mortality, or low expectation of life ; while those who sell them would prefer receiv- ing the price indicated by tables which give a lower rate of morta- lity. Hence arise bargains or sti- pulations according to either the Northampton or Carlisle tabulated rating of the duration of life. In assurances the reverse is the case : the shorter the time which a man is supposed to live, the more must he pay the office, that the latter may at his death have accumulated wherewithal to pay the amount. The Northampton tables, formed by Dr. Price, from observations of burials at Northampton, as com- pared with all other tables of au- thority, give too high a mortality at all the younger and middle ages of life, and, consequently, too low a value of the annuity. The Car- lisle tables, formed by Mr. Milne, give much less mortality than most of the old tables, and therefore a higher value of the annuities : they have been proved to represent the actual state of life among the middle classes Carmine (colour), a name originally given only to fine specimens of the tinctures of kermes and cochineal, and denoting generally at present any pigment which resembles them in beauty, richness of colour, and fineness of texture : hence we hear of blue and other coloured car- mines, though the term is princi- pally confined to the crimson and scarlet colours produced from cochineal by the agency of tin Cam, in Cornish mining, a rock; a heap of rocks ; a high rock Carnagioni (of the Italians), a colour which differs from terra puzzuoli in its hue ; in which respect, other variations and denominations arc 77 produced by dressing and com- pounding Carol, a small closet or enclosure to sit and read in Carpenter's square; the stock and blade are formed, in one piece, of plate-iron, and the instrument is thus constructed: one leg is 18 inches in length, numbered from the exterior angle ; the bottom of the figures are adjacent to the in- terior edge of the square, and con- sequently their tops to the exterior edge : the other leg is 12 inches in length, and numbered from the ex- tremity towards the angle ; the figures are read from the internal angle, as in the other side ; and each of the legs is about an inch broad. It is not only used as a square, but also as a level, and as a rule : its application as a square and as a rule is so easy as not to require any example ; but its use as a level, in taking angles, may be thus illustrated : suppose it were required to take the angle which the heel of a rafter makes with the back, apply the end of the short leg of the square to the heel-point of the rafter, and the edge of the square level across the plate ; ex- tend a line from the ridge to the "heel-point, and where this line cuts the perpendicular leg of the square, mark the inches : this will show how far it deviates from the square in 12 inches Carpenters' tools : the principal tools used in the rougher operations of carpentry are the axe, the adze, the chisel, the saw, the mortise and tenon-gauge, the square,the plumb- rule, the level, the auger, the crow, and the draw-bore-pin, or hook-pin, for draw-boring Carpentry is the art of combining pieces of timber for the support of any considerable weight or pres- sure. The theory of carpentry is founded on two distinct branches of mechanical science : the one in- forms us how strains are propagated CAR CARTOON. CAR through a system of framing; the other, how to proportion the re- sistance of its parts, so that all may he sufficiently strong to resist the strains to which they are exposed. The one determines the stability of position, the other the stability of resistance. Each of these may be considered in the most simple manner the subject admits of, with the addition of rules and practical remarks. Timber is wrought into various forms according to jthe principles of geometry ; and these forms are to be preserved in their original shape only by adjusting the stress and strain according to the laws of mechanics. Hence the import- ance of studying both these sciences is evident, and particularly the latter; for unless the stress and strain be accurately adjusted, the most careful attention to geometri- cal rules, and the most skilful work- manship, will he exerted in vain. If, for instance, the centre of an arch were to be drawn and worked ever so truly to the curve required, what would it avail if the centre changed its form with every course of stone laid upon it ? And it must be remarked, that this is not an imaginary case, but one that has frequently happened ; and not only to men ignorant of mechanics, but to some of the most celebrated en- gineers that France ever produced. The engineers of our own coun- try have been more successful, having succeeded in gradually in- troducing a better principle of con- structing centres than our neigh- bours. The greatest defect of the English centres is now an excess of strength, which, on principles of economy, it would be desirable to avoid in erections for temporary purposes Carpentry, in civil architecture, is the art of employing timber in the con- struction of buildings. The first operation of dividing a piece of timber into scantlings, or 78 boards, by means of the pit-saw, belongs to sawing, and is previous to any thing done in carpentry. The tools employed by the car- penter are a ripping- saw, a hand- saw, an axe, an adze, a socket- chisel, a firmer chisel, a ripping- chisel, an auger, a gimlet, a hammer, a mallet, a pair of pincers, and some- times planes ; but as these are not necessarily used, they are described under the head of joinery, in which they are absolutely necessary Carrara marble, a species of white marble : it is distinguished from the Parian or statuary marble by being harder and less bright. It takes its name from Carrara, in Italy Carrel, a pew, closet, or desk, with a seat placed under a window, where the monks were engaged in copying writings Carriage of a stair, the timber which supports the steps Carrick-bend, a kind of knot. Car- rick-bitts are the windlass-bitts Carrier, the piece of iron which is fixed by a set-screw on the end of a shaft or spindle to be turned in a lathe, to carry it round by the action of the driver of the centre chuck Carry away, a sea term, to break a spar or part a rope Cartoon, a distemper-coloured draw- ing, made on paper, linen, parch- ment, &c., of the exact pattern of a design intended to be executed either in tapestry, mosaics, or on glass : such are Raphael's divine pictures in Hampton Court Palace Cartoon, in painting, a design drawn on strong paper, sometimes after- wards calqued through, and trans- ferred on the fresh plaster of a wall, to be painted in fresco Cartouch, the same as modillion, ex- cept that it is exclusively used to signify the blocks or modillions on the eaves of a house Cartouche, an ornament representing a scroll of paper Carucru, or Chica, a new pigment, CAR CASTE LLA. CAS of a soft powdery texture and rich marrone colour, first brought from South America by Lieut. Mawe Carving and inlaying of woods had become pretty general at the latter end of the sixteenth century : " at Hard wick, in Derbyshire ( 1 5 7 0) , the wood-work, in several of the prin- cipal apartments, is oak, inlaid with ebony ornaments on the panels and stiles. The doors and shutters of ' Mary Queen of Scot's room,' as it is called, are framed in panels of light wood, inlaid with profiles of the Caesars, and other enrichments ; the stiles, of darker coloured oak. In the state-room, the walls are divided, at about half the height, by a stringing, the upper part filled with landscapes, figures, and ani- mals, relieved in plaster^ and painted in their proper colours on white ground ; and the lower divi- sion hung with tapestry. The chimney front is entirely occupied by a large armorial compartment, re- lieved in plaster and emblazoned" Caryates or Caryatides (Greek), figures used instead of columns, employed in architecture to represent the portraiture of the defeated Persians after the subjugation of the Carya- ta. The male figures are denomi- nated Persians, Telamones. or Atlan- tides : the female, Caryans or Cary- atides Caryatides, anthropostylar pillars or human figures (usually female ones) employed instead of columns to sup- port an entablature. Such figures ought always to be perfectly free from all attitudinizing, and to ap- pear to support their burden with- out any effort. Some very matter- of-fact critics object to caryatides as being at the best only beautiful absurdities ; as if statues so applied were particularly liable to be mis- taken for living persons subjected to a more severe punishment than that of being posted up in a niche, or on the top of a building Casa, according to Vitruvius, a cottage ; a small country-house 79 Cased tin, in Cornish mining, that which is re-framed by the gentlest current of water, and prevented from running off the frame by turf placed at'the bottom Case-hardening. The hardness and polish of steel may be united, in a certain degree, with the firmness and cheapness of malleable iron, by what is called case-hardening, an operation much practised, and of considerable use Casement, a frame enclosing part of the glazing of a window, with hinges to open and shut ; also an early English name for a deep hollow moulding Casement, the same as ' scotia,' the name of a hollowed moulding Casements, sashes or glass frames opening on hinges and revolving upon one of the vertical edges Cases, in Cornwall, very small fissures in the strata of the earth, through which small streams of water flow when they are opened by the work- ing underground, greatly to the hindrance of the workmen Casing/ of timber-work, the plastering a house all over on the outside with mortar and then striking it wet by a ruler with the corner of a trowel, or the like instrument, to make it resemble the joints of freestone, by which means the whole house appears as if built thereof Cassel earth, or Castle earth, an ochreous pigment of a brown co- lour, more inclined to the russet hue Cassia Fistula is a native vegetable pigment, though it is more com- monly used as a medicinal drug Cast, to pay a vessel's head off, in getting under way, on the tack she is to sail upon Cast after cast, in Cornwall, is throw- ing up of tin stuff, &c., from one stage of boards to another, each cast about 5 or 6 feet high Castella, square towers in the cele- brated Roman wall of Severus, which was raised to separate England from Scotland CAS CATARACT. CAT Castellated, built in imitation of an ancient castle Castellum, the receptacle in which the water was collected arid heated for the public baths of the Romans ; a castle Casting, among sculptors, the taking casts of impressions of figures, busts, medals, leaves, &c. Casting of draperies : by this term is implied the distribution of the folds, and draperies are said to be well cast when the folds are distributed in such a manner as to appear rather the result of mere chance than of art, study, or labour. In that manner or style of painting, which is called the grand, the folds of the draperies should be great, and as few as possible, because their rich simplicity is more sus- ceptible of great lights; but it is an error to design draperies too heavy and cumbersome, for they ought to be suitable to the figures, with a combination of ease and grandeur. Order, contrast, and a variety of stuffs and folds, consti- tute the elegance of draperies; and diversity of colours in these stuffs contributes extremely to the har- mony of the whole in historic com- positions Casting or Warping, in joinery, is the bending of the surfaces of a piece of wood from their original posi- tion, either by the weight of the wood or by an unequal exposure to the weather, or by the unequal tex- ture of the wood Cast-iron framing, for mill-work, pos- sesses great superiority over that of timber, for constructing the framing. It is not only much more durable, but, from the uni- formity of its texture, may be con- verted into any shape, so as to give it great advantage in arranging the materials with respect to strength, and proportioning it to the stress it has to sustain Cast-iron shoes for roofs. A prac- tice has been recently introduced into the construction of roofs 80 having the beams of wood, of pro- tecting their extremities from the damp and consequent decay to which they are liable, by resting immediately in contact with the brick or stone work of the walls of the building. This is effected by what the workmen call cast-iron shoes, which are attached to the ends of the tie-beams by means of bolts, nuts, &c. The iron shoe itself, of course, takes various forms, according to circumstances and the situation where it is introduced, and the particular views of the architect who employs it. In cases where, from the nature of the work carried on, every part is exposed to great heat and mois- ture, the defence afforded by such an attachment is of great import- ance ; the wood, unless thus pro- tected, being of course very liable to decay in those parts where damp and moisture might accumulate Castle, a fortified and strong mansion, situated and constructed and ar- ranged for the purpose of protect- ing its inmates against the assaults of enemies ; in modern use, domes- tic residences of the nobility and gentry, without the necessity of being garrisoned by armed men Cat, the tackle used to hoist the an- chor up to the cat-head Catacombs, subterraneous vaults or excavations used as burying-places Catamaran, a name given both in the East and West Indies to some kinds of rafts, which are used in short navigations along the sea-shore Cataract, a contrivance applied to Cornish engines for regulating the number of strokes per minute : it consists of a small pump fixed on a cistern ; the piston is raised at each stroke of the engine by a tappet on the plug-rod, and the water rises into the cylinder of the pump ; it is then forced through a cock by means of counterweights attached to a cross-head on the pump piston- rod: when the water has been forced CAT CATHEDRALS. CAT back into the cistern, a series of levers, acting on a rising rod, loosen catches which allow weights to act, by means of levers, to open or shut the steam, equilibrium, and exhaust valves Cataractes, a cataract, cascade, or sud- den fall of water from a higher to a lower level; according to Pliny, a sluice, flood-gate, or lock in a river Catch, a contrivance in machinery, acting on the principle of a latch Cafenary, in the higher geometry, a mechanical curve which a chain or rope forms itself into by its own weight, when hung freely between two points of suspension, whether these points be in the same hori- zontal plane or not Catgut, in turnery, the string which connects the fly and the mandril Cat-harpin, an iron leg used to con- fine the upper part of the rigging to the mast Cat 'head, in naval architecture, a large square piece of timber, one end of which is fastened upon the fore- castle and the other end projects without the bow, so as to keep the anchor clear of the ship when it is being drawn up by a tackle Cathedra, according to Horace, a chair without arms; according to Juvenal, a chair with a long deep seat Cathedral, the principal church of a diocese, in which the bishop's throne is placed Cathedral (the very ancient) of Usum- bar and other Armenian churches in Georgia have an arcade sur- rounding the outside of the build- ing, of which the arches are in the flattened Gothic style: the same form prevails in the windows, doors, &c., in the body of the church. These structures are of an earlier date than any Gothic architecture in Italy Cathedrals. Very few of the Gothic cathedrals on the Continent have the tower or spire springing from the centre of the cross, and resting on four pillars, tobalance the thrusts of the ranges of arches centering there; nor have those of Stras- burgh, Ulm, Vienna, Orleans, or Antwerp. "The distribution of light in a Gothic cathedral is admirably adapted to the grandeur of the edi- fice, and produces that effect which a painter aims at in his picture. At the entrance at the west, the win- dow being placed high, there is a low-toned light on the lower part of the pillars, and a shadow on the pavement, which, as we walk up the nave, graduates into light from the choir. The east window, always the broadest and the highest, pours in a greater body of light than is to be found in any other kind of build- ing. The altar, rather in shadow, surrounded by this strong light, gives additional effect by contrast. The light from the transept win- dows is softened down by painted glass. The small windows, placed high along the aisles, enlighten their roofs, but the lower part of the pillars and floor remain in shadow." Cathedral churches of Great Britain : NAME. Aberdeen, Old . . . Andrew (St.) . . . Asaph (St.) .... ORDER. Secular Canons Do. DATE. 1137 temp. Alex. I. 550 550 COUNTY. Aberdeenshire Fifeshire Flintshire Caernarvonshire Bath Brechin Bristol Canterbury .... Carlisle . . . . . Chester Chichester .... Benedictine Augustine Benedictine Augustine Benedictine SecularCanons 676 1140 1148 616 686 875 1075 Somersetshire Forfar Somersetshire Kent Cumberland Cheshire Sussex 81 CAT CAUTIONS IN CAU NAME. Coventry .... David's (St.) . . . Dornoch Dornoch Dublin, Cathedral of 1 the Holy Trinity J Dumblain .... Dunkeld ORDER. Benedictine Secular Canons Augustine DATE. 1102 577 1170 COUNTY. Warwickshire Pembrokeshire Caithness Sutherland Ireland Perthshire Do. Durham Elgin Benedictine Dominican 990 1233 Durham Moray Elv Benedictine 673 Cambridgeshire Exeter Do 1050 Devonshire Glasgow .... 4ugustine 1270 Renfrewshire Gloucester .... Hereford .... lona Lichfield Lincoln Lindisfarne .... Llandaff Benedictine SecularCanons Secular Canons Benedictine SecularCanons 680 825 656 635 635 635 522 Gloucestershire Herefordshire Argyleshire Staffordshire Lincolnshire Northumberland Glamorganshire Manchester .... Norwich Benedictine 9 Hen. V. 1096 Lancashire Norfolk Oxford . . Augustine 727 Oxfordshire Paul's (St.) .... Peterborough . . . Ripon Do. Benedictine SecularCanons 604 970 Wm. Conq. London Northamptonshire Yorkshire Rochester .... Ross Benedictine 600 Kent Ross-shire Salisbury .... Wells .... SecularCanons 905 766 Wiltshire Somersetshire Whitehorn .... Winchester .... Worcester .... York . Benedictine Do. SecularCanons 963 678 627 Kircudbright Hampshire Worcestershire Yorkshire Catherine-wheel, in architecture, an ornament that occurs in the upper part of the north and south tran- septs of ancient cathedrals Cathetus. The eye of the volute is so termed because its position is determined, in an Ionic or voluted capital, by a line let down from the point in which the volute generates CaVs-paw, a hitch made in a rope Cauliculus, the volute or twist under the flower in the Corinthian capital Caulking, in naval architecture, the art of driving a quantity of oakum, i. e. old ropes untwisted and soft- ened, into the seams of the planks, to keep out the water Gaunter and Counting, in Cornish 82 mining, Contra : when two lodes run across, the one, with respect to the other, is called a counter or contra lode Cautions in Architectural Construc- tion. UNION OF NEW AND OLD WORK. In attaching any new work to a building, every allowance must be made for the sinking of the footings under pressure, and for the settle- ment of the masonry into itself. Thus, while it is necessary that a vertical groove, or indent, be made in the old work, to receive a cor- responding piece of the new, it is still more essential that a freedom CAU CONSTRUCTION. CAU for the downward motion of the latter should be secured: otherwise, if it be tightly toothed and bonded into the old work, the result illus- trated in the annexed sketch may be anticipated. UNION OF ASHLAR FACING WITH BRICK OR RUBBLE BACKING. The same caution required in the latter case must be here equally observed. The backing (composed of small material and much mor- tar) will settle" more than the face; and the latter will consequently bulge. This is easily remedied by computing, and allowing for, the difference of settlement ; and by a due regard to the occasional bond- ing of the ashlar, so as to make the wall one substance, instead of two differently conditioned. The preceding sketch illustrates the consequence of weight pressing upon unbonded ashlar and upon yielding rubble. 83 INVERTED ARCHES. Inverted arches must be used cautiously. Here is an instance, in which the points A and A were prevented by the inverted arch from sinking with the points B B, which latter sunk the more from the pressure of the arch c in the direction of the dotted lines. It is not uncommon for the young architect to affect precautionary science, without a due considera- tion of the peculiar circumstances of his case. DRAINAGE, ETC. Always endeavour, if possible, to get your water-closet cess-pit out- side the building, so that it may be approached for cleansing with- out disturbing the interior. Be careful in the efficient use of dip- draps to prevent the ascent of rats from the outer sewer into the drains which are under the floors of the house. Rats are destructive in their operations, and if they die in the drain, prove, for a length of time, an unbearable nuisance. Drains may serve every purpose of carrying off soil and water; but the slightest opening in their upper part will allow the escape of effluvia into the space under the ground flooring, and thence into the rooms, unless that space be thoroughly ventilated with grated openings, allowing a thorough draught, or, at least, a free ingress of fresh air, and equal egress of foul. In the application of covered dry areas CAU CAUTIONS IN CAU round the excavated basements of buildings, on no account omit their entire ventilation. If this be not attended to, the main walling, which they are intended to preserve from damp, may remain even more continually moist than if in imme- diate connection with the natural ground. Moisture frequently rises up the walling from below its foundation, and, exuding from the face of the masonry, remains con- fined, unless it evaporate and es- cape. Without means to this end, a covered area will be merely a re- ceptacle for damp, and may keep the masonry continually wet, even when the ground outside is per- fectly dry. Be especially cautious that the water from the rain -pipes of the roofs and flats be not conducted by them into the foundations. FIRE OPENINGS. It will save much subsequent trouble and disturbance of masonry, to be assured as to the size and character of the stoves, grates, ranges, &c., which the proprietor will employ. In the kitchen and cooking-rooms, especially, precau- tionary care should be taken in suiting the openings to the intended apparatus. Do not forget to be prepared for a smoke-jack, &c. DWARF WALLS. In constructing these, do not omit the holes, &c., necessary for under-floor ventilation. PAVING. Be careful that the bottom, on which fine paving is laid, be dry and free from staining material. Common lime mortar is often in- jurious to pavements. Portland paving is especially liable to be disfigured by it. WROUGHT STONE-WORK. In putting wrought stone-work together, iron is to be avoided as the certain cause of its subsequent destruction. The stone cornices, architraves, and dressings of many a noble mansion have been brought 84 into premature ruin by the con- traction and expansion of iron under the effects of cold and heat. But there are careless contractors who will allow their Corinthian capitals and fluted shafts to be ruined, even before the entablature surmounts them; and the young architect will not, therefore, omit to insert a clause in his specifica- tion, (and to be peremptory in its enforcement,) that all cut stone- work be securely preserved, during the progress of the building, with wood casing. It is surprising how grossly indifferent each class of artificers is to the work of the others. It is still more surprising to observe how frequently they seem indifferent to the preserva- tion of their own. SLATING. Get rid of the masons and plas- terers and plumbers before your slaters begin. The injury done to slating by the afterwork of chim- ney -tops, &c., is much to be dreaded. The cementitious ' stopping ' to a roof will not be efficiently done without close supervision : the ridge, hip, and valley courses will not be properly formed of large cut slates, nor will every slate have its two nails, unless the architect see to it. PLASTERING. Clear may be your specification in forbidding salt sand, but, if your work be carried on in the vicinity of any estuary, the chances are (unless you be deemed cruelly strict) that the surface of your in- ternal walls will vary with the weather, from damp to dry, like a sea-weed, and throw out salt in abundance. BEAMS, JOISTS, AND OTHER TIMBERS. LINTELS, BOND, PARTITIONS. It is the office of walls to carry beams, &c. ; and that of beams to stay the walls from falling out- wards or inwards : but it is the duty of architects to see that the CAU CONSTRUCTION. CAU wood-work which supplants ma- sonry does not weaken the latter ; i. e. that the ends of timbers in- serted into walls may not, by com- pression or decay, leave the su- perincumbent masonry to loosen downwards. Thus, the beam A, though entering only a portion of ferH the wall, presses upon the thorough- stone e, which throws the weight upon the whole wall, and has, by means of an iron plate c, a hold to secure its perpendicularity. The cover-stone c presses on the surface of the timber to confirm its secu- rity: but should the timber rot, the cover-stone will not sink, be- cause sustained by the side-stones dd. To prevent rot, the backing and side-stones are left free of the timber, so that air may traverse round it. The habit of plac- ing the ends of beams on a template, as G, is bad. The only jus- <* tification of the employment of wood, so built into the walls, is when it forms a continuous plate, that it may act as a bond to pre- serve the perfect horizontal level of joists, which, however, should ex- tend a little beyond the plate, so as to have a bearing also on the solid of the wall. Careful inspection will then so manage the construc- tion of the wall in this part, as to leave it but little weakened by the air-hollows required for the plate 85 and joists; unless, indeed, it be very thin, as only one brick, for instance, when no law of common sense can justify the use of continu- HIM I HI I ous bond. Where joists uninter- ruptedly cross a thin wall, which is to support another story of ma- sonry, let there only be one plate, thin, and on its edge, in the centre of the w r all, so that at least a brick on edge may be placed on each side of it, to fill up the intervals between the joists, and give solid support to the superincumbent ma- sonry. On no account let the upper part of the wall be separated from the lower by a mere layer of perishable wood, or supported by a range of joists on their edge. It has often been seen that iron hoop- ing should be more used than it is as the internal bonding of walls. At the same time, it must be re- membered, that bond timbering is necessary, at intervals, to receive the nails of the battening. When, however, the wall is thin, it may be imperative to "avoid its use, em- ploying old oak bats for that pur- pose. In short, let it be the care of the young architect, so to con- trive the union of his masonry and carpentry, as that the entire re- moval of the latter may leave the former secure in its own strength. In the use of lintels especially, he should be cautious. They are use- ful as bonds to unite the tops of CAU CAUTIONS IN CAU piers, and as means for the fixing of the joinery ; but they ought never to be trusted to as a lasting support of masonry, that support being always really afforded by the relieving segment arch above the lintel. A bressummer may be termed a large lintel ; and by its adoption here, at least, the support of the masonry is truly intended. The use of the bressummer, in shop- front openings, is an evil necessity to which an architect must often submit ; and all that he can do, is to make the best of a bad job, by wrought-iron trussing, which will at least give adequate strength, though it may not insure perma- nent durability. If time spare it, fire may destroy it ; and the latter evil is not to be met even by iron, which, if wrought, will bend, if cast, will crack, with heat. Let the arch, then, or some modifica- tion of it, be always used if pos- sible. Partitions of wood should not be left to the sagacity of the carpenter. Under all circumstances where they have to support themselves over voids, or to bear, or participate in the bearing of, a pressure from above, they should be considered by the architect in his specifica- tion, and carefully studied in making the working drawings. It is not enough merely to say, that " they are to be trussed so as to pre- vent any injury to ceilings by their own pressure ;" marginal sketches 86 should be made, showing the dis- position of the skeleton framing, with whatever iron-work is neces- sary to its security. See, for in- stance, what a carpenter may do, unless well directed: a roof c, bearing partly on the partition A, when it should have borne only on the walls ; and, instead of distress- ing the partition, should have rather held it suspended : the par- tition A bearing down with its own weight, and that of the roof, on the floor B, instead of being so truss-framed in its length as to leave the floor unconscious of its existence. No ignorance in the young architect is presumed as to the manner of doing these things ; he is merely admonished not to imagine that they are so obvious as to be done without his guidance. In the framing of roofs, give a maximum strength to the purlins : the undulating surface of a weakly- purlined roof will soon proclaim its defect in this particular. The po- sition of the principals should not be observable from without. FLOORS ; SIMPLE AND FRAMED, ETC. For permanent and uniform strength, there is no floor so good as one composed of simple joists, stiffened by cross bonding : but, in very large rooms, there is more economy in the compound floor of binders and joists, or of joists, binders, and girders. There may be particular reasons for girders, &c. ; as, when the weight of the floor has to be thrown upon piers, and not on a continuous wall of uniform strength : but the usual motive to the use of the compound floor, in rooms which CAU CONSTRUCTION. CAU exceed 18 or 20 feet in width, is a legitimate economy of materials. It is only necessary to caution the young practitioner on the necessity of considering, that girders have to perform the duty of cross-walls; that they should be trussed to prevent their ' sagging' even with their own weight ; that their scant- ling should allow for the weakening effect of the cuttings made into their substance to receive the tim- bers they support ; that their trusses should be wholly of iron (and not partially of oak) ; and, especially, that the end of each girder, in- stead of being notched on perish- able templates of wood, and closely surrounded with mortar and ma- sonry, should be housed in a cavity with an iron holding -plate; or inserted into a cast-iron boxing, notched into a thorough - stone, leaving a space (however small) for the air to circulate about it, and prevent rot. The failure of a girder sometimes involves the failure of all the rest of the floor ; and, though all timbers inserted in masonry should have a more careful regard to their preservation from decay than it is usual to be- stow, it will be readily admitted, that too much care cannot be given to those leading bearing timbers, without the permanent duration of which the durability of the large remainder is of no avail. ROOFS. The same remarks, applying to the extremities of girders, apply also to tie-beams. CEILINGS. To procure a good ceiling in single-joist floors it is necessary 87 there should be ceiling joists cross- ing below the others : and it is a question whether the ceiling joists, under double-framed floors, instead of being chase-mortised into the binders, should not be in unbroken lengths nailed under the binders. "Where the ceiling joists (as under roofs) are likely to be trodden upon, they must be well secured. SOUND BOARDING. Always consider whether the occupants of any particular room will be annoyed by noises from the rooms below or above. Sound boarding and pugging considerably increase the weight of the floor, the scantling of whose timbers should, therefore, be thought upon. Water- closet partitions should be well pugged. MICE IN PARTITIONS AND SKIRT- INGS. The space behind the skirtings is often a thoroughfare for mice, which also contrive to travel from floor to floor in the hollows of the quarter- partitions, and become in several ways a great nuisance. Plaster or wood stopping is not always so efficacious as the use of broken glass in those secret passages which they are prone to frequent. COVERINGS TO GUTTERS, CISTERNS, ETC. The liability of gutters and cis- terns to become choked with snow, or filled up with leaves, &c., renders it advisable to protect them with a boarded covering, which may pre- serve the under current of water from receiving what may speedily produce a chokage or overflow. IRON COLUMNS, BEAMS, ETC. On this most important subject the young architect should not move a step without carefully con- sulting the experienced knowledge of the engineer. Tredgold's ' Prac- CAV CEILINGS. CEL tical Essay on the Strength of Cast Iron' should be well studied, whenever necessity compels the support of heavy and loaded su- perstructures by iron columns and beams. A careful computation of the weight of the mere building, added to that of its possible bur- then, with allowance for theoretical fallacy, and a due estimate of the increased strength of the hollow pillar, as compared with a solid one having the same amount of metal, must be made, examined, and re-examined, before the speci- fication be issued. Cavadium, one of the courts of a Roman house, most commonly sur- rounded by a covered passage, having the middle area exposed to the air Cavcedia. There are five kinds of cavaedia, which, from their mode of construction, are severally deno- minated Tuscan, Corinthian, tetra- style, displuviatum, and testudi- natum. They are termed Tuscan when the beams which are thrown across the court have timbers and gutters extending diagonally from the angles made by the walls of the court to those made by the junction of the beams, and the rafters of the eaves are made to incline every way towards the centre of the com- pluvium. The timbers and com- pluvia of Corinthian cavaedia have a disposition, in all respects, similar; but beams are made to project from the walls, and are supported upon columns arranged around the court Cavazion, in architecture, the hollow trench made for laying the founda- tion of a building; according to Vitruvius, it ought to be one-sixth part of the height of the whole building Cavetto, a hollow moulding whose profile is a quadrant of a circle ; principally used in cornices Cedar. Cedar wood was known and used in the earliest times, as in the construction of Solomon's Temple: 88 great varieties are produced in the eastern and western parts of the world : it is used in ship-build- ing, cabinet-work, pencil-making, and for various other purposes Ceiling, the upper side of an apart- ment, opposite to the floor, gene- rally finished with plastered work. Ceilings are set in two different ways: the best is where the setting- coat is composed of plaster and putty, commonly called ' gauge.' Common ceilings have plaster, but no hair: the latter is the same as the finishing coat in walls set for paper Ceiling, the under covering of a roof, under the surface of the vaulting in vaulted rooms and buildings. Ceil- ings in buildings of any dimensions at either story are the upper or over- head surfaces of the rooms respect- ively Ceilings. When ceilings are covered, the height of the cove should be regulated by the total height of the room. In proportioning the height of a room to its superficial dimen- sions, the best proportion for the cove is one-quarter of the whole height Celerity is the velocity or swiftness of a body in motion; or that affec- tion of a body in motion by which it can pass over a certain space in a certain time Cell, an enclosed space within the walls of an ancient temple; a term applied also to monkish sleeping- rooms in religious establishments Cella, the body or principal part of a temple, anciently written cela. It is thought to be derived from celandus,to be concealed or shut out from public view ; because in early temples the cella could only be entered by privileged persons Cellarino, that part of the capital in the Roman, Doric, and Tuscan orders which is below the annulets under the ovolo Cementation is the process of con- verting iron into steel, which is done by stratifying bars of iron in CEM CEMENTS. CEM charcoal, igniting it, and letting them continue in a kiln in that state for five or six days : the carhon of the charcoal is thus absorbed by the iron, and the latter converted into steel Cements, natural. When the propor- tion of clay in calcareous minerals exceeds 27 to 30 per cent., it is seldom that they can be converted into lime by calcination ; but they then furnish a kind of natural ce- ment, which may be employed in the same manner as plaster of Paris, by pulverizing it, and knead- ing it with a certain quantity of water. There are some natural cements which do not set in water for many days, and some which harden in less than a quarter of an hour : these last are the only ones which have been made use of at present. Though very useful in circum- stances where a quick solidification is indispensable, they are far from affording, in ordinary cases, the advantages of hydraulic mortars or cements of good quality. In fact, they merely adhere to the stone, owing to the roughness of its sur- face, and the entanglement result- ing from it; and, however dexterous or experienced the workman may be who makes use of them, he will be unable to connect the different parts of his masonry in one conti- nuous bond by means of them. This statement must be understood to apply only to cements which harden while in contact with bricks under water, because the adhesion of such as dry in the open air is well known to be much greater than what would be caused merely by asperities of the surface. It is not uncommon to see from twenty to thirty bricks stuck to one an- other by Roman cement, and pro- jecting at right angles from the side of a wall, as a proof of the excellence of the composition; and an instance has been mentioned in which thirty-three bricks were suc- 89 cessfully supported in this manner. Now, if we assume the weight of a brick and its corresponding joint of cement to be 6 tbs., and their thickness, when the bricks were joined one to another in the man- ner above alluded to (in which the longest dimension of the brick was placed vertically), to be 2 inches, then the cohesive force necessary to unite the first brick to the wall, with sufficient firmness to bear the strain occasioned by the weight of the remaining thirty -two supported by it, must have been nearly 91 fts. per square inch, or equivalent to a direct load of 3640 tbs. upon its whole surface of about 40 square inches. That which is in England very improperly termed Roman cement is nothing more than a natural ce- ment, resulting from a slight calci- nation of a calcareous mineral, containing about 31 per cent, of ochreous clay, and a few hundredths of carbonate of magnesia and man- ganese. A very great consumption of this cement takes place in Lon- don; but its use will infallibly be- come restricted, in proportion as the mortars of eminently hydraulic lime shall become better known, and, in consequence, better appre- ciated. Very recently, natural cements have been found in Russia and in France. They may be composed at once by properly calcining mix- tures made in the average propor- tions of 66 parts of ochreous clay to 100 parts of chalk. It is fair, however, to admit, that no artificial product has yet been proved to equal the English cement in point of hardness. The pure calcareous substances, when imperfectly calcined, be- come converted into sub -carbon- ates, possessed of certain proper- ties. These properties are to afford a powder, which, when kneaded with water in the same way as plaster of Paris, acquires in it, at CEN CENTRE FRAMES. CEN first, a consistency more or less firm, but which does not continue its progress at the same rate. The argillaceous limestones, and the artificial mixtures of pure lime and clay in the proportions requi- site to constitute hydraulic lime by the ordinary calcination, become natural or artificial cements when they have been subjected merely to a simple incandescence, kept up for some hours, or even for some minutes. This result, which has often occurred in the course of first experiments in burning the artificial hydraulic limestones, has been equally observed in Russia by Colonel Raucourt; and M. Lacor- daire, Engineer of Roads, has not only fully verified it with respect to the different argillaceous limestones of the neighbourhood of Pouilly, but has also made a useful and happy application of it in the works which have been erected at the junction of the Burgundy canal ; both in trans- forming these limestones into na- tural cements, and in turning to account the large quantity of half- burnt lime which is found in the upper layers of the kilns, when the intensity and duration of the heat is so regulated as not to exceed the limit proper for the lower strata of the charge. The history of these new cements will not be complete until authentic and multiplied experiments shall have established their power to resist the effects of air and frost, and the degree of adhesion with which they unite to the building- stone Cenotaphium, a cenotaph, an empty or honorary tomb, erected by the Greeks as a memorial of a person whose body was buried elsewhere, or not found for burial Censitores, surveyors of the Roman aqueducts Centaur, poetically, and in ancient mythology, a being represented as half man, half horse ; the Sagitta- rius of the Zodiac 90 Centering, temporary supports, prin- cipally of timber, placed and affixed under vaults and arches to sustain them while they are in course of building. Much ingenuity is dis- played in the centering for bridges and tunnels Centigrade, the division into grades or degrees by hundredth parts ; called alto centesimals Central forces, the powers which cause a moving body to tend to- wards or recede from the centre of motion. When a body is made to revolve in a circle round some fixed point, it will have a continued tendency to fly off in a straight line at a tangent in the circle, which tendency is called the centrifugal force ; and the opposing power by which the body is retained in the circular path is called the centri- petal force Centre, any timber frame, or set of frames, for supporting the arch- stones of a bridge during the con- struction of an arch. The qualities of a good centre consist in its being a sufficient sup- port for the weight or pressure of the arch-stones, without any sen- sible change of form taking place throughout the whole progress of the work, from the springing of the arch to the fixing of the key- stone : it should be capable of being easily and safely removed, and de- signed so that it may be erected at a comparatively small expense. In navigable rivers, where a cer- tain space must be left for the pas- sage of vessels, and in deep and rapid rivers, where it is difficult to establish intermediate supports, and where much is to be appre- hended from sudden floods, the frames should span the whole width of the archway, or be framed so as to leave a considerable portion of the archway unoccupied. In such cases, a considerable degree of art is required to make the centre an effectual support for the arch- stones, particularly when the arch CEN CENTRE-DRILL. CEN is large. But in narrow rivers, and in those where the above-mentioned inconveniences do not interfere with the work, the framing may be constructed upon horizontal tie- beams, supported in several places by piles, or frames fixed in the bed of the river ; and the construction is comparatively easy. In large arches, when the arch- stones are laid to a considerable height, they often force the centre out of form, by causing it to rise at the crown ; and it is sometimes necessary to load the centre at the crown to prevent such rising ; but this is a very imperfect remedy. Notwithstanding the subject has been considered by several very eminent men, their works are not much calculated to instruct the carpenter how to avoid this diffi- culty : indeed, their object seems to have been exclusively to calcu- late the strength of a centre al- ready designed, instead of showing the principles on which it ought to be contrived ; and even in calcu- lating the strength, they are very imperfect guides, because they have not attempted to find what forces would derange a centre, but only the force that might be supported without fracture. Centre, in a general sense, denotes a point equally remote from the ex- tremes of a line, surface, or solid : the word signifies a point Centre-bit, in joinery, an instrument with a projecting conical point nearly in the middle, called the centre of the bit : on the narrow vertical surface, the one most re- mote from the centre, is a tooth with a cutting edge. The under edge of the bit on the other side of the centre has a projecting edge inclined forward. The horizontal section of this bit upwards is a rectangle. The axis of the small cone in the centre is in the same straight line as that of the stock ; the cutting edge of the tooth is more prominent than the projecting 91 edge on the other side of the cen- tre, and the vertex of the conic centre is still more prominent than the cutting edge of the tooth. The use of the centre-bit is to form a cylindric excavation, having the upper point of the axis of the intended hole given on the surface of the wood. The centre of the bit is first fixed in this point ; then, by placing the axis of the stock and bit in the axis of the hole intended to be bored, with the head of the stock against the breast, and by turning the stock swiftly round by means of the handle, the hollow cone made by the centre will cause the point of the tooth to move in the circumference of a circle, and cut the cylindric surface progres- sively as it is turned round, while the projecting edge upon the other side of the centre will cut out the cone in a spiral-formed shaving. Centre-bits are of various sizes, for bores of different diameters. Centre-chuck, a chuck which can be screwed on the mandril of a lathe, and has a hardened steel core or centre fixed in it; also a projecting arm or driver Centre-drill, a small drill used for making a short hole in the ends of a shaft about to be turned, for the entrance of the lathe centres Centre of attraction of a body is that point into which, if all its matter were collected, its action upon any remote particle would still be the same as it is while the body re- tains its own proper form ; or it is that point to which bodies tend by their own gravity, or about which a planet revolves as a centre, being attracted or impelled towards it by the action of gravity. The common centre of attraction of two or more bodies is used to denote that point in which, if a particle of matter were placed, the action of each body upon it would be equal, and where it will remain in equilibrium, having no tendency to move one way rather than another CEN CENTRES. CEN Centre of a circle, that point in a circle which is equally distant from every point of the circumference, being that from which the circle is described Centre of a conic section, that point which bisects any diameter, or that point in which all the diameters intersect each other. This point in an ellipse is within the figure, in the hyperbola without, and in the parabola it is at an infinite dis- tance Centre of conversion, a mechanical term, the signification of which may be thus conceived: if a stick be laid on stagnant water, and drawn by a thread fastened to it, so that the thread makes always the same angle with it, the stick will be found to turn about a certain point; which point is called the ' centre of conversion ' Centre of a curve of the higher kind, is the point where two diameters concur; and when all the diameters concur in the same point, it is called the general centre Centre of a dial, that point where the gnomon or style, placed par- allel to the axis of the earth, inter- sects the plane of the dial Centre of an equilibrium is the same with respect to bodies immersed in a fluid as the centre of gravity is to bodies in free space, or it is a certain point on which, if a body, or system of bodies, be suspended, they will rest in any position Centre of friction is that point in the base of a body on which it revolves, in which, if the whole surface of the base and the mass of the body were collected and made to revolve about the centre of the base of the given body, the angular velocity destroyed by its friction would be equal to the angular velocity de- stroyed in the given body by its friction in the same time Centre of gravity of any body, or sys- tem of bodies, is that point upon which the body or system of bodies acted upon only by the force of 92 gravity will balance itself in all positions ; or it is a point on which, when supported, the body or sys- tem will be supported, however it may be situated in other respects. Hence it follows, that if a line or plane passing through the centre of gravity be supported, the body or system will also be supported ; and conversely, if a body or system balance itself upon a line or plane, in all positions, the centre of gravity is in that line or plane. In a simi- lar manner it will appear, that if a body rest in equilibrio when sus- pended from any point v the centre of gravity of that body or system is in the perpendicular let fall from the centre of suspension; and on these principles depends the me- chanical method of finding the cen- tre of gravity of bodies Centre of gyration, that point in a body revolving on an axis, into which, if the matter of the whole body were collected, the same an- gular velocity would be generated by the same moving force Centre of motion of a body is a fixed point about which the body is moved ; and the axis of motion is the fixed axis about which it moves Centre of oscillation, the point in which the whole of the matter must be collected, in order that the time of oscillation may be the same as when it is distributed Centre of percussion, that point of a revolving body which would strike an obstacle with the same force as if the whole of the matter were collected in it Centre of position, in mechanics, de- notes a point of any body, or system of bodies, so selected that we may properly estimate the situation and motion of the body or system by those points Centre of pressure, or meta centre of a fluid against a plane, is that point against which a force being applied, equal and contrary to the whole pressure, it will sustain it, so as that the body pressed on will not CEN CHAINS. CHA incline to either side. This is the same as the centre of percussion, supposing the axis of motion to be at the intersection of this plane with the surface of the fluid ; and the centre of pressure upon a plane parallel to the horizon, or upon any plane where the pressure is uniform, is the same as the centre of gravity of that plane Centre of spontaneous rotation, that point which remains at rest the in- stant a body is struck, or about which the body begins to revolve. If a body of any size or form, after rotatory or gyratory motions, be left entirely to itself, it will always have three principal axes of rota- tion; that is, all the rotary motions by which it is effected may be con- stantly reduced to three, which are performed round three axes per- pendicular to each other, passing through the centre of gravity, and always preserving the same position in absolute space, while the centre of gravity is at rest, or moves uni- formly forward in a right line Centre phonic, in acoustics, the place where the speaker stands in making polysyllabical and articulate echoes Centre phonocamptic, the place or object which returns the voice Centre-punch, a small piece of steel with a hardened point at one end Centres, in turnery, are the two cones with their axes horizontally posited for sustaining the body while it is turned Centre-velic or Velic-point, the centre of gravity of an equivalent sail, or that single sail whose position and magnitude are such as cause it to be acted upon by the wind when the vessel is sailing, so that the motion shall be the same as that which takes place while the sails have their usual positions Centrifugal force is that force by which a body revolving about a centre, or about another body, has a tendency to recede from it Centrifugal pump, a.ma.cl\ine for raising 93 water by centrifugal force combined with the pressure of the atmo- sphere Centripetal force is that force by which a body is perpetually urged onwards to a centre, and thereby made to revolve in a curve instead of a right line Cerium, a metal discovered in 1803 by Berzelius, and named after the planet Ceres. It is brittle, white, and volatile in a very intense heat : it is not acted upon by nitric acid, but is dissolved in aqua regia, nitro- hydrochloric acid Chain, in surveying, is a lineal mea- sure, consisting of a certain number of iron links, usually 100, serving to take the dimensions of fields, &c.: at every tenth link is usually fas- tened a small brass plate, with a figure engraved upon it, or else cut into different shapes, to show how many links it is from one end of the chain Chains, strong links or plates of iron, the lower ends of which are bolted through a ship's side to the tim- bers Chain-plates, plates of iron bolted to the side of a ship, to which the chains and dead-eyes of the lower rigging are connected Chain-pump, an hydraulic machine for raising water. It is made of dif- ferent lengths, and consists of two collateral square barrels and an endless chain of pistons of the same form, fixed at proper dis- tances Chain-timber, in brick-building, a tim- ber of large dimensions placed in the middle of the height of a story, for imparting strength Chairs. Anciently, in most apart- ments we find "two great chayers :" these were arm-chairs, with stuffed backs and sides, entirely covered, and similar to the lounging-chairs of the present day. Others are de- scribed as ' Flemish chairs/ ' scrolled chairs,' and ' turned chairs,' wrought in ebony, walnut, cherry-tree, c., with high backs, either stuffed in CHA CHANTING. CHA one long upright panel, or filled with wicker-work, &c. Chalcedony, a precious stone, in colour like a carbuncle; by some translated from the Scriptures as ' emerald' Chalcidicum, among the Romans, a large, low, and deep porch, covered with its own roof, supported on pi- lasters, and appended to the en- trance-front of a building, where it protected the principal doorway, and formed a grand entrance to the whole edifice Chalcidria, chambers attached to a basilica ; they were built at one end when the situation would admit of it Chalice, the cup used for the wine at the celebration of the Eucharist Chalk, in geology, forms the higher part of the series or group termed cretaceous: it is composed of nearly 44 parts of carbonic acid and 56 parts of lime Chambers, according to Palladio, are made either arched or with a flat ceiling : if in the last way, the height from the floor to the joists above ought to be equal to their breadth; and the chambers of the second story must be a sixth part less than them in height Chamfer. An edge or arris, taken off equally on the two sides which form it, leaves what is called a chamfer, or a chamfered edge. If the arris be taken off more on one side than the other, it is said to be splayed or bevelled Chamfering, the process of cutting the edge or the end of any thing bevel or aslope Champ, the flat surface of a wall Champe, the field or ground on which carving is raised Champ de Mars : in French history, the public assemblies of the Franks are said to have been held in an open field, and in the month of March ; whence the name Chancel, the choir or eastern part of a church appropriated to the use of those who officiate in the perform- ance of the services, and separated 94 from the nave and other portions in which the congregation assemble, sometimes by a screen Channel, in hydrography, the deepest part of a river, harbour, or strait, which is most convenient for the track of shipping; also an arm of the sea running between an island and the main, or continent, as the British Channel, &c. Channels, broad pieces of plank bolted edgewise to the outside of a vessel, used for spreading the lower rigging Chant, Chanting. The word ' chant' is derived from the Latin Cantus, which signifies singing ; a song, a tune, or melody, the sound of a trumpet, crowing of a cock (whence this bird is called 'chanticleer'): it also signifies the frequent repe- tition of the same thing. The word chant is not confined to merely a melody consisting of several notes; it may consist of one only : in this case it is called, in church music, ' intonation,' although in Gregorian music the word intonation has a somewhat different signification. (See Gregorian Chant.} Hence chanting is reciting in a musical tone, and is peculiarly adapted to a dignified utterance of the sublime language of the Liturgy. Chant- ing or intoning on a monotone, or single sound, is the simplest and easist method of reading and re- sponding the various prayers, ex- hortations, litanies, suffrages, Kyrie eliesons, Allelujahs, Gloria Patri, and the Amens, and is eminently more dignified and solemn than when there is neither elevation nor depression of the voice at any one termination. In chanting the greater and lesser Canticles, the Te Deum, Jubilate, Benedicite, Benedictus, Athanasian Creed, Ve- nite exultemus, Magnificat, Can- tate Domino, Nunc dimittis, Deus misereatur,as also the prose Psalms, the chant may consist of more than one tone, although it is prefer- able to use a small number. The method of chanting the Psalter in CHA CHEMISTRY. CHE the English church is different from that adopted on the Continent, where it appears to be governed by no rule ; whereas the Gregorian chant is governed entirely by rule Chant late, in building, a piece of wood fastened nearthe ends of the rafters, and projecting beyond the wall, to support two or three rows of tiles, so placed to hinder the rain-water from trickling down the sides of the walls Chantry, an ecclesiastical benefice or endowment to provide for the chant- ing of masses Chapel, a small building attached an- ciently to various parts of large churches or cathedrals, and sepa- rately dedicated; also a detached building for divine sendee : in Eng- land, chapels are sometimes called chapels of ease, built for the accom- modation of an increasing popu- lation j Chapetting, wearing a ship round, when taken aback, without bracing the head-yards Chapiter, the capital of a column Chaplet, in architecture, a small orna- ment carved into round beads, &c. Chaps, the two planes or flat parts of a vice or pair of tongs or pliers, for holding any thing fast, and which are generally roughed with teeth Chapter-house, an establishment for Deans and Prebendaries of cathe- drals and collegiate churches ; the apartment or hall in which the monks and canons of a monastic establishment conduct their affairs connected with ecclesiastical regu- lations Char or Chare, to hew, to work charred stone ; hewn stone Character, in a picture, is giving to the different objects their appropriate and distinguishing appearance Charcoal consists mainly of carbon procured from the decomposition of wood by burning. This ope- ration is generally conducted in pits made in the ground, and in iron cylinders. Wood is essentially composed of carbon, oxygen, and 95 hydrogen. Charcoal has the same properties : it is black, lighter than water, and full of pores, occasioned by the expulsion of the bodies vola- tilized Charge, in electricity, is the accumu- lation of the electric matter on one surface of an electric, as a pane of glass, Leyden phial, &c., whilst an equal quantity passes off from the opposite surface Charge, in mining: any quantity of ore put at one time into a furnace to fuse is called a ' charge ;' letting it out is called ' tapping' Chargers, large dishes, sometimes de- scribed as ' flat pieces ' Cheeks, the shears or bed of the lathe as made with two pieces for con- ducting the puppets Cheeks, the projection on each side of a mast, upon which the trestle- trees rest ; the sides of the sheet of a block Cheerly, quickly ; with a will Chemistry. The science of chemistry has for its object the study of the nature and properties of the dif- ferent substances of which the earth, the waters, the air, and their inhabitants, (namely, plants and animals,) are composed. In a word, it embraces the study of every thing under heaven accessible to man. In its highest branches it aims at discovering the laws or rules which regulate the formation of chemical compounds generally ; and in its useful applications it has been already exceedingly service- able in directing and improving the various arts of common life, as . agriculture, the working of metals, dyeing, and many other pursuits. It serves also to guide the medical man in the preparation of his re- medies, and also occasionally in distinguishing between diseases which are in other respects much alike. There is, indeed, scarcely a situation in life in which a know- ledge of chemistry may not prove directly useful. It is a science the study of which, from its simplest CHE CHIMES. CHI beginnings to its highest attempts, is rendered delightful by the con- stant succession of new and inter- esting things brought before the eye and the mind. Cherry-tree, a hard, close-grained wood, of a pale red-brown colour : when stained with lime, and oiled and varnished, it resembles maho- gany, and is used for furniture, &c. Chess-trees, pieces of oak fitted to the sides of a vessel, abaft the fore- chains, with a sheave in them, to board the main-tack to ; not much used Chest, a piece of furniture for the re- ception of all kinds of goods, parti- cularly household conveniences, de- posited therein for security, and for plate ; placed also in churches, for the keeping of the holy vessels, vest- ments, &c.: the seaman's chest con- tains all the personalities of a sailor. Coffers and chests were the general repositories for articles of every kind ; writings, apparel, food, and even fuel, were kept within them. Many of these chests, which were raised on feet to protect them from damp and vermin, were beau- tifully ornamented with carving and other sumptuous enrichments. Large trunks, in which clothes, hangings, &c., were packed for removal, were called ' Trussing Chests :' they were substantially made, and bound in every direction with iron straps, wrought into fan- ciful forms, and secured by locks of artful and curious contrivance. Two " standard chests " were de- livered to the laundress of King Henry VIII. ; "the one to keep the cleane stuff, and the other to keep the stuff that had been occupied." " In ivory coffers," says Grameo, "I have stuffed my crowns ; in cypress chests, my arras, counter-points, &c." Cypress wood was selected for its rare properties of neither rotting nor becoming worm-eaten. Chestnut wood is very durable, and was formerly much used in house carpentry and furniture 96 Cheval defrise, a square or octagonal beam of wood, from 6 to 9 feet in length, and pierced by iron rods or wooden pickets 6 feet long, which are pointed at each end, and shod with iron : the pickets are placed 6 inches asunder, and pass through two opposite faces of the beam, in directions alternately at right angles to each other, the cheval resting on the ground at the lower extremity of the pickets Chevet, the termination of a church behind the high altar, when of a semicircular or polygonal form Chevron, a moulding of a zig-zag cha- racter, of the Norman style parti- cularly, but sometimes to be found with the pointed arch Chiaro-oscuro, a drawing made in two colours, black and white ; also the art of advantageously distributing the lights and shadows which ought to appear in a picture, as well for the repose and satisfaction of the eye as for the effect of the whole together Chiliad, an assemblage of several things ranged by thousands; applied also to tables of logarithms, which were at first divided into thou- sands Chiliaedron, a solid figure of a thou- sand faces Chiliagon, in geometry, a regular plane figure of a thousand sides and angles Chimes, a set of bells tuned to the modern musical scale, and struck by hammers acted on by a pinned cylinder, or barrel, which revolves by means of clock-work : also ap- plied to the music or tune p duced by mechanical means from the bells in a steeple, tower, or common clock Chimney, in locomotive engines. The chimney is regulated in size for each engine so as to act in union with the blast-pipe, to produce a proper blast on the fire. This is done by each exhaust of steam from the cylinders creating a partial vacuum in the chimney ; hence a cm CHISELS. CHI rush of air takes place through the fire and tubes to fill this vacuum ; and these successive rushes of air ' blow the fire.' This vacuum ranges from 2 to 8 inches of a water-gauge. The mild blast produces the least vacuum and the least consumption of fuel Chimney-pieces. The Egyptians, the Greeks, and the Romans, to whom architecture is so much indebted in other respects, living in warm cli- mates, where fires in the apart- ments were seldom necessary, have thrown but little light on this branch of the science. Palladio only men- tions two which stood in the mid- dle of the rooms, and consisted of columns, supporting architraves, whereon were placed the pyramids or funnels through which the smoke was conveyed. Scamozzi mentions only three in his time, placed simi- larly. In England, Inigo Jones designed some very elaborate chim- ney-pieces. The size of the chim- ney must depend upon the dimen- sions of the room wherein it is placed : the chimney should always be situated so as to be immediately seen by those who enter : the mid- dle of the side partition wall is the best place in halls, saloons, and other rooms of passage to which the principal entrances are com- monly in the middle of the front or of the back wall ; but in drawing- rooms, dressing-rooms, &c., the middle of the back wall is the best situation ; the chimney being then farthest removed from the doors of communication Chinese architecture, & style peculiar to China, where the material employed is principally wood. It is a style not congenial to English taste or climate : its monstrosity may be seen at Brighton Chinese Yellow (colour), a very bright sulphuret of arsenic, brought from China Chime, to thrust oakum into seams with a small iron Chisel, a tool with the lower part in 97 the form of a wedge, for cutting iron plate or bar, and with the upper part flat, to receive the blows of a hammer, in order to force the cutting edge through the substance of the iron Chisel, an instrument used by car- penters. The large chisels used by millwrights for heavy work are ge- nerally composed of iron and steel welded together. Chisels are also employed in turning, and they are driven more or less by blows : those used by the joiner are similar ; but those used by cabinet-makers are straight across the end Chisels in general. A chisel is an edge tool for cutting wood, either by leaning on it or by striking it with a mallet. The lower part of the chisel is the frustrum of a cuneus or wedge ; the cutting edge is al- ways on and generally at right angles to the side. The basil is ground entirely from one side. The two sides taper in a small de- gree upwards, but the two narrow surfaces taper downwards in a greater degree. The upper part of the iron has a shoulder, which is a plane surface at right angles to the middle line of the chisel. From this plane surface rises a prong in the form of a square pyramid, the middle line of which is the same as the middle line of the cuneus or wedge : the prong is inserted and fixed in a socket of a piece of wood of the same form : this piece of wood is called the handle, and is generally the frustrum of an octa- gonal pyramid, the middle line of which is the same as that of the chisel : the tapering sides of the handle diminish downwards, and terminate upwards in an octagonal dome. The use of the shoulder is for preventing the prong from split- ting the handle while being struck with the mallet. The chisel is made stronger from the cutting edge to the shoulder, as it is some- times used as a lever, the prop being at or very near the middle, CHI CHOCOLATE LEAD. CHO the power at the handle, and the resistance at the cutting-edge. Some chisels are made with iron on one side and steel on the other, and others consist entirely of steel. There are several kinds of chisels, as the mortise-chisel, the ripping-chisel, and the socket- chisel Chisel, the firmer, is formed in the lower part similar to the socket- chisel; but each of the edges above the prismoidal part falls into an equal concavity, and diminishes upwards until the substance of the metal between the concave narrow surfaces becomes equal in thickness to the substance of that between the other two sides, produced in a straight line, and meeting a protu- berance projecting equally on each side. The firmer chisel is used by carpenters and joiners in cutting away the superfluous wood by thin chips : the best are made of cast steel. When there is a great deal of superfluous wood to be cut away, sometimes a stronger chisel, consist- ing of an iron back and steel face, is first used, by driving it into the wood with a mallet ; and then a slighter one, consisting entirely of steel sharpened to a very fine edge, is used in the finish. The first used is called a firmer, and the last a paring chisel, in the application of which only the shoulder or hand is employed in forcing it into the wood Chisel, the mortise, is made exceed- ingly strong, for cutting out a rectangular prismatic cavity across the fibres, quite through or very deep in a piece of wood, for the purpose of inserting a rectangular pin of the same form on the end of another piece, and thereby uniting the two. The cavity is called a mortise, and the pin inserted, a tenon ; and the chisel used for cut- ting out the cavity is, therefore, called a mortise-chisel. As the thickness of this chisel from the face to the back is great, in order 98 to withstand the percussive force of the mallet, and as the angle which the basil makes with the face is about 25, the slant dimen- sion of the basil is very great. This chisel is only used by percussive force given by the mallet Chisel, the ripping, is only an old socket-chisel used in cutting holes in walls for inserting plugs, and for separating wood that has been nailed together, &c. ' Chisel, the socket, is used for cutting excavations : the lower part is a prismoid, the sides of \vhich taper in a small degree upwards, and the edges considerably downwards: one side consists of steel, and the other of iron. The under end is ground into the form of a wedge, forming the basil on the iron side, and the cutting edge on the lower end of the steel face. From the upper end of the prismoidal part rises the frustrum of a hollow cone, increasing in diameter upwards : the cavity or socket contains a handle of wood of the same conic form: the axis of the handle, the hollow cone, and the middle line of the frustrum, are all in the same straight line. The socket-chisel, which is commonly about 1 or H inch broad, is chiefly used in cutting mortises, and may be said to be the same as the mor- tise-chisel employed in joinery Chisel, in turnery, a flat tool, skewed in a small degree at the end, and bevelled from each side, so as to make the cutting edge in the mid- dle of its thickness Chock, in navigation, a wedge used to secure any thing with, or for any thing to rest upon. The long-boat rests upon two large chocks when it is stowed Chocolate lead, a pigment prepared by calcinating oxide of lead with about a third of that of copper, and reducing the compound to a uniform tint by levigation Choke. An adit is said to be choked when any earth or stone falls in and prevents the current of water CHO CHRONOMETRICAL GOVERNOR. CHR through it : the place or part so filled is called ' the choke ' Chopping block, a block of wood used for reducing bricks to their intended form by axing them : it is made of any chance piece that can be ob- tained, and commonly from 6 to 8 inches square, supported generally upon two 14-inch brick piers, if two men are to work at it ; but if four men, the chopping-block must be lengthened and supported by three piers, and so on, according to the number : it is about 2 feet 3 inches in height Choragic monuments, in Grecian story, monuments in honour of those who had gained a prize as choragus, or leader of the play and choruses Choragic monument (the) of Lysicra- tes, known as the Lantern of De- mosthenes, was built in the lllth Olympiad, and is still entire : it is considered the most exquisite and perfect specimen of the orders Choragic monument of Thrasycles, &c., now the church of our Lady of the Grotto. It is built against the rock of the Acropolis : above it stand two columns, on which tripods have been placed, and on each side of it the rock has been chiseled away in such form as evidently shows that similar buildings had been erected contiguous to it Chord, in geometry, is the right line joining the extremities of any arc of a circle Chorobates (Greek), an instrument for determining the slope of an aqueduct, and the levels of the country through which it was to pass. It differed but slightly from a common carpenter's level, which consists of a straight rule support- ing a perpendicular piece, against which hangs a plumb-line Chorography, the art of making a map of a particular country or province, or of teaching geography Chromatics, a division of the science of optics, by which the properties of the colours of light and of na- tural bodies are illustrated 99 Chromascope, or optical chromatics : there are three species of optical effects of colours, that of refrac- tion of prisms and lenses, that of the transmission of light through transparent media, and that of the reflection of specula, &c. Chromate of mercury is improperly classed as a red with vermillion ; for though it is of a bright ochreous red colour in powder, it is, when ground, of a bright orange ochre hue, and affords, with white, very pure orange-coloured tints Chromatics, the science of the rela- tions of light, shade, and colours Chrome greens are compound pig- ments of which chrome yellow is the principal colouring substance Chrome orange is a beautiful orange pigment, and one of the most durable and least exceptionable chrornates of lead, but not of iron Chrome yellow is a pigment of modern introduction into general use, and of which there are many varieties, mostly chromates of lead, in which the latter metalmore or less abounds. They are distinguished by the pure- ness, beauty, and brilliancy of their colours, which qualities are great temptations to their use in the hands of the painter; they are, however, far from unexceptionable pigments Chromium, a very rare metal, found either in the form of chrbmate of lead or chromate of iron Chronometer, a time-keeper, used for determining the longitude at sea, and for other purposes where great accuracy is required Chronometrical governor, an improved regulator for rendering the mean velocity of an engine uniform. The mechanism is as follows : a spindle placed vertically has a pulley fixed upon the top, to receive motion from the crank-shaft ; below the pulley two bevel- wheels of equal diameters are placed face to face ; the upper wheel is fixed to the spindle, and the lower one is free to turn upon it, and has an arm or crank attached CHR CHURCH MUSIC. CHU to its under side, to act as a driver for the pendulous ball : between the two wheels, and communicating with them, is a third wheel, fixed upon a spindle placed horizontally, and connected at one end to the vertical spindle, so as to turn round it; the other end is supported by a carriage resting upon a plate, and is connected to a spring or counter- weight on one side, and on the other side to the throttle-valve; the ball being suspended from a spherical bearing near the top of the rod. The spring is adjusted so that when the velocity of the engine is as required, the upper and lower wheels revolve at the same speed : when the velocity increases, the centrifugal force causes the ball to rise, and retards the motion of the lower wheel; then the inter- mediate wheel distends the spring, and moves forward upon the lower wheel as a rack, and closes the throttle-valve : when the velocity diminishes, the ball falls, and the lower wheel requires less power, so that the spring pulls back the inter- mediate wheel and opens the valve. The above is a modification of Mr. James Wood's governor, and is pa- tented by Mr. C. W. Siemans j Chrysolite, a precious stone, probably the tenth on the high priest's pec- toral, bearing the name of Zebulon : it is transparent, the colour of gold, with a mixture of green, which dis- plays a fine lustre Chuck, a piece of wood or metal fixed on the end of the mandril for keep- ing fast the body to be turned Church Music. By this term is com- monly understood all music set to words of a sacred character: hence we have not only the language of Scripture set to music in the shape of anthems, &c., but also metrical versions and paraphrases thereof, used and considered by many as church music. Indeed it too often happens that these are adapted to secular melodies melodies not ori- ginally intended to be applied to 100 words of a sacred character, and yet the music is then termed sacred, probably from an idea that there is no such thing as sacred and profane music. But this is a great error, and arises solely from ignorance of the existence of sacred music, we mean especially church music. Ex- amine any of the ancient authorized liturgical books, and there will be found an order of music that can- not be mistaken for profane, which is not only sacred in its character, but eminently grand, dignified, noble, and sublime ; in short, it is for church purposes so superior to all other music, that it alone can properly be called church music. Church music is the music of the holy offices, is that music in which the whole church, priests andpeople, can participate. It is easy to exe- cute, being simple and plain (plain chant). It can be sung by every one, and is always most majestic when sung by all; hence it is also called the full chant (cantus ple- nus). For a long period, and until very lately, scarcely a remnant of church music was to be found, eveu in those places where we had a right to expect to find it : the plain chant was banished entirely in some places, and mutilated in others, so that it could scarcely be discerned; but it is now being restored, and we hear the priest intoning his part in the offices of morning and evening prayer, and the people singing, in response, the ancient authorized melodies of the church ; we hear the Psalter chanted to fine old (so called) Gregorian tones ; we hear the Litany chanted to its own proper music, that of the church : we also hear the soul-stirring music in the Communion office, the Gloria in ex- celsis, the Credo, and Sanctus ; the latter moreover in its proper place. We can have also, if so disposed, the church music for the matri- monial, baptismal, and burial offices, as well as an immense variety of tunes for the metrical psalms, of a CHU CIRCLE. CIN true church character, unlike any other kind of music, and which is truly church music, inasmuch as it is the church's peculiar property, and would he totally misused in any other place. Our definition of church music is, music which is adapted for the services and pur- poses of the church, and unfit for any other place or purpose. Church music, such as is here shortly defined, is unisonous ; and harmonized music is not fit for congregational purposes; it is pro- per only in those parts of divine worship which may be called extra- liturgical, such as the anthem. Singing harmonized chants, canti- cles, Te Deum, &c., is thrusting out the congregation, that is, the chief part of the church present. The harmonies should be left entirely to the discretion of an intelligent organist, to be executed on the organ alone. Harmonized music requires accomplished and well- informed musicians for its perform- ance, and can be sung only by the few. The anthem, in cathedral worship, is edifying only when it is performed by the choir-men in a masterly manner, not only with correct musical execution, but with care and attention, to develop all the piety, sublimity, grandeur, dig- nity, and whatever else the music is capable of. Before the latter half of the 15th century, the liturgy was chanted in unison ; and it is from this period we can trace the gradual departure from the rigid church style of music, in the compositions of Josquin de Pres especially. In the early part of the 16th century, we find that Adrian Willaert, who was made sing- ing-master at St. Mark's, Venice, was the first who harmonized the psalm melodies for two or more choirs; then followed the motet, or harmonized antiphon, which before had been chanted in unison, as it is done at this day in the Romish chapels in England, where there 101 are not accomplished singing men to perform the motet. During this century, the use of harmony had not only driven the people away from their part in the performance of the service, but also corrupted the music itself so much, that it was only saved from being wholly forbidden by the grave and devo- tional motets and other compo- sitions of the renowned Palestrina, whose works were imitated with great success by the disciples of his school, and this in a very eminent degree by the English church mu- sicians. The harmonies used by Tallis, Morley, Gibbons, and the rest of the masters of church music of this age, are truly sublime Church ornament consists principally of the painted and stained glass windows of the emblem of the Trinity, of the passion of our Lord, of the evangelists, sacred mono- grams, statues of the holy apostles, of the holy evangelists, and of the saints commemorated by the church Church in rotundo, that whose plan is a perfect circle, in imitation of the Pantheon Chymol, a hinge, anciently called a grimmer Ciborwm, an arch supported by four pillars placed over the high altar Cilery, in architecture, the drapery or leavage that is wrought upon the heads of pillars Cimellare, the vestry or room where plate, vestments, and other rich things belonging to the church are kept Cincture, a ring, list, or fillet at the top and bottom of a column, serving to divide the shaft from the capi- tal and its base Cinder-frame, in locomotive engines, a wire-work frame placed in front of the tubes, to arrest the ascent of large pieces of ignited coke Cinque-foil, an ornamental foliation or feathering, used in the arches of the lights and tracery of windows, panellings, &c. Cinque Ports, the sea-port towns of CIP CITRINE COLOUR. CIT Dover, Sandwich, Hastings, Hythe, and Romney, to which three others were afterwards added, viz. Win- chelsea, Rye, and Seaford. These towns possess peculiar privileges, and are under the government of a Lord Warden Cipher, a secret mode of writing Cippus (Latin), a low column, some- times round, but more frequently rectangular, used as a sepulchral monument Circinus, a pair of compasses. Those used by statuaries, architects, ma- sons, carpenters, &c., were often represented on their tombs Circinus, according to Vitruvius, a pair of compasses employed by archi- tects, carpenters, &c., for describing circles, measuring distances, and taking the thickness of solids Circle, a plain figure contained by one line, which is called the cir- cumference, and is such that all straight lines drawn from a certain point within the figure to the cir- cumference are equalto one another, and this point is called the centre of the circle The circumference of a circle is known to be about 3'14159 times its diameter, or, in other words, the ratio of the circumference to the diameter is represented by 3*14159: for this number writers generally put the Greek letter TT Circular saw. Circular saws, revolv- ing upon an axis, have the advantage that they act continually in the same direction, and no force is lost by a backward stroke: they are also susceptible of much greater ve- locity than the reciprocating saws, an advantage which enables them to cut more smoothly : used prin- cipally for cutting mahogany for veneering, and for other woods cut into thin layers Circus, an area used by the Romans for chariot-races and horse-races, and for other public sports Cissoid of Diocles, in the higher geo- metry, a curve line of the second order 102 Cistern. There were cisterns through- out Palestine, in cities and in pri- vate houses. As the cities were mostly built on mountains, and the rains fall in Judea at two seasons only (spring and autumn), people were obliged to keep water in ves- sels. There are cisterns of very large dimensions at this day in Palestine. Near Bethlehem are the cisterns or pools of Solomon: they are three in number, situated in the sloping hollow of a mountain, one above another, so that the waters of the uppermost descend into the second, and those of the second descend into the third. The breadth is nearly the same in all, between 80 and 90 paces, but the length varies : the first is about 160 paces long; the second, 200; the third, 220. These pools formerly supplied the town of Bethlehem and the city of Jeru- salem with water. Wells and cis- terns, fountains and springs, are sel- dom correctly described in Scripture Cistern, in the steam engine, the ves- sel which surrounds the condenser, and contains the injection water Cisterna, an artificial tank or reser- voir, sunk in the ground and covered in with a roof, for the purpose of collecting and preserving good water for the use of a household. Near the baths of Titus are nine subter- raneous cisterns, 17i feet wide, 12 feet high, and above 137 feet long Citrine, or the colour of the citron, is the first of the tertiary class of colours, or ultimate compounds of the primary triad, yellow, red, and blue, in which yellow is the archeus or predominating colour, and blue the extreme subordinate ; for ci- trine being an immediate compound of the secondaries, orange and green, of both which yellow is a constituent, the latter colour is of double occurrence therein, while the other two primaries enter singly into the composition of citrine ; its mean or middle hue comprehending eight blue, five red, and six yellow, of equal intensities CLA CLASSIC ORDERS. CLI Citrine lake is a durable and better drying species of brown pink, pre- pared from the quercitron bark Clack, the valve of a pump piston ; | the can-lead, in Derbyshire Clacks, in locomotive engines, the complete valves of the pumps where the ball-valve is enclosed in a frame or cage, to limit its rise, and guide its fall into the steam-tight seat of the orifice of the pipe Clack-box, in locomotive engines, the box fitted on to the boiler where a ball-clack is placed, to close the orifice of the feed-pipe, and pre- vent steam or hot water reaching the pumps. The ball of the clack is raised from its seat by the stroke of the pump-plunger forcing the water against it, and which water then passes into the boiler, while the instant fall of the ball prevents egress from the boiler Clack-door, a square iron plate screwed on to the side of a bottom-pump, or small bore for convenience of changing the clack or valve Clack-seats, in locomotive engines, two recesses in each pump, for the clacks to fit into Clack-valve, in the steam engine, a flat valve in the cold-water pump, with a hinge joint Clamp, a kiln built above the ground, for the purpose of burning bricks in Clamp, a piece of wood fixed to the end of a board by mortise and tenon, or by groove and tongue, so that the fibres of the one piece, thus fixed, traverse those of the board, and by this means prevent it from casting : the piece at the end is called a clamp, and the board is said to be clamped Clamps, in naval architecture, thick planks in a ship's side, which sup- port the ends of the beams Clamping, in joinery: when a piece of board is fitted with the grain to the end of another piece of board across the grain, the first board is said to be clamped Clamp-nails, used to fasten on clamps in the building of ships 103 Classic orders, in architecture : of these there are but three, the Doric, Ionic, and Corinthian : two others, the Tuscan and Composite, are often improperly classed with them, and the whole denominated ' the five orders of architecture.' For the proportions of the respective orders, see the Synopsis, p. 26 Cleading,in locomotive engines,is usu- ally made of narrow strips of tim- ber, neatly fitted round the boiler and fire-box, to prevent the radi- ation of the heat. Externally, this is sometimes covered with zinc, and a coating of dry hair felt is com- monly placed between the boiler andthetimber, for the same purpose Clearing the deads, a term for clearing a shaft or drift, &c. Cleat, a piece of wood used in different parts of a vessel to belay ropes to Cleavage, in geology, is an indicator of peculiar fossility in certain rocks, which is independent of, and meets at a considerable angle, the surfaces of lamination or deposition. Clay slate furnishes the best examples of this phenomenon Cleithral, a covered Greek temple Cleithros, an enclosed place; a temple whose roof covers or encloses it Clerestory, an upper story or row of windows in a Gothic church, rising clear above the adjoining parts of the building Clew, the lower corner of square-sails, and the after corner of a fore-and- aft sail Clew-garnet, a rope for hauling up the clew of a fore-sail or main-sail in a square-rigged vessel Clew-line, a rope for hauling up the clew of a square-sail : the clew- garnite is the clew-line of a course Clicket, a latch-key; the latch of a door Clinch, in navigation, the great ring connected with the mooring-chains Clinch, a half -hitch stopped to its own part Clinker-bar, in steam engines, the bar fixed across the top of the ash-pit for supporting the rods used for clearing the fire bars COAL. COA Clinkers, bricks which, by the vio- lence of the fire, are run together and glazed over Clinkers, hard bricks imported from Holland Cloaca, a common sewer. The term cloaca is generally used in reference to those spacious subterraneous vaults, either of stone or brick, through which the foul waters of the city, as well as all the streams brought to Rome by the aqueducts, finally discharged themselves into the Tiber Cloaca, according to Livy, a large subterraneous canal, constructed of masonry or brick- work, for the pur- pose of carrying off the rain-water from the streets of a town, and the impurities from private houses, which were thus discharged into some neighbouring river Cloacarium, the sewers' rate; a tax which was levied in Rome for the expenses of cleansing and repairing the sewers Cloister, a covered ambulatory, form- ing part of a monastic or collegiate establishment. Cloisters are always attached to a college cathedral, and arranged round three or four sides of a quadrangular area, with large windows, not often glazed, looking into the quadrangle Close-hauled, a term applied to a vessel sailing with her yards braced up so as to get as much as possible to windward Closer, a brick-back inserted where the distance will not permit of a brick in length Closet, a small chamber or private room Clove-hitch, two half-hitches round a spar or other rope Clove-hook, an iron clasp, in two parts, moving upon the same pivot and overlapping one another, used for bending chain-sheets to the clews of sails Clubbing, drifting down a current with an anchor out Club-haul, to bring a vessel's head round on the other tack, by letting 104 go the lee anchor, and cutting or slipping the cable Clue-garnets, in navigation, tackles fixed to the clews or lower corners of the fore and main sail, to clew them up to the yards. (See Cleiv- garnet.) Clustered column, a pier which con- sists of several columns or shafts clustered together Clutch, an apparatus for engaging o* disengaging two shafts : it consists of two pieces of metal formed so that when placed together, project- ing pieces on one (which is made to slide to andfro on the shaft, but turn with it) fit into recesses in the other, which is fixed on the driving shaft, so that the first being pulled back, its shaft will remain at rest Coaking, in ship -building, uniting pieces of spar by means of tabular projections, formed by cutting away the solid of one piece into a hollow, so as to make a projection in the other in such a manner that they may correctly fit, the buts pre- venting the pieces from drawing asunder Coal belongs to the third series of the Wernerian principle, viz., car- boniferous rocks, coal measures, carboniferous limestone, and old red sandstone ; it is admitted to be of vegetable origin, and comprises 1. Lignites, aspeciesof mineral char- coal or intermediate gradation from wood to coal ; 2. Ordinary bitu- minous coal, of numerous varieties; 3. Anthracite, found generally in connection with the lowest portion of the third series, and sometimes in the primary rocks themselves. Coal, then, appears to have been formed of large vegetable masses of considerable extent, in strata varying from a few inches to many feet in depth, the strata alter- nating with rocks wonderfully uni- form, and which consist, in most cases, of the following : sandstone, slate clay or shale, fire-clay, iron- stone, limestone, &c. Rocks are found participating of both clay COA COCOA WOOD. COC and sandstone texture, greatly pre- dominating. The coal beds are indiscriminately accompanied by rocks either of sandstone or shale, which often rest upon fire-clay. It is in the shale accompanying the coal that the fossil impressions are so numerous; for they are seldom found in the sandstones, or in the shales considerably distant from the coal beds. The organic remains of coal formation consist of many shells of fresh-water origin. The fossils, with land plants, occur in great abundance and variety, be- longing to extinct species, but bearing considerable analogy to those now growing only in tropical climates. These plants are mostly succulent, and are of enormous growth Coal-gas. Carburetted hydrogen, coal- gas, when freed from the obnoxious foreign gas, may be propelled in streams out of small apertures, which, when lighted, form jets of flame, and are called gas-lights Coal-tar, tar made from bituminous coal Coamings, in ships, raised work round the hatches, to prevent water from getting down into the hold Coat. Mast-coat is a piece of canvas tarred or painted, placed round a mast or bowsprit where it enters the deck Coat, in building, a stratum or thick- ness of plaster-work Cob (Cornish), to break or bruise : a cobber, a bruiser of tin. Cobbed ore is spoiled which is broken out of the solid large stones with sledges, and not put to water, being the best ore : the same as bing ore in the lead mines Cobalt. The ancient name for this mineral is not known. Theophrastus mentions its use for staining glass. No cobalt has been discovered in any of the remains of ancient paint- ing. It makes a colour, according to Vitruvius, between scarlet and purple Cobalt, in chemistry, a metal, when pure, of a white colour, inclining to bluish or steel gray : at the com- mon temperature its specific gravity is more than 8-5 Cobalt-blue is the name now appro- priated to the modern improved blue prepared with metallic cobalt, or its oxides, although it properly belongs to a class of pigments in- cluding Saxon blue, Dutch ultra- marine, Thenard's blue, royal blue, Hungary blue, smalt, Zaffoe or enamel blue, and Dumont's blue. These differ principally in their degrees of purity, from the nature of the earths with which they are compounded Cobalt-green. There are two pig- ments of this denomination, the one a compound of cobalt-blue and chromic yellow, which partakes of the qualities of those pigments, and may be formed on the palette Coboose, the place where the victuals are cooked on board of merchant and passenger ships Cob wall, a wall built of unburnt clay mixed with straw Cochineal is extremely rich in the finest red colouring matter, and has been long employed in scarlet dye- ing, and in the manufacture of carmine Cochlea, a term used by the ancients to denote something of a spiral form ; a spiral pump for raising water, &c. Cock, or stop-cock, a kind of valve contrived for the purpose of per- mitting or arresting at pleasure the flow of a liquid through a pipe Cock-boat, a small boat used on rivers Cock-pit, that part of a ship which is appropriated to the use of the sur- geon, being the place where the wounded are dressed; it is near the hatchway, and under the lower gun-deck Cockle, the skiorl.of the Swedes and the school of the Germans : a laminated mineral substance of a blackish brown colour, like tin Cocoa wood, the heart of which is sel- dom sound, is much used in turnery 105 E 5 COG COKE. COK Coctilis, according to Pliny, a brick hardened by burning Cod-line, an eighteen-thread line Co-efficients, in algebra, are numbers or letters prefixed to other letters or unknown quantities, into which they are supposed to be multiplied ; and therefore with such letters, or the quantities represented by them, making a product, or co-efficient product Cwlum, according to Vitruvius, a soffit or cieling Cambium, anciently a monastery of monks or friars C6fer, in Cornish mining, a small wooden trough which receives the tin cleansed from its impurities or slime Coffee-tree, a wood of a light greenish brown, close-grained, and small in stature, sometimes used by cabinet- makers Coffer, a deep panel in a ceiling ; also applied to a casket for keeping jewels, and sometimes to a chest Coffer-dam, a hollow space formed by a double range of piles, with clay rammed in between, for the purpose of constructing an en- trance lock to a canal, dock, or basin, or for the piers of a bridge Coffin, in Cornish mining, old work- ings which were all worked open to grass, without any shafts, by digging and casting up the tin stuff from one stall of boards to another Coffin, a wooden case in which a dead body is placed, sometimes en- cased in lead: anciently, stone coffins were used for interment Cog, the wooden tooth of a large wheel Cog-teeth are formed of a different ma- terial from the body of the wheel : a timber tooth on a cog-wheel is one made of wood, when the teeth stand perpendically to the plane of the wheel Cog-wheel, an iron wheel with wooden teeth or cogs Cohesion of fluids. M. Monge and others assert that the phenomena 106 of capillary tubes are referable to the cohesive attraction of the su- perficial particles only of the fluids employed, and that the surface must consequently be formed into curves of the nature of linteariae, which are supposed to be the results of a uniform tension of a surface resist- ing the pressure of a fluid, either uniform or varying according to a given law Cohesion, the attraction which takes place between the particles of bo- dies, denoting that force by which the particles firmly cohere Cohesion and resistance of fluids, as examined by the force of torsion. Pressure does not augment the friction ; on the contrary, the re- sistance is greater when the im- mersion is only partial. Greasing wood does not lessen the friction : the friction of oil is 17^ times as great as that of water. A part of the friction is proportional to the velocity: the constant part is al- most insensible. Thus a circle *195 metre in diameter, turning in water with a velocity equal to '14 m. in 1", meets a resistance equivalent to a weight of 1 gramme acting on a lever of '143 m. The portion pro- portional to the velocity is equiva- lent to -042 gr. for a surface equal to twice such a circle moving in its own direction with a velocity of 01 m. Cohesive strength of materials. The force of cohesion may be defined to be that force by which the fibres or particles of a body resist separa- tion, and is proportioned to the number of fibres in the body, or in the area of its section. Coiling, a serpentine winding of ropes, by which they occupy a small space, and are not liable to be entangled amongst one another in working the sails of a ship Coin or quoin, the angle of a building; used also for the machicolation of a wall Coke, charred pitcoal Coke. The most valuable of the se- COK COKE. COK condary products of a gas estab- lishment is coke. The best kind is obtained from coal when car- bonized in large masses, in ovens constructed on purpose. In a gas manufactory , the production of coke being of minor importance to the formation of good gas, it is gene- rally of an inferior quality to that made in coke ovens, where it is the primary, and indeed sole object for which the coal is carbonized. But gas-coke is excellent for many pur- poses in the arts and manufactures, producing as clear a fire as that of the first quality, though it is neither so lasting nor so free from slag : for domestic use, however, it is unob- jectionable, and maybe burnt both in the drawing-room and kitchen with economy and comfort. The distinguishing characters of good coke are, first, a clean, granu- lar fracture in any direction, with a pearly lustre, inclining to that exhibited by cast iron. Secondly, density, or close proximity of its particles, which adhere together in masses, and specific gravity of I'lO, or rather higher. Thirdly, when exposed to a white heat, it consumes entirely away , without leaving either slag or ashes. It is invariably the case that the quality of the coke is inversely as that of the gas. The manufacturer must not expect to produce both of the best quality. The process by which the best gas is made gene- rally leaves the coke light, spongy, and friable, although an increase of quantity is gained ; for the simple reason, that the degree of heat and other circumstances required to form perfect coke must be entirely changed when gas of a high specific gravity is to be obtained. Thus large masses of coal exposed to a red heat in close vessels are acted upon by slow degrees, the external portions preventing heatfrom pene- trating into the interior until most of the bituminous portions are given off in condensable vapour, or as 107 charcoal and free hydrogen; the after-products being light carbu- retted hydrogen, carbonic oxide and carbonic acid gases. The re- sidue is a carbon of a dense granular composition Coke, as prepared for use in locomo- tive and other steam engines, may be regarded as purified coal, or coal from which the extraneous matters not conducive to combustion have been expelled by the application of heat. It appears from experiments that the heating power of every description of fuel, whether coal, coke, wood, lignite, turf, or peat, is proportional to the quantity of carbon it contains, and that from 83 to 86 per cent, of this element enters into the composition of any given weight of Newcastle, Durham, or Lancashire coal, the other in- gredients being hydrogen, azote, oxygen, and ashes. The exact pro- cess which takes place in the con- version of coal into coke is not yet thoroughly understood, although the result can be readily estimated, and is found to depend, to a con- siderable extent, upon the manner in which the process is performed. Thus, by coking in close ovens, Welsh coal loses about 30 per cent, of its weight ; but if the coking be effectedin uncovered heaps of coarse lumps, as it often is in the Welsh coal and iron districts (where abun- dance is allowed, as the excuse for extravagance and waste), the loss of weight is from 50 to 55 per cent. While the weight is thus diminished by coking in close ovens, the bulk is increased from 22 to 23 per cent. The rapid and complete combustion of the carbon 'which takes place in the burning of coke has the effect of preventing, to a considerable ex- tent, the emission of that palpable smoke which arises from the com- bustion of coal, and for this pro- perty coke was resorted to for use in locomotive engines, when the non-emission of smoke was imposed as one of the conditions upon which COL COLLEGIATE CHURCHES. COL railway companies were empowered by Act of Parliament. The prac- tical advantages since found to be derived from the burning of coke instead of coal are, its greater power in evaporating water and producing steam, and the less rapid destruction of the boiler which ensues from its employment Colarin, the little frieze of the capital of the Tuscan and Doric column, placed between the astragal and the annulets Cold chisel, a piece of steel flattened and sharpened at one end, which is properly tempered, so that it may be used for cutting metal Cold-harbour, an inn ; a shelter from the cold ; a protection on the way- side for travellers benighted or be- numbed Coldshort z'ron,iron in an impure state Cold-water well and reservoir. To effect the condensation of steam, the water is very commonly raised, by means of the cold-water pump, from a reservoir or well. This ab- sorbs from the engine some portion of its pow r er. Indeed, when the wells are deep, the quantity of power thus expended is so great, that the condensing system can no longer be judiciously applied. This may be known by the follow- ing investigation : Rule. Multiply the weight of water, in pounds,by the feetthrough which it passes in a minute, and divide the product by 33,000 ; the quotient will exhibit, friction ex- cluded, the horses' power expended. Example. To condense 103 ; Weight of cold water lOtbs. per gallon, at 62 of tem- perature, Engine, nominal power. . 4 horses. Water, per horse power . . 4 gals. Lift of do., or height raised, 230 feet per minute. 4 x 40 x 230 HenCC 33,000- =Hh. power. Cold-water pump, the pump for sup- plying the water for condensation Collar, in ships, an eye in the end or bight of a shroud or stay, to go over the mast-head Collar, in turnery, a ring inserted in the puppet for holding the end of the mandril next the chuck, in or- der to make the spindle run freely and exactly Collar, a plate of metal screwed down upon the stuffing-box of a steam engine, with a hole to allow the piston-rod to pass through Collar of a shaft, the timber and boarding used to secure the upper- most part of a shaft in loose rub- ble from falling in Collar-beam, a beam framed across and between two principal rafters Collegiate Churches of Great Britain (list of). The Colleges generally omitted in the Books amount to 130 in number, scattered mostly over England alone, and are con- sequently not here included. NAME. Abergwilly .... Arundel Astley Attilbury .... Axminster .... Barnard Castle . . Battlefield . . . . Beverley Biggar Bishop Auckland . . Bunbury Bolton, within thel Castle of) . . J 108 ORDER. Secular Canons Do. Do. Do. Do. Do. Do. Do. Do. DATE. 1287 1375 Edw. III. Hen. IV. temp. Athels, Rich. III. ]403 928 1545 1239 1389 Richard II. COUNTY. Carmarthenshire Sussex Warwickshire Norfolk Devonshire Durham Shropshire Yorkshire Lanarkshire Durham Cheshire Yorkshire COL COLLEGIATE CHURCHES. COL NAME. ORDER. DATE. COUNTY. Bosehara .... Henry I. Sussex Botham 1418 Haddingtonshire Bothwell .... 1398 Lanarkshire Bradgrove .... Secular Canons Richard II. Kent Brecknock .... Henry VIII. Brecknockshire Bridgnorth .... Wm. Rufus Shropshire Brorayard .... temp. H. III. Herefordshire Burford Edward Shropshire Carnworth .... 1423 Lanarkshire Chester-le-Street . . Do. 1286 Durham Chumleigh .... temp. Ed. I. Devonshire Clovelley .... Do. Richard II. Do. Constantin .... Cornwall Corstorpliin . . 1429 Edinburghshire Cotherstoke. . <* . Do. 1336 Northamptonshire Crail 1517 Fifeshire Crediton 905 Devonshire Crichton 1449 Edinburghshire Dalkeith James V. Do. Darlington .... Durham Dirleton . Do. Edinburghshire Dirleton 1444 Haddingtonshire Dumbarton . . 1450 Dumbartonshire Dunbar . . ..*,.. 1392 Haddingtonshire Dunglass . . <* i. 1450 Do. Eton '"'' Henry VI. Buckinghamshire Fotheringay . . . Do. 1411 Northamptonshire Foulis Jas. II. Scot. Forfar Glasency . . *' . Augustine 1270 Cornwall Gnoushall .... Henry I. Staffordshire Graystoke .... 1359 Cumberland Guthry .... Jas.III.Scot. Forfar Hamilton .... 1451 Lanarkshire Hastings .... Henry I. Sussex Hemmingburgh Secular Canons 1426 Yorkshire Heytesbury .... 1300 Wiltshire Higham Ferrers . . Do. Henry V. Northamptonshire Holyhead .... Anglesea Howden 1266 Yorkshire Inetolingburgh . . Do. Edward III. N ortham ptonshir e Ingham 1360 Norfolk Irtlingburgh . .. ' Richard II. Northamptonshire Kilmaurs . . V ? 1403 Ayrshire Kilmund. . . *,-.. 1442 Argyleshire Kirkheugh . . ^ "-. Fifeshire Lanchester . . . ; . Do. 1283 Durham JLcdburv Do. 1400 jj crcfordsliirc Llancadane . . ..'. ;.-- Premonstrant 1283 Carmarthenshire Llandewi Brevi ..;-' ;.- 1187 Cardiganshire Ludlow . . . < . Shropshire Maidstone .... Secular Canons 1269 Kent Edward III. Rutlandshire Maybole .... 1441 Ayrshire 109 COL ( X)LLEGIATE ( CHURCHES. COL NAME. ORDER. DATE. COUNTY, &C. Merewell .... Secular Canons Hampshire Methvin 1433 Perthshire Mettingham Richard II. Suffolk Middleham .... Do. 1476 Yorkshire Newark . Do. 1330 Leicestershire Newport Do. Shropshire North Cadbury . . Do. Henry V. Somersetshire Northwell .... Do. temp. H.I V. Bedfordshire Norton Durham Norton sub Cross . . Edward III. Norfolk Noseley ..... temp. Ed. I. Leicestershire Ottery Wm. Conq. Devonshire Penkridge .... John Staffordshire Fleshy Do. Richard II. Essex Ponsbury .... Shropshire Restrairig .... 1515 Edinburghshire Roslin 1446 Do. Rotherham .... Do. 1481 Yorkshire Rushworth .... Do. 1342 Norfolk Ruthyn 1310 Denbighshire Semple 1505 Renfrewshire Seton 1493 Edinburghshire Shottesbrooke . . . Do. 1337 Berkshire Sibthorp Do. Edward II. N ottinghamshire South Mailing . . . Sussex Southwell .... Do. 630 Nottinghamshire Stafford Staffordshire Staindrop .... Do. emp.Hen.IV Durham Stansted le Thele . . Do. 1315 Hertfordshire Stoke Do. 1115 Suffolk Stratford on Avon Edward III. Warwickshire St. Buriens .... Cornwall St. David's .... Do. 1365 Pembrokeshire St. Elizabeth . . . Do. 1300 Winchester St. Giles 1466 Edinburgh St. Martin's le Grand Do. 700 London St. Mary . . . . Do. 1123 Warwick St. Mary .... Do. King Steph. Stafford St. Mary's .... Edinburgh St. Mary Magdalen . 1426 Linlithgowshire St. Mary Ottery . . Do. 1000 Devonshire St. Michael, Crooked 1 lane . . . . J Do. 1380 London St. Stephen's . . . Benedictine 1292 Westminster St. Salvator .... 1458 Fifeshire Sudbury Secular Canons 1374 Suffolk Tamworth .... Staffordshire Tattershall .... Do. Henry VI. Lincolnshire Tayne 1481 Ross-shire Thornton upon Humber Augustine 1139 Lincolnshire Tonison . Edward III. Norfolk Tonge Secular Canons 1410 Shropshire Totenhall .... Wm. Conq. Staffordshire 110 COL COLOURS, SYMBOLIC. COL NAME. Towcester .... Trinity Tullibardine . . . Tuxford ORDER. Secular Canons DATE. Henry VI. 1463 1446 Edward III. COUNTY. Northamptonshire Edinburghshire Perthshire N ottin gham shire Wallingford. . . . Warwick .... Westbury .... "Winburn .... Windsor, (St. George's Chapel) .... Wingfield .... Wingham .... Wenslow .... Wolverhampton . . Wye Do. Do. } Do. Do. Do. Do. Do. Edward I. 1123 824 1349 Wra. Rufus 1286 Richard II. 996 1447 Berkshire Warwickshire Gloucestershire Dorsetshire Berkshire Suffolk Kent Yorkshire Staffordshire Kent W 7 ykeham .... Tester Do. 1387 Winchester Haddinstonshire Collision,***, mechanics. Whenever two bodies act on each other so as to change the direction of their rela- tive motions, by means of any forces which preserve their activity un- diminished at equal distances on every side, the relative velocities with which the bodies approach to or recede from each other will al- ways be equal at equal distances Colluviarium, anciently a well or open- ing formed at intervals in the chan- nel of an aqueduct for procuring a free current of air along its course, and to facilitate the operation of clearing away foul deposits left by the waters Cologne earth is a native pigment, similar to the Vandyke brown in its uses and properties as a colour Colonnade, arange of columns, whether attached or insulated, and support- ing an entablature Colosseum, a name given to the theatre of Vespasian, either from its mag- nitude or from its colossal statue of Nero ; also the name of a fine building in the Regent's Park Colossus, a statue of gigantic dimen- sions, or very much beyond the proportions of nature Colour. The term colour being used synonymously for pigment is the cause of much ambiguity, particu- 111 larly when speaking of colours as sensible or in the abstract ; it would be well, therefore, if the term pig- ment were alone used to denote the material colours of the palette Colouring, in painting, the art of dis- posing the tints, so as to produce either an imitation of the natural colours of the objects represented, or force and brightness of effect Colouring, though a subject greatly inferior to many others which the painter must study, is yet of suffi- cient importance to employ a con- siderable share of his attention; and to excel in it, he must be well ac- quainted with that part of optics which has the nature of light and colours for its object. Light, how- ever simple and uncompounded it may appear, is nevertheless made up, as it were, of several distinct substances; and the number and quantity of component parts have been happily discovered by the moderns Colours (symbolic), in antiquity, the middle ages, and modern times. The history of symbolic colours is but little known. Colours had the same signification amongst all nations of the remotest antiquity : this conformity indicates a common origin, which extends to the earliest COL COLOURS, SYMBOLIC. COL state of humanity, and develops its highest energies in the religion of Persia: the dualism of light arid darkness presents, in effect, the two types of colours which become the symbols of two principles, benevo- lence and malevolence. The an- cients admitted but two primitive colours, white and black, whence all others are derived. The language of colours, inti- mately connected with religion, passed into India, China, Egypt, Greece, and Rome, and re-appeared in the middle ages; the large win- dows of Gothic cathedrals found their explanation in the books of the Zends, the Vedas, and the paintings of the Egyptian temples. Among the Egyptians, the pro- phets did not allow metal-founders or statuaries to represent the gods, lest they should deviate from the rules. At Rome, the penalty of death was incurred by selling or being clothed in a purple stuff. At this day, in China, any one who wears or buys clothes with the prohibited design of the dragon or phrenix, is subjected to 300 stripes and three years' banishment. Symbolism explains this severity of laws andcustoms: to each colour, to each pattern, appertained a re- ligious or political idea ; to change or to alter it was a crime of apo- stacy or of rebellion. Archaeologistshaveremarkedthat Indian and Egyptian paintings, and those of Greek origin, named Etrus- can, are composed of plain tints of a brilliant colour, but without demi-tints ; the pattern and the colour had a necessary signification, it was essentially restrictive: per- spective, chiaro-oscuro, and demi- tints, would have led to confusion. Christianity, in recalling these forgotten significations, restores a new energy to the language of colours : the doctrine taught by Christ was not therefore new, since it borrowed the symbols of ancient 112 religions. The Son of God, in lead- ing back mankind to the truth, came not to change, but to fulfil the law; this law was the worship of the true God. The three languages of colours, divine, consecrated, and profane, classify, in Europe, the three estates of society, the clergy, the nobles, and the people. The large glass windows of Christian churches, like the paint- ings of Egypt, have a double sig- nification, the apparent and the hidden ; the one is for the uniniti- ated, and the other applies itself to the mystic creeds. The theocratic era lasts to the renaissance ; at this epoch, symbolic expressions are ex- tinct; the divine language of colours is forgotten, painting became an art, and is no longer a science. The aristocratic era commences; and symbolism, banished from the church, takes refuge at the court : disdained by painting, it is found again in heraldry. Modern paint- ing still preserves its symbolism in church pictures : St. John wears a green robe, Christ and the Virgin are likewise draped in red and blue, and God in white. Natural philosophy recognizes seven colours, which form the solar ray, decomposed by the prism; namely, violet, indigo, blue, green, yellow, orange, and red. Painting admits butfive primitives, the first and last of which are rejected by natural philosophy, white, yellow, red, blue, and black. From the combination of these five colours every hue is produced. According to symbolism, two principles produce all colours, light and darkness. Light is represented by white, and darkness by black; but light does not exist but by fire, the sym- bol of which is red : setting out from this basis, symbolism admits two primitive colours, redandwhite. Black was considered as the ne- gation of colours, and attributed to COL COMBUSTION. COM the spirit of darkness ; red is the symbol of divine love ; white, the symbol of divine wisdom. From these two attributes of God, love and wisdom, the creation of the universe emanates. Secondary colours represent dif- ferent combinations of the two prin- ciples ; yellow emanates from red and white ; it is the symbol of reve- lation of the love and of the wis- dom of God. Blue emanates likewise from red and white ; it indicates divine wis- dom manifested by life, by the spirit or the breath of God (air, azure) ; it is the symbol of the spirit of truth. Green is formed by the union of yellow and blue; it indicates the manifestation of love and wisdom in action ; it was the symbol of charity, and of the regeneration of the soul by works. Gold and yellow were, in Chris- tian symbolism, the emblems of faith : St. Peter was represented by the illuminators and miniaturists of the middle ages with a golden- yellow robe, and the rod or the key in his hand. Christianity restored truth to mankind, and re-instated symbolic language in its original purity. In the transfiguration,the countenance of our Lord became resplendent as the sun, and his vesture shone like the light. Such, in their highest energy, are the symbols of divine love and wisdom. The angel who rolled away the stone from the se- pulchre reproduced them in an in- ferior order, his face shone like lightning, and his robe was white as snow. Finally, in the last de- gree, appeared the just, in robes washed white in the blood of the Lamb. The artists of the middle ages preserved their precious tra- ditions, and gave to Jesus Christ, after the resurrection, white or red costume. Columbaria, the holes left in walls for the insertion of pieces of tini- 113 her ; so called from resembling the niches of a pigeon-house. The niches of a mausoleum, made to receive the cineral urns, were like- wise termed columbaria Columbarium, a place of sepulture used for the ashes of the Romans, after the custom of burning the dead had been introduced among them Columen, the term applied to the upright timbers of a roof, cor- responding to the modern king- posts Column, in architecture, a member of a cylindrical form, consisting of a base, a shaft or body, and a capi- tal. It differs from the pilaster, which is square on the plan. Columns should always stand per- pendicularly Columna (Latin), a pillar or column, used in architecture (as described in the orders), placed upright for support of buildings, principally wrought in stone, and made de- corative in conformity to the order and style of architectural compo- sition Columns, in architecture, according to Vitruvius, of the three orders. The proportions of Corinthian co- lumns are in every respect, except- ing their capitals, similar to those of Ionic ; although their form is more graceful and proportionably more delicate, by reason of the greater height of the capitals ; for Ionic capitals are a third part only of the lower diameter of the co- lumns, whereas the Corinthian ca- pital is equal in height to an entire diameter. The peculiar character of the capitals, which admits of their being higher than those of Ionic columns by two-thirds of a diameter, gives beauty to them, by permitting an increase of the height without violating the laws of symmetry Combustion, the operation of fire upon an inflammable substance, by which it smokes, flames, and is reduced to ashes COM COMPARTMENT. COM Combustion, Spontaneous. Few or no chemical combinations can take place without a disturbance in the equilibrium of caloric in the sub- stances to be so combined; and when caloric is thereby evolved in sufficient extent and rapidity, and when one or all the bodies engaged may be freely combustible, ignition takes place. When this is unin- tentional, or is the result of igno- rance or carelessness, it is con- venient to call it spontaneous com- bustion. Thus we frequently hear of hayricks, &c., on fire; occasion- ally, of carts loaded with quick- lime being burned by the rain fall- ing upon the lime. There are also somewhat apochryphal accounts of coal in coal-yards being destroyed in like manner. But the most im- portant instance of this class, as far as regards the preservation of Government establishments, is the combustion that infallibly and ra- pidly ensues when greasy hemp, flax, or cotton, is allowed to re- main loosely heaped together, in any quantity, in a confined unven- tilated space. Full proof of this has been made by experiment in the dockyards ; and there is much reason to at- tribute many fires in former days to carelessness in the rope-walks and hemp stores ; in consequence of which, rigorous orders have been of late years issued as to the immediate disposal of loose oakum and hemp sweepings all more or less greased or oiled. The very oil-rags used by engravers in cleaning plates, when heaped together to any amount, will be consumed in a few hours. The combination in question seems to be between the oil and the oxygen of the atmosphere. Oil has always an affinity for oxygen ; though, when the bulk of the for- mer is considerable in proportion to the surface, the action is but feeble, and the results not ordinarily ap- 114 preciable : but in the case of ad- mixture of such fibrous vegetable bodies as hemp, flax, or cotton with oily matters, where the ratio of surface to solidity is great, and when the conditions for accumu- lating heat are favourable, this accumulation soon produces igni- tion amongst such inflammable bodies as those just enumerated Come. i Come home ; ' said of an an- chor when it is broken from the ground, and drags. To ' come up ' a rope or tackle, is to slack it off Commandry, a religious house be- longing to a body of knights of the order of St. Bernard and St. Anthony Commissure, the joint between two stones in masonry Common pitch, an old term still ap- plied by country workmen to a roof in which the length of the rafters is about three-fourths of the entire span Common sewer of Rome : it was near the Senatorian bridge, and was 16 feet in diameter Communication valves, the valves in a steam-pipe which connects two boilers to an engine, for cutting off the communication between either boiler and the engine Communion table, a piece of church furniture usually placed near the wall of the east end of the chancel, and enclosed by rails, within which the clergyman stands to administer the Sacrament Companion, a wooden covering over the staircase to a ship's cabin Compartition, the division or distri- bution of the ground-plan of an edifice into its various apartments Compartment of the streets within a city. According to Palladio, re- gard must be always had to the temperature of the air, and also to the region of heaven, or the cli- mate under which the place is situated ; because where the air is cold or temperate, there the streets ought to be made large and noble, since thereby the city will become COM COMPOSITE ORDER. COM more wholesome, convenient, and beautiful: it being certain that by how much less piercing, and withal by how much freer the air is, by so much the less will it offend the head; and therefore by how much more a town is situated in a cold place, or in a piercing air, and that the houses are high, by so much the longer ought the streets to be made, that they may be visited by the sun in every part of them Compartment, a division or separate part of a general design. Compass (Harris's magneto-electric). The inventor's object, in the appli- cation of his discovery of the stea- dying action of the copper ring, " is the combination of great sensi- tiveness with stability and simpli- city of construction ; so that while the needle is free to obey the mag- netic force of the earth in the most perfect way, it yet remains tran- quil amidst the disturbing motions to which a ship is exposed ; and this stability is obtained without the aid of friction or other me- chanical impediment, which often produce an apparent steadiness, or rather sluggishness of the compass (arising from indifference to mo- tion), at the expense of accuracy. " When the horizontal position of the card is disturbed by any alteration of dip incidental to a change of latitude, it is to be cor- rected by moving the silver sliders on the needle. " Should the compass be out of use, care must be taken to let the needle hang freely in the meridian; and if put into a store-room, or otherwise set by, the card and needle should be removed alto- gether, and placed with the needle downward in the shallow box pro- vided for it, the north point being on that part of the keeper marked with a cross, thus x . A good compass is liable to deterioration and damage when stowed away without regard to its magnetic 115 properties, and without due care being taken to preserve the agate and the point of suspension in a perfect state." Compasses, an instrument with two long legs, working on a centre pin at one extremity ; used for draw- ing circles, measuring distances, setting out work, &c. Compass-headed, in ancient architec- tecture, circular Compass-plane, in joinery, a tool si- milar to the smoothing-plane in size and shape, but the sole is convex, and the convexity is in the direction of the length of the plane. The use of the compass- plane is to form a concave cylin- drical surface, when the wood to be wrought upon is bent with the fibres in the direction of the curve, which is in a plane surface perpen- dicular to the axis of the cylinder : consequently, compass-planes must be of various sizes, in order to accommodate different diameters. joss-roof, a roof in which the braces of the timbers are inclined so as to form a sort of arch. Compass-saw, in joinery, a tool for cutting the surfaces of wood into curved surfaces: for this purpose it is narrow, without a back, thicker on the cutting edge, as the teeth have no set : the plate is about an inch broad, next to the handle, and diminishes to about one quar- ter of an inch at the other extre- mity ; there are about five teeth in the inch : the handle is single Compass-window, a bay window, or oriel Complement (the) of an arch or angle is what it wants of 90 degrees : thus the complement of 50 is 40, and the complement of 40 is 50. Compluvium (Latin), the interval be- tween the roofs of porticoes which surround the cavaedium. The rain was admitted through this opening, and fell upon the area below, which was termed by some authors the impluvium Composite Order : by some considered COM CONCRETE. CON not a distinct order, but a variety of the Corinthian. For its height and proportion, see Architecture, Orders. Care must be taken in Compo- site as well as in Corinthian capi- tals, that the feet of the lower leaves do not project beyond the upper part of the column, as at St. Carlo, in the Corso at Rome, and at the Banqueting-house in London ; for nothing can be uglier. Neither are these leaves, as they mount, to bend forwards, as in many of the antiques, and in some modern buildings, because they then hide a considerable part of the upper row of leaves, and give a stunted disagreeable form to the whole capital. The different divi- sions of the acanthus leaf, and bunches of olive or parsley which compose the total of each leaf, must be firmly marked, and massed in a very distinct manner : the stems that spring from between the upper leaves are to be kept low upon the vase of the capital, while rising between the leaves, then spring gradually forwards, to form the different volutes ; and the ornaments, which sometimes are used to adorn the sides of the angular volutes, are never to pro- ject beyond the fillets between which they are confined. Composition of motion, in mechanics, an assemblage of several directions of motion resulting from several powers acting in different though not in opposite directions Composition, in painting, is a tasteful and proper distribution of the ob- jects of a picture, in grouping, in the attitudes, and in the draperies, and the management of the back- ground Composition and symmetry of tem- ples. The several parts which con- stitute a temple ought to be sub- ject to the laws of symmetry, the principles of which should be fami- liar to all who profess the science of architecture. Symmetry results 116 from proportion, which, in the Greek language, is termed analogy. Proportion is the commensuration of the various constituent parts with the whole ; in the existence of which, symmetry is found to con- sist; for no building can possess the attributes of composition in which symmetry and proportion are disregarded, nor unless there exists that perfect conformation of parts which may be observed in a well-formed human being Compound arch, according to Profes- sor Willis, an arch which has the archivolt moulded or formed into a series of square recesses and angles, on the principle that " it may be resolved into a number of concen- tric archways successively placed within and behind each other" Compound pier, a term applied to a clustered column Compression, the result of pressing or squeezing matter so as to set its parts nearer to each other, and to make it occupy less space Computation, the method of esti- mating time, weights, measures, &c. Concamerate, to arch over Concameratio, arched work Concave, a term denoting the curvi- linear vacuity of hollow bodies Concentric, having a common centre; as concentric circles, ellipses, &c. Concha, according to Dr. Whewell, a term for the concave ribless sur- face of a vault Conclave, a private or secret council; an inner room for meeting pri- vately Concluding line, a small line leading through the centre of the steps of a rope or Jacob's ladder Concrete, a composition of lime, sand, pebbles, or other materials, now commonly used for the founda- tions of buildings. The general employment of the mixture of lime and gravel, com- monly known by the name of con- crete, in all foundations where, from the nature of the soil, pre- CON CONCRETE. CON cautions against partial settlements appear necessary, and the great probability of an extension of its use in situations where the mate- rials of which it is composed are easily and cheaply procured, must of course render it a subject of great interest to the engineer. Much valuable information on this subject Mill be found in a prize essay by Mr. G. Godwin, published in the ' Transactions of the Institute of British Architects.' In this essay, many instances are brought forward of the employment by the ancients of a mixture ana- logous to concrete, both for founda- tions and for walls. Several cases are also mentioned in which, of late years, it has been used advan- tageously for foundations, by some of the most distinguished architects and civil engineers. In these lat- ter instances, the proportion of the ingredients varies from one of lime and two of gravel, to one of lime and twelve of gravel, the lime being in most cases Dorking lime, and the gravel, Thames ballast. The proportion, however, most commonly used now, in and about London, is one of lime to seven of ballast ; though, from experiments made at the building of the West- minster New Bridewell, it would appear that one of lime to eight of ballast made the most perfect con- cretion. Concrete, compounded solely of lime and screened stones, will never assume a consistence at all equal to that of which sand forms a part. The north wing of Buck- ingham Palace affords an instance of this : it was first erected on a mass of concrete composed of lime and stones, and when subsequent alterations made it necessary to take down the building and remove the foundation, this was found not to have concreted into a mass. Mr. Godwin states, as the result of several experiments, that two parts of stones and one of sand, 117 with sufficient lime (dependent on the quality of the material) to make good mortar with the latter, formed the best concrete. As the quality of the concrete depends, therefore, on the goodness of the mortar composed of the lime and sand, and as this must vary with the quality of the lime, no fixed proportions can of course be laid down which will suit every case. The proportions must be deter- mined by experiment ; but in no case should the quantity of sand be less than double that of the lime. The best mode of compounding the concrete is to thoroughly mix the lime, previously ground, with the ballast in a dry state ; sufficient water being then thrown over it to effect a perfect mixture, it should be turned over at least twice with shovels, and then wheeled away instantly for use. In some cases, where a great quantity of concrete has to be used, it has been found advisable to employ a pug-mill to mix the ingredients : in every case it should be used hot. With regard to the quantity of water that should be employed in forming concrete, there is some difference of opinion ; but as it is usually desirable that the mass should set as rapidly as possible, it is not advisable to use more water than is necessary to bring about a perfect mixture of the ingredients. A great change of bulk takes place in the ingredients of concrete when mixed together: a cubic yard of ballast, with the due proportion of lime and water, will not make a cubic yard of concrete. Mr. God- win, from several experiments made with Thames ballast, concludes that the diminution is about one-fifth. To form a cubic yard, therefore, of concrete, the proportion of lime being th of the quantity of ballast, it requires about 30 cubic feet of ballast, and 3f cubic feet of ground lime, with sufficient water to effect the admixture. CON CONDUCTION, ELECTRICAL. CON An expansion takes place in the concrete during the slaking of the lime, of which an important use has been made in the underpinning of walls : the amount of this ex- pansion has been found to be about fths of an inch to every foot in height ; and the size thus gained, the concrete never loses. The examples from which the above rules are deduced are princi- pally of buildings erected in or about London; the lime used is chiefly from Dorking, and the bal- last from the Thames. It is very desirable that a more extended collection of facts should be made, that the proportions of the mate- rials, when other limes and gravels are used, should be stated, in order that some certain rules may be laid down by which the employment of concrete may be regulated under the various circumstances which continually present themselves in practice. The Dorking and Hailing limes are slightly hydraulic. Will com- mon limes, such as chalk, and common stone-lime, answer for forming foundations of concrete, where the soil, although damp, is not exposed to running water ? Is it possible, even with hydraulic lime, to form a mass of concrete in running water ? If common lime will not answer, may it not be made efficient by a slight mixture of cement ? These, and questions similar to these, are of great in- terest; and facts which elucidate them will be valuable contributions to the stock of knowledge on this subject. It is a question for consideration, whether a great variety of sizes in the materials used would not form the most solid as well as the hardest wall. The walls of the fortress of Ciudad Rodrigo, in Spain, are of concrete. The marks of the boards which retained the semi-fluid mat- ter in their construction are every where perfectly visible ; and besides 18 sand and gravel, there are every where large quantities of round boulder-stones in the walls, from 4 to 6 inches in diameter, procured from the ground around the city, which is every where covered with them. Condensation, the conversion of va- pour into water by cold Condenser, in steam engines, the ves- sel connected with the exhaust-port of the cylinder of a low-pressure engine, and also with the air-pump, by a passage at the bottom fitted by the foot-valve of the pump : it receives the steam from the cylin- der, and condenses it by a jet of cold water, thus forming a vacuum for the return stroke : the water, air, &c. is then drawn off by the air-pump, and discharged into the hot well Conditorium, a secret place; a sepul- chre ; a vault Conduction, electrical, a series of phenomena in electricity, giving origin to a classification of sub- stances as conductors of electricity. The substances which properly come under this conducting or non- electric class are principally as fol- lows : LIST OF ELECTRICAL CONDUCTORS. Every metallic substance known. Well-burned charcoal. Plumbago. Concentrated and diluted acids, and saline fluids. Water, and moist vegetable matter. Living animal matter. Flame smoke steam. The distinctive difference in the conducting and non -conducting property of bodies may be readily illustrated in the following way : Excite a glass tube and wire, and bring the ball of the wire into contact with any of the electrics, as a rod of glass, a stick of sealing- wax, or brimstone rendered per- fectly dry : the attractive power of the ball and wire, together with the tube, will not be in any sensi- ble degree impaired. Let the elec- CON CONDUCTION, ELECTRICAL. CON trifled ball now touch the walls of the room or other conducting sub- stance communicating with the ground ; the attractive power will instantly vanish. It is evident from these facts that all electric substances are non- conductors or insulators, as they are appropriately termed; whilst, on the other hand, non-electric substances are transmitters or con- ductors of electrical action. When, therefore, any conduct- ing substance is placed on an elec- trical support, such as a rod of glass or shell-lac, it is considered to be insulated, and is termed an insulated conductor; when elec- trified by contact with any excited or other electrified body, it is said to be charged. The electrical charge thus communicated to an insulated conductor appears to be collected about its surface, and to be rather dependent on that than on the solid content. Thus, if two metallic spheres or cylinders, the one solid, the other hollow and extremely light, be suspended by silk lines, or placed on dry insu- lating supports, and be charged by contacts with an excited tube, the attractive energy of each upon any light substance presented to it will be found quite alike in each. In this experiment the insulators must be very dry and perfect. The best insulating substances are of the vitreous and resinous class, such as shell-lac, brimstone, dry glass rods, vitrified and crys- talline bodies: to these may be added silk. The best conducting substances are principally metallic bodies, sa- line fluids, and common charcoal. It should, however, be here un- derstood, that modern researches, especially those of Faraday, lead us to conclude that there are really no substances which perfectly con- duct or perfectly obstruct electrical action. The insulating and con- ducting power is, in fact, a differ- 119 ence of degree only : still, the ex- treme differences are so great, that if classed in relation to such dif- ferences, those at the extremes of the series admit of being considered the one as insulators, the other as conductors ; whilst the interme- diate terms are made up of sub- stances which may be considered as imperfect, taken as either. Con- versely, every substance is capable of excitation by friction; yet the differences in this respect are so great as to admit of some bodies being called electrics and others non-electrics, with an intermediate class between these extremes, which may be termed imperfect electrics. Series of conductors and insu- lators. Metals and concentrated acids are found at the conducting extremity of such a series, shell- lac, brimstone, all vitreous and resinous bodies, at the other or electric extremity ; whilst the im- perfect or intermediate substances comprise such matter as common earth and stones, dry chalk, mar- ble, porcelain, paper, and alkaline matter. The attractive power evinced by any electrical body in a state of excitation, although the first and usually the most evident electrical effect, is yet not the only force which seems to result from this curious condition of common mat- ter. On a closer examination of the phenomena, a new class of facts present themselves, of re- markable interest. If the excita- tion be considerable, and the at- tracted body insulated, it will, after being drawn into contact with the electrified substance, rebound from it with great violence, as if repelled by some new power, and will not be again attracted until it has had conducting communication with the earth, or some other mass of matter capable of reducing it to its original condition before the con- tact. CON CONSERVATORY. CON Conduit, a structure forming a reser- voir for water, and from which it is drawn for use Cone, a solid body having a circular base, and its other extremity ter- minating in a single point or vertex. Cones are either right or oblique Cone-plate, a strong plate of cast iron fixed vertically to the bed of a lathe, with a conical hole in it, to form a support for the end of a shaft which it is required to bore Confessional, a recess or seat in which the priest sits to hear the confes- sions of penitents Conge, another name for the echinus or quarter-round, as also for the cavetto : the former is called the swelling conge, the latter the hol- low conge Conic sections, the curves formed by the intersection of a circular cone and a plane ; the former being either oblique or right Conical points, in turnery, the cones fixed in the pillars for supporting the body to be turned: that on the right hand is called the fore centre, and that on the left hand, the back centre Conissinet, the stone which crowns a pier, or that lies immediately over the capital of the impost, and under the sweep. The bed of it is level below, and curved above, receiving the first rise or spring of the arch or vault Conisterium, an apartment in the pa- laestra, in which sand was kept for sprinkling the athletae, after they had been anointed Connecting-rods, in locomotive en- gines, the strong iron rods which connect the piston to the driving- wheel axle, and thus give motion to all the machinery Connecting-rods, in locomotive en- gines, outside or side rods, those which connect together the wheels of goods engines. They are seen outside the wheels, making an ir- regular forward motion, like water- men rowing a boat. By connect- ing the wheels together, one pair 120 cannot slip without the others, and the greatest practicable adhe- sion is thus obtained Connecting-rod straps, in locomotive engines, strong pieces of iron bent like the letter Cj, which fit the ends of the connecting-rod, and into which the axle-bearing is fitted in two parts. They are attached to their respective ends of the rod by keys and cotters, which are taken out, and the half of the bearing also, when a connecting- rod has to be put on. The strap and half-bearing are then brought over the axle or cross-head, the other half-bearing put into the strap, the end of the rod brought up against the bearing, and secured by the keys and cotters. Taking off a rod is of course the reverse of putting one on Connecting-rod bearings, in locomo- tive engines, the gun-metal or composition-metal bearings fitted into the straps, to suit the parti- cular part they are to work on Conning, directing the helmsman in steering a vessel Conservation, the ceremony of sancti- fying or making holy Conservatory, a superior kind of greenhouse, for preserving curious and rare exotic plants. It is made with beds of the finest composts, into which the trees and plants are removed for culture and preserva- tion. Its construction is more ca- pacious than the ordinary green- house, and it is furnished in a supe- rior style, provided with a free ad- mission of light, and, in addition, with flues or boiling-water pipes to raise the temperature when ne- cessary, and also contrivances for the introduction of fresh air Consideration (the), w r hich one ought to have before he begins to build. Palladio says, " The first thing that requires our consideration, when we are about to build, is the plan, and the upright of the edifice we propose to erect." Three things, according to Vitruvius, are chiefly CONTOURING. CON to be considered, without which a building cannot be of any value. These are, conveniency, solidity, and beauty : for no edifice can be allowed to be perfect, if it be com- modious and not durable; or, if being durable, it be subject to many inconveniences ; or if having both solidity and conveniency, it has no beauty or uniformity. Consistory court, a spiritual court, formerly held in the nave of the cathedral church Console, a bracket or truss, mostly with scrolls or volutes at the two ends, of unequal size and con- trasted, but connected by a flowing line from the back of the upper one to the inner convolving face of the lower Constant white, permanent white, or barytic white, is a sulphate of ba- rytes, and, when well prepared and free from acid, is one of the best whites for water-painting, being of superior body in water, but desti- tute of this quality in oil Construction, in architecture : for this the chief requisites are, magnitude and strength, and the art of distri- buting the different forces and strains of the parts and materials of a building in so scientific a manner as to avoid failure and to insure durability Continuous imposts, according to Pro- fessor Willis, are the mouldings of an arch which are continued with- out interruption down the uprights to the ground or base, the impost point having no mark or distinc- tion of any kind Contouring (surveying altitudes and levels). This term is applied to the outline of any figure, and con- sequently to that of any section of a solid body ; but when used pro- fessionally, in connection with the forms of ground, or of works of defence, the outline of a horizontal section of the ground, or works, is alone to be understood by it. When the forms of ground, or works, are described by contours, 121 or horizontal sections, these sec- tions are taken at some fixed ver- tical interval from each other, suited to the scale of the drawing, or to the subject in hand ; and the distance of each, above or below some assumed plane of compari- son, is given in figures at the most convenient places on the plan. When the scale of the drawing is about 100 feet to an inch, 2 or 3 feet will be found a convenient vertical interval between the con- tours ; and however large the scale of the plan, it will scarcely be found necessary to obtain contours with a less vertical interval than 2 feet. If the scale of the plan be about 250 feet to an inch, or the ordinary special survey scale of 4 chains to an inch, 5 feet will prove a convenient vertical interval ; and with a horizontal scale of from 500 to 800 feet per inch, 10 feet may be taken as the vertical interval. In tracing and surveying the contours of ground, the following process may be adopted: com- plete the survey of the occupation of the ground, the streams, &c., and determine carefully the alti- tudes of the trigonometrical points employed above the intended place of comparison : take an accurate trace from the plot of one of the triangles, which, if the distances between the trigonometrical points are properly proportioned to the scale of the plan, will generally be a convenient piece in point of size to contour : take this trace to the ground, and find upon the ground, and mark upon the trace, the points where each of the intended con- tours will cut the boundary lines of the triangle. Contraction, the effect of cold upon a warm body, causing a diminution in its size by the particles ap- proaching each other Contramure, an out-wall built about the wall of a city or fortification Convent, a building appropriated to religious persons ; a nunnery CON CORINTHIAN ORDER. COR Convocation and Convocators, or par- liament of tinners. All Stannary laws are enacted by the several convocations, and carry with them all the force and law of acts of parliament. Coopertorium, the roof of a huilding Co-ordinates, in the theory of curves, any absciss and its corresponding ordinate Coping, the reversing course of a wall, either flat or sloping on the upper surface, to throw off water Coppe-house, anciently a tool-house Copper, one of the six primitive metals, and the most ductile and malleable after gold and silver. Of this metal and lapis calaminaris is made brass, which is compara- tively a modern invention Copper green (colour) ; the appellation of a class rather than of an indi- vidual pigment, under which are comprehended verdigris, verditer, malachite, mineral green, green bice, Scheele's green, Schweinfurt or Vienna green, Hungary green, emerald green, true Brunswick green, lake green, mountain green, African green, French green, Saxon green, Persian green, patent green, marine green, Olympian green, &c. The general characteristic of these greens is brightness of colour, well suited to the purposes of house- painting, but not adapted to the modesty of nature in fine art. Coral wood is of a fine red colour, hard, and polishable Corbel, or Corbeille, a short piece of timber or stone let into a wall half its length or more, as the burthen superimposed may require, to carry a weight above it, and projecting from the general face of the work : it is carved in various fanciful ways ; the commonest form is, however, that of an ogee Corbel, in Gothic architecture, a pro- jecting stone or piece of timber which supports a superincumbent weight Corbel-table, a row of corbels sup- porting a parapet or cornice 122 Corbel-table, a cornice supported by corbels Corbie steps, steps up the sides of a gable, found in old houses in Flanders, Holland, &c. Corbona, in mining, a dropper from a lode in irregular masses Core, with the Cornish tinmen, is a division of time and labour Corinthian Order. The three columns in the Campo Vaccino, supposed remains of the temple of Jupiter Stator, are generally allowed to be the most perfect models of the Corinthian order amongst the an- tiques at Rome. Palladio, in his fourth book, where he gives the whole profile at large, acknow- ledges that he never had seen any work better executed, or more deli- cately finished ; that its parts are beautifully formed, well-propor- tioned, and skilfully combined ; all which last qualities are certainly signified by his Benissimo intesi. With these favourable senti- ments, it is extraordinary that, in his design of the Corinthian order, he should have so very considerably deviated from this excellent origi- nal as scarcely to leave the smallest shadow of resemblance. Vignola, in his Corinthian pro- file, has chiefly imitated the above- mentioned fragment, and the inte- rior order of the Pantheon, another very perfect model. His compo- sition is uncommonly beautiful, and, without dispute, superior to that of any other master : he art- fully collected all the perfections of his originals, and formed a whole far preferable to either of them. (For height and proportion, see Architecture, Orders.) Corner-stones, in architecture, the two stones which stand one in each joint of the chimney Cornice, the projection, consisting of several members, which crowns or finishes an entablature, or the body or part to which it is annexed. The cornice used on a pedestal is called the cap of the pedestal COR CORNISH ENGINE. COT Cornish engine, a single-acting beam engine, used for raising water : the steam is worked very expansively, and used for the down-stroke only, to raise an immense weight, fas- tened to the pump-rod, at the end of the heam : the steam having acted for the down-stroke, and the entrance-valve being closed, a com- munication is formed between the top and bottom of the cylinder, by lifting a valve in the steam passage, called an equilibrium valve : the pressures on the piston are thus equalized, and the weight acts to force the water up, and raise the piston Cornucopia, or horn of plenty: among architects, painters, &c., it is repre- sented under the figure of a large horn, out of which issue fruit, flowers, &c. Corollary, an inference or deduction Coromandel wood, the produce of Ceylon and the coast of India, is shipped in logs and planks from Bombay and Madras ; it is of a red hazel-brown colour, handsome for furniture wood, and turns well Corona, the members constituting the uppermost of the three divisions of the entablature of a portico, or any other building in which columns are introduced: this division is termed cornice Corona, that flat, square, and massy member of a cornice, more usually called the drip or larmier, whose situation is between the cymatium above and the bed-moulding below: its use is to carry the water drop by drop from the building Corporax cloth, a linen cloth or nap- kin spread upon the altar, on which the host and chalice are placed at the mass in the Catholic service Corpse-gate, a covered place at the entrance to a churchyard, intended to shelter the corpse and mourners from rain Corridor, a gallery or open communi- cation to the different apartments of a house Corsa, the name given by Vitruvius to ~ 123 a platband or square fascia whose height is more than its projecture Cortile, a small court enclosed by the divisions or appurtenances of a building Cortis, in the middle ages, a court surrounded by edifices Coryceum, a room similar to a tennis- court Costean pits, in Cornish mining, are shallow pits sunk to trace or find tin Costeaning, in mining, the discover- ing of lodes by sinking pits in their vicinity, and drawing transversely to their supposed direction Cot, in nautical phraseology, a bed- frame suspended from the beams of the ship, or otherwise Cotton, a white woolly or downy substance, found in a brown bud, produced by a shrub, the leaves of which resemble those of the syca- more-tree. The bud, which grows as large as a pigeon's egg, turns black when ripe, and divides at top into three parts : the cotton is as white as snow, and with the heat of the sun swells to the size of a pullet's egg. Scripture speaks of cotton. Cotton manufactures and trade. Cot- ton was woven by the Hindoos and Chinese many centuries before the Christian era. The Egyptians are supposed to have imported woven cotton before the plant had begun to be cultivated in their country; and the Romans received woven cotton from India long before the cotton-plant was known in Europe. The extension of the manufacture of it has now become enormous. The export of cotton goods from England, in 1846, was 25,600,693 in value. Cotton spinning: the spinning of cot- ton into the form of yarn or thread requires many preparatory pro- cesses ; but the inventions and im- provements in machinery that have been effected in recent years have rendered the process simple and of great national value Cotton and Calico printing, the art COT COUNTRY RESIDENCES. COU of staining woven fabrics of cotton with various figures and colours Cotton cultivation and trade. The distinctive names by which cotton is known in commerce are mostly derived from the countries which produce it : the exceptions are, sea- island cotton, and upland cotton. The former of these was first cul- tivated in the low sandy islands near the coast of Charleston in America ; while the latter is grown in the inner or upland country. The sea-island cotton is the finest of the several varieties. The upl and is often called Bowled Cotton. ! Cotton, gun, is prepared with cotton wool, and explodes at 400 Fahr. Gunpowder explodes at 600 ! Couched, laid close, as in a stratum j Couissinet. (See Conissinet.} \ Coulisse, any piece of timber which has grooves in it ; also pieces of wood which hold the floodgates in a sluice . Counter, that part of a vessel between the bottom of the stern and the wing transom and buttock Counterfort,, a pier, buttress, or oblique wall, built up against a wall to strengthen and support it 1 Counter-gauge, in carpentry, a method of measuring joints by transferring the breadth of a mortise to the place on another timber where the tenon is to be made Counter-lath, in tiling, a lath placed by the eye Counterpoise, any weight which, placed in opposition to another weight, produces an equilibrium ; but it is more commonly used to denote the weight used in the Ro- man balance, or steelyard Countersinks, in joinery, are bits for widening the upper part of a hole in wood or iron, for the head of a screw or pin, and have a conical head. Those for wood have one cutter in the conic surface, and have the cutting edge more remote from the axis of the cone than any other part of the surface. Coun- tersinks for brass have eleven or 124 twelve cutters round the conic sur- face, so that the horizontal section represents a circular saw. These are called rose-countersinks. The conic angle at the vertex is about 90 degrees. Countersinks for iron have two cutting edges, forming an obtuse angle. Count-house, a reckoning-house, in Derbyshire ; a house or room on the mine used for keeping accounts of the products, &c. Country residences. There are im- portant advantages which deserve to be brought into notice, whether for comfort and convenience, for gratifying taste or fashion. Addi- tional rooms appropriated for new purposes are often requisite. For- merly a gallery, although there were no works of art to fill it, was a ne- cessary part of a mansion ; of late years, the billiard-room and the conservatory enter into the arrange- ments of an architect ; and a suit of well-planned nursery-rooms have been made a necessary part of the plan of a country mansion. The gallery is again about to resume its importance, and perhaps we may hereafter imitate the Romans in having covered walks contiguous to the house, in order to enjoy fresh air in the many rainy and snowy days at a country residence in an English winter. The irregu- lar style admits of such additions, and loses nothing of the picturesque effect. The exterior decorations of terraces, parterres, stairs of com- munication, and different gardens filled with groups of the many flow- ery shrubs and plants, are admirably in harmony with this style of archi- tecture. While we thus decorate closely around the house, it becomes less necessary to sacrifice so much to the park. The masonry of such irregular architecture requires not the expensive labour bestowed on a Grecian or Roman mansion. The whole should be in rough rubble- work, excepting the parapets, the corners, the windows, and doors. cou COUPLINGS. COV Many very good designs of castel- lated dwellings have been, in the execution, deprived of their effect, by being built of smooth, hewn free- stone. If circular or square towers are introduced in a composition of the irregular style, they should, in every case, be of great dimensions, as much for their being applied to useful rooms, as to produce that grandeur of appearance which bulk in towers always gives. Country seats (the) of the Italians have been copied by most civilized na- tions of Europe; celebratedby poets, visited and admired by travellers : they have not, however, been de- scribed or represented as they de- serve. They are so arranged as to produce the best effect, and ad- vantage of the nature of the site has been taken with admirable skill. The regularities of the gardens ac- company the decoration, and sup- port the architecture. (See Parker's 'Villa Rustica,' recently published.) Couple-close, a pair of spars of a roof; also used by heralds as a diminu- tive of the chevron Coupled columns. When, from the extent between columns sometimes necessary for the introduction of doors, windows, niches, or other decorations, neither the eustylos nor the diastylos intercolumniation can be used, coupled columns are fre- quentlyintroduced. In this case two sistylosintercolumniations are used; the column which would otherwise occupy the middle of the space being brought to the distance of only half a diameter (or sufficient room for the projection of the capitals) from the extreme column. The middle space will then be three diameters and a half. This species has been called araeosistylos. When buildings are small, the intercolumniations will not require such particular at- tention to the foregoing rules, for columns should never be placed nearer to each other than 3 feet, which will allow for the easy pas- sage of a bulky person. 125 Coupling, in machinery, is the name given to various arrangements by which the parts of a machine may be connected or disconnected at pleasure, or by which a machine j may be disengaged from, or re- ! engaged with, a revolving wheel or shaft, through which it receives ; motion from a steam engine, water- wheel, or other prime mover Couplings, in mill- work: it is fre- quently necessary to convey motion much farther than would be prac- ticable by any one shaft, and there- fore often requisite to connect two or more shafts together. These connections are denominated coup- lings, and may be divided into two classes : 1st, Those having two bear- ings; 2ndly, Those having one bear- ing. Couplings having two bearings have been long in use, and before those having one bearing, and are generally more simple in their con- struction. Coupling-box, a metal box for joining the ends of two shafts, so that they may revolve together Course, a continuous range of stones or bricks, of uniform height, in the wall of a building Course, in Cornish mining, is a tin or copper course; a phrase for work- ing of the lode Courses, sails that hang from a ship's lower yards : the fore-sail is called the fore-course, and the main-sail the main-course Courts of Justice : there were in Rome twelve halls or courts of justice, where causes were heard and tried : they were adorned with statues, fine columns, and porticoes with double rows of columns Cove, a cave, a recess ; any kind of concave moulding; the concavity of an arch or of a ceiling Coved ceiling, the upper surface of an apartment formed in an arched or coved shape at its junction with the side walls Cover, in slating, the part of the slate that is hidden ; the exposed part being called the margin cov CRANK. CRA Cover-way, in roofing, the recess or internal angle left to receive the covering Come or Covey, a pantry Coving, the exterior projection of the upper parts of a building beyond the limits of the ground-plan Coving, a term applied to houses, &c., that project over the ground-plot Coving of a fire-place,the vertical sides, inclining backwards and inwards, for the purpose of reflecting the heat Cowl, a cover for the top of a chim- ney, made to turn round by the wind, and used to facilitate the escape of smoke Coxswain, the person who steers a boat, and has charge of her Crab, a wooden apparatus, something like a capstan,butnotfurnishedwith a drum-head ; it is used for similar purposes, with holes made to insert the bars Crab, a machine with three claws, used to launch ships, to heave them into the dock, or off the quay Cradle, a frame placed under the bot- tom of a ship, in order to conduct her steadily into the water when she is to be launched, at which time it supports her weight while she slides down the descent or sloping passage, called the ways, which are for this purpose daubed with soap or tallow Craft, a general name for all sorts of vessels employed to load or dis- charge merchant ships, or to carry alongside or return the guns, stores, or provisions of a man-of-war: such are lighters, hoys, barges, &c. Cramp, a short bar of iron, with its ends bent so as to form three sides of a parallelogram : at one end a set-screw is inserted, so that two pieces of metal, being placed be- tween, can be held firmly together by the screw Crane, a machine used for hoisting and lifting stones, ponderous weights, and heavy goods, principally at wharfs and warehouses, now much employed for hoisting heavy build- 126 ing materials ; also as travelling cranes on framed scaffolding, for the assistance of masons, brick- layers, and other artizans in build- ing, saving the time and labour formerly so much prolonged in the execution of the work to be done. (For a succinct account of all kinds of cranes, see Glynn's work in the ' Rudimentary Series.' ) Cranes, pieces of iron or timber at a vessel's sides, used to stow boats or spars upon Crank, the condition of a vessel when she is inclined to lean over a good deal, and cannot bear much sail: this may be owing to her construc- tion, or to her stowage Crank, the arms projecting from the main shaft of an engine, joined to- gether at the outer ends Crank, in mechanics, a square piece projecting from a spindle, serving by its rotation to raise and fall the pistons of engines : it also denotes the iron support for a lantern, and the iron made fast to the stock of a bell Crank, in machinery, is a bend in an axle, by which a reciprocating mo- tion in a rod is made to produce a revolving motion of an axle and of a wheel which may be connected with it Crank, in turning, that part of the axle of the fly which is bent into three knees, or right angles, and three proj ecting parts : one of the parts is parallel to the axis, and has the upper part of the crank- hook collared round it Crank-axle, the driving axle con- nected to the piston-rods of a loco- motive engine Crank-hook, in turning, sometimes also called the connecting-rod, as it connects the treadle and the fly Crank-pin, the cylindrical piece join- ing the ends of the crank arms, and attached to the connecting- rod, or, in vibrating engines, to the piston-rod : if the crank has only one arm. the pin projects from the end of it CRA CROSS (CHURCH). CRO Crayon, a chalk ; a species of mate- rial for drawing. Black chalk, found in Italy, white chalk, found in France, and red chalk, form three of the best varieties of cray- ons : each has its own peculiar value as a drawing material. Creazes, in mining, the work or tin in the middle part of the buddle or dressing Credence, the small table at the side of the altar, or communion table, on which the bread and wine were formerly placed before they were consecrated Creeper, an iron instrument like a grapnel, with four claws, used for dragging the bottom of a harbour or river, to find anything lost Crenelle, the embrasure of a battle- ment, or loopholes Crepido, according to Pliny, any raised basement upon which other things are built or supported, as of a temple, altar, obelisk, &c. Cresset, a candlestick or lamp to con- tain a light Crest, a term in heraldry ; the orna- ment of the helmet Creste, the ornamented finishing sur- rounding a screen or canopy of a building Crest-tiles, those used to cover the ridge of a roof, upon which they fit on the principle of a saddle Cringle, a short piece of rope with each end spliced into the bolt-rope of a sail, confining an iron ring or thimble Criplings, short spars at the sides of houses Crista, a crest ; the apex or highest part of a shrine Crocket, an ornament of foliage or animals running up the back of a pediment, arch-pinnacle, or spire, from the corbels below to the finial above, in which latter the crockets on both sides appear to merge Crockets, projecting leaves, flowers, or bunches of foliage, used in Gothic architecture to decorate the angles of spires, canopies, pinna- cles, &c. 127 Cromlech, in British antiquity, high, broad, and flat stones, raised upon other stones set on end, apparently for the purpose of an altar Crop, ore or tin of the first quality, after it is dressed or cleaned for smelting Crosette, a truss, or console, in the flank or return of an architrave of a door, window, or other aperture in a wall Crosettes, in decoration, the trusses or consoles on the flanks of the ar- chitrave, under the cornice Cross, a gibbet constructed of two pieces of wood placed transversely, whether they cross each other at right angles at the top, like a T, or in the middle of their length, like an X Cross, the symbol of the Christian religion Cross, cross crusse, cross bar, cross goffan, cross lode, either a vein of a metallic nature, or a soft earth, clay, or flookan, like a vein, which unheads and intersects the true lode Cross-bars, round bars of iron bent at each end, used as levers to turn the shank of an anchor Cross-chocks, pieces of timber fayed across the deadwood amidships, to make good the deficiency of the heels of the lower futtocks Cross (church), or a Greek cross, that in which the length of the trans- verse part is equal to that of the nave ; so called because most of the Greek churches were built in that form Cross (church), or a Latin cross, that whose nave is longer than the cross part, as in most Gothic churches Cross-grained stuff', in joinery, wood having its fibres running in con- trary positions to the surfaces, and which consequently cannot be made perfectly smooth when planed in one direction, without turning it or turning the plane Cross-heads, in locomotive engines the part of the motion into which the piston-rod is fitted on the cy- CRO CRYPT. CRY Under side and the connecting-rod attached on the driving wheel axle side Cross-head guides, in locomotive en- gines, the parallel bars between which the cross-head moves in a right line with the cylinder and driving wheel axle: they are also called motion Mrs Cross-head blocks, in locomotive en- gines, the parts which slide between the parallel guides. The ends of the cross-head are fitted into these blocks. The cross-head, cross- head guides, and block, constitute what is called ' the motion of the engine/ Cross-head, in the steam engine, a cross-bar fixed centrally on the top of a piston-rod, and connected to the beam : its motion is confined to a direct line by guides at each end; or, in the side-lever and beam engines, by an apparatus called a ' parallel motion' Cross-jack : the cross-jack yard is the lower yard on the mizen mast Cross-spales, pieces of timber placed across a vessel, and nailed to the frames, to keep the sides together until the knees are bolted | Cross-somer, a beam of timber i Cross-springer, in groined vaulting, the rib which extends diagonally from one pier to another Cross-trees, pieces of oak supported by the cheeks and trestle-trees at the mast-heads, to sustain the tops on the lower mast, and to spread the top-gallant rigging at the top- mast head Cross vaulting is formed by the inter- section of two or more simple vaults of arch-work Croud, or Crowde, a crypt, or under- croft of a church ! Crow, in mechanics, an iron lever, made with a sharp point at one end, and two claws at the other ; used in heaving and purchasing great weights Crow-foot, a number of small lines rove through to suspend an awning Crown, in geometry, a plane ring in- 123 eluded between two concentric perimeters, generated by the mo- tion of part of a right line round the centre, to which the moving part is not contiguous Crown of an anchor, the place where the arms are joined to the shank Crown of an arch, that line or point upon its surface which is the highest or most elevated from its springing Crown-post, the middle post of a trussed roof Crown-ivheels. Circular motion is communicated at right angles by means of teeth or cogs situated parallel to the axis of the wheel. Wheels thus formed are denomi- nated ' crown' or ' contrate wheels :' they act either upon a common pinion or upon a lantern. Crozier, the pastoral staff of a bishop or mitred abbot, having the head curled round somewhat in the man- ner of a shepherd's crook Crucifix, a representation of our blessed Saviour on the cross Crust ce, figures or images in low relief, embossed upon plate Crust arius, an artist; an engraver for inlaid work, &c. Crutch, a knee or piece of knee timber, placed inside a vessel to secure the heels of the cant-tim- bers abaft Cryophorus, an instrument by which the freezing qualities of the atmo- sphere may be ascertained Crypt, a vault beneath a building, either entirely or partly under- ground, frequently under churches and cathedrals Crypta, or Crypt, among the Romans, any long narrow vault, whether wholly or partially below the level of the earth Crypto Portico, an enclosed gallery or portico having a wall with openings or windows in it, instead of columns at the side Ctesibica machina, a double-actioned forcing pump invented by Ctesibius of Alexandria Cuare (Cornish), a quarry of stones CUB CUPBOARDS. CUP Cubature, the cubing of a solid, or measuring of the space compre- hended in a solid, as in a cone, pyramid, cylinder, &c. Cube, in geometry, a regular or solid body consisting of six square and six equal faces and sides, and its angles all right, and therefore equal Cube, or Hexahedron, a solid regular body, consisting of six equal square sides Cubes, or Cube numbers in arithmetic, and the theory of numbers, are those whose cube root is a com- plete integer ; or they are numbers produced by multiplying a given number twice into itself, or by the multiplication of three equal fac- tors Cube root, of a number, say 8, the number which multiplied into itself twice will produce 8 namely, 2 ; or it is that number by which, if you divide a number twice, the quotient will be equal to itself Cubic foot of water, what a vessel 1 foot square and 1 foot deep will hold Cubicule, among the Romans, a bed- chamber, tent, or balcony Cubiculum, according to Pliny, a room furnished with a sofa or bed Cubile, the ground-work or lowest course of stones in a building Cubit, a measure used among the ancients, and which the Hebrews call ' amma,' the mother of other measures. A cubit was originally the distance from the elbow to the extremity of the middle finger; which is the fourth part of a well- proportioned man's stature. Cubital, a bolster or cushion for the elbow to rest upon, for invalids Cuboch, a name for the unit or in- teger of a power, being the effect produced by one cubic foot of water in one foot perpendicular descent 'uckold's-neck, a knot by which a a rope is secured to a spar, the two parts of the rope crossing each other and seized together 129 F 5 Cuddy, a cabin in the fore part of a boat Cullis, a gutter in a roof; any groove or channel Culm, stone coal, resembling the Kil- kenny coal of Ireland Culmen, the roof of a house or church Culverhouse, a dove-cot or pigeon- house Culvert, an arched drain for the pas- sage of water Culvert, an arched passage or bridge beneath a road, canal, or railway Culver-tail, to dove-tail Cuneus, the division of the audience part of a theatre comprehended between two adjoining scalaria or staircases which lead from one prsecinctio to another : so called from its form, which resembles a wedge. The foremost cunei were termed ' cavae prima ;' the middle, ' cavse media ;' and the uppermost, ' cavae summa.' The whole of the audience part, exclusive of the orchestra, was likewise called ' 'cavae.' Cupboards answered in some respects | to the sideboards of the pre- sent day. They were sometimes mere planched tops, resting on 1 trestles, or fixed with legs against the wall ; at others, framed on stages, rising one above another, and moveable : these were called 'joined cupboards,' occasionally carved, and, like tables, covered with carpets. At the marriage of Prince Arthur, son of Henry VII., in the hall was a triangular cup- board, five stages high, set with ' plate, valued at JE1200, entirely j ornamental ; and in the " utter chamber," where the princess dined, was another cupboard, " set with gold plate, garnished with stone and pearl," and valued at 20,000. Cupola, a small room, either circular or polygonal, standing on the top of a dome : by some it is called a lantern Cupola, a spherical or spheroidal CUP CYCLOIDAL CURVES. CYC covering to a building, or any part of it Cup-valve, for a steam-engine : it re- sembles a conical valve, made to fit a cover in the form of a vase or of the portion of a sphere Curia, in architecture ; the building in which the highest council of the Roman state assembled, des- cribed by Vitruvius as being ad- jacent to the agora or forum Cur ling -stuff, in joinery, that which is produced by the winding or coiling of the fibres round the boughs of a tree, when they begin to shoot out of the trunk Current, a stream or flux of water in any direction. The setting of the current is that point of the com- pass towards which the waters run ; and the drift of a current is the rate it runs per hour. Curtilage, a term formerly applied to the division or boundary of manor- ial lands Curve, in geometry, a line wherein the several points of which it con- sists tend several ways, or are posited towards different quarters Curvilinear, consisting of curved lines Cushion-capital, the capital of a co- lumn so sculptured as to resemble a cushion pressed down by the weight of its entablature Cushions and window -pillows were, in Tudor times, stuffed not unlike the woolsack of the lord chancellor in round, square, and oblong shapes, covered with carpet- work, velvet, or embroidery; the family armsfrequentlysupplyingthe device Cusp, an ornament generally in Gothic windows or doors : it is to be found in the concave bends of stone-work Cusps, projecting points forming the featherings or foliation in Gothic tracery, archery, panels, &c. Cut, in mining, to intersect a vein, branch, or lode, by driving hori- zontally or sinking perpendicularly at right angles Cutter, a small boat ; also a kind of sloop Cutting. Cutting instruments act in 130 dividing bodies upon the same principle as the wedge. The blade of the instrument is in general a thin wedge, but the edge itself is usually much more obtuse. Cutwater, in a ship, is the sharp part of the head under the beak or figure Cycle, a round of time ; a space in which the same revolution begins again ; a periodical space of time Cycle, lunar, a period of nineteen years Cycle, solar, a period of twenty-eight years, after which the days of the month return to the same days of the week Cyclograph, or Arcograph, an instru- ment for drawing arcs of circles without centres, used in architec- tural and engineering drawings when the centres are too distant to be conveniently accessible Cycloidal curves are defined as fol- lows : 1. When a circle is made to rotate on a rectilinear basis, the figure described on the plane of the basis by any point in the plane of the circle is called a trochoid : a circle concentric with the gene- rating circle, and passing through the describing circle. 2. If the describing point is in the circum- ference of the rotating circle, the two circles coincide, and the curve is called a cycloid. 3. If a circular basis be substituted for a rectilinear one, the trochoid will become an epitrochoid, and the cycloid an epicycloid. Cyclopian Architecture, a class of building supposed to have preceded the invention of the classic orders in Greece, and attributed to the Cyclopes Cyclopean wall, the oldest example of mason-work in Italy : in town-walls only has this style of building been used. The history of its origin is obscure. A large irregular mass of stone, having three, four, five, or more sides, hewn only on the irregular sides to be built upon, begins a wall : to this mass others are added, the sides of which are CYC CYMA, DADO. CY made to fit the irregular sides of the first block ; and on these again others of similar forms are built in the same manner. Cyclostylar, relating to a structure composed of a circular range of columns without a core; with a core, the range would be a peristyle Cylinder, a body having two flat sur- faces and one circular: for in- stance, a roller is a cylinder Cylinder, a roller used for levelling and condensating the ground in agri- cultural and other operations Cylinders, in steam engines, hollow cylindrical vessels : within the cy- linder the steam exerts its power upon the piston, which, by means of its rod, transmits it to the other parts of the engine Cylinders, in locomotive engines, hollow vessels, usually made of cast iron, and bored out accurately, into which pistons are fitted steam- tight, yet easily moveable by the pressure of the steam Cylinder cocks, in steam engines, cocks placed in convenient parts of the cylinder for admitting oil to lubricate the piston, or by which to blow out the condensed steam, or any deposit in the cylinders Cylinder cover, in steam engines, the lid bolted to a flanch round the top of a cylinder, so as to be perfectly steam-tight : it has a stuffing-box cast in the centre, through which the piston-rod alternates Cylindrical vault, a vault without groins, resting upon two parallel walls DAC ACTYLUS, aGreek measure of length, the sixteenth part of an English foot lado, a term for the die or plane face of a pedestal. The dado em- ployed in the interior of buildings is a continuous pedestal, with a plinth and base moulding, and a cornice or dado moulding sur- mounting the die. 131 Cylindrical walling is that erecte( upon a circular plan, forming cylinder, or a part less than a cy linder, according as the plan is a entire circumference or a less por tion Cyling, anciently ceiling. Cyma, called also cymatium, its nam arising from its resemblance to wave ; a moxilding which is hollo\ in its upper part, and swelling be low. There are two sorts, th Cyma recta, just described, anc the Cyma reversa, whose uppe part swells, whilst the lower par is hollow. Cymatium, a moulding whose section or profile is convex below and con cave above, somewhat resembling the letter S Cymophane, a mineral of a green colour, resembling the chrysobery Cypress-tree, one of the evergreens very proper to mix with pines anc firs in forming clumps. The wood of the cypress is very valuable, when grown to a size fit for planks, which dimension it attains in as short a time as oak. It was much used by the ancients, and was em- ployed in the original doors of St. Peter's at Rome, which, on being replaced, after six hundred years, by gates of brass, were found to be perfectly free from decay, and with- in to have retained part of the ori- ginal odour of the wood. Cyrtostyle, a circular projecting por- tico Cyzicenus, anciently a hall decorated with sculpture DAD Dado, the solid block or cube forming the body of a pedestal, in classical architecture, between the base mouldings and cornice; an archi- tectural arrangement of mouldings, &c. round the lower part of the walls of a room Dagger, in ship-building, a piece of timber that crosses all the poppets DAG DATA. DAT of the bulge-ways, to keep them together: the plank that secures the heads of the poppets is called the dagger-plank Dagger knees are lodging knees, with side arms cast down and bolted through the clamp : they are placed at the lower decks of some ships, instead of hanging knees, to pre- serve as much stowage in the hold as possible Dairy-house, a place for keeping milk Dais, in early domestic architecture, the chief seat at the high board or principal table (cross-table) in a baronial hall; also the principal table itself, and the raised part of the floor on which it is placed Dais, a canopy to cover an altar, throne, or tribunal; the chief or upper table in a monastery Dam, a bank or obstruction built across a river or stream, for the purpose of raising the level of the water on the upper side of it. Dams built for the purpose of in- land navigation, or for that of se- curing a water power, may be con- sidered as having a more permanent character. Damascus steel, a sort of steel brought from the Levant, greatly esteemed for the manufacture of cutting in- struments Damasquine, a term applied to orna- mental work of gold or silver, in- crusted on iron or steel Damonico or Monicon, an iron ochre, being a compound of terra di sienna and Roman ochre, burnt, and hav- ing all their qualities : it is rather more russet in hue than the orange de Mars, has considerable transpa- rency, is rich and durable in colour, and affords good flesh tints i Damper, a valve placed in a chimney, to diminish the draught when the heat is too intense Damper, in locomotive engines, a kind of iron Venetian blind, fixed to the smoke-box end of the boiler, in front of the tubes : it is shut down when the engine is standing, and thus stops the draught and econo- 132 mizes fuel ; but it is opened when the engine is running Damps : various kinds of permanently elastic fluids generated in mines are thus named by the miners : choke-damps consist mostly of carbonic acid gas, and fire-damps of carburetted hydrogen gas Dancette, in heraldry, zigzag or chevron fret; seen in Norman buildings Data useful in various calculations of the properties of materials. [The data correspond to the mean tem- perature and pressure of the atmo- sphere ; the materials are assumed to be dry, and the temperature is measured by Fahrenheit's scale.] AIR. Specific gravity, 0-0012; weight of a cubic foot, 0-0753 ft., or 527 grains (Shuckburgh) ; 13*3 cubic feet, or 17 cylindric feet of air, weigh 1 ft>. ; it expands -^ or 00208 of its bulk at 32 by the addition of one degree of heat (Dulong and Petit). ASH. Specific gravity, 0'76 ; weight of a cubic foot, 47'5fts. ; weight of a bar 1 foot long and 1 inch square, 0-33 ft. ; will bear without permanent alteration a strain of 3540 fts. upon a square inch, and an extension of -^^ of its length ; weight of modulus of elas- ticity for a base of an inch square, 1,640,000 fts. ; height of modulus of elasticity, 4,970,000 feet; mo- dulus of resilience, 7'6 ; specific resilience, 10. (Calculated from Barlow's experiments.) Compared with cast iron as unity, its strength is 0-23 ; its extensibi- lity, 2-6 ; and its stiffness, 0-089. ATMOSPHERE. Mean pressure of, at London, 28-89 inches of mercury = 14'18fts. upon a square inch. (Royal Society.) The pressure of the atmosphere is usually estimated at 30 inches of mercury, which is very nearly 14f fts. upon a square inch, and equivalent to a column of water 34 feet high. BEECH. Specific gravity, 0*696 weight of a cubic foot, 45-3 fts. DAT weight of a bar 1 foot long and 1 inch square, 0'315 ft.; will bear without permanent alteration on a square inch, 2360 fts., and an ex- tension of ^3^5- of its length; weight of modulus of elasticity for a base of an inch square, 1, 345,000 fts. ; height of modulus of elasticity, 4,600,000 feet ; modulus of resi- lience, 4-14; specific resilience, 6. (Calculated from Barlow's Experi- ments.) Compared with cast iron as unity, its strength is 0'15 ; its extensibi- lity, 2-1; and its stiffness, 0-073. BRASS, cast. Specific gravity, 8-37; weight of a cubicfoot,523fts.; weight of a bar 1 foot long and 1 inch square, 3 '63 fts. ; expands Sagoo of its length by one degree of heat (Troughton); melts at 1869 (Daniell) ; cohesive force of a square inch, 18,000 fts. (Rennie); will bear on a square inch without perma- nent alteration, 6700 fts., and an extension in length of 7-^33-; weight of modulus of elasticity for a base of an inch square, 8,930,000 fts. ; height of modulus of elasticity, 2,460,000 feet; modulus of resi- lience, 5 ; specific resilience, 0-6 (Tredgold). Compared with cast iron as unity, its strength is 0'435 ; its extensibility, 0*9 ; and its stiffness, 0-49. BRICK. Specific gravity, 1-841; weight of a cubic foot, 115 fts. ; absorbs -^ of its weight of water ; cohesive force of a square inch, 275 fts. (Tredgold) ; is crushed by a force of 562 fts. on a square inch (Rennie.) BRICK-WORK. Weight of a cubic foot of newly built, 117 fts. ; weight of a rod of new brick-work, 16 tons. BRIDGES. When a bridge is covered with people, it is about equivalent to a load of 120 fts. on a superficial foot ; and this may be esteemed the greatest possible ex- traneous load that can be collected on a bridge ; while one incapable 133 DATA. DAT of supporting this load cannot be deemed safe. BRONZE. See Gun-metal. CAST IRON. Specific gravity, 7'207 ; weight of a cubic foot, 450 fts. ; a bar 1 foot long and 1 inch square weighs 3'2 fts. nearly ; it expands T ^oo- of its length by one degree of heat (Roy) ; greatest change of length in the shade in this climate, yyVs"'' greatest change of lengthwhen exposed tosun'srays, -j^; melts at 3479 (Daniell), and shrinks in cooling from -^ to ^ of its length (Muschet) ; is crushed by a force of 93,000 fts. upon a square inch (Rennie) ; will bear without permanent alteration, 15,300 fts. upon a square inch, and an extension of -j^W of its length ; weight of modulus of elasticity for a base 1 inch square, 1 8,400,000fts.; height of modulus of elasticity, 5,750,000 feet; modulus of resi- lience, 12- 7 ; specific resilience, 1-76 (Tredgold). CHALK. Specific gravity, 2-315; weight of a cubic foot, 144' 7 fts. ; is crushed by a force of 500 fts. on a square inch. (Rennie.) CLAY. Specific gravity, 2-0 ; weight of a cubic foot, 125 fts. COAL, Newcastle. Specific gra- vity, 1-269 ; weight of a cubic foot, 79-31 fts. A London chaldron of 36 bushels weighs about 28 cwt., whence a bushel is 87 fts. (but is usually rated at 84 fts.) A New- castle chaldron, 53 cwt. (Smea- ton.) COPPER. Specific gravity, 8'75 (Hatchett) ; weight of a cubic foot, 549 fts.; weight of a bar 1 foot long and 1 inch square, 3'81 fts. ; ex- pands in length by one degree of h ea t> lo/aoo (Smeaton) ; melts at 2548 (Daniell) ; cohesive force of a square inch, when hammered, 33,000 fts. (Rennie). EARTH, common. Specific gra- vity, 1-52 to 2-00 ; weight of a cubic foot, from 95 to 125 fts. ELM. Specific gravity, 0-544 ; weight of a cubic foot, 34 fts. DAT DATA. DAT weight of a bar 1 foot long and 1 inch square, 0-236 ft. ; will bear on a square inch without perma- nent alteration, 3240 fts., and an extension in length of ^j-^ ; weight of modulus of elasticity for a base of an inch square, 1, 340,000 fts. ; height of modulus of elasticity, 5,680,000 feet; modulus of resi- lience, 7 '8 7 ; specific resilience, 14-4. (Calculated from Barlow's Experiments.) Compared with cast iron as unity, its strength is 0-21 ; its extensi- bility, 2-9 ; and its stiffness, 0-073. FIR, red or yellow. Specific gra- vity, 0-557 ; weight of a cubic foot, 34-8 fts. ; weight of a bar 1 foot long and 1 inch square, 0-242 ft. ; will bear on a square inch without permanent alteration, 4290 fts. = 2 tons nearly, and an extension in length of %$$ ; weight of modulus of elasticity for a base of an inch square, 2,016,000 fts. ; height of modulus of elasticity, 8,330,000 feet; modulus of resilience, 9-13; specific resilience, 16'4. (Tred- gold.) Compared with cast iron as unity, its strength is 0'3 ; its extensibi- lity, 2-6, and its stiffness, 0-1154, FIR, white. Specific gravity, 0-4 7; weight of a cubic foot, 29'3 fts. ; weight of a bar 1 foot long and 1 inch square, 0-204 ft.; will bear on a square inch without perma- nent alteration, 3630 fts., and an extension in length of -5^. ; weight of modulus of elasticity for a base of an inch square, 1,830,000 fts. ; height of modulus of elasticity, 8,970,000 feet; modulus of resi- lience, 7'2 ; specific resilience, 15-3. (Tredgold.) Compared with cast iron as unity, its strength is 0-23 ; its extensibi- lity, 2-4 ; and its stiffness, 0-1. FLOORS. The weight of a super- ficial foot of a floor is about 40 fts. when there is a ceiling, counter- floor, and iron girders. When a floor is covered with people, the 134 load upon a superficial foot may be calculated at 120 fts.: therefore, 120 + 40 = 160 fts. on a superficial foot is the least stress that ought to be taken in estimating the strength for the parts of a floor of a room. FORCE. See Gravity, Horse, &c. GRANITE, Aberdeen. Specific gravity, 2-625 ; weight of a cubic foot, 164 fts.; is crushed by a force of 10-910 fts. upon a square inch. (Rennie.) GRAVEL. Weight of a cubic foot, about 120 fts. GRAVITY generates a velocity of 32 feet in a second in a body falling from rest ; space described in the first second, 16^ feet. GUN-METAL, cast (copper 8 parts, tin 1). Specific gravity, 8-153; weight of a cubic foot, 509 fts. ; weight of a bar 1 foot long and 1 inch square, 3-54 fts. (Tredgold) ; expands in length by 1 of heat, flflpgo (Smeaton) ; will bear on a square inch without per- manent alteration, 10,000 fts., and an extension in length of -^^ ; weight of modulus of elasticity for a base 1 inch square, 9,873,000 fts.; height of modulus of elasticity, 2,790,000 feet; modulus of resi- lience, and specific resilience, not determined (Tredgold). Compared with cast iron as unity, its strength is 0-65 ; its extensibi- lity, 1-25 ; and its stiffness, 0-535. HORSE, of average power, pro- duces the greatest effect in draw- ing a load when exerting a force of 187ifts. with a velocity of 2 feet per second, working 8 hours in a day. (Tredgold.) A good horse can exert a force of 480 fts. for a short time. (Desaguliers.) In calculating the strength for horse machinery, the horse's power should be considered 400 fts. IRON, cast. See Cast Iron. Iron, malleable. Specific gravity, 7'6 (Muschenbroek) ; weight of a cubic foot, 475 fts. ; weight of a bar 1 foot long and 1 inch square, DAT DATA. DAT 3-3 fts. ; ditto, when hammered, 3-4 fts.; expands in length by lof heat TTsVoo- ( Smeaton ) ; good English iron will bear on a square inch without permanent alteration, 17,800 fts. = 8 tons nearly, and an extension in length of ^ Q ; cohe- sive force diminished ^oW D J r an elevation 1 of temperature; weight of modulus of elasticity for a base of an inch square, 24,920,000 fts. ; height of modulus of elasticity, 7,550,000 feet; modulus of resi- lience, and specific resilience, not determined (Tredgold). Comparedwith cast iron as unity, its strength is 1-12; its extensibi- lity, 0-86 ; and its stiffness, 1-3. LARCH. Specific gravity, '560 ; weight of a cubic foot, 35 fts. ; weight of a bar 1 foot long and 1 inch square, 0-243 ft. ; will bear on a square inch without perma- nent alteration, 2065 fts., and an extension in length of -^^ ; weight of modulus of elasticity for a base of an inch square, 10,074,000 fts. ; height of modulus of elasticity, 4,415,000 feet; modulus of resi- lience, 4; specific resilience, 7*1. (Calculated from Barlow's Experi- ments.) Compared with cast iron as unity, its strength is 0-136 ; its extensi- bility, 2-3 ; and its stiffness, 0-058. LEAD, cast. Specific gravity, 11-353 (Brisson) ; weight of a cubic foot, 709-5 fts.; weight of a bar 1 foot long and 1 inch square, 4-94 fts. ; expands in length by 1 degree of heat, g^oo (Smeaton) ; melts at 612 (Crichton) ; will bear on a square inch without per- manent alteration, 1500 fts., and an extension in length of -^^ ; weight of modulus of elasticity for a base 1 inch square, 720,000 fts. ; height of modulus of elasticity, 146,000 feet; modulus of resi- lience, 3-12; specific resilience, 0-27 (Tredgold). Comparedwith cast iron as unity, its strength is 0-096 ; its extensi- bility, 2-5 ; and its stiffness, 0-0385. 135~ MAHOGANY, Honduras. Specific gravity, 0-56 ; weight of a cubic foot, 35 fts.; weight of a bar 1 foot long and 1 inch square, 0-243 ft. ; will bear on a square inch without permanent alteration, 3800 fts., and an extension in length of -^^ ; weight of modulus of elasticity for a base 1 inch square, 1,596,000 fts.; height of modulus of elasticity, 6,570,000 feet; modulus of resi- lience, 9-047; specific resilience, 16-1. (Tredgold.) Comparedwith cast iron as unity, its strength is 0*24 ; its extensibi- lity, 2-9 ; and its stiffness, 0-487. MAN. A man of average power produces the greatest effect when exerting a force of 31-1 fts. with a velocity of 2 feet per second, for 10 hours in a day. (Tredgold.) A strong man will raise and carry from 250 to 300 fts. (Desaguliers.) MARBLE, white. Specific gra- vity, 2*706; weight of a cubic foot, 169 fts. ; weight of a bar 1 foot long and 1 inch square, 1-17 ft. ; cohesive force of a square inch, 1811 fts.; extensibility, Tg ^ of its length ; weight of modulus of elas- ticity for a base of an inch square, 2,520,000 fts. ; height of modulus of elasticity, 2,150,000 feet; mo- dulus of resilience at the point of fracture, 1*3; specific resilience at the point of fracture, 0-48 (Tred- gold) ; is crushed by a force of 6060 fts. upon a square inch (Rennie). MERCURY. Specific gravity, 13-568 (Brisson); weight of a cubic inch, 0-4948 ft.; expands in bulk by 1 of heat, ^fa (Dulong and Petit) ; weight of modulus of elasticity for a base of an inch square, 4,417,000 fts.; height of modulus of elasticity, 750,000 feet (Dr. Young, from Canton's Experi- ments). OAK, good English. Specific gravity, 0-83 ; weight of a cubic foot, 52 fts.; weight of a bar 1 foot long and 1 inch square, 0'36ft. ; will bear upon a square inch with- DAT DATA. DAT out permanent alteration, 3960 fts., and an extension in length of -^^ ; weight of modulus of elasticity for a base 1 inch square, l,700,000fts,; height of modulus of elasticity, 4,730,000 feet; modulus of resi- lience, 9'2; specific resilience, 11. (Tredgold.) Compared with cast iron as unity, its strength is 0*25; its ex- tensibility, 2-8; and its stiffness, 0-093. PENDULUM. Length of pendu- lum to vibrate seconds in the lati- tude of London, 39-1372 inches (Kater); ditto to vibrate half- seconds, 9'7843 inches. PINE, American yellow. Specific gravity, 0'46 ; weight of a cubic foot, 26ffts.; weight of a bar 1 foot long and 1 inch square, 0-186 ft. ; will bear on a square inch without permanent alteration, 3900 fts., and an extension in length of TIT 5 weight of modulus of elas- ticity for a base of an inch square, 1, 600,000 fts. ; height of modulus of elasticity, 8,700,000 feet; mo- dulus of resilience, 9-4 ; specific resilience, 20. (Tredgold.) Compared with cast iron as unity, its strength is 0-25 ; its ex- tensibility, 2-9; and its stiffness, 0-087. PORPHYRY, red. Specific gra- vity, 2 '8 71 ; weight of a cubic foot, 1 79 fts. ; is crushed by a force of 35,568 fts. upon a square inch. (Gauthey.) ROPE, hempen. Weight of a common rope 1 foot long and 1 inch in circumference, from 0-04 to 0'46 ft. ; and a rope of this size should not be exposed to a strain greater than 200 fts. ; but in com- pounded ropes, such as cables, the greatest strain should not exceed 120 fts.; and the weight of a cable 1 foot in length and 1 inch in circumference does not exceed 0-027 ft. The square of the cir- cumference in inches multiplied by 200 will give the number of pounds j a rope may be loaded with ; and 136 multiply by 120 instead of 200 for cables. Common ropes will bear a greater load with safety after they have been some time in use, in con- sequence of the tension of the fibres becoming equalized by repeated stretchings and partial untwisting. It has been imagined that the im- proved strength was gained by their being laid up in store ; but if they can there be preserved from deterioration, it is as much as can be expected. ROOFS. Weight of a square foot of Welsh rag slating,! l^fts.; weightof a square foot of plain tiling, 16^ fts. ; greatest force of the wind upon a superficial foot of roofing may be estimated at 40 fts. SLATE, Welsh. Specific gravity, 2-752 (Kirwan) ; weight of a cubic foot, 1 72 fts. ; weight of a bar 1 foot long and 1 inch square, 1-19 ft. ; cohesive force of a square inch, 1 1,500 fts. ; extension before frac- ture, YgVo' weight of modulus of elasticityfor abase of an inch square, 15,800,000 fts.; height of modulus of elasticity, 13,240,000 feet; mo- dulus of resilience, 8-4 ; specific re- silience, 2 (Tredgold). SLATE, Westmoreland. Cohe- sive force of a square inch, 78 70 fts. ; extension in length before fracture, TsVo weight of modulus of elas- ticity for a base of an inch square, 12,900,000 fts. (Tredgold). SLATE, Scotch. Cohesive force of a square inch, 9600 fts. ; exten- sion in length before fracture, l6 \ 5 ] weight of modulus of elasticity for a base 1 inch square, 15, 790,000 fts. (Tredgold). STEAM. Specific gravity at 2 12 is to that of air at the mean tem- perature as 0-472 is to 1 (Thomson) ; weight of a cubic foot, 249 grains ; modulus of elasticity for a base of an inch square, 14f fts. ; when not in contact with water, expands T i 75 - ofitsbulkbylofheat(Gay-Lussac). STEEL. Specific gravity, 7'84 ; weight of a cubic foot, 490 fts.; a bar 1 foot long and 1 inch square DAT DATA. DAT weighs 3-4 tbs.; it expands in length by 1 of heat, T7r7 ^ TnT (Roy); tern- pered steel will bear without per- manent alteration, 45,000 tbs. ; co- hesive force of a square inch, 130,000 fts. (Rennie) ; cohesive force diminished ^oVo" ^Y elevating the temperature 1; modulus of elasticity for a base of an inch square, 29,000,000 fts. ; height of modulus of elasticity, 8,530,000 feet (Dr. Young). STONE, Portland. Specific gra- vity, 2-113 ; weight of a cubic foot, 132 fts. ; weight of a prism 1 inch square and 1 foot long, 0-92 ft. ; absorbs T ^ of its weight of water (R. Tredgold) ; is crushed by a force of 3729 fts. upon a square inch (Rennie) ; cohesive force of a square inch, 857 fts. ; extends be- fore fracture T7 V^ f ^ ts length ; modulus of elasticity for a base of aninch square, l,533,000fts.; height of modulus of elasticity, 1,672,000 feet ; modulus of resilience at the point of fracture, 0*5 ; specific re- silience at the point of fracture, 0-23 (Tredgold). STONE, Bath. Specific gravity, T975 ; weight of a cubic foot, 123-4 fts.; absorbs ^ of its weight of water (R. Tredgold) ; cohesive force of a square inch, 478 fts. (Tredgold). STONE, Craigleith. Specific grav- ity, 2-362 ; weight of a cubic foot, 14 7-6 fts.; absorbs $ of its weight of water; cohesive force of a square inch, 7 72 fts. (Tredgold); is crushed by a force of 5490fts. upon a square inch (Rennie). STONE, Dundee. Specific grav- ity, 2-621 ; weight of a cubic foot, 163-8 fts. ; absorbs -^ part of its weight of water ; cohesive force of a square inch, 2661 fts. (Tredgold); is crushed by a force of 6630 fts. upon a square inch (Rennie). STONE-WORK. Weight of a cubic foot of rubble-work, about 140 fts.; of hewn stone, 160 fts. TIN, cast. Specific gravity, 7'291 (Brisson) ; weight of a cubic foot, 137 455-7 fts. ; weight of a bar 1 foot long and 1 inch square, 3-165 fts. ; expands in length by 1 of heat, ,^ 10 (Smeaton); melts at 442 (Crichton) ; will bear upon a square inch without permanent alteration, 2880 fts., and an extension in length of 1 g 1 00 ; modulus of elas- ticity for a base of an inch square, 4,608,000; height of modulus of elasticity, 1,453,000 feet; modulus of resilience, 1-8 ; specific resilience, 0-247 (Tredgold). Compared with cast iron as unity, its strength is 0-182 ; its extensibi- lity, 0-75 ; and its stiffness, 0-25. WATER, river. Specific gravity, 1-000; weight of a cubic foot, 62-5 fts. ; weight of a cubic inch, 252-525 grains ; weight of a prism 1 foot long and 1 inch square, 0-434 ft. ; weight of an ale gallon of water, 10-2 fts.; expands in bulk by 1 of heat, ^^_ (Dalton) ; ex- pands, in freezing, -^ of its bulk (Williams); andthe expandingforce of freezing water is about 35,000fts. upon a square inch, according to Muschenbroek's valuation ; modu- lus of elasticity for a base of an inch square, 326,000 fts.; height of modulus of elasticity, 750,000 feet, or 22,100 atmospheres of 30 inches of mercury (Dr. Young, from Can- ton's Experiments). Water has a state of maximum density at or near 40, which is considered an exception to the general law of expansion by heat : it is extremely improbable that there is any thing more than an apparent exception, most likely arising from water at low temperatures absorbing a considerable quantity of air, which has the effect of expanding it, and consequently of causing the appa- rent anomaly. WATER, sea. Specific gravity, 1-0271 ; weight of a cubic foot, 64-2 fts. WATER is 828 times the density of air of the temperature 60, and barometer 30. WHALE-BONE. Specific gravity, DAT DEBRIS. DEB 1'3 ; weight of a cubic foot, Sifts.; will bear a strain of 5600 fts. upon a square inch without permanent alteration, and an extension in length of T^-; modulus of elas- ticity for a base of an inch square, 820,000 fts. ; height of modulus of elasticity, 1,458,000 feet; modulus of resilience, 38'3 ; specific resili- ence, 29. (Tredgold.) WIND. Greatest observed ve- locity, 159 feetper second (Rochon); force of wind with that velocity, about 57f fts. on a square foot. ZINC, cast. Specificgravity,7'028 (Watson) ; weight of a cubic foot, 4394- fts. ; weight of a bar 1 inch square and 1 foot long, 3'05 fts. ; expands in length by 1 of heat, srthjcr (Smeaton); melts at 648 (Daniell) ; will bear on a square inch without permanent alteration, 5700 fes. = 0-365 cast iron, and an extension in length of ^^ 00 = ^that of cast iron (Tredgold) ; modulus of elasticity for a base of an inch square, 13, 680,000 fts. ; height of modulus of elasticity, 4,480,000 feet ; modulus of resilience, 2-4 ; specific resilience, 0'34 (Tredgold). Compared with cast iron as unity, its strength is 0'365 ; its extensibi- lity, 0-5; and its stiffness, 0'76 Data, a term for such facts, things, or quantities as are given or known, in order thereby to find other things that are unknown Davit, in navigation, a short boom fitted in the fore channel, to hoist the flukes of the anchor to the bow, which is called ' fishing the anchor' Day or Bay, in architecture, one of the lights or compartments between mullion and mullion, in the great windows of the pointed style Days, in early domestic architecture, the bay or lights of a window; the spaces between the mullions Dead colouring is the first layer of colours, consisting usually of some shade of grey. Its design is to receive and preserve the finishing colours ; and it is called dead be- 138 cause it is not seen when the work is completed Dead doors, in ship building, fitted to the outside of the quarter-gallery doors, in case the quarter-gallery should be carried away Dead eyes, fixed in the channels, with three holes to receive the lanyard of the shrouds Dead fiat, the name of a midship board Dead lights, in navigation, wooden shutters for the cabin windows, which are fastened on when the sea runs high Dead reckoning, the estimation which seamen make of the ship's place, by keeping an account of her way by the log, by the course steered, and by rectifying the whole by al- lowance for drift, leeway, &c. Dead shore, a piece of timber worked up in brick-work, to support a su- perincumbent mass until the brick- work which is to carry it has set or become hard Dead water, the eddy water imme- diately at the stern of a ship while under way Dead wood, pieces of timber fayed on the keel to seat the flow-tim- bers on afore and abaft the floors, and continued as high as the cutting down of the floors Deafening sound boarding, the pugging used to prevent the passage of sound through wooden partitions Deam, a door-post, or threshold ; to conceal, or shut up Deambulatory, an ambulatory or clois- ter for exercise ; also the aisles of a church, or the porticoes round the body of a church Debacle, a great aqueous torrent, a breaking up and transport of mas- sive rocks and gravel by an enor- mous rush of water Debris, fragments of rocks, boulders, gravel, sand, trunks of trees, &c., detached from the summits and sides of mountains by the effect of the elements Decade, the sum of ten Decagon, in geometry, a plain figure of ten sides DEC DEFINITIONS IN GEOMETRY. DBF Decalogue, the Ten Commandments delivered to the Israelites from Mount Sinai, in which the moral law is summarily comprehended. The Jews call these precepts ' The Ten Words.'* In the building of new churches, and in the restora- tion of those of olden times, a pro- per and effective style of painting and embellishing the words of the ten commandments in face of the altar has been introduced. Decanicum, an ecclesiastical prison Decastyle, in architecture : a temple is said to be decastyle when its por- tico contains ten columns in a line Decastyle, a portico consisting of ten columns in front Decempeda, a ten-foot rod employed by architects and surveyors for taking measurements Decemremis, a vessel with ten banks of oars on a side Decimal, the tenth part Deck, the floor of a ship Decoration, the combination of orna- mental objects which are employed in great variety, principally for the interior and exterior of all kinds of edifices, and for purposes of art generally. Decoration, when judi- ciously introduced, becomes in many instances a language, intel- ligible only, however, when the artist is capable of speaking it correctly and the spectator of comprehending it. It is then a system of hieroglyphic writing, and the building to which it is ap- plied becomes historical, and tells its tale more nobly and appro- priately than it can ever do through the undignified medium of mural inscriptions. Nothing can be more judicious or appropriate than the sculpture in the metopes and pedi- ment of the Parthenon. Ornament here not only creates a variety on the surface of the work, but re- lates, by the aid of the sculptor, a history intimately connected with the religious and moral destination of the edifice to which it is applied. Decorative style of Gothic Architec- ture : first introduced in the reign of Edward I., it was matured in England, and prevailed during the greater part of the 14th century. Its distinguishing features, says Dr. "Whewell, are characterized by its window-tracery, geometrical in the early instances, flowing in the later; but also, and perhaps bet- ter, by its triangular canopies, crocketed and finialed ; its niched buttresses, with triangular heads ; its peculiar mouldings, no longer a collection of equal rounds, with hollows like the early English, but an assemblage of various members, some broad, some narrow, beauti- fully grouped and proportioned. A capital with crumpled leaves, a peculiar base and pedestal, also belong to this style. Definitions in geometry : 1. A point is that which hath no parts, or which hath no magni- tude. 2. A line is length without breadth. 3. A superficies has length and breadth. 4. A solid is a figure of three di- mensions, having length, breadth, and thickness. Hence surfaces are extremities of solids, and lines the extremities of surfaces, and points the extremities of lines. If two lines will always coincide, however applied, when any two points in the one coincide with the two points in the other, the two lines are called straight lines, or otherwise right lines. A curve continually changes its direction between its extreme points, or has no part straight. Parallel lines are always at the same distance, arid will never meet, though ever so far produced. Ob- lique right lines change their dis- * To these the Saviour added another: " A new commandment I give unto you, That ye love one another ; as I have loved you. that ye also love one another," (John ziii. 34.) DEF DEFINITIONS IN GEOMETRY. DEF tance, and would meet, if pro- duced. One line is perpendicular to an- other when it inclines no more to one side than another. A straight line is a tangent to a circle "when it touches the circle without cutting, when both are produced. An angle is the inclination of two lines towards one another in the same plane, meeting in a point. Angles are either right, acute, or oblique. A right angle is that which is made by one line perpendicular to another, or when the angles on each side are equal. An acute angle is less than a right angle. An obtuse angle is greater than a right angle. A plane is a surface with which a straight line will every where coincide ; and is otherwise called a straight surface. Plane figures, bounded by right lines, have names according to the number of their sides, or of their angles, for they have as many sides as angles : the least number is three. An equilateral triangle is that whose three sides are equal. An isosceles triangle has only two sides equal. A scalene triangle has all sides unequal. A right-angled triangle has only one right angle. Other triangles are oblique- angled, and are either obtuse or acute. An acute-angled triangle has all its angles acute. An obtuse-angled triangle has one obtuse angle. A figure of four sides, or angles, is called a quadrilateral, or quad- rangle. A parallelogram is a quadrilate ral, which has both pairs of its opposite sides parallel, and takes the following particular names : 140 A rectangle is a parallelogram, having all its angles right ones. A square is an equilateral rect- angle, having all its sides equal, and all its angles right angles. A rhombus is an equilateral parallelogram whose angles are oblique A rhomboid is an oblique-angled parallelogram, and its opposite sides only are equal. A trapezium is a quadrilateral, which has neither pair of its sides parallel. A trapezoid hath only one of its sides parallel. Plane figures, having more than four sides, are in general called polygons, and receive other parti- cular names according to the num- ber of their sides or angles. A pentagon is a polygon of five sides, a hexagon of six sides, a hep- tagon seven, an octagon eight, an enneagon nine, a decagon ten, an undecagon eleven, and a dodecagon twelve sides. A regular polygon has all its sides and its angles equal ; and if they are not equal, the polygon is irregular. An equilateral triangle is also a regular figure of three sides, and a square is one of four ; the former being called a trigon, and the latter a tetragon. A circle is a plane figure, bounded by a curve line, called the circumference, which is every where equidistant, from a certain point within, called its centre. The radius of a circle is a right line drawn from the centre to the circumference. A diameter of a circle is a right line drawn through the centre, terminating on both sides of the circumference. An arc of a circle is any part of the circumference. A chord is a right line joining the extremities of an arc. A segment is any part of a circle bounded by an arc and its chord. DEF DEFINITIONS IN GEOMETRY. DEF A semicircle is half a circle, or a segment cut off by the diameter. A sector is any part of a circle bounded by an arc, and two radii drawn to its extremities. A quadrant, or quarter of a cir- cle, is a sector having a quarter part of the circumference for its arc, and the two radii perpendicular to each other. The height or altitude of any figure is a perpendicular let fall from an angle or its vertex to the opposite side, called the base. The measure of any right-lined angle is an arc of any circle con- tained between the two lines which form the angle, the angular point being the centre. A solid is said to be cut by a plane when it is divided into two parts, of which the common sur- face of separation is a plane, and this plane is called a section. Definitions of solids : A prism is a solid, the ends of which are similar and equal paral- lel planes and the sides parallelo- grams. If the ends of the prism are per- pendicular to the sides, the prism is called a right prism. If the ends of the prism are oblique to the sides, the prism is called an oblique prism. If the ends and sides are equal squares, the prism is called a cube. If the base or ends are paral- lelograms, the solid is called a parallelepiped. If the bases and sides are rect- angles, the prism is called a rect- angular prism. If the ends are circles, the prism is called a cylinder. If the ends or bases are ellipses, the prism is called a cylindroid. A solid, standing upon any plane figure for its base, the sides of which are plane triangles, meeting in one point, is called a pyramid. The solid is denominated from its base, as a triangular pyramid is one upon a triangular base, a 141 square pyramid one upon a square base, &c. If the base is a circle or an ellip- sis, then the pyramid is called a cone. If a solid be terminated by two dissimilar parallel planes as ends, and the remaining surfaces joining the ends be also planes, the solid is called a prismoid. If a part of a pyramid next to the vertex be cut off by a plane parallel to the base, the portion of the pyramid contained between the cutting plane and the base is called the frustrum of a pyramid. A solid, the base of which is a rectangle, the four sides joining the base plane surfaces, and two oppo- site ones meeting in a line parallel to the base, is called a cuneus or wedge. A solid terminated by a surface which is every where equally dis- tant from a certain point within it is called a sphere or globe. If a sphere be cut by any two planes, the portion contained be- tween the planes is called a zone, and each of the parts contained by a plane and the curved surface is called a segment. If a semi-ellipsis, having an axis for its diameter, be revolved round this axis until it come to the place whence the motion began, the solid formed by the circumvolution is called a spheroid. If the spheroid be generated round the greater axis, the solid is called a prolate spheroid. If the solid be generated round the lesser axis, the solid is called an oblate spheroid. A solid of any of the above structures, hollow within, so as to contain a solid of the same struc- ture, is called a hollow solid Deflagrator, an instrument for pro- ducing intense light and heat Deflection, a term applied to the dis- tance by which a curve departs from another curve, or from a straight line DEF DESCRIPTIVE GEOMETRY. DES Deflection, the deviation of a ship from its course Degree, the 360th part of the circum- ference of a circle ; 60 geographical miles Degree, consisting of three figures of three places, comprehending units, tens,' and hundreds Deliquiee, according to Vitruvius, gut- ters, or drains Delivery valve, the upper valve in the air-pump, or that through which the water is lifted into the hot well ; also used when speaking of any sort of pump Delphica, a table made of marhle or bronze, and resembling a tripod Delubrum, a font or baptismal basin Delubrum, in antiquity, a church, chapel, temple, or consecrated place Delubrum, that part of a Roman temple in which the altar or statue of the deity was erected Demesne, lands belonging to the lord of a manor, and which are conti- guous to the manor-house Demi-relievo, in sculpture, half-raised figures from the plane, as if cut in two, and only half fixed to the plane Demi-tint is that shade seen when the sun shines on a house, or any other object, making an angle of nearly 45 on the ground plane, or when it shines more on the front than on the end. Dendrometer, an instrument for the measuring of trees Denticulus, a member in the Ionic and Corinthian entablatures, occur- ing between the zophorus and corona, and properly speaking, a part of the latter: so called be- cause it represents denticuli, or small teeth, placed at equal inter- vals apart Dentils, ornaments resembling teeth, used in the bed-mouldings of Ionic, Corinthian, and Composite cornices Departure, in navigation, is the east- ing or westing of a ship with re- spect to the meridian from which it departed or sailed; or it is the difference of longitude between the 142 present meridian and where the last reckoning was made Depression of the pole, in navigation : so many degrees as you sail from the pole towards the equator, so many you are said to depress the pole, because it becomes so much lower in the horizon Derrick, a Cornish word for a miner Derrick, in navigation, a tackle used at the outer quarters of the mizen- yard; it also signifies a prop or support to sheers, &c. Derrick. Sheers and Gyn have one object in common, to find a point or fulcrum in space to which the pulley, in the shape of block and tackle, is to be supplied ; and this is effected by the above, on one, two, and three legs, respectively. In the derrick and sheers, stability is given by guys ; in the gyn, they are unnecessary. Wherever these guys are used, great attention must be paid to their being well fixed, or being (when requisite) duly eased- off: when accidents occur from neglect in this respect, they are generally very severe. Describent, in geometry, is the line or surface from the motion of which a surface or body is supposed to be generated or described Descriptive geometry: the applica- tion of geometrical rules to the representation of the figures and the various relations of the forms of bodies, in accordance to forms applicable to civil, military, and naval architecture, civil and me- chanical engineering, and the other arts that require more correct scien- tific representations than have hi- therto been afforded to the student Desiccation, the chemical operation of drying bodies, sometimes effected by drying in the air, sometimes in warm chambers, by the air-pump, &c. Design, a term in the fine arts, is em- ployed first to signify the art of drawing or representing in lines the form of any object; next it ex- presses that combination of inven- DES DIAPER. DIA tion and purpose which enables the artist to compose a picture or a group, without reference to the material in which it is executed Destina, according to Vitruvius, a column or pillar to support an edi- fice Device, an emblem or ensign for- merly borne on shields or em- broidered upon banners as a cogni- zance; contemporary, in the history of heraldry, with coat armour it- self Device, in heraldry, painting, &c., any emblem used to represent a certain family, person, action, or quality, with a suitable motto, applied in a figurative sense Dexter, in heraldry, an appellation given to whatever belongs to the right side of a shield or coat of arms, as the bend dexter, dexter point, &c. Diagonal, a line drawn from angle to angle Diagonal rib, a projecting baud of stone or timber passing diagon- ally from one angle of a vaulted ceiling across the centre to the opposite angle Diagonal scale. Equidistant parallel lines cut all lines drawn across them into equal parts ; consequently a set of equidistant parallels laid down upon a ruler, with oblique lines of various lengths drawn across them, give with the compasses the means of immediately taking off various proportions of those lines. Diagram, a delineation of geometrical figures ; a mathematical illustration Dial, an instrument for the measuring of time ; not mentioned in Scrip- ture before the reign of Ahaz, A.M. 3262. It is not clearly ascertained, even after this time, how the Jews divided the time by hours. The word hour occurs first in Tobit, which may confirm the opinion that the invention of dials came from beyond the Euphrates. Dialling. In all dials, the gnomon represents the axis of the earth ; hence its angle with the horizon is 143 the latitude of the place, and it lies in the plane of the meridian. There are a great variety of dials, according to whether they are hori- zontal, oblique, or vertical, and also depending on their aspect with re- ference to the sun, &c. Diamicton, according to Pliny, a term used by the Roman builders to de- signate a particular manner of con- structing walls, the exterior of masonry, and the interior of rub- ble Diamond, a genus of precious stones of a fine pellucid substance of great hardness, and never debased by any admixture of earthy or other coarse matter. When pure, it is perfectly colourless. It is the most valuable of all gems, and is found only in the East Indies and the Brazils. It is constituted solely of carbon in its densest form. Diamond, glaziers', the pencil dia- mond, used in cutting glass, is a small fractured piece of diamond Diaper ornament, of flowers, applied to a plain surface, either carved or painted: if carved, the flowers are entirely sunk into the work below the general surface ; they are usually square, and placed close to each other, and are various in their pattern and design: it was first introduced in the Early English style in some of the principal Gothic structures in England Diaper, a panel or flat recessed sur- face covered with carving or other wrought work in low relief ; a kind of linen cloth, wrought with figures in the process of weaving Diastyle, an arrangement of columns in Grecian and Roman architecture, in which the intercolumniation or space between them is equal to three or four diameters of the shaft Diathyra, the vestibule before the doors of a Greek house, correspond ing with the prothyra of the Ro- mans Diatom, the angle stones of a wall, wrought on two faces, and which, DIA DILAPIDATIONS. DIL stretching beyond the stones above and below them, form a good band or tie to the work Diatoni, according to Vitruvius, the girders or band-stones formerly em- ployed in constructing walls ; cor- ner stones Diatretum, an enchased or curiously engraved vase or drinking-cup Diaulon, a race-course, the circuit of which was two stadia, or 1200 feet ; whence it was used to signify a measure of two stadia Dicrotum, a boat with two oars Die, the cube or dado of a pedestal Die, or Dye, a naked square cube : thus the body of a pedestal, or that part between its base and its cap, is called the die of the pe- destal Dies, two pieces of hardened steel, which, when placed together, form a female screw (or a screw in a nut) which has cutting edges, used for making a screw on a bolt Die-sinking: in the preparation of coined money and of medals, the most important feature is the en- graving of the die which is to form the stamp. The piece of steel is prepared with care, and brought to a soft state when about to be submitted to the hands of the en- graver. By the aid of small, fine, hardened steel tools, the engraver cuts away the steel until he has produced, in cavity or intaglio, an exact reverse of the design for the medal or coin. Dieu et mon droit ' God and my right/ in heraldry, the motto of the royal arms of England, first assumed by Richard I. Differential thermometer. This in- strument was invented by the same gentleman who contrived the pho- tometer and aetherioscope, and was used by him in his investi- gations on heat. Its principal use to the meteorologist is to make experiments on the light and heat of the moon, &c., by concentrating its rays by a lens upon the sentient ball. This can only be dpne when the moon is on the meridian. It is peculiarly adapted for measuring the effect of radiation. Digester, a boiler invented by Papin for raising water to a higher tem- perature than the common boiling point, 212: this is effected by forming a vessel somewhat resem- bling a kitchen pot ; the mouth is formed into a flat ring, so that a cover may be screwed tightly on ; this cover is furnished with a safety- valve, loaded to the required pres- sure Digit, a finger ; a term employed to signify any symbol of number from to 9 : thus ten (10) is a number of two digits Digit, a measure of length, containing three-fourths of an inch Diglyph, in architecture, an imperfect triglyph, with only two channels instead of three Dilapidation, decay for want of repair ; not unfrequently a point of dispute between a party in possession of a house and another party having an interest therein. Where there is a right to use lands or houses, ques- tions will arise as to the manner in which they ought to be used, and by whom dilapidations, whether caused by accident or decay, ought to be supplied. The rights of par- ties with respect to immoveable property so closely border on each other, and the line of demarcation between them is so indistinct, that one man, in the fancied exercise of his right, is continually liable to encroach upon or disregard the right of another. No person, how- ever absolute his property in land, can put it to any use he pleases : his right to use is restrained by the rights of his neighbour ; he is bound to take care that his manner of using does not interfere with the inoffensive and profitable occu- pation by his neighbour of his land. (See the second edition, just pub- lished, of Mr. Gibbons's elaborate work on the ' Law of Dilapidations and Nuisances.') 144 END OF PART I. DIL DISTEMPER IN PAINTING. DIS Dilettante ( Italian), an ardent admirer of the fine arts. The Dilettanti Society, consisting of many dis- tinguished noblemen and gentle- men, has done much to rescue the noble monuments of Grecian art from otherwise inevitable ruin Dilleuiny, a Cornish word for a method of washing or finishing the dress- ing of tin in very fine hair sieves Diluvial formation, the superficial deposits of gravel, clay, sand, &c., which lie far from their original sites on hills, and in other situ- ations, to which no forces of water now in action could transport them Dimension, a term used in the same sense as degree Diminution, a term expressing the gradual decrease of thickness in the upper part of a column Diminution of columns. The shafts of columns are diminished in dia- meter as they rise, sometimes from the foot itself of the shaft, some- times from one-quarter, and some- times from one-third of its height. The diminution at top is seldom less than one-eighth or more than one-sixth of the inferior diameter of the column. Dioptase, or emerald copper, a crys- tallized silicate of copper, the pri- mary form of which is a rhomboid. Its colour varies from emerald to blackish green: it is translucent and brittle Dioptra, a geometrical instrument employed in measuring the altitude of distant objects, and for taking the levels of a source of water intended to be conveyed to a distance by means of an aqueduct Diorama, a mode of scenic exhibi- tion invented by two French artists, Daguerre and Bouton Dip, in mining, the greatest inclination of a stratum to the horizon Di Palito is a light yellow ochre, affording tints rather purer in co- lour than the stone ochre, but less so than Naples yellow. Many pleasing varieties of ochreous co- lours are produced by burning 145 and compounding with lighter, brighter, and darker colours, but often very injudiciously and ad- versely to that simple economy of the palette which is favourable to the certainty of operation, effect, and durability. Diplinthius, according to Vitruvius, two bricks thick Dipping-needle, in navigation, a mag- netic needle, so hung that one end dips, or inclines to the horizon, and the other is proportionally elevated, forming an angle equal to the dip- ping of the needle at the place where the experiment is made Dipteral, having a double range of columns all round : a dipteral tem- ple usually had eight in the front row of the end porticoes, and fifteen at the sides, the columns at the angles being included in both Dipteron, in ancient architecture, a temple surrounded with a double row of columns which form porti- coes, called wings or aisles Dipteros, in Greek architecture, a temple with a double row of co- lumns on each of the four sides Direct-action engine, an engine having the rotatory motion communicated to a crank placed directly over the cylinder, so as to save height, and lessen the weight of the engine : the term applies more particularly to marine engines Discharging arch, an arch formed in the substance of a wall, to relieve the part which is below it from the superincumbent weight : it is fre- quently used over lintels and flat- headed openings Discord, a term applied to painting when there is a disagreement of the parts or the colouring ; when the objects appear foreign to each other, and have an unpleasing and unnatural effect Disembogue, to pour out at the mouth of a river Distemper, in painting, the working- up of colours with something else besides mere water or oil. If the colours be prepared with the first, DIS DOCKS. DOC it is called limning; and with the last, painting in oil Distemper is a preparation of colours without oil, only mixed with size, whites of eggs, or any such proper glutinous or unctuous substance : with this kind of colour all the an- cient pictures, hefore the year 1410, were painted, as also are the cele- brated cartoons of Raphael Ditrigtyph, an interval between two columns, admitting two triglyphs in the entablature; used in the Doric order Dividiculum, in Rome, a tower on an aqueduct, containing a large reser- voir Diving lell, a machine contrived for safely lowering a man to any rea- sonable depth under water, so that he may remain there for a consi- derable time Division of an Order. The general division of an order being into two parts, namely, the column and en- tablature, the column is subdivided into three unequal parts, viz. the base, the shaft, and the capital. The entablature consists also of three unequal parts, which are, the architrave, the frieze, and the cor- nice. Each of these divisions con- sists of several smaller parts, which by their variety and peculiarity dis- tinguish the orders from each other. Dock, a place artificially formed for the reception of ships, the entrance of which is generally closed by gates. There are two kinds of docks, dry docks and wet docks : the former are used for receiving ships for repair, the latter for the purpose of keeping vessels afloat. Docks are enclosed artificial recepta- cles for shipping, and are usually formed by excavation of the soil, and constructed walls of masonry, with inlets and gates for admitting the passage of vessels. Docks are usually distinguished as wet docks or basins, and dry or graving docks. The former of these are already described under the head Basin; the latter may be described as follows : 146 Graving docks, in which repairs of vessels are effected, are con- structed of various dimensions, ac- cording to the class of vessel for which provision is intended. Se- veral splendid works of this kind have, within the last few years, been executed in the English dock- yards. One of these, the Eastern Dock in Her Majesty's Dockyard at Woolwich, is 282 feet in ex- treme length, 81 feet in width on the ground level, and 39 feet in the bed. The depth from the ground level to the bed is 27 feet. The inclined sides and curved end of the masonry are formed into a series of steps or altars, by which access is readily obtained to all parts of the dock, and fixing-places obtained for the struts with which the sides of the vessel under repair are maintained in an upright posi- tion, when the water is discharged from the dock. The river-wall of this structure was originally con- structed of concrete block-facings with rough concrete backing, ac- cording to a plan introduced into this country by Mr. Ranger ; but these were abandoned, and granite facings substituted, the entire mass of the wall being supported on timber-piling. The whole of the piers, apron, and coffer-dam walls w y ere executed by tide-work, in the following manner : a small space was surrounded by sheet-piling, which was carried up from 6 to 8 feet above the level of low water : into the enclosure thus formed a pipe from two 18 -inch pumps, worked by a steam engine, was led, and the pumps set to work as soon as the tide fell below the sheet-piling. The subsequent ex- cavation for the dock reached a bed of chalk, which was found to be sufficiently firm to dispense with the inverted arch of masonry usu- ally constructed beneath the bed of these docks, and the floor was con sequently constructed of a hori- zontal paving of blocks of granite DOC DOCKS, GRAVING. DOC 2 feet in thickness, each stone being joggled to the adjacent stones with dove-tail joggles of Valentia slate bedded in cement. The river water is admitted into the dock through a culvert 5 feet high and 3 feet wide, passing through each pier, and which culverts are worked by sluices of cast iron. The front of the dock is closed with a caisson formed of plate iron, fixed with rivets to ribs of angle iron; the form of the caisson being similar to that of a vessel, namely, with a continuous keel along the bottom and up each end, and a swelling outline tapering towards the end keels, and reduced to a width nearly parallel in the deck-level. This continuous keel, which is of oak, and formed in two pieces, fits into a recess in the masonry at the en- trance of the dock, and the admis- sion of water into it is regulated by sluices and pumps. From the description given of graving docks, it will be under- stood that their action and efficiency depend upon the command of an adequate depth of water, and a sufficient rise and fall of tide to leave the vessel dry or to float her, as occasion requires. The use of these docks also compels the re- tention of the vessel during the action of the tide, and thus involves a considerable lapse of time, which sometimes cannot be afforded for trifling repairs or examination of a vessel in active service. For situations in which no tide exists, a different arrangement be- comes necessary, and a construc- tion called a 'slip' is commonly substituted for a graving dock. The slip which has been the most extensively used is that known as ' Morton's slip,' and which was secured by a patent dated March 23, 1819, granted to T. Morton, for a method of dragging ships out of water for repairs, &c. This slip consists of an inclined plane, formed of timber framing laid upon 147 suitable foundations of masonry, or cut in the surface of the rock. Upon this framing longitudinal metal racks are fixed, and a move- able carriage, upon which the ves- sel is received, (by running the carriage to the lower part of the plane, beneath the water, and se- curing the vessel upon it,) is fitted with cog-wheels, or other suitable apparatus for working upon these racks. The moving carriage con- sists of a succession of small strong blocks or carriages, any number of which may be connected together, according to the length of vessel to be hauled up. Each of these blocks or carriages, which are laid in corresponding pairs on each side of the central line of the slip, so as to leave a continuous inter- mediate space to receive the keel of the vessel, is fitted with rollers, upon which it may be moved trans- versely ; and thus the distance be- tween the two blocks of each pair, or on each side of the centre, may be adjusted according to the sec- tional form of the ship. These motions are ingeniously effected with the aid of cross ropes or lines which are fixed to the blocks, and by which means the entire action of the apparatus is much facili- tated. The combined carriage, when loaded with the vessel, is hauled up the slip by cables at- tached to a drum apparatus, with suitable gearing fixed in a building at the head or upper end of the slip. The power required is of course in proportion to the weight to be hauled up, and to the rate of inclination of the slip, and is usu- ally supplied by a steam engine. This principle is susceptible of being extended, so as to provide berths for several vessels with only one hauling-up slip and machinery. For this purpose it has been sug- gested to construct a series of frames arranged radially round a centre, and capable of motion' and of adjustment, with one slip con- DOD DOGS OR ANDIRONS. DOG structed in such a direction as to correspond with a produced radius of the same circle. This arrange- ment, which would be similar to that of the polygonal engine-houses now erected on several lines of railway, offers great facilities for extended operations in the repair of vessels, but of course requires great space for the construction of the radial frames. In order to provide for cases in which sufficient tidal difference cannot be had for raising vessels of deep draughts on to a dry dock, floating docks have been introduced in North America, and found to act satisfactorily. These floating docks are constructed with a buoy- ant bed, or cradle, capable of sup- porting a vessel within the dock, with its keel above the surface of the water. This float or cradle is made in a box-like form, composed of strong logs, jointed firmly, and well caulked, so as to make it water-proof. The capacity of the float must be such that when freed from water by pumping, and loaded with the vessel, workmen, &c., it shall sustain this load with safety. The float moves within a recess of masonry, by which its motion is guided and secured. Suitable shores, blocks, struts, &c., are used in making the vessel steady within the float, which is fitted with valves in the lower part. The action of this floating dock is as follows : The cradle or float, being full of water (the valves being open), is sunk so that the vessel may be brought over it, and temporarily secured in position : the valves are then closed, and the pumps set to work to clear the water from the float, which rises in consequence, and brings up the vessel to a dry level. When the ship is again ready for sea, the opening of the valves admits the water, and sinks the float, leaving the vessel free above it to pass out of the dock. The docks and basins of London 148 and Liverpool comprise some of the largest specimens of works of this kind. Those of the latter port were commenced in 1708, and con- sist of several docks of great ex- tent. The first public docks for merchant shipping in London were the West India Docks, opened in 1805, the great basin of which is 420 yards in length, and 230 yards in width. This is connected with the river by another basin of about three acres in area. The London Docks were commenced soon after the West India Docks, and opened in the same year, viz. 1805. The principal basin of these docks is 420 yards in length, and 276 yards in width. The East India Dock for unloading inwards is 470 yards in length, and 173 yards in width ; and that for loading outwards is 260 yards in length, and 140 yards in width. The St. Katherine's Docks occupy an area of 24 acres. Dodecagon, in geometry, a figure of twelve angles and sides Dodecahedron, in geometry, one of the regular bodies comprehended under twelve equal sides, each of which is a pentagon Dodecastyle, a building having twelve columns in front Dogs, or andirons, creepers, braziers, &c. Long after the general intro- duction of chimneys, wood was the ordinary fuel for all sorts of apart- ments. Coals formed no part of the ' liveries,' but wood was com- monly included in them. A ' cra- dle for sea coal' is, however, fre- quently mentioned as belonging to the chief rooms in superior houses, though the usual way of warming, or rather airing, bed-chambers was with braziers or chafing-dishes. Andirons are a larger and higher sort of irons, made to support the wood, and have usually long necks rising up before, to prevent the wood from falling upon the floor. Creepers are smaller and lower irons, with short necks, or none at all, which are placed between the DOG DOMES. DOM andirons, to keep the ends of the wood and the brands from the hearth, that the fire may burn more freely. Dog-kennel, a lodgement for dogs kept for the purpose of field sports : it is almost as invariable an ap- pendage to the manor-house as it was formerly to the baronial castle. Bishop Percy observes, "that a nobleman in the dark ages, retired within his castle, had neither books, nor newspapers, nor literary correspondence, nor visits, nor cards, to fill up his leisure : his only amusements were field sports ; nor did the love for these decline in the Tudor period." Dog wood, a small underwood, free from silex : small splinters are used by watch-makers for cleaning out the pivot-holes of watches ; it is also used by butchers for making skewers Dolomite, massive magnesian lime- stone, used by the ancient sculptors in their best works Dolphin, a technical term applied to the pipe and cover at a source for the supply of water Dome, a term applied to a covering of the whole or part of a building : the word dome is strictly applied to the external part of the spheri- cal or polygonal roof, and cupola to the internal part Dome or cupola, a roof, the base of which is a circle, an ellipsis, or a polygon, and its vertical section a curve line, concave towards the in- terior. Hence domes are called circular, elliptical, or polygonal, according to the figure of the base. The most usual form for a dome is the spherical, in which case its plan is a circle, the section a seg- ment of a circle. The top of a large dome is often finished with a lantern, which is supported by the framing of the dome. The interior and exterior forms of a dome are not often alike, and in the space between, a staircase to 149 the lantern is generally made. Ac- cording to the space left between the external and internal domes, the framing must be designed. Sometimes the framing may be trussed with ties across the open- ing; but often the interior dome rises so high that ties cannot be inserted. Accordingly, the construction of domes may be divided into two cases : viz. domes with horizontal ties, and those not having such ties. Dome, in locomotive engines, the conical part of the boiler, forming a steam chamber, and terminating the top of the fire-box part. In a locomotive engine the safety- valves are usually placed on the top of the dome or the body of the boiler Dome cover, in locomotive engines, the brass or copper cover which encloses the dome, to prevent the radiation of heat Dome Cathedral of Pisa, the first model of that Tuscan style of ar- chitecture, so solid, grave, and im- posing, neither Greek nor Gothic, was begun in the eleventh century ; and in the thirteenth was founded the majestic church of Santa Maria del Fiori at Florence, of which the dome equals in size that of St. Peter's at Rome, and was its model Dome of St. Paul's Cathedral (the) is elliptical, and built of wood ; it is confined by strong chains, consist- ing of iron bars : that of the Pan- theon at Rome is nearly circular, and its lower parts are so much thicker than its upper parts as to afford sufficient resistance to their pressure; they are supported by walls of great thickness, and fur- nished with many projections which answer the purpose of abutments and buttresses Domes in Asia are probably more ancient than in Italy. At Lanker- rood, at Dhay-nain, at Sin-sin, five or six days' journey south of Tehe- ran in Persia, towns are all de- DOM DOMESTIC ARCHITECTURE. DOM serted : there are about a hundred large dwelling-houses quite entire, of a very singular construction. Each edifice stands separate, and is constructed of several central arches supporting a pointed dome ; while smaller divisions project from the body of the building, also arched, and the whole finished with the greatest neatness, having remains of stucco-painted walls within. It is probable that the arch and vault and dome were not unknown to the nations in the East, beyond the Indies, in a very remote age ; but in Greece and in Asia Minor there are no traces of them before their introduction by the Romans. To the Romans they were familiar at a very early period of their his- tory; a knowledge of which they borrowed perhaps from the Etrus- cans, or from the supposed extinct people who possessed a city on the site of Rome itself, before the Romans. Domestic Architecture in England. At the termination of the York and Lancaster wars, the fortified style of architecture was gradually aban- doned in England ; and as we had no other model of domestic archi- tecture than the gable and the cot- tage, by the duplication of this simple form, in various positions, was constructed what has been called the Old English Manor- house style. If we take a common two-floored English gable and cot- tage, add to it one, two, or three cottages side by side, of the same size ; and in order to gain rooms out of the roof on the sides of this double or triple cottage, raise gable ends either projecting from the DOM DOMESTIC BUILDINGS AND CASTLES. DOO ground to the top of the roof, or merely raised from the eaves-drop ; if we insert broad low windows, divided by simple wooden or stone mullions, in these projecting gable ends, and similar windows at the ends of this double or triple cot- tage; ornament the inclined sides of the gable ends above the eaves- drop by steps or small pinnacles, or both ; then add a parapet, plain or embattled, we have a manor-house in the most florid style. Many such houses came afterwards to be adorned by a centre of architec- tural decoration, in which Roman, Grecian, and Gothic were strangely mixed. There is, however, a cer- tain degree of antique-like gran- deur in such houses, which pro- duces a very striking impression. This step towards a better style took place before the time of Inigo Jones. " The mansion at South Elmham (represented onthe'preceding page), when entire, formed a quadrangle, as usual, of which stables and offices made up a part. The do- mestic and ecclesiastical styles are singularly combined in this build- ing, though the latter seems to predominate; and the occasional discovery of old floor-stones, of a sepulchral character, intimates that the projecting porch led to the chapel of the dwelling, not into the hall; and yet the ceilings of the chambers where the two wings and upper windows are observed, on the right hand of the porch, are flat, divided into small squares by the girders above, and covered with plastered mouldings, in the manner usually seen in dwellings of an early period." Domestic buildings and castles. The towns and ordinary houses of the Normans were entirely built of wood, and, for the most part, are so to this day. Their castles, having but one destination, that of defence, aimed at nothing but strength in their plan or construc- tion. A site was also selected 151 which was already fortified by nature. The plan of the Norman castles was as nearly the same as the di- versity of ground would allow. The principal feature was always the keep, which contained the apartments of the lord of the castle, and was also meant to be the last refuge of the garrison, if the outer works were forced. The keep was usually raised on an artificial mound, or placed on the edge of a precipice. The walls, strengthened in every way that art could devise, were of immense thickness, and composed of grouting poured in between two solid walls of stone. The facing consisted sometimes of irregular courses, and sometimes of small squared stones, after the Ro- man manner. Ashler was usually introduced at the angles of the building. The windows were few, and little more than chinks, unless very high up, or turned to the court. The door of entrance could only be reached by a staircase. Under the keep were usually vaults, or dungeons, for the recep- tion of prisoners. The keep was enclosed in two courts surrounded by walls flanked with towers. The tower at the entrance was called the barbican, and served at once for an outwork and post of observation. The whole fortress was defended by a moat. The remains of the Norman cas- tles which exist scarcely afford any specimens of early Norman con- struction, almost all these castles having been besieged, destroyed, and rebuilt, over and over again. The keep of Falaise is perhaps the only castellated remnant of early Norman times. The castle of Gizors, which was built by William Rufus, retains nothing of its original construction. Domus, a private house occupied by a single proprietor and his family Doors (Antique). The Greeks in the temple of Minerva Polias, at DOO DOORS, ANGLO-NORMAN. DOO Athens, and also the Romans in the temple of Vesta, or the Sibyl, at Tivoli, made the doors and win- dows smaller at top than at bot- tom : the architrave or dressing always constituted an agreeable decoration when in character with the building. Those of the win- dows in the Grecian temple have a projection, or what is sometimes termed a knee, at their upper angle ; while those of the temple of Vesta, whose apertures have the same form, continue without interrup- tion, and are surmounted by a cor- nice ; but the cornice above the door is separated from the archi- trave by a frieze, while the cornice of the windows joins the archi- trave. In the temple of Minerva, the architrave of the windows rests only on a plain socle ; those of the temple of Vesta rest also on a socle orsupport,the face of which is sunk. Doors (Modern). There are two doors, designs of Vignola, w r hich offer in their profiles and propor- tions a happy medium between the antique and modern compositions ; and all other designs of this kind are either derived from them, or possess a vague character which renders them unworthy of imita- tion. There are breaks in the archi- trave, as in those of the temple of Minerva Polias ; and the ter- mination or lower extremity of these breaks determines the length of the consoles, which gives har- mony to the arrangement. These consoles are also placed against a second architrave, beyond which the first projects. The design of the door of the church of St. Lo- renzo is more regular. Doonuay (Anglo-Norman). The Anglo-Norman builders bestowed much pains and evinced consider- able artistic skill in very elaborately ornamenting the portal entrances to churches in their style of ar- chitecture, by a profusion of orna- mental mouldings and of sculpture. Very many ex- amples are to be met with in great variety in several of the counties of England, particu- larly in the coun- ties of Norfolk and Suffolk. The example repre- sented in the an- nexed engraving is a beautiful spe- cimen taken from the church of St. Botolph, at Cove, in the county of Suffolk. 152 DOR DORIC ORDER. DOS Doorways. In the Gothic, and the architecture of the middle ages, doorways are striking and import- ant features, affording in the cha- racter of the mouldings and orna- ments the style and period of the edifice. Doric Order. The Doric order, says Palladio, was invented by the Do- rians and named from them, being a Grecian people which dwelt in Asia. If Doric columns are made alone without pilasters, they ought to be seven and a half or eight diameters high. The intercolumns are to be little less than three diameters of the columns ; and this manner of spacing the columns is by Vitruvius called Diastylos. The ancients employed the Doric in temples dedicated to Minerva, to Mars, and to Hercules, whose grave and manly dispositions suited well with the character of this or- der. Serlio says it is proper for churches dedicated to Jesus Christ, to St. Paul, St. Peter, or any other saints remarkable for their forti- tude in exposing their lives and suffering for the Christian faith. Le Clerc recommends the use of it in all kinds of military build- ings ; as arsenals, gates of fortified places, guard-rooms, and similar structures. It may likewise be employed in the houses of gene- rals or other martial men, in mausoleums erected to their me- mory, or in triumphal bridges and arches built to celebrate their vic- tories. Vitruvius himself makes the Doric column in porticoes higher by half a diameter than in temples ; and most modern architects have, on some occasions, followed his exam- ple. In private houses, therefore, it may be 16, 16, or IGf modules high ; in interior decorations, even seventeen modules, and sometimes perhaps atriflemore; which increase in the height may be added entirely to the shaft, as in the Tuscan order, without changing either the base or capital. The entablature, too, may remain unaltered in all the aforesaid cases ; for it will be suffi- ciently bold without alteration. Doric Order. The height of the Doric column, including its capital and base, is sixteen modules ; and the height of the entablature, four modules ; the latter of which being divided into eight parts, two of them are given to the architrave, three to the frieze, and the remain- ing three to the cornice. In most of the antiques, the Doric column is executed without a base. Vitruvius likewise makes it without one; the base, accord- ing to that author, having been first employed in the Ionic order, to imitate the sandal or covering of a woman's foot. Scamozzi blames this practice ; and most of the moderns have been of his opinion, the greatest part of them having employed the Attic base in this order. Dorman tree, a large beam lying across a room ; a joist, or sleeper Dormer window, a window pierced through a sloping roof, and placed in a small gable which rises on the side of the roof Dormitory, a sleeping apartment; a term formerly applied to the sleeping-room of the inmates of monasteries and other religious houses Dormond, a large beam lying across a room; a joist, or sleeper: same as Dorman Doron, a hand-breadth, or palm : among the Greeks, their bricks or tiles were termed tetradoron, four hands' breadth, or pentadoron, five hands broad : the word also im- plies a gift : hence, probably, the origin of the English word dowry Dosel, hangings round the walls of a hall, or at the east end, and some- times the sides, of the chancel of a church, made of tapestry or car- pet-work; used also in churches, and frequently richly embroidered with silks, and gold and silver 153 G5 DOS DRAINAGE OF MARSHES. DRA Dosel, ornamental and rich stuff for the back of a chair, a throne, or a screen of ornamental wood- work Double-acting pump, a pump which lifts and forces water at the same time, by means of a solid piston, and an entrance and exit-valve communicating with each side Double-beat valve, a valve used in Cornish engines and water-works. It has two beats, or seatings, one above the other : the bottom one is similar to an ordinary circular valve seating; the top one is some- what less in diameter than the bot- tom one, and is supported from it by ribs, and forms a cover nearly the size of the inner passage. A shell with two beats to correspond with the seatings shuts the sides : when raised, (which requires but little power, as the fixed cover before mentioned bears nearly all the pressure, its diameter being nearly equal to that of the shell,) the steam or water escapes at the sides both of the top and bottom beat. Double cylinder engine, a marine en- gine with two cylinders placed at right angles to the crank-shaft, and at a small distance apart, to give space for the vibration of the rod connecting the crank to the long end of a shaped cross-head, which slides in grooves between the cy- linders : the upper ends of the cross-head are connected to the piston-rods. This form of engine is patented by Messrs. Maudsley. Dove-tail, in carpentry, a method of joining two boards together by letting one piece into another in the form of the tail of a dove, when that which is inserted has the ap- pearance of a wedge reversed Dove-tailing, a method of fastening together two pieces of metal or wood, by projecting bits cut in the form of dove-tails in one piece, to fit into corresponding hollows in the other Dowel. A round dowel or coak is the piece of timber to which the 154 felloes of a carriage-wheel are united Dowsing cheeks, in ship-building, pieces fayed across the apron, and lapped on the knightheads or inside stuiF above the upper deck Draft-engine, an engine used for pumping Drag-bar, a strong iron rod with eye-holes at each end, connecting a locomotive engine and tender by means of the drag-bolt and spring Drag-bolt, the strong bolt coupling the drag-bar of a locomotive engine and tender together, and remove- able at pleasure Drag-hook and chain, the strong chain and hook attached to the front of the engine buffer-bar, to connect it on to any other locomotive en- gine or tender: also attached to the drag -bars of goods waggons Drag-link, a link for connecting the cranks of two shafts : it is used in marine engines for connecting the crank on the main-shaft to that on the inner paddle-shaft Drag-spring, a strong spring placed near the back of the tender. It is attached by the ends to the drag- bar which connects the engine and tender, and by the centre to the drag-bar which connects the train to the tender. Dragon's blood (colour), a resinous substance brought from the East Indies. It is of a warm semi-trans- parent, rather dull -red colour, which is deepened by impure air, and darkened by light. There are two or three sorts, but that in drops is the best. White lead soon de- stroys it, and it dries with extreme difficulty in oil. It is sometimes used to colour varnishes and lac- quers, being soluble in oils and alcohol; but notwithstanding it has been recommended as a pigment, it does not merit the attention of the artist. Drainage of marshes and fen lands. The steam engine is used to raise the water above the level of those lands which he too low to be drained DRA DRAINAGE OF FENS. DRA by natural outfall, and also in situ- ations where the fall is not sufficient to carry off the superfluous water in time to prevent damage to the crops. Mr. Glynn has applied steam power to the drainage of land in fifteen districts, all in England, chiefly in Cambridgeshire, Lincoln- shire, and Norfolk. The quantity of land so drained amounts to more than 125,000 acres, the engines em- ployed being seventeen in number, and their aggregate power 870 horses : the size of the engines varies from 20 to 80 horses. Mr. Glynn was also engaged in draining by steam power the Hammerbrook district, close by the city of Ham- burgh; and in another level near to Rotterdam, an engine and ma- chinery with the requisite buildings have been erected from his plans by the Chevalier Conrad, and the works successfully carried into effect. In British Guiana the steam en- gine has been made to answer the double purpose of drainage and irri- gation. Some of the sugar planta- tions of Demerara are drained of the superfluous water during the rainy reason, and watered during the dry season. In many of the swampy levels of Lincolnshire and Cambridgeshire, much had been done to carry off the water by natural means, and many large cuts had been made and em- bankments formed, especially in the Bedford Level, which alone con- tains about 300,000 acres of fen- land : the Great Level of the fens contains about 680,000, formerly of little value, but now rich in corn and cattle. The general plan is to carry away the water coming off the higher grounds, and prevent it, as much as possible, from running down into the marsh by means of the catch- water drains, leaving the rain alone which falls upon the district to be dealt with by mechanical power. As the quantity of rain falling on 155 the Great Level of the fens seldom exceeds 26 inches in the year, and about two-thirds of this quantity is carried off by evaporation and ab- sorption, or the growth of plants, it is only in extreme cases that 2 in- ches in depth require to be thrown off by the engines in any one month, which amounts to 1 cubic foot of water upon every square yard of land, or 7260 feet to the acre. The standard and accepted mea- sure of a horse's power is 33,000 fos. raised 1 foot high in a minute, or 3300 tfes. raised 10 feet high in the same time ; and as a cubic foot of water \veighs 62^tbs., and a gallon of water lOlbs., so one horse's power will raise and discharge, at a height of 10 feet, 330 gallons, or 52^ cubic feet of water in a minute. Consequently this assumed excess of 7260 cubic feet of water fallen upon an acre of land will be raised and discharged at an elevation of 10 feet in about two hours and twenty minutes. If the quantity of land be 1000 acres of fen or marsh, with the upland waters all banked out, the excess of rain, ac- cording to the foregoing estimate, will amount to 726,000 cubic feet. A steam engine of 10-horse power will throw off this water in 232 hours, or in less than twenty days, working twelve hours a day. This calculation has been found fully supported in practice. Although the rain due to any given month may fall in a few days, yet in such case much of it will be absorbed by the ground; and the drains must be made of sufficient capacity to receive and contain the rain as it falls ; besides, in case of necessity, the engine may be made to work twenty hours a day in- stead of twelve, until the danger be past. The main drains have generally been cut 7 feet deep, and of width sufficient to give them the required capacity to contain the excess of rain, and to bring the watej freely DRA DRAINAGE OF FENS. DRA down to the engine. In some in- stances, where the districts are ex- tensive and their length great, it has been found necessary to make them somewhat deeper. In all cases where it has been requisite to use steam power, Mr. Glynn has applied scoop-wheels to raise the water. These scoop-wheels somewhat resemble the undershot wheel of a water-mill, but instead of being turned by the impulse of the water, they are used to lift it, and are kept in motion by the steam engine. The floats or ladle-boards of the wheels are made of wood, and fitted to work in a trough or track of masonry ; they are generally made 5 feet in length, that is to say, they are immersed 5 feet deep in the water, and their width or horizontal dimension varies from 20 inches to 5 feet, according to the power of the engines employed, and the head of water to be overcome. The wheel-track at the lower end com- municates with the main drain, and at the higher end with the river ; the water in the river being kept out by a pair of pointing doors, like the lock-gates of a canal, which close when the engine ceases to work. The wheels themselves are made of cast iron, formed in parts for convenience of transport. The float-boards are connected with the cast-iron part of the wheel by means of oak- starts, which are stepped into sockets cast in the circum- ference of the wheel to receive them. There are cast-iron toothed seg- ments fitted to the wheel, into which works a pinion fixed upon the crank-shaft of the steam engine. When the head of water in the river or delivering drain does not vary much, it is sufficient to have one speed for the wheel; but where the tide rises in the river, it is desirable to have two speeds or powers of wheel-work, the one to be used at low water, the other 156 more powerful combination to act against the rising tide. But in most cases it is not requisite to raise the water more than 3 or 4 feet higher than the surface of the land intended to be drained ; and even this is only necessary when the rivers are full between their banks, from a continuance of wet weather, or from upland floods. In some instances, the height of the water in the rivers being affected by the tide, the drainage by natural outfall can take place only during the ebb ; and here, in case of long- continuing rains, the natural drain- age requires the assistance of me- chanical power. It has been stated that the main drains have generally been made 7i feet deep, or more in larger dis- tricts, so that the water may never rise higher than within 18 inches or 2 feet of the surface of the ground, and the ladles or float-boards dip 5 feet below the water, leaving a foot in depth below the dip of the wheel, that the water may run freely to it, and to allow for the casual obstruction of weeds in the main drain, which, if it be sufficiently capacious and well formed, will bring down the water to the engine with a descent of 3 inches in a mile. Suppose then that the wheel dips 5 feet below the surface of the water in the main drain, and that the water in the river into which this water must be raised and dis- charged has its level 5 feet above that in the drain, the wheel in such case will be said to have 10 feet head and dip, and ought to be made 28 or 30 feet in diameter. Mr. Glynn has found it practi- cable to throw out the water against a head of 10 feet with a dip of 5 feet, that is to say, 15 feet of head and dip, with a wheel of 35 feet in di- ameter; but in another engine, more recently erected, he has made the wheel 40 feet in diameter. The engine that drives this wheel is of 80-horse power, and is situated on DRA DRAINAGE OF LANDS. DRA the Ten-mile Bank, near Littlepool, in the Isle of Ely. The largest quantity of water delivered by one engine is from Deeping Fen, near Spalding : this fen contains 25,000 acres, and is drained by two engines, one of 80 and one of 60 horse power. The 80 -horse engine has a wheel of 28 feet in diameter, with float- boards or ladles measuring 5 feet by 5 feet, and moving with a mean velocity of 6 feet per second; so that the section of the stream is 27^ feet, and the quantity dis- charged per second 165 cubic feet; equal to more than 4^ tons of water in a second, or about 16,200 tons of water in an hour. It was in 1825 that these two engines were erected, and at that time the district was kept in a half- cultivated state by the help of forty- four wind-mills, the land at times being wholly under water. It now grows excellent wheat, producing from four to six quarters to the acre. In many districts, land has been purchased at from 10 to 20 an acre, by persons who foresaw the consequencesoftheseimprovements, and which they could now sell at from 50 to 70 an acre. This increase in value has arisen, not only from the land being cleared from the injurious effects of the water upon it, but from the im- proved system of cultivation it has enabled the farmers to adopt. The fen-lands in Cambridgeshire and great part of the neighbouring counties are formed of a rich black earth, consisting of decomposed vegetable matter, generally from 6 feet to 10 feet thick, although in some places much thicker, resting upon a bed of blue gait, containing clay, lime, and sand. Draining, as applied to lands, towns, and buildings, is the art of drawing or conveying away refuse liquid and other matters, the accumula- tion of which would be detrimental to animal and vegetable existence. In that department which re- 157 lates to lands, draining compre- hends also the methods of irriga- ting or supplying water for agri- cultural purposes, for which the natural supply is inadequate. Re- ferring to towns and buildings, this art includes also, for the purpose of thorough cleansing, the artificial supply of water. According to this comprehensive definition, which will be found to have greater practical convenience than any more limited one, Drain- ing comprises observations of the relative levels of districts and of their geological structure; of the several sources of water, and the amount of their products ; and the construction and arrangement of all the artificial appliances required for the supply, conduct, and dis- posal of water, and for conveying and discharging refuse matters generally. The sources of water are rains and the ocean. The former, pass- ing into the earth, descend along the lower surfaces, and form streams and rivers ; or penetrate into some permeable media, and accumulating in subterranean depositories, form springs. An examination of the super- ficial and structural features of the soil enables us to estimate the quantity of water present in a dis- trict, and to determine the means that will be available for supplying the deficiency or discharging the excess. The same observations afford ge- neral information required in order to arrange the artificial channels, drains, sewers, &c., by which the supply and refuse matters are to be conducted and disposed of. Soils are retentive of water in proportion to their density arid compactness. Thus, on clay-lands an excess of water is commonly found, while, from the porous tex- tures of gravel and loose sand, water passes rapidly away, and they are thus kept in a dry condition. DRA DRAWBRIDGE. DRA The size of the channels or drains, by which the water is con- ducted away, will be adapted to the superficial extent to be drained, and the quantity of water due to the district, as computed from its relative position and structure. The construction of the drains will depend upon the materials of the soil, and the proximity of those suitable for the purpose. Generally, covered drains are far preferable to open ones ; and those formed with a duct of earthen piping are more durable and economical than any others. The implements used are rods and levels, for measuring dis- tances and ascertaining inclinations of surface ; tools for boring the soil, to examine substrata, and de- tect springs, consisting of augers, chisels, punches, &c. ; spades, shovels, and picks of various forms and dimensions ; and hoes, scoops, &c. for clearing out and finishing the form of drains. For the draining of towns and buildings, including the artificial supply of water, the best available sources such as rivers and springs are resorted to, and the advan- tageous use of these will require a careful consideration of the quali- ties of the water obtained, and its suitability for domestic and manu- facturing purposes. Arrangements are required for making the water furnished by rains available to the full extent, and rendering it and all other waters fit for use by subsi- dence, filtration, and purification. For discharging the refuse mat- ters from houses and other build- ings, and from streets and public thoroughfares, drains and sewers of various forms and materials are to be selected, made of ample di- mensions and permanent construc- tion, with such vertical inclination, and so arranged, that their con- tents shall always have a tendency to run off, and never suffer inter- ference from the discharge of other channels. 158 As a final point to be observed in any system of town-drainage, that of the ultimate disposal of the refuse matters is one of the highest importance in both a sanatory and an economical point of view. Col- lected in proper reservoirs, and judiciously treated, these matters may be distributed in fertilizing streams over the fields and the gardens of the suburbs, and will thus realize immense value in im- proved and augmented crops : al- lowed to accumulate in cesspools beneath human dwellings, they en- gender malignant and fatal disease, and if finally discharged into a river, by way of getting rid of them, they pollute waters otherwise whole- some, and, in dry seasons, send forth from the banks the most un- healthy gases. Draught, in ship draughting, the draw- ing or design by which the ship is to be built, which is generally by a scale of one-fourth of an inch to a foot Draute-chamber, a retiring or with- drawing room Draw-bore, the pinning a mortise and tenon, by piercing the hole through the tenon nearer to the shoulder than the holes through the cheeks from the abutment in which the shoulder is to come in contact Draw -bore pins, pieces of steel in the shape of the frustrum of a cone, somewhat tapered, and inserted in handles with the greatest diameter next to the handle, for driving through the draw-bores of a mor- tise and tenon, in order to bring the shoulder of the rail close home to the abutment on the edge of the style : when this is effected, the draw-bore pins, when more than one are used, are taken out singly, and the holes filled up with wooden pegs Drawbridge. All drawbridges are composed of two distinct parts, viz. the platform, which revolves on a horizontal axis, acting as a barrier or gate when in a vertical position, DRA DRAWING. DRE and becoming a bridge when in a horizontal position; and the con- trivance necessary to balance the platform in every position. The equilibrium should be such that friction is the only force to be overcome in raising or lowering the platform. The chief difference between drawbridges lies in the arrange- ment of this latter contrivance; for the platforms only differ in small details of construction, which have very little influence on the qualities which are essential to the arrange- ment of the balancing apparatus. These qualities remain the same, whether the drawbridges are used for closing communications in for- tified works, or merely for forming passages across navigable canals. They are principally as follows : 1st. The whole system should possess sufficient strength to be perfectly free from danger in all positions and at all times, and should therefore be constructed of solid and lasting materials. 2nd. A small number of men should be able to raise or lower the bridge in a short space of time. This quality requires all the parts to be in equilibrium when friction is not considered. 3rd. The machinery for raising and lowering the bridge should not obstruct the communications either in front or in rear of the buttresses of the gateway where it is placed ; and also the space formed by rais- ing the bridge should be as wide as possible, for this space consti- tutes the chief use of the bridge. 4th. The counterpoise and the machinery attached to it should be raised as little as possible above the platform when vertical, in or- der that it may not be much ex- posed to an enemy's fire, and that it may be easily covered by the ad- vanced works; besides that, by raising it, the expense of construct- ing and the inconvenience of work- ing the machinery are increased, 159 and the strength of the gateway or postern is sometimes diminished. 5th. The counterpoise and its machinery should not be much be- low the level of the ground, and particularly very little below the level of the surface of the water in wet ditches. At all events, the descending parts should be enclosed in narrow shafts of masonry secure from damp. In order not to weaken the postern walls, they should be at least 3 feet in rear of them. Drawing is the art of representing objects on a flat surface by lines describing their forms and contours alone, independently of colour or even shadow, although the latter is closely allied with drawing, both in practice and theory Drawings in pencil are sometimes re- quired to be fixed: this can be done by using water-starch made to the consistency of that employed by laundresses: it should be ap- plied with a broad camel's hair brush, as in varnishing. Isinglas size, and rice-water, are sometimes used, but are not so good as the first-named substance. Dredge's Suspension Bridge consists in making the chains of sufficient magnitude and strength at the points of suspension to support with safety the greatest permanent and contingent load to which, un- der the circumstances of locality, they are ever likely to be exposed; and from thence, to taper or dimi- nish them gradually to the middle of the bridge, where the strain be- comes essentially evanescent. The gradual diminution of the chains, however, is not the only peculiarity which characterizes this mode of construction, and marks its utility. The suspending-rods or bars that support the platform, or roadway, instead of being hung vertically or at right angles to the plane of the horizon, are inclined to it in angles which vary in magnitude from the abutments to the middle of the bridge, where the obliquity, as well DRE DRUMMOND LIGHT. DRY as the stress upon the chains, at- tains its minimum value. Dredging machines, mechanical con- trivances placed in the hull of a vessel, and floated in situations for the dredging and clearing away of deposited matter from the beds of rivers, canals, harbours, basins, &c. Some machines for these purposes are to be compared to harrows or shovels, which loosen the deposit preparatory to its removal either by the action of the tide or stream; but for the more general purposes of dredging, vast improvements have been effected. The machinery of the best construction is described in Weale's ' Quarterly Papers on Engineering.' Dressings, the mouldings and sculp- tured decorations of all kinds which are used on the walls and ceilings of a building for the purpose of or- nament Drift, a piece of hardened steel, notched at the sides and made slightly tapering: it is used for enlarging a hole in a piece of metal to a particular size by being driven through it Drift, the horizontal force which an arch exerts with a tendency to overset the piers from which it springs Drifts, in the sheer draught, are where the rails are cut off and ended with a scroll. Pieces fitted to form the drifts are called drift- pieces. Driftway, in mining, is a passage cut under the earth from shaft to shaft Drill, a tool for cutting a circular hole in a piece of metal Drilling machine, a machine for cut- ting circular holes in metal by means of a revolving drill Drilling, the art of boring small holes. Drilling may be effected in a lathe. The drill is screwed upon the spin- dle, so that its point shall turn ex- actly opposite that of the screw in the shifting head. Various inge- nious improvements have recently been made. 160 Drip, the projecting edge of a mould- ing channeled beneath, so that the rain will drip from it : the corona of the Italian architects Dripstone, called also the 'label,' 'weather moulding,' and 'water table,' a projecting tablet or mould- ing over the heads of doorways, windows, archways, niches, &c. Driver, the foremost spur in the bulge-ways, the heel of which is fayed to the foreside of the fore- most poppet, and the sides placed to look fore and aft in a ship Driver, the bent piece of iron fixed in the centre chuck, and projecting over it to meet the carrier, and drive it forward Driving shaft, any shaft which gives motion to another shaft Driving springs, the springs fixed upon the boxes of the driving axle of a locomotive engine, to support the weight and to deaden the shocks caused by irregularities in the rails Driving wheels, the large wheels of a locomotive engine, which are fixed upon the crank-axle, or main shaft of the engine Drum, in architecture, thebell-formed part of the Corinthian and Compo- site capitals Drum, a hollow cylinder fixed on a shaft, for driving another shaft by a band Drummond light, a peculiar light invented by the late Capt. Drum- mond, called a heliostat, which re- flected the sun's rays in sufficient abundance to render the station which was to be observed visible. This invention obviated the diffi- culty of distinguishing the stations chosen for the angular points of the triangles in a geodesical sur- vey : where those stations are many miles asunder, it is necessary to have recourse to illuminations even in day-time. Druxey, timber in a state of decay, with white spongy veins Dryness is a term by which artists express the common defect of the DRY DYNAMICS. DYN early painters in oil, who had but little knowledge of the flowing con- tours which so elegantly show the delicate forms of the limbs and the insertion of the muscles ; the flesh in their colouring appearing hard and stiff, instead of expressing a pleasing softness. The draperies of those early painters, and parti- cularly of the Germans, concealed the limbs of the figures, without truth or elegance of choice; and even in their best masters, the dra- peries very frequently either de- meaned or encumbered the figures. Dry-rot, a disease affecting timber, and particularly the oak employed for naval purposes. Many contri- vances are employed as remedies which have recently been patented, and have been successfully applied. Dub, to work with the adze Ductilimeter, an instrument for com- paring the ductility of lead, tin, &c. Ductility is that property of bodies which admits of their being drawn out in length, while their diameter is diminished, without any actual fracture. Gold, silver, platinum, iron, copper, zinc, tin, lead, nickel, are ductile in the order here given : wire-drawing depends on ductility. Ductility, the property possessed by certain bodies of yielding to percus- sion, and receiving a change of form without breaking Dums (in Cornish), frames of wood like the jambs of a door or the frame of a window ; set in loose ground in adits and places that are weak and liable to fall in or tumble down Dungeon, a place of incarceration, for- merly the principal tower or keep of a castle : it w r as always the strongest and least accessible part of a building Durbar (Persian), a court or building where the sovereign or viceroy gives audience Dutch Pink, English and Italian Pinks, are bright yellow colours used in distemper and for paper- staining, and other ordinary pur- poses. The pigment called 'stil,' 161 or ' stil de grain,' is a similar pre- paration, and a very fugitive yellow, the darker kind of which is called Brown Pink. Dutch School of Painting. This school of art cannot be said to possess the perfections that are to be observed in the Flemish school ; their subjects are derived from the tavern, the smith's shop, and from vulgar amusements of the rudest peasants. The expressions are suf- ficiently marked ; but it is the ex- pression of passions which debase, instead of ennobling human nature. It must be acknowledged, at the same time, that the Dutch painters have succeeded in several branches of the art. If they have chosen low subjects of imitation, they have re- presented them with great exact- ness ; and truth must always please. If they have not succeeded in most difficult parts of the chiaro-oscuro, they at least excel in the most striking, such as in light confined in a narrow space, night illuminated by the moon, or by torches, and the light of a smith's forge. The Dutch understandthegraflationsof colours. They have no rivals in landscape painting, considered as the faithful representation of a particular scene; but they are far from equalling Titian, Poussin, Claude Lorraine, &c., who have carried to the greatest perfection the ideal land- scape ; and whose pictures, instead of being the topographical repre- sentation of certain places, are the combined result of every thing beau- tiful in imagination or in nature. Dyeing is the art of staining textile substances with permanent colours Dyke, in coal mining, the banks of basalt or whin, by which the coal strata are frequently divided Dynamics, the science of moving powers, or of the action offerees on solid bodies when the result of that action is motion. GENERAL DEFINITIONS. 1. The mass of a body is the quantity of matter of which it is DYN EARLY ENGLISH ARCHITECTURE. DYS composed, and is proportional to its weight, or to the force which must be applied to the body to prevent its gravitating to the earth, and which, being greater or less as the mass is greater or less, w r e regard as a measure of the mass itself. 2. Density is a word by which we indicate the comparative close- ness or otherwise of the particles of bodies, and is synonymous with the term, specific gravity. Those bodies which have the greatest number of particles, or the greatest quantity of matter, in a given magnitude, we call most dense; those which have the least quantity of matter, least dense. Thus lead is more dense than freestone ; freestone more dense than oak; and oak more dense than cork. 3. The velocity with which a body in motion moves, is measured by the space over which it passes in any given time; the unit usually assumed being one second. 4. If the body passes over an equal space in each successive unit of time, the body is said to move uniformly, or to have a uniform velocity, and the measure of such velocity is the space actually passed over by the body in each second. 5. If, however, the body passes over a greater space in each suc- cessive second than it did in the preceding, then it is said to move with an accelerated velocity : when the differences between the spaces moved over in any two successive seconds is the same, at whatever period of the body's motion they be taken, or in other words, wiien the successive spaces form an arithme- tical progression, the body is said to move with a uniformly accele- rated velocity ; but when the spaces passed over in successive seconds EAR Early English Architecture, the first of the pointed or Gothic styles of architecture used in England. It 162 increase according to any other law, the body is then said to have its velocity variably accelerated. 6. If, on the other hand, the body passes over a smaller space in each successive second than it did in the preceding, then it is said to move with a retarded velocity ; which, if the successive spaces form a de- creasing arithmetical series, is said to be uniformly retarded; if other- Vfise,itissaidto\)evariably retarded. 7. The velocity of a body whose motion is variable is expressed at any moment by the space which it would pass over in a second, if its velocity at the moment spoken of were to continue uniform for that period. 8. Mechanical effect is measured by the product of the mass or weight of the body into the space over which it has been moved ; no regard being had to the time occu- pied. The unit of mechanical effect is a weight of one pound raised through a space of one foot. 9. The momentum of a body in motion means the mechanical effect which such a body will produce in a moment (or second) of time, and varies as the weight of the body multiplied by its velocity. 10. The vis viva of a body in motion is the whole mechanical effect which it will produce in being brought to a state of rest, no regard being had to the time in which the effect is produced, and it varies as the weight of the body multiplied by the square of its velocity. Dynamometer, an instrument which measures any thing to which the name of power has been given, whether that of an animal or other- wise Dysodile, a papyraceous brown coal EAR immediately succeeded the Norman towards the end of the 12th cen- tury, and gradually merged into EAR EARTH-WORK. EAR the Decorated at the end of the 13th. The mouldings consist of alternate rounds and deeply cut hollows, with small fillets, pro- ducing a strong effect of light and shadow. The arches are usually equilateral orlanced-shaped, though drop-arches are frequently met with, and sometimes pointed seg- mented arches : trefoil and cinque- foil arches are also often used in small openings and panelings. The doorways of this style, in large buildings, are often divided into two by a single shaft or small pin, with a quatre-foil or other ornament. The windows are al- most universally of long and narrow proportions, and are used singly, or in combinations of two, three, five, and seven : when thus com- bined, the space between them sometimes but little exceeds the width of the mullions of the later styles. Groined ceilings are very common in this style. The pillows usually consist of small shafts ar- ranged round a larger circular pier, but others of a different kind are sometimes found. The capitals consist of plain mouldings, or are enriched with foliage and sculpture characteristic of the style. Earth-work. The patented excavator, originally an American invention, is capable of cutting and levelling earth-work for the making of rail- ways and for other works at a cost considerably below manual labour, and which has the additional ad- vantage of saving much time : it forms an important consideration in railway making. By the attendance of the engine- man and assistant, together with the labour of six men for carting away the removed earth-work, this machine, it is said, can be made to excavate 1500 cubic yards in twelve hours, at a cost of fuel of 163 EAR EARTH-WORK. EAS 12*. per diem. The cost of the machine is 1500. Earth- work in England has generally been taken at Wd. to 1*. per yard. This apparatus is a strong rect- angular frame of wood, or other material, mounted upon wheels, supported, together with the ma- chine, on a temporary railroad : at one end of this frame is a strong crane, consisting of a vertical shaft or pillar, with the jib supported by diagonal stays, or arms : to the end of the chain tackle is suspended a scoop, shovel, or scraper, made of strong boiler-plate iron, and consisting of two sides, end, and bottom, the edge of which latter is provided with four or more pro- jecting points or cutters ; and be- tween these, and at their roots, is a steel edge, well tempered, so as to resist stone or other hard sub- tance with which it may come in contact: the chain tackle is at- tached to the sides of the shovel, and passes over a pulley at the end of the jib, and over another pulley fixed on the top of the pillar or support of the crane, and from thence to the barrel, upon which it is made to coil: the periphery of the last-mentioned pulley is formed with indentations to receive the links of the chain, for the pur- pose of giving motion to the pulley, which has on its axis a bevel- wheel, taking into and driving a similar wheel, upon the end of an inclined shaft, which shaft actuates certain machinery fixed to and supported by the diagonal arms of the crane. This machinery con- sists of a barrel, with other appur- tenances, round which is passed a chain, with its ends attached to the opposite ends of a beam or arm, which is also fixed to the shovel or scraper. The crane is capable of being moved round, so as to turn the scoop, when ele- vated, either to the right or left, in a horizontal direction : for this purpose a ' horse -shoe pulley,' 164 having a groove in its periphery, is affixed to the upper part of the crane: a chain, attached at each end to a transverse bar, passes round this pulley, and over certain horizontal and vertical guide pul- leys, to a barrel, in such a manner that, by reversing the motion of the barrel, the jib of the crane can be turned either to the right or left. A steam engine is erected at one end of the rectangular frame, or platform, for the purpose of giving motion to the various parts of the apparatus. When com- mencing operation, the shovel, or scraper, is suspended by the chain tackle in a nearly vertical position, with the steel points towards the ground : by releasing the clicks, or catches, of the chain barrel, and applying the brake, the shovel will be lowered, and force itself, by its own weight, into the ground ; then by communicating motion to the chain barrel, the tackle will be raised, and, by means of the in- dented grooved pulley, motion will be given to the shaft, which ac- tuates the machinery on the dia- gonal arms, which in its turn will force forward the shovel into the ground. At the same time that this motion is going forward, the sho- vel, or scraper, is being raised or lifted up by the tackle, by which means the shovel has a double motion, a thrusting forward mo- tion and a lifting motion. When the shovel has become filled, and attained its proper altitude, these motions stop ; and the shovel being prevented from returning by the clicks, or catches, the other barrel is thrown into gear by means of a coupling or clutch -box, and the crane turned round so as to bring the shovel over the cart, or other place of deposit ; and by certain arrangements it is turned up so as to empty itself ; in which position it is again ready for another operation. Easel, for painters, the frame on EAS EFFECTS OF BUILDINGS. EFF which the canvas is laid, stretched for painting East Indian Black wood grows to an immense size, and is much used for making furniture Easter, a moveable feast held in com- memoration of the Resurrection. Being the most important and most ancient in observance, it governs the other moveable feasts through- out the year. Eaves, the lower edge of a sloping roof which overhangs the face of a wall, for the purpose of throwing off the water Ebony wood is of several colours, as yellow, red, green, and black. The latter is always preferred, and is much used. It is. imported princi- pally from the East, and is used for cabinet, mosaic, and turnery work, for flutes, handles of doors, knives, surgeons' instruments, piano-forte keys, &c. Eborarim, a term applied by the Ro- mans to a kind of ivory-work Eccentric, or Excentric, a circular disc revolving within a strap or ring, and having its axis of revolution on one side of the centre. It is used as a substitute for a crank for giving a reciprocating motion to the slide-valve or to the feed-pump of a steam engine. Eccentrics are circular sheaves with a hole for the driving-wheel axle, about 2 inches out of the centre of the sheave of a locomotive engine, which thus makes it project some 4 inches more from the centre of the driving axle on one side than on the other. It is this eccentricity of motion which works the slide- valve gear and pumps in a very satisfactory manner. Eccentrics are fitted in two parts, and secured to the axle by a hoop and set- bolts. Eccentric hoops, hoops fitted round the projecting part of the eccentric sheaves of a locomotive engine, to strengthen them Eccentric rod and strap, the rod, the strap end of which encircles the 165 eccentric sheave, and the other end connects it with the quadrant, or rocking-shaft, according to the class of a locomotive engine. In some engines the end is forked to go on the stud of the rocking- shaft, and opens out something like the letter V ; or when only one rod is used for both back and forward movements, it resembles the letter X. In other engines it is attached to the quadrants by a bolt, one rod for forward gear, and another rod for backward gear. Eccentric rod, the rod connecting the eccentric strap to the lever which moves the slide-valve Eccentric strap, a brass ring formed by two pieces bolted together, and fixed to the eccentric rod: the ring fits a grooved part in the cir- cumference of the eccentric Echinus, the egg and anchor, or egg and tongue ornament found carved on the ovolo, in classical architec- ture Echinus, a member of the Doric capi- tal ; so called from its resemblance to the echinus, or large vase, in which drinking-cups were washed Ecphora, the projection of any mem- ber or moulding before the face of the member or moulding next be- low it Eduction pipe, the pipe from the ex- haust passage of the cylinder to the condenser Effect is the art of giving to a draw- ing a striking appearance, or so- lemnity, awe, sadness, mirth or tranquillity, by a judicious combi- nation of objects, and by strong light and shadow. It is a faithful representation of the appearance of nature, best seen under certain cir- cumstances and at certain times, such as morning effect, evening effect, twilight effect, and stormy effect, torch-light and candle-light effects, &c. Effects of buildings. " The site adap- ted for buildings, and the accompa- niments of terraces, gardens, and other decorations to set off their EGY EGYPTIAN ARCHITECTURE. ELA architectural designs, are subjects for consideration in which we are influenced by the desire to raise and extend the theory and practice to what we consider belongs to the art. It was in Italy, when the -fine arts were in perfection, that the laying out great villas was prac- tised by artists who often combined the practice of painting and archi- tecture ; and until it be adopted in England, the designs of the archi- tect never will have justice done to them in the execution. Our parks may be beautiful, our mansions faultless in design ; but nothing is more rare than to see the two pro- perly connected. Let the architect by study and observation qualify himself to include in his art the decorations around the immediate site of the intended building, toge- ther with its interior adornment, furniture, and upholstery, and the growing taste among the gentry of England will second such laudable efforts." Egyptian Architecture had its origin 2222 years before Christ, and ad- vanced and flourished under dif- ferent dynasties. The first includes the two great dynasties of Theban princes, who governed Egypt dur- ing her " most high and palmy state," when Thebes sent forth her armies to distant conquest. In the second period is comprised the erection of the Pyramids. The third includes the reigns of the Ptolemies and earlier Caesars, un- der whom Egyptian architecture flourished in a second youth, and almost attained its original splen- dour. Egyptian architecture, so massive and so sombre, with its vast aisled halls without windows, its close files of gigantic columns, and its colossal statues, owes many characteristic forms and effects to earlier cavern temples in Ethiopia. One of the most striking peculiari- ties of the style is the pyramidal character of the ascending lines : it is observed in the outline of the 166 portal and the gigantic pylon, in walls, doorways, pedestals, and screens : it pervades the whole system, and must have been occa- sioned by circumstances connected with its origin. The representa- tions given in ancient paintings show a remarkable love of uniform- ity of arrangement of their do- mestic houses and gardens. In an ordinary house a number of cham- bers were ranged round a rectan- gular court, as at Pompeii. The larger mansions sometimes consist- ed of an assemblage of such courts, the whole occupying a square or oblong plot. Sometimes a central group of buildings was surrounded by a narrow court. A spacious area often extended from front to rear, with a chief and side entrances at either end : the exterior had no- thing of the ponderous character of temple structures, which would have been ill-suited to the wants and festivities of social life. Houses two and three stories high were common; but large mansions ap- peartohave been low and extensive rather than lofty. The terraced top was covered by an aw r ning or roof, supported on light graceful columns. Eidograph, an instrument contrived for the purpose of copying draw- ings Ekeing, in ship-building, a piece fitted to make good a deficiency in length on the lower part of the supporter under the cat-head, &c. ; likewise the piece of carved work under the lower end of the quarter-piece at the aft part of the quarter -gal- lery Elastic, springy, having the pow r er of returning to the form from which it was distorted Elastic force of steam. The French reckon an atmosphere to be equal to a column of mercury *76 of a metre in height, w r hich is only 29'92 inches, and the boiling point of their thermometer is adapted thereto ; whereas, since about the ELD ELEMENTARY INSTRUCTION. ELE commencement of the present cen- tury, the English have reckoned it to be 30 inches. This circumstance accounts in some degree for their scale of temperatures differing from Mr. Southern's. The French account of the occa- sion of making their experiments on the temperatures corresponding to different elasticities of steam, in 1829, contains the following pas- sage : " Science did not then pos- sess this knowledge, and engineers appointed to superintend the con- struction of steam engines had no other guidance than some discord- ant measures upon the tempera- tures which correspond to the elas- ticities between one and eight at- mospheres: for higher pressures there was no result of direct expe- riments, nor any theory which could supply the deficiency." Elder wood. The branches of the elder contain a very light kind of pith, which is used, when dried, for elec- trical purposes ; the wood is also frequently used for carpenters' rules, weavers' shuttles, &c. Electrical state of the atmosphere. The electrical condition of the air in serene and tempestuous weather has been too much overlooked by meteorologists. The atmosphere is generally found to be in an elec- trical state. The apparatus for these observations is simply a me- tallic rod, insulated at its lower extremity, elevated at some height above the ground, and communi- cating with an electroscope. When the amenity of the weather will permit, a kite should be raised, in the string of which a metallic wire should be interwoven : this will collect the electricity of the higher regions of the air. The atmosphere is usually found to be positively electrified, and its electricity is stronger in the winter than in the summer ; and during the day than in the night. Electricity (from electrum, amber), was a name given at first to some 167 peculiar effects observed on rub- bing that substance, and gradually extended to an immense collection of facts of a similar kind, as well as to the cause of these effects, whatever it may be, and to the science which investigates their laws. This science is sometimes divided into five or six branches, according to the modes in which electric ef- fects may be brought about. The term atmospheric electricity applies to that which is naturally exhibited at nearly all times, but especially in thunder-storms ; common or frictional electricity, to that deve- loped by mere mechanical actions ; galvanism or voltaic electricity, to that developed by chemical action; j^erwo-electricity, by the action of heat; magneto-electricity, by that of magnetism ; and animal electri- city, by the will of certain fishes, which use this power as a defence. A more modern and comprehensive division is into 1. Electro-statics, or tensional electricity, referring to those effects in which the agency seems to have the equilibrium of its distribution disturbed, so as to be excessive or deficient in certain bodies, making them appear in dif- ferent states. 2. Electro-dynamics, or current electricity, describing those effects in which the agency appears to be moving from place to place, and displaying momentum. Electrum, from the Greek, a name given to amber, or to a mixture of metals composed of gold and silver Electrum, argentiferous gold; an alloy of silver Elegance, in a design, is a manner which embellishes and heightens objects, either as to their form or colour, or both, without destroying or perverting truth Elementary Instruction. Before en- tering into practice, it will be ne- cessary to bear the following rules and tables always in mind; and although we are to suppose every one already well acquainted with ELE ELEMENTARY INSTRUCTION. ELE them, they may yet possibly be found useful and essential here. SIGNS AND MARKS. + Plus, or more : the sign of ad- dition; as 5 + 6 = 11 Minus, or less : the sign of sub- traction, as 20 5 = 15 x Multiply by : the sign of multi- plication, as 8 x 9 = 72 -f- Divide by : the sign of division, as 16-^-4 = 4 = Equal to : the sign of equality, as 27 cubic feet = 1 cubic yard : : Proportion : the sign of propor- tion, as 3 : 6 : : 8 : 16 fi Fraction V Square root. V Cube root LINEAL MEASURE. 7'92 inches .... 1 link 12 inches .... 1 foot 3 feet 1 yard 5-3- yards . 1 rod. pole, or perch 4 poles, 100 links . 1 chain 40 poles, 10 chains . Ifurlong 8 furlongs, 1760 yards, 1 mile 80 chains, 8000 links 1 mile SaUARE OR SUPERFICIAL MEASURE. 144 square inches . 1 square foot 9 square feet . . 1 square yard 30} square yards { ' 40 perches ... 1 rood 4 roods ... 1 acre 640 acres .... 1 square mile CUBIC OR SOLID MEASURE. 1728 solid inches . 1 cubic foot 27 solid feet . . 1 cubic yard Proceeding to the various forms of plane surfaces, and the methods of measuring them, and beginning with the square, which has four A B equal sides and four right angles, as A, B, c, D, Rule : Multiply the given side by itself, and the product is the area required. Ex. 12 x 12 = 144. The next figure will be a paral- lelogram, or oblong square. Rule Multiply the length by the breadth, and the product gives the an Ex. 18' 0"x6'0"=108'0". The next figure will be a rhom- bus, which has four sides all equal, but no right angle. Rule : Multi- ply the base by the perpendicular height, and the product is the area. Ex. 16' 0" x 14' 0" = 224' 0". The next figure will be the rhomboid, which has its two sides equal and parallel, but no right angle : it is a long square pushed A" ~ ysr ~ 7 Zl / aside. Rule : Multiply the longer side by the perpendicular heig v * i or breadth, and the product is the area. Ex. 18'0" * 5' 6" = 99' 0". The next will be a right-angled triangle, having one of its angles a true square, or just 90 degrees. 168 ELE ELEMENTARY INSTRUCTION. ELE Rule: Multiply one of the legs forming the right angle by half the other ; the product is the area. Ex. 16' 0"-f-2 = 8'x20 / 0" = 160' 0". The next figure will be a tri- angle. Rule: Multiply the longest side by one-half the perpendicular, and the product is the content. Ex. 14' 0" + 2 = 1' 0" x 24' 0" = 168' 0", area required. The next figure will be the tra- pezium, which consists of four un- equal sides and four unequal an- gles; it is, indeed, two triangles., aad may be measured at twice, as shown in the preceding triangle, or by this Rule : Multiply the diagonal by one-half- the sum of the two perpendiculars. Ex. 8' 0" + 4' 0" = 12' 0" -r- 2 = & 0" x 20' 0" = 120' 0", the area required. The next figure will be the area of a circle. Rule : Square the diameter, and multiply that pro- duct by -7854, a decimal, and that product will be the content. Ex. 12' 0" x 12' 0"= 144' 0" x -7854 = 113-0976. The next dia- gram will be a segment or part of a section of a circle: to mea- sure this, mul- tiply half the sum of the two arches by one of the ends, and the product will give the area. Ex. 24' 0" + 18' 0" = 42' 0" -=-2 = 21' 0"x 2' 0" = 42' 0", which is the area required. Where the figure is found of the shape annexed, with two right angles, aiid the sides not parallel, hi stead of dividing it and measuring it as a parallelogram and an angle, take the mean of the two per- pendiculars, and multiply by the length; the product will give the area required. Ex. 12' 0" + 8' 0" = 20' 0"+2 =10' 0"= x 32' 0" = 320' 0". It is now necessary to take into consideration the methods of mea- suring solid or cubic bodies; for example, to begin with a cube, viz. a solid bounded by six square sides, similar to a die. Rule : Mul- tiply the side by itself, and that product by the side again; the last product will be the solid content. Ex. 6' 0" x 6' 0" = 36' 0" x 6' 0" = 216' 0" cubic feet. 169 ELE ELEMENTARY INSTRUCTION. ELE The next figure is the parallelo- pipedon, or ob- long cube. Rule: Multiply the breadth by the depth, and that product by the length ; this last product will be the content of it. Ex. 6'0 " x 8' 0" = 48 / 0"x32 / 0" = 1536' 0" = the required con- tent of the paral- lelopipedon. Next proceed to the prism, to measure which, find the area at the end, multiply that by the length, and that product is the content. Ex. The perpendicular height, 6' 0" -* 2 = 3' 0"xl2' 0" = 36' 0" The inclined plane and wedge may be measured by the same rule as the prism ; but the readier way is to j multiply one - half of | the thickness of the base by its width, and that by the perpendicular or length. Ex. 3' 0" x 15' // = 45 / 0" x 20' 0" = 900' 0" = content of inclined plane. This figure will be found in all earth-work, passing from cutting to embankment. Again, 6' 0" x 15' 0" = 90' 0" x 20' 0"=1800' 0", content of the wedge. The next figure is a square pyra- mid, and the one-half of which is a very prominent formation in banks, and is measured by multi- plying the area of the base by one- third the height or length. Ex. V 0" x & 0" = 36 7 0" x 6' 0" = 216' 0" content. Arriving now at the cylinder, this is measured by multiplying the area of the base or end by the length. Ex. 12' 0" x 12' 0" = 144'0"x -7854 = 113-0976 x 20' 0" = 2260'0". The cone is also measured by multiplying the area of the base by one-third the perpendicular height, Ex. 12' 0" x 12' 0" = 144' 0" x 7854 = 113' 0" x & 8" = 753' 4". 170 ELI EMBANKMENTS. EMB The next figure is the frustrum of a square pyramid, which also is a form peculiar in embankments and cuttings. Rule : To four times the area of the mean base add the area of each end, which divide by 6 ; mul- tiply the product by the length, you will find the con- tents. Ex. 4' 0" + 6' 0"=10' 0"-r-2 = 5' 0", the mean height of the base or thickness will be 5' 0" ; 5' 0" x 5' 0" = 25' 0"x 4' 0" = 100'0"+36'0" = 136'0' / + 16'0 // =152 / 0"; 152'0" -f-6' 0" = 25' 4"x 20' 0" = 506' 8" content. The same rule applies to the frustrum of a cone. Elizabethan Architecture, the style which prevailed in England at the time of Queen Elizabeth, and im- mediately subsequent to the Tudor style of Henry VIII. Ellipse : this curve is one of the conic sections, and next in importance to the circle and the straight line Ellipsis, an oval figure generated from the section of a cone by a plane cutting both sides of the cone, but not parallel to the base, and meet- ing with the base when produced Elliptic compasses, a term given to any machine for describing ellipses Elliptoffraph, an instrument for draw- ing ellipses Elm, atiraber-tree, of European growth, and of which there are five species : mean size, 44 feet long, 32 inches diameter : it is not liable to split, and bears the driving of nails, bolts, &c. : much used in building ; also for the keels of vessels, and for wet foundations. Elongation, the act of lengthening Elutriation, the separation of foul sub- stances from pure, by pulverization 171 Elvan, (in Cornish), a hard close- grained stone, said to be a bastard limestone Embankments, raised mounds or dykes to preserve the proper and useful course of rivers, &c. ; and also for forming a level line of railway Embankments (some) executed on the Continent. On the banks of the Po, two sorts of dykes are used to prevent the river from overflowing during the winter, or the flood season. They are called ' in froldi' when immediately upon the banks of the river, and 'in golene' when at any considerable distance, as it is sometimes found advisable to allow the river to spread over a large surface of the adjacent valley, either for the purpose of admitting it to deposit the mud in suspension, or to allow it to lose its torrential character. The maintenance of the works of these dykes is con- fided to the Government engineers, who are under the control of a syndicate of the proprietors of the property most liable to be affected by inundations. When the river passes from one state to another, as from Piedmont to Modena, a mixed commission is charged with the joint superintendence. The Haarlem lake, besides the very remarkable steam engines de- scribed by Mr. Dempsey, merits observation for the extensive works executed for the defence of the land, and for the canals reserved for the navigation. The enclosure dyke is 50,000 metres long, or rather more than 31 miles. It has two outfall dykes, which serve for the navigation, 9000 metres, about 5^ miles ; one-half of which is 40 m - (131 ft. 2 in.) wide at the bottom or floor line; the other 43 m> 20 (141ft. 10 in.) The ordinary tides are, at the flux, 2 ft. 4 in. above the scale or datum line at Amsterdam ; at the reflux, 2 ft. 8 in. below the same datum : the difference between high and low water is then, on the EMB ENAMELLING. ENC average, about 5 feet. With vio- lent winds from the N. w. however, the tides rise sometimes 6 ft. 6 in. above the average. The tides of the Y, near the lake, are + 16 C- (or 6 1 in.) and 23 C> (or 9 in.), giving a total variation of 1 ft. 3^ in. The estimated cost of reclaiming the 18,000 hectares was 8 millions of florins, or 667,000 English, nearly, about 13 per acre. Pre- viously to undertaking this colos- sal work, the Zind Plas, of 4600 hectares superficial (nearly 11,500 acres), had been reclaimed at a cost of 3 millions of florins, or 250,000; not far from 22 per acre. The heights of the enclosure dyke are + or the datum line at Amsterdam, or the mean level of the sea in that port. Embankment of the flooded part of the Amsterdam and Haarlem Rail- way. The bottom part consists of treble ranges of fascines, tied down by longitudinal poles 1 metre apart from centre to centre, and 0'25 C< diameter; two double stakes at each end of the poles, and two ties in the intermediate distances. The interstices of the fascines and the space between the rows are filled in with sand. The upper part, form- ing the encasement for the ballast, is made of three rows of treble fas- cines, well staked, and wattled to- gether. A core of sand or clay, faced with step fascines, is made up to low- water mark. Upon this a bed of rushes, fastened down by stakes and wattles, is laid ; and the upper portion of the bank is faced with fascines of a regular slope of 1 to 1. Embattled, a term applied to any building with a parapet, and having embrasures to resemble a battery Emblema, an emblem, or inlaid orna- ment of divers colours Embolus, in mechanics, a wedge ; an- ciently, among the Greeks, the prow or beak of a vessel, or a body of soldiers in the form of a wedge Embossing, forming work in relievo, 172 whether cast or cut with a chisel ; or in modern times, the art of pro- ducing raised figures upon wood or other materials by means of pressure, either applied by a sudden blow, as in a stamping press, or in a more gradual manner, as by an ordinary screw or hydraulic press, orbymeans of revolving cylinders Embrasure, the crenelles or intervals between the merlons of a battlement Embroidery, a mode of working de- vices on woven substances Emerald green is a new colour of cop- per green upon a terrene base : it is the most vivid of this tribe of colours, being rather opaque, and powerfully reflective of light : it appears to be the most durable pig- ment of its class Emissarium, a sluice, flood-gate, or channelby which an outlet is formed to carry off stagnant or foul water : accordingto Pliny, an artificial canal formed for the draining of stagnant waters Emplecton, a method of constructing walls introduced by the Greeks and copied by the Roman architects, in which the outside surfaces on both sides were formed of ashlar laid in regular courses, and the central space between them filled in with rubble-work, layers of cross stones being placed at intervals in regular courses, and of sufficient size to ex- tend through the entire thickness of the wall from side to side, and so act as girders to bind the whole together Emporium, a mart or factory, a large building containing ranges of bond- ing warehouses, in which foreign merchandise brought by sea is de- posited for sale Enamelling, the art of using enamel, which is divided into transparent and opaque. The first is employed for the purpose of ornamenting gold and silver ; the second, commonly in the manufacture of watch and clock dials, and of plates for pic- tures, &c. Encarpa, according to Vitruvius, fes- ENC ENGINEERING, CIVIL. ENG toons of carved fruit and flowers, employed as decorative ornaments Encarpus, a festoon of fruit, flowers, &c.,used as ornaments on friezes Encaustica, the art of encaustic paint- ing, i. e. in colours mixed with wax, and afterwards hardened by the ac- tion of fire Encaustic painting, a kind of painting in which, by heating or burning in, the colours are rendered permanent in all their original splendour Enchasing, the art of enriching and beautifying gold, silver, and other metal work, by some design or figure represented thereon in low relievo Enclosure, a fence, a wall, or hedge, or other means of protection and se- curity surrounding land Endecagon, in geometry, a plane figure of eleven sides and angles End-irons, andirons or dogs, articles of household furniture in earlier times, used in fire-places to sustain the ends of logs of wood Engineering, Civil. This profession may be said to have originated in England about the middle of the last century. Before that period, whenever the prospects of great profit induced individuals or bodies to incorporate themselves for the purpose of undertaking extensive systems of drainage, or for the supply of water, requiring the as- sistance of an engineer, recourse was generally had to those great masters of hydraulic engineering, the Dutch. True it is that some so- litary exceptions bave occasionally beenfound; men who, like Sir Hugh Myddelton, combined a speculative turn of mind with some mechanical knowledge, and to tbese two quali- ties added an untiring energy of pur- pose, leading them to persevere in any undertaking, even under the most discouraging circumstances. But these men were rare instances of a peculiar talent, which, though it thus displayed itself occasionally, was far too uncommon a gift to allow the possessors of it to form a 173 class or profession. The case is very different now : a demand for this peculiar talent has been created of late years by the extraordinary de- velopment of our system of internal communication, as well as by the application of steam to the purposes of our manufactures ; and employ- ment is now found for hundreds where one was sufficient, not fifty years since, for the whole business of the country. So great indeed has been the demand, that the profes- sion may be said to be divided into two distinct bodies, viz. those who turn their attention to subjects which come more particularly within the scope of the duty of a civil en- gineer, such as docks, bridges, canals, railroads, &c., and those who devote themselves altogether to the manufacture of machinery. The duties which are involved in the practice of these two branches of the profession, though apparently dissimilar in character, are yet founded upon the same general principles ; and the acquirements which are necessary to enable the individual of one class to distin- guish himself, or even to practise his profession with a moderate chance of success, will be found equally necessary for those of the other class. These acquirements are partly abstract and theoretical, and partly experimental or practical. A civil engineer should, in addition to the knowledge required to fit him as well as others for the active duties of life, have such a knowledge of ma- thematics as will enable him to in- vestigate as well as to apply the rules laid down by writers on those branches of the mixed sciences to which his attention will most fre- quently be drawn. He should be well acquainted with the principles of mechanics,hydraulics,and indeed with all the branches of natural philosophy; an da certain amount of chemical knowledge will be found very valuable : he should be able to ENG ENGINEER, STEAM-BOAT. ENG draw neatly, and should understand the principles of projection upon which all engineering drawings are constructed: a general knowledge of the principles of architecture will also be essential. Having acquired the requisite amount of theoretical information, the next step is to gain that practical knowledge which is essential in order to the proper ap- plication of this information. The best mode of gaining this experience is to enter into the employment of some eminent man in the profession, in whose office there will be every opportunity offered to the young beginner of witnessing the mode in which the various descriptions of work are carried on. He will there be employed, first as a draughtsman, in copying drawings : as he becomes more acquainted with practical de- tails, he will have more responsi- bility thrown upon him, and be placed in charge of works, at first of small importance, but, by degrees, of those of such magnitude as will require all his theoretical know- ledge, and all the practical expe- rience he may have gained, to enable him to carry out the work to the satisfaction of his employers : he should cultivate a habit of observa- tion, and make a point of taking ample notes and sketches of what- ever he may see which in any way bears upon his profession. Having thus by degrees acquired a sufficient amount of information to give him a confidence in his own judgment upon any subject which may be submitted to him, and having be- come known as an active and intel- ligent agent of others, he will very possibly be called upon to plan and execute a work himself, and then, by degrees, with industry and ac- tivity, may work his way upwards in a profession where merit alone can lead to distinction. The course of the man who de- votes himself to the machinery branch of the profession differs but little, up to a certain point, from 174 that just described : his theoretical acquirements should be the same, but the practical part of his edu- cation will commence at the bench, where he will learn the use of all the tools and machinery by working at them with his own hands : he will then be placed in the drawing room, and go through much the same routine of instruction as before described, and will by degrees work his way up to the position of fore- man ; then, distinguishing himself by a power of applying general prin- ciples to particular cases, he will show himself capable of assuming the direction of an establishment for the manufacture of machinery, Engineer, Steam-boat. A steam-boat engineer is a person employed for the purpose of keeping the engine or engines of a steam vessel in as efficient a state as possible, and to superintend their working. He must set the engines to work, regulate their speed, and stop them as may be required. His duties while the engines are at work are various. He must take care that every moving part is properly lu- bricated ; that no steam is allowed to pass through valves or joints that ought to be steam-tight ; that no air is permitted to enter into any of the parts of the engine where it is essential that a vacuum should be kept up ; and that none of the bolts, or pins, or keys, work loose by the vibration, and shift their position, or come out of their places. He must also take care that none of the working parts become overheated by any undue amount of friction, arising from any want of proper lu- brication, any excessive tightness, or any other disturbing cause ; and if they should become overheated, he must take prompt and energetic measures to remedy the evil, and prevent any serious consequences arising therefrom. He must from time to time carefully observe the effect produced by the gradual wear of the working parts, so that if the ENG ENGINEER, STEAM-BOAT. ENG truth or accuracy of any of these seems to be materially affected, he may take steps to rectify the defects when lying up in harbour. He must also be careful to observe if the frame of the engine ever begins to move or work iu any way, and en- deavour to discover the cause, in order that it may be remedied when the engines are "at rest. One of the most important of his duties is to take care that the engines are kept clean, and any grit or dirt prevented from getting into the bearings or moving parts : he must wipe away all oil and grease most carefully and completely as soon as they have passed through the bearings, and prevent them from running down the rods or remaining about the engine. The boiler requires his unremit- ting and particular attention, in order that the proper supply of steam, neither too much nor too little, may be generated for the en- gine. To insure this, the manage- ment of the fires must be duly at- tended to, both in the supply of coal in the proper quantities at the pro- per intervals, and in the periodical clearing of the fires from the earthy matters of the coal, which may have become vitrified in the furnace, and formed what are called clinkers. By due attention to the former, the smoke in all well-proportioned boil- ers maybe very greatly abated; and, by due attention to both, the con- sumption of fuel (when the engines are prevented by a strong head wind, or by the deep immersion of the paddle-wheels on the commence- ment of a long voyage, from making the proper number of strokes, and thus using the proper amount of steam,) may be reduced in an equal or greater degree than has taken place in the consumption of steam. The due and constant supply of water to the boiler, to compensate for the constant evaporation of the water in the formation of the steam, must be assiduously attended to. 175 Another of the most important of the duties of a steam-boat engineer, during the time that the engines are at work on a voyage at sea, is to attend to the degree to which the water in the boilers may be- come saturated with salt by the con- tinued evaporation which is going on, and to take care that this satu- ration is not allowed to be carried to such an extent as that a deposi- tion of the salt and other matters contained in sea-water should take place. After the boilers have been in operation for three or four hours in salt water, so that the water in them has become brine, he ought to test the strength of it, that is, he ought to ascertain the degree of sa- turation to which it has reached, and continue this examination pe- riodically, whether the engines are fitted with an apparatus for the con- tinuous discharge of a portion of the brine, to be exchanged for a portion of sea- water, or whether this system of exchange is left entirely at his discretion, to be attended to by means of the common blow-off cocks. The best test is the common hydrometer, though the thermome- ter has hitherto been more com- monly applied to this purpose, as the brine is considered to be of a proper strength when it boils under atmospheric pressure at a tempera- ture 2 higher than that at which the common sea-w r ater will boil at the same time, under the same cir- cumstances. Before coming into port, it may occasionally be advantageous to take indicator diagrams, to see whether the action of the valves continues to be correct. The duties of a steam-boat en- gineer, on arriving in port after a long voyage, are also various, and equally important with those he has to perform when out at sea. Im- mediately on coming to anchor, it is a good practice to test the tight- ness of the steam -valves and pistons, by putting them in such a position ENG ENGINEER. ENG that it can be seen if they allow any steam to pass when it ought not to do so. If any imperfections in these the most vital parts of the engines are discovered, he mustdrawout the valves, or lift the cylinder covers, to get at the pistons, and rectify the defects in the best manner that he can with the means within his power. He should also occasionally examine all the interior parts of the engines, and rectify any incipient defects. He must now also rectify any want of truth in the parallel mo- tion or in any of the shafts or work- ing parts caused by wear, and tighten or make good any of the fastenings of the frame if he has found them to be loose, and put to rights any other such defects. Any parts sub- ject to corrosion should be carefully examined, cleaned, and dried, and painted if need be. The water should be blown off out of the boilers as completely as possible, and all ashes and soot thoroughly cleaned out of the furnaces and ffoaes as soon as possible. The fur- naces and flues must then be tho- roughly examined, and the slightest leak or defect that can be discovered made good ; as it is especially im- portant in a boiler to stop these defects at the first, as otherwise they spread very rapidly. No pains should be sparedto discover any sus- pected leak of steam on the top of the boiler, as nothing tends more to corrode and destroy a boiler than this. Inside the boilers, any scale that may have been deposited from the brine having been allowed to be- come too strong must be removed, and the whole thoroughly cleaned out from every part of the boiler, from below as well as from the tops and sides of the furnaces and flues. The take-up, the inside of the steam- chests, and of theroofs of the boilers, which are the parts most subject to corrosion from the interior, should be very carefully examined, and after being duly scraped and cleaned and dried, they should be well 176 painted with two or three coats of red lead, or done over with some other preservative. The paddle-wheels should also be thoroughly examined, and any bro- ken floats or hook -bolts replaced by new ones. The whole of the iron- work should be thoroughly scraped and cleaned, and, when dry, painted with three coats of red lead, or done over with black varnish, once every four months at least. When in harbour, especially if lying in a stream or tideway, the wheels ought to be turned round every three or four days, to change the parts ex- posed to the action of the water, and thus prevent corrosion. He must now also get his supply of stores made good, so as to be ready for another voyage. To qualify an engineer to per- form these duties, he should be trained as a mechanic, and be a fair workman in iron, brass, and wood. He should be able to work not only at the lathe or vice, but also at a smith's forge. His education should be such as to make him able to keep accounts, and make notes in his log of all that occurs in the engine- room. He should have sufficient knowledge of mechanical drawing to enable him, in the event of any important part of the engines being broken when at a distance from any manufactory, to make such a draw- ing of it as would enable a manu- facturer to replace it. He should have some knowledge of the first principles of mechanics, a general knowledge of the leading principles of hydrostatics, hydraulics, and pneumatics, without which he can- not fully understand many of the principles carried on in the engine, and on which its power depends. Some knowledge of heat, of the theory of combustion, of ebullition, and of evaporation, may also be reckoned as almost indispensable : to which should be added, if pos- sible, an acquaintance with the sub- ject of steam, especially as regards ENG ENGINEER, MECHANICAL. EPI its temperature, pressure, and latent heat. Engineer, Mechanical, one who is effi- cient in the invention, contrivance, putting together, and the adjustment of all kinds of machinery ; who is acquainted with the strength and quality of the material used, and who also possesses a thorough knowledge of the power of steam andthe engine in all its modifications, andthe uses for which this motive power is ap- plied : he should also be duly ac- quainted with mill-work of the several kinds, whether impelled by steam, water, or wind. English School of Painting. This school, which is but of recent date, is connected with the Royal Aca- demy in London, instituted in 1 766 ; and although as a school it did not exist before that period, yet since the revival of the arts, and the con- sequent encouragement given to them by the sovereigns of Europe, England has possessed portrait- painters of no inconsiderable ability; and it is probably owing to the re- markable partiality of the nation for this branch of the art, that historical painting has been, until recently, comparatively neglected. Latterly, however, painters of the highest eminence in this superior branch of the art have distinguished themselves, and given earnest of the rise of a school that may, ere long, surpass others of the present age. Entablature, those members of a por- tico which were constructed upon the columns, consisting of the epi- stylium, zophorus, and corona. Vi- truvius uses the words ornamenta columnarum to signify these mem- bers; and sometimes he includes the three several parts in the term epistylia. Entablature, the superstructure that lies horizontally upon the columns in the several orders or styles of architecture. It is divided into architrave, the part immediately above the column ; frieze, the cen- tral space ; and cornice, the upper projecting mouldings. Each of the orders has its appropriate entabla- ture, of which both the general height and the subdivisions are regu- lated by a scale of proportion derived from the diameter of the column. Entablatures, and their subdivision. The entablature, though architects frequently vary from the proportions here specified, may, as a general rule, be set up one-fourth the height of the column. The total height thereof thus obtained is in all the orders, except the Doric, divided into ten parts, three of which are given to the architrave, three to the frieze, and four to the cornice. But in the Doric order the whole height should be divided into eight parts, and two given to the architrave, three to the frieze, and three to the cornice. The mouldings which form the detail of these leading features are best learned by reference to re- presentations of the orders at large. Palladio and Vignola, the restorers of genuine architecture, are the authors whose works may be con- sulted with greatest advantage by those who desire to make any advance in the science, and most particularly by those who wish to obtain further knowledge on the use and abuse of its details. Entail, a term used in the middle ages to signify elaborated sculptured or- naments and carvings Entasis, the swell of the shaft or co- lumns of either of the orders of ar- chitecture Enterclose, a passage between two rooms in a house, or that leading from the door to the hall Entresol, in architecture, a floor be- twe'en two other floors. The en- tresol consists of a low apartment usually placed above the first floor: in London, frequently between the ground floor and the first floor. Ejihebeum, an apartment in the pa- lestra appropriated to wrestling and other athletic exercises Epicycle, a little circle whose centre is in the circumference of a greater 177 H5 EPI EVOLUTION. EVO Epicycloid, a curve generated by the revolution of the periphery of a circle along the convex or concave part of another circle Epicycloidal wheel, a wheel for con- verting circular into alternate mo- tion, or alternate into circular Episcenium, a division of the scene of a Greek theatre : it sometimes con- sisted of three divisions made by ranges of columns one above the other: the lower was termed scena, and the others episcenia Epistomium, the cock or spout of a water-pipe, or of any vessel contain- ing liquids to be drawn off in small quantities when required Epistylium,ihe lower of three divisions of an entablature or superstructure upon the columns of a portico, formed by pieces etxending from centre to centre of two columns Epistylium, the architrave or hori- zontal course resting immediately upon columns. Epistylar arcuation is the system in which columns sup- port arches instead of horizontal architraves and entablatures. Epitithidas, a term applied by some writers, by way of distinction, to the cymatium on the sloping or raking cornices of a pediment, which su- perimposed moulding (as its name implies) was frequently largely de- veloped, and enriched with an or- namental pattern Epitithides, the upper members of the corona surmounting the fastigium of a temple, which was also con- tinued along the flanks Equation, an equal division : in alge- bra, a mutual comparing of things of different denominations : in as- tronomy, the difference between the apparent and mean motion of the sun ' Equilateral, having all sides equal i Equilibrium, equipoise, equality of weight Equilibrium valve, the valve in the steam passage of a Cornish engine for opening the communication be- tween the top and bottom of the cylinder, to render the pressure equal on both sides of the piston 178 Era. The year 5611 of the Jewish era commences September 7, 1850 ; Ramadan, the month of abstinence observedbytheTurks, July 11, 1850; the year 1267 of the Mohammedan era, Nov. 6,1850 ; and the Christian era, 1849 since the birth of Jesus Christ, for 1850 years, on the 1st of January, 1850. Ergastulum, a sort of prison or house of correction contiguous to the farms and country villas of the Romans Ergata, a capstan or windlass Ermine, in heraldry, a white field or fur, powdered and interspersed with black spots, resembling the skin of an animal so named Escape, the scape of a column in ar- chitecture Escutcheon, a shield charged with armorial bearings Etching, a branch of engraving in which the lines are drawn by a stylus or etching-needle, on copper, steel, or stone, prepared by a che- mical process Eudiometer, an instrument used to ascertain the purity of air, or rather the quantity of oxygen contained in any given bulk of elastic fluid Euripus, any artificial canal or water- course, of greater or lesser extent, such as were made, according to Pliny, to ornament a Roman villa ; also an arm of the sea Eustyle, that intercolumniation which, as its name would import, the an- cients considered the most elegant, viz. two diameters and a quarter of the column. Vitruvius says, this manner of arranging columns ex- ceeds all others in strength, con- venience, and beauty Evaporation, the transformation of a liquid into a gaseous state by the action of heat Evolute, a particular species of curve Evolution, in geometry: the equable evolution of the periphery of a circle, or any other curve, is such a gradual approach of the circum- ference to rectitude as that all the parts meet together, and equally evolve or unbend EXA EXPANSIVE STEAM. EXP Ewry, an office of household service, where the ewers, &c., were formerly kept Examen, the tongue on the beam of a balance, rising perpendicularly from the beam, and moving in an eye affixed to the same, by which it serves to point out the equality or inequality of weight between the objects in the scale Exedra, an assembly-room or hall of conversation ; according to Vitru- vius, a large and handsome apart- ment ; also a by-place, or jutty Exedra, or Exhedra, the portico of the Grecian palaestra, in which dispu- tations of the learned were held : so called from its containing a num- ber of seats, generally open, like the pastas or vestibule of a Greek house Exemplar, a pattern, plan, or model ; resemblance Exhaust-port, the exit passage for the steam from a cylinder Exhaust -valve, the valve in the educ- tion passage of the steam cylinder of a Cornish engine, placed between the cylinder and air-pump, and worked by the tappet motion, so as to open shortly after the equili- brium valve, and admit the steam to the condenser Expansion joint, a stuffing-box joint connecting the steam pipes, so as to allow one of them to slide within the enlarged end of the other when the length increases by expansion Expansion valve, an auxiliary valve placed between the slide-valve and the steam cylinder: it is worked by a cam or other contrivance, so as to cut off the steam at a given period, and cause the remainder of the stroke to be performed by ex- pansion Expansive steam. The expansive pro- perties of steam are now well under- stood, and extensively applied to practice in manufacturing districts. In Cornwall, and in some other parts ofthekingdom,the application is attended with highly beneficial results. But it should be stated 179 that this system can be introduced with much greater advantage in en- gines that are employed in raising water, than in those which are en- tirely devoted to manufacturingpur- poses. In these last, the power is opposed to a continually varying resistance ; while, in the former, the resistance is commonly the same, or of equal intensity. To pumping engines, the adop- tion of the expansive system to an almost unlimited extent is recom- mended, even to the exclusion of any further ingress of steam to the cylinder after the piston has passed through but one-eighth or one- ; ninth of its stroke. Expansive steam may be thus ! explained : If we allow steam to flow into the cylinder of a steam engine until the piston be de- pressed to one-half of the stroke, and then prevent the admission of any further quantity, the piston will, if the engine be properly weighted, continue its motion to the bottom. The pressure of the steam, so long as the supply is continued from the boiler, will be equal, it is presumed, to ten pounds upon the inch. With this force it will act upon the piston until it completes one-half of the i stroke : the further supply of steam i will then be excluded, and that ( which is in the cylinder will ex- pand as the piston descends, so that when the stroke is completed it will occupy the entire capacity. The pressure of the steam will then be half of its former amount, or five pounds upon the inch. During the descent of the piston, the pressure of the steam does not suddenly decrease from ten pounds to five ; but it gradually declines, through the successive intervals, until at the final point it yields that force. It is by this gradual expan- sion and diminution of pressure that the superior action is produced. Experiments on Brass. Dr. Young made some experiments on brass, EXP EXPERIMENTS IN BRASS. EXT from which he calculated the height of the modulus of elasticity of brass plate to be 4,940,000 feet, or 18,000,000fts. for its weight to a base of 1 square inch. For wire of inferior brass he found the height to be 4,700,000 feet. As cast brass had not been sub- mitted to experiment, a cast bar of good brass was procured, with which the following experiment was made : The bar was filed true and regu- lar : its depth was 0*45 inch, and breadth 07 inch ; the distance be- tween the supports was 12 inches, and the scale suspended from the middle. tbs. inch.. 12 bent the bar 0-01 23 .. . . 0-02 f~ The bar was n f.,, I relieved seve- " r; <> ral times, but ittooknoper- [_ ceptible set. n n ^ f relieved, the D 1 set was -01. . . 0-1S C slipped between the , r.,y I supports, bent more | than 2 inches, but did t not break. Hence 52 tbs. seems to be about the limit which could not be much exceeded without permanent change of structure. It is equiva- lent to a strain of 6 700 tbs. upon a square inch, and the corresponding extension is 13 1 33 of its length. Ab- solute cohesion above 21, 000 tbs. per square inch. The modulus of elasticity according to this experi- ment is 8,930,000 tbs. for a base of an inch square. The specific gra- vity of the brass is 8 '3 7, whence we have 2,460,000 feet for the height of the modulus. Expression principally consists in, re- presenting the human body and alt its parts in the action suitable to it ; in exhibiting in the face the several passions proper to the figures, and marking the motions 180 38 52 65 110 they impress on the other external parts Expression, in painting, consists in the representation of those atti- tudes of the body, and variations of the countenance, which always accompany and indicate the imme- diate influence of the passions on the mind Expression of colour. Every pas- sion and affection of the mind has its appropriate tint ; and colour- ing, if properly adapted, lends its aid, with powerful effect, in the just discrimination and forcible ex- pression of them : it heightens joy, warms love, inflames anger, deep- ens sadness, and adds coldness to the cheek of death itself. External thermometer (the) should be a mercurial one, well exhausted of air, and the graduated scale divided to tenths of a degree, or into quar- ters of a degree, or with whole divisions large enough to be di- vided into as many parts by the eye. Choose a locality for the instrument, where it will be well exposed to the ambient air, apart from the reflection of sunbeams, &c., and where it may be dis- tinctly read off without inconve- nience. It should be read off as quickly as possible. For uniformity of system, it should be read off at stated periods, the same time at which the barometer, &c., are noted:, and carefully watched in the interim, to see whenever any remarkable change occurs ; before and after storms, during eclipses of the sun and moon, or the passage of dense clouds of vapour, &c. Extract of gamboge is the colouring matter of gamboge separated from its greenish gum and impurities by solution in alcohol and precipita- tion, by which means it acquires a powdery texture, rendering it miseible in oil, &c., and capable of use in glazing. It is at the same time improved in colour, and retains its original property of working well in water and gum. EXT FARM. FAR Extrados, the exterior curve of an arch, measured on the top of the voussoirs, as opposed to the soffit or intrados Eye, a name given to certain circular parts and apertures in architecture, FAB FABER, a name given by the Romans to any artisan or mechanic who worked in hard materials Fabrica, according to the Romans, the workshop of any mechanic Fabrilia, according to Horace, me- chanics' tools Fapade, the face or front of any con- siderable building to a street, court, garden, or other place Face-jriece, in ship-building, a piece wrought on the fore-part of the knee of the head, to assist the con- version of the main-piece, and to shorten the upper bolts of the knee of the head Fahrenheit, a native of Dantzic, was born in 1686 : he invented the scale so called after his name : he also im- proved the thermometer by substi- tuting mercury instead of spirits of wine, and formed a new scale for the instrument,founded on accurate experiments, fixing the freezing point of water at 32, and that of boiling at 212 Faldstool, or folding stool, a portable seat made to fold up in the man- ner of a camp stool : it was made either of metal or wood, and some- times covered with rich silk FaUe roof, the space between the ceiling and the roof above it, whe- ther the ceiling is of plaster or a stone vault, as at King's College chapel, Cambridge, and St. Jaques' church, Liege Fan-tracery vaulting : this was used in late Perpendicular work, in w r hich all the ribs that rise from the springing of the vault have the same curve, and diverge equally in every direction, producing an effect like the bones of a fan : very fine examples of it exist in Henry the 181 but more especially to the central circle of the Ionic volute ; to the circular or oval window in a pedi- ment ; to a small skylight in a roof, or the aperture at the sum- mit of a cupola FAR Tilth's chapel, Westminster, St. George's chapel, Windsor, and King's College chapel, Cambridge Fanal, a pharos or lighthouse, or the lantern placed in it Fanum, a Roman temple or fane, usu- ally consecrated to some deity Fang, in mining, a niche cut in the side of an adit, or shaft, to serve as an air course : sometimes a main of wood pipes is called a fanging Fanners, vanes or flat discs revolving round a centre, so as to produce a current of air ; generally used in- stead of bellows for forges Farm. Vitruvius says "The mag- nitude of the buildings must de- pend wholly upon the quantity of land attached to them, and upon its produce. The number of courts and their dimensions must be pro- portioned to the herds of cattle and the quantity of oxen employed. The kitchen should be situated in the warmest part of the court, and the stable for the oxen contiguous to it: the stalls should be made to face the hearth and the east ; because when oxen are constantly exposed to light and heat, they be- come smooth -coated. No hus- bandman, however ignorant, will suffer cattle to face any other quarter of the heavens than the east. The width of the stables ought not to be less than ten nor more than fifteen feet, their length proportioned to the number of yokes, each of which should oc- cupy an extent of seventeen feet. The scalding-rooms should adjoin the kitchen, in order that the ope- ration of cleaning the utensils may be performed upon the spot. The courts for sheep, &c., should be FAR FEED-PIPE. FEE so spacious as to allow not less than four and a half nor more than six feet to each animal. " The granaries should be above ground, and made to front either the north or the north-east, in order that the grain may not be liable to ferment; but, on the contrary, by exposure to a cold atmosphere, may be preserved a long time : all other aspects encourage the pro- pagation of worms and insects de- structive to grain. The stables should be built in the warmest part of the villa, most distant from the hearth; because when horses are stalled near fire they become rough-coated. It is likewise ex- pedient to have stalls for oxen at a distance from the kitchen, in the open air : these should be placed so as to front the east, because if they are led there to be fed in winter, when the sky is unclouded they will improve in appearance. The barns, the hay-yards, the corn- chambers, and the mills, ought to be without the walls ; so that the farm may be less liable to accidents from fire." Farm, in Cornish mining, that part of the lord's fee which is taken for liberty to work in tin mines only that are bounded, which is gene- rally one-fifteenth of the whole Fascia, a flat architectural member in an entablature or elsewhere; a band or broad fillet. The architrave in the more elegant orders of archi- tecture is divided into three bands, which are called fasciae : the lower is called the first fascia, the middle one the second, and the upper one the third fascia. Fasciae, the bands of which the epi- stylium of the Ionic and Corinthian orders are composed. The ante- pagments of Ionic doorways were generally divided into three fasciae or corsae. Fasciae were bands which the Romans were accus- tomed to bind round the legs. Fast and loose pulleys, two pulleys placed side by side on a shaft 182 which is driven from another shaft by a band: when it is required to stop the shaft, the band is trans- ferred to the loose pulley Fastigium, the pediment of a portico ; so called because it followed the form of the roof, which was made like a triangle, the sides being equally inclined to carry off the water Fastiffium, in architecture, the sum- mit, apex, or ridge of a house or pediment Faux, according to Vitruvius, a nar- row passage which formed a com- munication between the two prin- cipal divisions of a Roman house, the atrium and peristylium Fay, in ship-building, to join two pieces of timber close together Feathering, or foliation, an arrange- ment of small arcs or foils sepa- rated by projecting points or cusps, used as ornaments in the mould- ings of arches, &c. in Gothic architecture Feed-head, a cistern containing water and communicating with the boiler of a steam engine by a pipe, to supply the boiler by the gravity of the water, the height being made sufficient to overcome the pressure within the boiler Feed-pipe, the pipe leading from the feed-pump, or from an elevated cistern, to the bottom of the boiler of a locomotive engine Feed-pipe cocks, those used to regulate the supply of water to the boiler of a locomotive engine, and the handle of which is placed conveniently to open and shut at pleasure Feed-pipe strainer, or strum, a perfo- rated half-spherical piece of sheet iron, after the manner of the rose end of a watering pot : it is placed over the open end of the feed-pipe in the locomotive tender tank, to protect it Feed-pipes, the copper pipes reaching from the clack-box to the pump and from the pump to the tender, to convey water to the boiler of a locomotive engine FEE FENESTRATION. FIL Feed-pump, a forcing-pump, worked by the steam engine, for supplying the boiler with water Feed-pump plunger, the solid piston, or enlarged end of the pump-rod, fitting the stuffing-box of the pump of a steam engine Felling timber, the act of cutting down a full-grown tree, which doubtlessly should be done late in the autumn, when less moisture exists in all trees, and which ren- ders the timber less liable to dry- rot Felspar, a mineral of foliated struc- ture Felucca, in navigation, a little vessel used in the Mediterranean, capable of going either stem or stern fore- most ; also a small open boat, row- ed with six oars Femerell, a lantern, louvre, or covering placed on the roof of a kitchen, hall, &c. for the purpose of venti- lation or the escape of smoke Femur, in architecture, the long flat projecting face between each chan- nel of a triglyph ; the thigh, or a covering for the thigh Fender-piles, those driven to protect work either on land or in water Fenestella, the niche at the side of an altar containing the piscina ; a ves- sel for holding water to wash the hands of the officiating priest ; also a little window Fenestra, a window, an entrance Fenestral : window-blinds or case- ments closed with paper or cloth, instead of glass, are so termed Fenestration, termed by the Germans Fenster-architektur, is, in contra- distinction to columniation, the system of construction and mode of design marked by windows. Fenes- tration and columniation are so far antagonistic and irreconcileable, that fenestration either interferes with the effect aimed at by colum- niation with insulated columns, as in a portico or colonnade, or re- duces it, as is the case with an engaged order, to something quite secondary and merely decorative. 183 Astylar and fenestrated ought, there- fore, to be merely convertible terms ; but as they are not, that of co- lumnar -fenestrated has been in- vented, to denote that mode of composition which unites fenestra- tion \vith the semblance, at least, of the other. Employed as a collec- tive term, fenestration serves to express the character of a building or design with regard to the win- dows generally : thus it is said, the fenestration is excellent, or the con- trary, ornate or meagre, well arranged or too crowded, which last circumstance is a very common fault, and is destructive both of grandeur and of repose. Feretory, a bier, or coffin; a tomb, or shrine Ferrule, a metal ring fixed on the handle of a tool to prevent the wood from splitting Fesse, in heraldry, a band or girdle possessing the third part of the escutcheon over the middle Festoon, an ornament of carved work, representing a wreath or garland of flowers or leaves, or both inter- woven with each other: it is thick- est in the middle, and small at each extremity, a part often hanging down below the knot Festoon, in architecture, an ornament of carved work, in the form of a wreath or garland of flowers, or leaves twisted together Fictile, an earthen vessel or other article, moulded and baked Fie tor, among the Romana, an artist, a deviser, or potter Field, in heraldry, the whole surface of the shield Fiyulus, an artist who makes figures and ornaments Filagree, in the arts, a kind of en- richment in gold and silver File, a well-known instrument having teeth on the surface for cutting metal, ivory, wood, &c. File, a strip or bar of steel, the sur- face of which is cut into fine points or teeth, which act by a species of cutting closely allied to abrasion. FIN FINLAYSON'S TABLES. FIR When the file is rubhed over the material to be operated upon, it cuts or abrades little shavings or shreds, which, from their minuteness, are called file-dust, and, in so doing, the file produces minute and irregular furrows of nearly equal depth, leav- ing the surface that has been filed more orless smooth, accordingto the size of the teeth of the file, and more or less accurately shaped, according to the degree of skill used in the ma- nipulation of the instrument. The files employed in the mechanical arts are almost endless in variety. Finial, sometimes called a pinnacle, but more truly confined to the bunch of foliage which terminates pinnacles, canopies, pediments, &c. in Gothic architecture Finite force, a force that acts for a finite time, such as the force of gravity Fillet, a small flat face or band, used principally between mouldings to separate them from each other in classical architecture: in the Gothic, Early English, or Decorated styles of architecture, it is also used upon larger mouldings and shafts Finlayson's Tables of the value of life assurance and annuities differ in several respects widely from either the Northampton or the Carlisle cal- culated Tables. In framing them for Government annuities from obser- vations made on the mortality in tontines and amongst the holders of Government annuities, Mr. Fin- layson, in his calculations, is in- clined to take a favourable view of the duration of human life, and his Tables coincide very nearly with the Carlisle, except that he makes a distinction between males and females, the latter being consi- dered rather longer lived than the former. As regards annuities, these observations may be thus illustrat- ed : the present value of an an- nuity of 1 for the life of a person aged twenty-five, calculated at 4 per cent, interest, would be, ac- cording to the 184 Northampton Tables, 15 4 Carlisle do. ... 17 6 Government, Male . 16 9 Do. . . .Female. 18 1 Fire-bar frame, in alocomotive engine, a frame made to fit the fire-box on which the fire-bars rest : a plan of dropping all the bars at once by a moveable frame, acted on by a lever and handle outside the fire-box, has been frequently tried, but the action of the intense heat soon puts it out of working order Fire-bars, in a locomotive engine, wedge-shaped iron bars fitted to the fire-box with the thick side uppermost, to support the fire : the ends rest on a frame : they are in- clined inwards, with an air space between each, to promote combus- tion, and are jointed at one end, and supported by a rod at the other, so that the rod being withdrawn, the bars fall, and the fire-box is emptied Fire-box, in a locomotive engine, the box (usually made of copper) in which the fire is placed. The out- side is of iron, separated from the copper fire-box by a space of about 3 inches all round for water Fire-box door, the door opening into the fire-box, facing the locomotive tender, by which coke is supplied to the fire Fire-box partition: in large fire-boxes a division is made in the box, into which water is admitted: this di- vision is about the height of the fire-box door, and divides the fire into two parts in a locomotive en- gine, thereby increasing the heating surface of the fire-box Fire-box stays, in a locomotive engine, deep strong iron stays bolted to the top of the copper fire-box, to enable it to resist the pressure of the steam : round copper or iron stays are also used to connect the outside shell to the inside box, in the proportion of about one stay to every 4 square inches of flat surface Fire-brick or Fire-bricks are used for FIR FIRE-BRICKS. FIR lining furnaces, and for all kinds of brick-work exposed to intense heat which would melt common bricks. They are made from a natural com- pound of silica and alumina, which, when free from lime and other fluxes, is infusible under the great- est heat to which it can be subjected. Oxide of iron, however, which is present in most clays, renders the clay fusible when the silica and alumina are nearly in equal pro- portions, and those fire-clays are the best in which the silica is greatly in excess over the alumina. When the alumina is in excess, broken crucibles, glass-house pots, and old fire-bricks, ground to pow- der, are substituted for the common silicious sand used in the ordinary processes of brick -making, but which, in this case, would be in- jurious, as having a tendency to render the clay fusible. Fire-clay being an expensive ar- ticle, it is usual, when making fire- bricks at a distance from mines, to mix with it burnt clay, for the sake of economizing the clay and diminishing its contraction. Mr. Pellatt states that Stourbridge clay, when carefully picked, ground, and sifted, will bear, for brick-making, two proportions (by weight) of burnt clay to one of native clay. The following Table shows the constituents of several infusible clays : Authority . . Dr. Ure. Vauquelin. Wrightson. Description. Kaolin, or porcelain clay. Plastic clay of forge les eaux. Sagger clay, from the Staffordshire potteries. Silica . . . 52 63 54-38 Alumina . . 47 16 26-55 Iron .... 0-33 8 8-38 Lime . . . 1 Carbonic acid . 3-14 Water . . . 10 7-28 99-33 98 99-73 Remarks . . { Used for making glass-house pots and pottery. Used for making saggars and fire- bricks. Fire-clay is found throughout the coal formation, but that of Stour- bridge is considered the best. The fire-clays of Newcastle and Glasgow are also much esteemed. Fire- bricks are brought to London from Stourbridge and from Wales ; the latter, however, will not stand such intense heat as the Stourbridge bricks. Fire-bricks are also made at the village of Hedgerly, near Windsor, of the sandy loam known by the name of Windsor loam, and these are much used in London 185 for fire-work, and also by chemists for luting their furnaces, and for similar purposes. The relative merits of Windsor, Welsh, and Stourbridge fire-bricks are best shown by their value in the market. The following prices are from the ' Contractor's Pocket-Book for 1850.' They include carriage to London and delivery on the works : Fire-bricks per M. . s. d. Windsor ... 5 8 Welsh ... 8 12 Stourbridge . .11 6 FIR FIRES OF THE ANCIENTS. FIR Fire-bricks. The parts of furnaces exposed to heat are built of bricks made of a description of clay which is to different extents infusible, the qualities chosen for use being regu- lated by the degree of heat to which they are to be exposed. They are known in commerce by the names of Bristol, Stourbridge, Newcastle, Welsh, and Windsor bricks. The first of these are composed almost entirely of silex, and are infusible at the greatest heat of the blast- furnace ; but they are very costly, and seldom used. The second quality are made from clay found in the neighbourhood of Stour- bridge, lying in a stratum of con- siderable thickness between the upper soil and the coal formations : they are used in the construction of furnaces required to resist great heat, such as those for smelting iron ores, glass-making, &c., and sometimes for the linings of retort ovens : for this latter purpose they are considered too expensive, except for the arch immediately over the furnace, as the heat is not intense. The third variety are composed of the clay lying above the coal mea- sures in Northumberland, and for the construction of retort furnaces and ovens are the most desirable. Fire-damp, in coal mines, is impure carburetted hydrogen Fire-place, a space within a chimney- piece for the burning of fuel to warm the temperature of the air, and in communication with a shaft or chimney-flue Fire-tubes, or tube-flues, are those through which the fire passes, for obtaining a large heating surface, fixed longitudinally in the middle compartment of a locomotive en- gine, between the fire-box and smoke-box Fires of the Ancients. Palladio says, " Finding that this subject about fires of the ancients had not been treated of distinctly by any body, I resolved to compose something about it. We are ignorant of most 186 things delivered thereupon by the ancients which might give us some light upon the matter: we must have recourse to the inventions of later times, thereby gradually to obtain a more ample knowledge of it. The Romans were sensible that a continual flame and a great heat from live coals were hurtful to the eyes ; they therefore went very wisely about finding out a remedy. They found how dangerous it was to carry fire about the house from one room to another. Stoves are an abominable invention : they cause a continual stench, swell the head, and make men drowsy, dull, and lazy. Most people that use them grow tender and weak : some cannot stir out of those rooms all the winter. The ancients used to light their fire in a small furnace under the earth. Thence they conveyed a great many tubes of different sizes into all the different stories and rooms of the house, which tubes or pipes were invisi- ble, but laid in the thickness of the walls and ceilings, just like water- pipes. Each of these opened at that part of the furnace which joined to the very wall of the house, and through these ascended the heat, which was let in whenever they had a mind it should, whether in dining-rooms, bed-chambers, or closets, much in the manner as we see the heat or steam of water contained in an alembic to ascend and warm the parts most distant from the fire-place. The heat in that manner used to spread so equally that it warmed the whole house alike. It is not so with chimneys or hearths; for if you stand near, you are scorched; if at any distance, you are frozen ; but here a very mild warm air spreads all around, according as the fire that warms the pipes laid along the wall opposite to the hearth is more or less burning. Those pipes which dispensed the heat did not open into the very furnace, on purpose FIR FLAMBOYANT STYLE. FLE that neither smoke nor flame should get into them, but only a warm steam should enter, which they let out again ; thereby creating a con- tinual moderate heat. The fire needed not to be large, provided it was continual, to supply those confined and enclosed pipes with a sufficient power of warming. They dressed their meat at the mouth of the furnace; and all along the walls were disposed kettles, or other vessels, filled with hot water, to keep the meat warm." Fir-poles, small trunks of fir-trees, from 10 to 16 feet in length ; used in rustic buildings and out-houses Fish, a machine employed to hoist and draw up the flukes of a ship's anchor towards the top of the bow, in order to stow it after it has been catted Fissure, or Gulley, is that crack or split in the strata of the earth which is the receptacle of mineral particles, whose contents are styled a 'lode' Fistuca, among the Romans, an in- strument used for ramming down pavements and threshing-floors, and the foundations of buildings Fistula, a water-pipe, according to Yitruvius, who distinguishes three modes of conveying water : by leaden pipes, by earthen pipes, and by channels of masonry Five species of temples (the). There are five species of temples : namely, the pycnostyle, in which the columns are placed far apart; the systyle, in which they are more remote ; the diastyle, whose columns are at an ample distance from each other; the araeostyle, in which the inter- vals between the columns are too great ; and the eustyle, whose inter- columniations are justly propor- tioned. In the pycnostyle species the interval between the columns is equal to one diameter and a half: there is an instance of this in the temple of Julius, and another in the temple of Venus, which is erected in the forum of Caesar : in 187 all temples of this species the same interval between the columns is observed. In the systyle species there should be an interval between the columns equal to two diameters : this arrangement would leave the space between the plinths of the bases of the columns equal to the extent of the plinths themselves. Flake white is an English white lead, in the form of scales or plates, some- times grey on the surface. It takes its name from its figure, is equal or sometimes superior to crems white, and is an oxidized carbonate of lead, not essentially differing from the best of the above. Other white leads seldom equal it in body ; and when levigated, it is called ' body- white.' Flamboyant Style of Architecture, the decorated and very ornamental style of architecture, of French in- vention and use, and contemporary in France with the Perpendicular style in England. One of the most striking and universal features is the waving arrangements of the tracery of the windows, panels, &c. The foliage used for enrichments is well carved, and has a playful and frequently a good effect. Planning, the internal splay of a win- dow-jamb Flaring, in ship-building, over-hang- ing, as in the topside forward Flatting, in house-painting, a mode of painting in oil in which the surface is left, when finished, with- out gloss. The material is pre- pared with a mixture of oil of tur- pentine, which secures the colours, and, when used in the finishing, leaves the paint quite dead. Flemish bricks are used for paving : seventy-two will pave a square yard : they are of a yellowish co- lour, and harder than the ordinary bricks Flemish School of Painting. This school is highly recommended to the lovers of the art by the disco- very, or at least the first practice, of painting in oil. It has been FLO FLORENTINE SCHOOL. FLO generally attributed to John Van Eyck, who was, it is said, accus- tomed to varnish his distemper pictures with a composition of oils, which was pleasing on account of the lustre it gave them. In the course of his practice he came to mix his colours with oil, instead of water, which he found rendered them brilliant without the trouble of varnishing. From this and sub- sequent experiments arose the art of painting in oil ; and this w r on- derful discovery, whether made by Van Eyck or not, soon acquired notice all over Europe. The atten- tion of the Italian painters was soon excited. John of Bruges was the founder of painting as a profession in Flanders. Peter Paul Rubens was the founder of the art. Float, a flat piece of stone or other material attached to a valve in the feed-pipe of the boiler of a steam engine, and supported upon the sur- face of the water by a counter- weight ; used either for showing the height of the water, or regu- lating the supply from the cistern FlooJcan, in Cornish, an earth or clay of a slimy glutinous consistence ; in colour, for the most part blue or white, or compounded of both Floor-hollow, in ship-building, an elliptical mould for the hollow of the floor timbers and lower fut- tocks Floors, in early English domestic ar- rangements, were generally covered with rushes, carpets being seldom used for such purposes even at the close of Elizabeth's reign, although instances occur of tapestry cloths for the feet to rest upon as early as Edward I. It does not, indeed, appear to have been the custom at any time to leave floors bare, whether boarded or paved. Our poets, and particularly Shakespeare, all speak of rushes and other vege- table substances being strewed in the principal apartments. Floor-timbers, in ship-building, are those placed immediately across 188 the keel, and upon which the bot- tom of the ship is framed Floran, an exceedingly small-grained tin, scarcely perceivable in the stone, though perhaps very rich Florentine lake colour is extracted from the shreds of scarlet cloth: the same may be said also of Chinese lake Florentine School of Painting. This school is remarkable for greatness ; for attitudes seemingly in motion ; for a certain dark severity ; for an expression of strength by which grace is perhaps excluded ; and for a character of design approaching to the gigantic. The productions of this school may be considered as overcharged ; but it cannot be denied that they possess an ideal majesty which elevates human na- ture above mortality. The Tuscan artists, satisfied with commanding the admiration, seem to have con- sidered the art of pleasing as be- neath their notice. This school has an indisputable title to the veneration of all the lovers of the arts, as the first in Italy which cul- tivated them. Flower-garden (the) " should be an object detached and distinct from the general scenery of the place ; and whether large or small, whe- ther varied or formal, it ought to be well protected from hares and smaller animals by an inner fence : within this enclosure rare plants of every description should be en- couraged, and a provision made of soil and aspect for every different class. Beds of bog-earth should be prepared for the American plants : the aquatic plants, some of w r hich are peculiarly beautiful, should grow on the surface or near the edges of water. The nu- merous class of rock-plants should have beds of rugged stone pro- vided for their reception, with- out the affectation of such stones being the natural production of the soil; but, above all, there should be poles or hoops for those kinds FLO FONT. FON of creeping plants which sponta- neously form themselves into grace- ful festoons, when encouraged and supported hy art." Tlower-garden. There is no orna- ment of a flower-garden more ap- propriate than a conservatory or greenhouse, where the flower- garden is not too far from the house ; but amongst the refine- ments of modern luxury may be reckoned that of attaching a green- house to some room in the man- sion. Fluccan, in mining, a soft clayey sub- stance, generally found to accom- pany the cross courses and slides Fluke, in mining, the head of a charger ; an instrument used for cleansing the hole previous to blasting Flush, a term common to workmen, and applied to surfaces which are on the same plane Flutings or Flutes, the hollows or channels cut perpendicularly in the shafts of columns, &c., in clas- sical architecture : they are used in the Doric, Ionic, Corinthian, and Composite orders Flux, in metallurgy, saline matters which facilitate the fusion of ores and other substances which are not easily fusible in assays; used also in the reduction of ores Fly, in mechanics, that part of a machine which, being put in mo- tion, regulates the rest Fly-wheel, a wheel with a heavy rim, fixed upon the crank-shaft of a land engine, for the purpose of equalizing the motion by the cen- trifugal force absorbing the sur- plus force at one part of the ac- tion, to distribute it again when the action is deficient Flyers, stairs that go straight and do not wind, the fore and back part of each stair and the ends respect- ively being parallel to each other Focus, among the Romans, an altar, a fire-place or hearth : hence the Latin motto, ' pro aris et focis,' ' for our altars and fire-sides ' 189 Fodina, a mine or quarry Foye, Cornish, a forge or blowing- house for smelting tin Foils, foliation ; the spaces between the cusps of the featherings of Gothic architecture Fons, a font, or a natural spring of water, frequently converted into ornamented fountains by the Greeks and the Romans. The latter also erected edifices of various degrees of splendour over natural springs, such as the Grotto of Egeria, near Rome, where the natural cave is converted by the architect into a temple. Font, the vessel which contains the water for the purposes of baptism. The font is the only relic of our ancient architecture which in its form is at all analogous to the Grecian and Roman vases. The shape which has at different pe- riods been given to it is a subject of some interest. Norman fonts are generally square or circular; the first frequently placed on five legs ; but which may be the older form, the square or circle, is not yet known. The circular form continued to be much used during the Early English period ; so occa- sionally was the square. Through- out the continuance of the Deco- rated style, the octagon was gene- rally used, sometimes the hexagon. During the Perpendicular style, the octagon was almost always used. Until the Reformation, and occa- sionally after, dipping was prac- tised in this country. Pouring or sprinkling was not unusual pre- vious to the Reformation ; for as early as the year 754, pouring, in cases of necessity, was declared by Pope Stephen III. to be lawful; and in the year 1311, the Council of Ravenna declared dipping or sprinkling indifferent : yet dipping appears to have been in this coun- try the more usual mode. The Earl of Warwick, who was born in 1381, was baptized by dipping : so Prince Arthur (eldest son of Henry FOO FORCING-PUMP. FOR VII.), King Edward VI., and Queen Elizabeth, were all baptized in a similar manner. Font of the time of Edward II. Foot, an ancient measure of tin, con- taining two gallons ; now a nominal measure, but in weight 60 tbs.; also a lineal measure of twelve inches Foot-pace, the dais or raised floor at the upper end of an ancient hall Foot-plate, the platform on which the engine-man and fire-man of a loco- motive engine attend to their duties Foot-stall, the plinth or base of a pillar Foot-valve, the valve in the passage between the condenser and air- pump of an engine, opening towards the air-pump Foot-waleing, the plank withinside a ship, below the lower deck Force of the wind. Air, when in continuous motion in one direction, becomes a very useful agent of machinery, of greater or less energy according to the velocity with which it moves. Were it not for its vari- ability in direction and force, and the consequent fluctuations in its supply, scarcely any more appro- priate first mover could generally be wished for ; and even with all its irregularity, it is still so useful as to require a separate considera- tion. 190 The force with which air strikes against a moving surface, or with which the wind strikes against a quiescent surface, is nearly as the square of the velocity; or, more correctly, the exponent of the ve- locity varies between 2-03 and 2-05 ; so that in most practical cases the exponent 2, or that of the square, may be employed without fear of error. Forceps, tongs used by smiths to take the hot metal from the fire Force-pumps, the plunger pumps for supplying the boiler of a locomo- tive engine : the plunger rods are connected to the piston-rods of the steam cylinder Forcer, in Cornish, a small pump worked by hand, used in sinking small simples, dippas, or pits Forcing-pump (the) differs but little from a syringe : the latter receives and expels a liquid through the same passage, but the former has a separate pipe for its discharge, and both the receiving and discharging orifices are covered with valves. By this arrangement it is not ne- cessary to remove a pump from the liquid to transfer the contents of its cylinder, as is done with the sy- ringe, but the operation of forcing up water may be continuous, while the instrument is immoveable. A forcing-pump, therefore, is merely a syringe furnished with an induc- tion and eduction valve, one through which water enters the cylinder, the other by which it es- capesfromit. The ordinary forcing- pump has two valves : the cylinder is placed above the surface of the water to be raised, and consequently is charged by the pressure of the atmosphere: the machine, there- fore, is a compound one, differing from that described, which is purely a forcing-pump, the water entering its cylinder by gravity alone. Forecastle, a short deck at the fore- part of a ship, above the upper deck, on which castles were for- FOR FOSSES D'AISANCES. FOS merly erected, or places to shelter the men in time of action Fore-foot, the foremost piece of the keel of a vessel Fore-ground, the front of a picture Foreyn, an ancient term to signify a drain or cesspool Forge, a smith's furnace for heating metals, to render them soft and more malleable Fork, a short piece of steel which fits into one of the sockets or chucks of a lathe, and is used by wood- turners for carrying round the piece to be turned : it is flattened at the end, like a chisel, but has a pro- jecting centre point, to prevent the wood from moving laterally Formosity, beauty, fairness, &c. Form-peys, an ancient term for form- pieces ; the lower terminations of mullions which are worked upon sills Forms and motions of tools. The principles of action of all cutting tools, and of some others, whether guided by hand or by machinery, resolve themselves into the simple condition, that the work is the combined copy of the form of the tool and of the motion employed : thus the geometrical definitions em- ployed convey the primary ideas of lines, superficies, and solids; that is, the line results from the motion of a point, the superficies from the motion of a line, and the solid from the motion of a superficies. Formula (pi. Formula), a prescribed rule in arithmetic or mathema- tics ; a maxim : in law, an action, process, or indictment Formulary, a book containing set forms, rules, or models Fornax, among the Romans, a kiln for baking pottery Forum, a large open space used by the Romans for the sale of merchan- dise, and for public assemblies ; also a court of justice Forum and Basilica. The Greeks built their forum with spacious porticoes, two tiers in height, ar- ranged in a square form : the co- lumns of the porticoes were placed 191 at small intervals from each other, supporting stone or marble enta- blatures ; and galleries were made over the lacunaria of the lower porticoes, or places of exercise. In Italy, the mode of constructing the forum was different; because, by a custom sanctioned by its anti- quity, the show of gladiators was exhibited there ; and therefore the intervals between the columns sur- rounding the area were greater. The lower porticoes were occupied as the offices of bankers, which si- tuation was calculated to facilitate the management of the public re- venue : the upper contained seats for the spectators of the diversions practised in the forum. Fortification, the science of military architecture ; a defensive building Forward, the fore-part of a ship Fosses d'aisances : the cesspools of Paris are so called; and they are usually made 3 m *00 long in the clear by l m< 70, by l ni -50, to the springing of the semicircular head (9 ft. 10 in. x 5 ft. 7 in. x 4 ft. 11 in. English, nearly): a man-hole, l m -00 by O m> 35 is left for the pur- poses of emptying and visiting them (3 ft. 3 T 7 x 1 ft. 2 in.) The walls which surround them, as well as the bottom, are exclusively formed of such materials as are most effica- cious in preventing the filtration of the matters contained within them. Of late years the usual custom has been to employ the meuliere, or mill-stone, bedded in mortar composed of lime and cement ; the inside being well pointed, and rendered throughout with this mortar. No cesspool is allowed to be used until after an examination, to be certified by the municipal authority. Any infil- tration to a neighbour's property gives a title to damages, and the architect and builder are both re- sponsible for ten years to the pro- prietor, as also to the neighbours, in case any nuisance arises from de- fects in the execution of the works. FOS FOSSES D'AISANCES. FOS When the cesspools require clean- ing, notice is given to the Board of Public Health (aux agents de la salubrite publique), who authorize and direct the operations. In win- ter these are carried on between 10 P.M. and 7 A. M. ; and in sum- mer, between 11 P.M., and 6 A.M. The carts, as well as all the other material of the nightmen, are under the inspection of the above-named officers, and must be, as nearly as possible, both water-tight and air- tight. They contain not more than 2 m -00 cube each, or nearly 71 ft. cube English. The contents of the cesspools are usually (especially in the modern houses) sufficiently fluid to allow of their extraction by pumps. In this case a small furnace is placed over the bung of the cart, to burn the gas as it rises : the bung itself is plastered over directly the cart is filled. When the contents are too solid to be pumped out, they are conveyed from below in small vessels of wrought iron, called ' tinettes/ holding about 3| feet (t^th of a metre cube) each ; and the lids are plastered over before the vessels are removed from the cess- pool. Of late years a system of what are called ' fosses mobiles' has been introduced into the better class of houses. It consists of air-tight tubs, placed in a vault (rendered also as air-tight as possible), which receive the ends of the soil-pipes. These tubs are removed at stated intervals, the openings plastered over, and may in that state be transported at any time of the day. This system obviates the terrible infection of the old kind of cesspool, and is gaining rapidly. Indeed, as the French people are fond of gilt ornaments in their dwellings, and the gases from the cesspools turn them black at once, unless great precautions be observed in covering them, whenever a cesspoolis opened, it is easy to understand that the 192 nles,' which obviate this inconvenience, should become of general use. Until of late, all the carts were obliged to pass through the Bar- riere du Combat to deposit their contents at the laystalls of Mont- faucon ; but some new works have been constructed at Bondy, so as to allow the suppression of this gigantic nuisance at the immediate gates of Paris. The cleaning of the cesspools of Paris is executed by several private companies, the most important of which is 'La Compagnie Richer,' who do at least one-half of this business : their capital was about .200,000, in land, plant, and build- ings. They employ 150 horses and 300 men, of whom 60 are for the repairs of the plant. Their charge is 8f., 9f., and lOf. per metre cube (35|feet English, nearly), according to the distance. No cesspool is allowed to be used after being emptied until it has been visited by an ' agent de la salubrite,' to ascertain whether it be water-tight. The laystalls of Montfaucon con- sist of two large reservoirs, at a high level, into which the carts are emptied. These reservoirs are about 2 acres superficial, and apparently 12 feet deep, with a dam between them, to allow of one being used when the other is being emptied. An overflow drain, with sluice-gates at each end, allows the liquid matter to run off to a large basin on a lower level, where it deposits any thing which may be merely in a state of mechanical suspension. On the banks of this reservoir are some important sal-ammoniac works. In the centreisalso a sluice-gate, which allows the surplus liquid matters to pass into two smaller reservoirs, where deposition takes place with- out any interference from the pump- ing apparatus of the chemicalworks. From thence the waters pass off into four other basins, in which any FOS FOUNDATIONS. FOU fertilizing properties they may con- tain are precipitated by means of straw, dead leaves, &c., and the water, comparatively pure, is at length let off into the main sewer, which discharges itself into the Seine, below Paris. The surface of the intermediate basins is about 250 ra - by 60 m - (or 3f acres) ; that of the four last basins is about 350 m ' by 110 m> (or nearly 9^ acres). These reservoirs do not belong to the city of Paris, and some diffi- culties have arisen from the pro- posal to remove them : all the carts containing the night-soil -being obliged to discharge at Montfau- con, the farming of the contents of the basins became a source of considerable profit. They were let on the last occasion for a sum of 500,500francs per annum (20,020 sterling) ; the previous letting hav- ing been 166,000 francs (6640 sterling). The increased rent and the exorbitant w^ages paid during the republican excitement of 1848 proved injurious to the company. The ground occupied by the town, moreover, is not sufficiently exten- sive for the operations connected with the manipulation of the ' pou- drette,' and the company were obliged to rent about 7^ acres more land for the purpose of spreading and drying the compost. The land necessary for this operation had been taken on lease by the out- going company, and they succeed- ed in obtaining a sum of 60,000 for the remainder of their term, as no other land was to be had in the neighbourhood. The rent and labour in conversion costs the company from 12,000 to 16,000 per annum. The 'pou- drette' is sold to agriculturists at 8 francs le setier, a measure equal to 12 bushels English. In one plan adopted for empty- ing the cesspools, the carts are made of strong boiler plate; they are placed under an air-pump, and exhausted ; the pipes are con- 193 nected with the carts and the cess- pools, and the atmospheric pressure on the latter forces up the liquid contents. Investigations have been made respecting the general health of the workmen employed at Mont- faucon, the reservoir of all the ex- crementitious matter of a city which contains about 1,000,000 inhabi- tants, and it has been ascertained, that although they were' not af- fected by the cholera in 1849, they are very short-lived men : acute fevers, and gangrene on the slightest accident, carry them off in a fright- ful manner. Unfortunately the dwellers in the neighbourhood also are subject to the same action, and the mortality from these causes is very great. The action of the 'poudrette' upon agriculture is somewhat ex- traordinary. In the time of Henri Quatre, the wines of Suresnes were highly esteemed: the vines pro- duced little, but of a superior quality: since the poudrette has been used to force them, the quan- tity of their produce has been in- creased, but the quality has totally changed: from a superior rank, the wines of the neighbourhood of Paris have fallen to that of what is vul- garly called ' du petit bleu.' Fossil, a mineral, many kinds of which are peculiarly and elegantly shaped Fossiliferous, a geological term ap- plied to a district abounding in fossils Foundations, according to Palladio, ought to be twice as thick as the walls to be raised upon them, so that both the quality of the earth and the greatness of the building are to be regarded, making the foundations larger in a soft and loose ground, or where there is a great weight to be supported. The plane of the trench must be as level as possible, so that the weight may press equally, and not incline more on one side than the other, which occasions the cleaving of the walls. FOU FOUNDATIONS. FOU For this reason the ancients were accustomed to pave the plane with Tivertine ; but we most commonly lay planks or beams to build on. The foundations ought to be made sloping, that is to say, to diminish as they rise ; but yet in such a manner that the middle of the wall above may fall plumb with the mid- dle of the lowest part ; which must be also observed in the diminution of walls above ground, because by that means the building becomes much stronger than by making the diminution any other way. Sometimes, to avoid charges, (especially in marshy grounds, where there is a necessity to use piles,) foundations are arched like a bridge, and the walls are built upon those arches. In great build- ings it is very proper to make vents through the body of the walls from the foundations to the roof, because they let forth the winds and other vapours, which are very prejudicial to buildings : they lessen the charges, and are of no small convenience, espe- cially when there is occasion for winding-stairs from the bottom to the top. If it be necessary to construct vaults below ground, their foundations must be more substantial than the walls of the buildings which are to be raised upon them. The walls, pillars, and columns of the latter must be placed immediately over those below them, so that solid may bear upon solid ; for if walls or columns project beyond the substructure, their duration must necessarily be short. The value of concrete in founda- tions was rendered obvious in a building erected by Mr. Clegg at Fulham, in 1829. The foundation was a quicksand. After the exca- vation was got out to the depth of 15 feet, an iron rod sunk, with little more than its own weight, 15 feet more; it was, in fact, as bad a foundation as could possibly occur. In about twelve days after it was built, it had settled bodily down IG-g inches, without a crack, or deviating in the least from the plumb. It therefore follows, that the only disadvantage attending a bad natural foundation is the ex- pense of making an artificial one. The following extract relates to the erection of an extensive building upon bad ground. "The building for the Albion Mills was erected upon a very soft soil, consisting of the 'made ground' at the abutment of Blackfriars' Bri'dge : to avoid the danger of settlement in the walls, or the ne- cessity of going to a very unusual depth with the foundations, Mr. Rennie adopted the plan of forming inverted arches upon the ground over the whole space upon which the building was to stand, and for the bottom of the dock. For this purpose the ground upon which all the several walls were to be erected was rendered as solid as is usual for building by driving piles where necessary, and then several courses of large flat stones were laid to form the foundations of the several walls ; but to prevent any chance of these foundations being pressed down in case of the soft earth yielding to the incumbent weight, strong inverted arches were built upon the ground between the foun- dation courses of all the walls, so as to cover the whole surface in- cluded between the walls ; and the abutments or springings of the in verted arches being built solid into the lowercourses of the foundations they could not sink unless all the ground beneath the arches hac yielded to compression, as well as the ground immediately beneath the foundation of the walls. By this method the foundations of all the walls were joined together so as to form one immensebase, which woulc have been very capable of bearing the required weight, even if th ground had been of the consistency FOU FOUNDATIONS. FRA of mud; for the whole building would have floated upon it as a ship floats in water ; and whatever sinking might have taken place, would have affected the whole building equally, so as to have avoided any partial depressions or derangement of the walls ; but the ground being made tolerably hard, in addition to this expedient of augmenting the bases by inverted arches, the building stood quite firm." When the foundation has been properly disposed of, the brickwork may be commenced. The bricks should be well burned, and set with a thin joint, four courses not occu- pying more depth than llf inches. Foundations of Temples. In preparing foundations for works of this kind, it will be first necessary to dig down to a regular stratum, if such is to be met with; and upon this the foundations, constructed with great attention to their strength, are to be laid: their solidity must be pro- portioned to the magnitude of the building in contemplation. The piers above ground, below the co- lumns, should be thicker than the diameter of the columns they are to support by one-half, that these substructures, which are called ste- reobatae, on account of their sus- taining the whole weight, may be enabled by their greater solidity to support what is built upon them. The bases of the columns, when fixed, ought not to project before the face of the stereobatse on either side. The intervals between the piers should either be made solid by means of piles, or arched over, BO as to connect the piers. If no compact stratum is to be found, but the ground, on the con- trary, is loose or marshy to a great depth, trenches must be dug, and piles of charred alder, olive, or oak, placed close together, be driven in by means of machines : the inter- vals between them should be filled up with charred timber, and upon 195 this substratum the foundations should be formed with solid ma- sonry. Thefoundationsbeingreared to the same level all around, th:; stylobate is next to be constructed. Upon this the columns are to be arranged, in the manner already described, at intervals which are determined by the species of temple intended to be built, whether pyc- nostyle, systyle, diastyle, or eustyle. In the araeostyle species the co- lumns may be placed at any dis- tance asunder. Foundations of a Bridge : these con- sist, properly, of the underground work of the piers and abutments, which it is within the province of a civil engineer to construct : the necessity of firmness and solidity in the execution of such works will be deemed of importance just in proportion to the intended ex- tent and magnificence of the struc- ture they are designed to support Foundry, a place where masses of metal are melted and run into moulds, so as to assume the re- quired form Four-way ^cock, a cock having two separate passages in the plug, and communicating with four pipes Fox-tail wedging, in carpentry. This is done by sticking into the point of a wooden bolt a thin wedge of hard wood, which, when the bolt reaches the bottom of the hole, splits, expands, and secures it. Frame, the strong frame-work, out- side the wheels, which supports the boiler and machinery on the axles of a locomotive engine Frame, inside, in locomotive engines. Some engines have the supporting frames within the wheels, and are called inside-framed engines. Be- sides this frame, resting on the axles, there are also other strong stays from the fire-box to the smoke-box, called inside framing or stays, for supporting the works and strengthening the boiler. Frames, the bends of timbers that are bolted together: in small ships there FRA FRESCO. FRI are two bolts in every shift of tim- ber, and three in large ships. The bolts should be disposed clear of the chain and preventer -bolts, scupper, lodging knee-bolts, and port cells. Frankfort -black is said to be made of the lees of wine from which the tartar has been washed, by burning in the manner of ivory-black. Fine Frankfort-black, though almost con- fined to copper-plate printing, is one of the best black pigments we possess, being of a fine neutral colour, next in intensity to lamp- black, and more powerful than that of ivory. Frater-house, the refectory or hall of a monastic establishment Fredstole, a seat near the altar Freedom, in drawing, is a bold and spirited manner, with evident li- berty of the pencil ; i. e. where the drawing is apparently accomplish- ed with ease Freemason, as applied to ancient ar- chitecture : a person learned in the art of building, more particularly in ecclesiastical construction, and who, by his learning in the science and his taste in constructions of edifices, travelled from one country to another, and executed models of everlasting renown. The term may also be applied to a free-stone mason, or a cutter and worker in stone, without reference to the so- ciety called Freemasons. Free-stone, building stone which may be easily cut into blocks and worked with a chisel; so called from having no grain : it may therefore be cut in any direction Free-stuff, that timber or stuff which is quite clean or without knots, and works easily, without tearing French chalk is an indurated mag- nesian mineral, employed to remove grease stains French School of Painting. This school has been so different under different masters, that it is difficult to characterize it. Some of its artists have been formed on the 196 Florentine and Lombard styles, others on the Roman, others on the Venetian, and a few of them have distinguished themselves by a style which may be called their own. In speaking in general terras of this school, it appears to have no pe- culiar character, and can only be distinguished by its aptitude to imitate easily any impressions; and it may be added, speaking still in general terms, that it unites in a moderate degree the different parts of the art, without excelling in any one of them. Fresco, a kind of painting performed on fresh plaster, or on awall covered with mortar not quite dry, and with water colours. The plaster is only to be laid on as the painting pro- ceeds, no more being done at once than the painter can despatch in a day. The colours, being prepared with water, and applied over plaster quite fresh, become incorporated with the plaster, and retain their beauty for a great length of time. The Romans cut out plaster paint- ings on brick walls at Sparta, packed them up in wooden cases, and trans- ported them to Rome. Fret, an ornament used in classical architecture, formed by small fil- lets intersecting each other at right angles Friars (the orders of) in England and Wales, previous to their abolition, including the Nuns Minoresses, amounted to Black or Dominican friars . 54 Grey or Franciscan friars . 62 Minoresses or nuns of the order of St. Clare ... 4 Friars of the order of the Holy Trinity for the re- demption of captives . . 12 Order of the Carmelites or White friars .... 50 Crutch ed or Crossed friars 10 Austin friars 32 Friars de pcenitentia or of the sac ...... 9 Bethlemite friars ... 6 Friction, the act of rubbing two bodies FRI FURNACE. FUR together, or the resistance in ma- chines caused by the contact of different moving parts. Friction is proportional to the pressure ; that is, every thing remaining the same, the friction increases as the pres- sure increases. Friction-clutch, a shell or box fixed on the end of a driving shaft, fitted by a conical piece which slides on a feather, or raised part, at the end of another shaft, so that it can be engaged at pleasure by the cone being forced into the shell by a lever or screw. This apparatus is very useful for driving machines, the parts of which are subjected to violent strains, as the pressure upon the clutch can be regulated so as to allow it to slide when the strain is too great to be borne safely by the machine. Frieze, the middle division of an en- tablature, that which lies between the architrave and the cornice Frigidarium, the cold bathing-room in the baths of the ancients, as well as the vessel in which the cold water was received Frigidarium, the cold bath : the re- servoir of cold water in the hypo- caustum, or stove-room, was termed ahenum frigidarium Frithstool or Freedstool, a seat or chair near the altar, for those espe- cially who sought the privilege of sanctuary Frontal or Fronter, the hanging with which the front of an altar was formerly covered Fronton, a French word to express an ornament over a door or pedi- ment Frowy stuff, short or brittle and soft timber Fucus, a name given by the Romans to certain false dyes and paints Fuel, the matter or aliment of fire Fulcrum, the prop or support by which a lever is sustained Fullers' -earth, a soft unctuous marl, used by fullers in the process of cleansing cloth, &c. Fulling-mill, an engine, or mill, in 197 which cloth is cleansed by being beaten with hammers Fulminating gold or silver, in che- mistry, ammonia combined with the oxides of gold or silver Fumarium, a chimney ; an upper room used among the Romans for collecting the smoke from the lower apartments : used also for smoking or ripening wines Furling, in navigation, the wrapping up and binding of any sail close to the yard Furlong, a measure of length; the eighth part of a mile Furnace. The furnace is one of the most important parts of the high- pressure engine. The whole action and power of the machine depend on its construction, and on the effect obtained from it, inasmuch as fire is the prime agent. Too much industry, exactitude, and in- timate knowledge of the subject, cannot be brought to bear on the construction of the furnace, in order to attain the two great objects of its action ; namely, first, to produce as perfect a combustion of the fuel as possible ; and secondly, to apply as much as possible of the heat so developed effectively to the boiler. These two requirements for a good furnace are, however, not so easily satisfied. Much remains to be ac- quired as to the conditions under which the whole of the caloric may be perfectly developed from the fuel, although the best manner of apply- ing the heat to the boiler is well understood. Furniture : anterior to the Tudor age, household furniture was in general of a rude, substantial character ; the tables were formed of boards or trestles, the seats of massive oak benches or stools, and the floors strewed with straw Furniture of the hall: this consisted of but few articles, such as clumsy oak tables covered with carpet, benches or joined forms of the same material, and cupboards for plate, pewter, ' treene,' leather jugs, glass, FUR GALLERY. FUT &c., with a reredos or fire-iron in the centre of thefloor, against which fagots were piled and burned, the smoke passing through an aperture in the roof; the fender, formed by a raised rim of stone or tile, and a ' fier forke' and tongs Furrings, slips of timber nailed to joists or rafters, in order to bring them to a level, and to range them into a straight surface, when the timbers are sagged, either by casting, or by a set which they have ob- tained by their weight in the course of time Fusarole, in architecture, a moulding or ornament placed immediately under the echinus in the Doric, Ionic, and Composite capitals ; the shaft of a column, pilaster or pillar, or that part comprehended between the shaft and the capital GAB GABLE, the upright triangular end of a house, from the cornice or eaves to the top of the building, some- times called a sloped roof; the up- per part of a wall, above the level of the eaves. Examples in English and foreign Domestic and Gothic architecture are various, and gene- rally have a most picturesque effect. Goblets, small ornamental gables or canopies formed over tabernacles, niches, &c. Gaff, a sort of boom used in small ships to extend the upper edge of the mizen, and employed for the same purpose on those sails whose foremost edges are joined to the masts by hoops or lacings, and which are usually extended by a boom below: such are the main- sails of sloops, brigs, and schooners Gage or Gauge, an instrument used for measuring the state of rarefaction in the air-pump, variations in the baro- meter, &c. ; a measure, a standard Gal, in Cornish, rusty iron ore Galilee, a porch or chapel at the en- trance of a church. The galilee at Lincoln cathedral is a porch on the 198 Fustic, a wood of a species of mul- berry growing in most parts of South America, the United States, and the West Indies : it is a large and handsome tree, principally used for dyeing greens and yellows, and also in mosaic cabinet-work and turnery FattocJc, in ship-building. Every single timber is called a futtock, and distinguished by the terms lower, or first, second, third, &c., except the floors, long and half- timbers, top timbers, stern tim- bers, &c. Futtocks, the lower timbers raised over the keel, and which hold the ship together Futtock shrouds, in ship rigging, small shrouds that go from the main- mast, fore-mast, and mizen-mast shrouds to those of the top-mast GAL west side of the south transept : at Ely cathedral it is a porch at the west end of the nave : at Durham it is a large chapel at the west end of the nave, which was built for the use of the women, who were not allowed to advance further into the church than the second pillar of the nave. Gallery, an apartment generally of greater length in proportion to the width, applied for the purpose of exhibiting pictures or sculpture : used formerly in early English Do- mestic architecture, in large houses, as a place of resort for dancing and other amusements Galliot, a Dutch vessel, carrying a main and a mizen mast, and a large gaff main-sail Gall-stone (colour), an animal calcu- lus formed in the gall-bladder, principally of oxen. This concre- tion varies a little in colour, but is in general of a beautiful golden yellow, more powerful than gam- boge, and is highly reputed as a water colour : nevertheless, its co- lour is soon changed and destroyed GAL GARDEN. GAR by strong light, though not subject to alteration by impure air. Galvanism comprises all those elec- trical phenomena arising from the chemical agency of certain metals with different fluids Galvanometer, an instrument con- trived to measure minute quanti- ties of electricity Gamboge, or, as it is variously written, Gumboge, Gambouge, Cambogia, Gambadium, &c., is brought from Cambaja, in India, and is the pro- duce of several kinds of trees. It is, however, principally obtained from the tree called Gokathu, which grows in Ceylon and Siam. From the wounded leaves and young shoots the gamboge is collected in a liquid state, and dried. Gam- boge is a concrete vegetable sub- stance, of a gum-resinous nature, and beautiful yellow colour, bright and transparent, but not of a great depth. When properly used, it is more durable than generally re- puted, both in water and oil, and conduces, when mixed with other colours, to their stability and dura- bility, by means of its gum and resin. It is deepened in some de- gree by ammoniacal and impure air, and somewhat weakened, but not easily discoloured, by the ac- tion of light. Gammoning, in navigation, seven or eight turns of a rope passed over the bowsprit, and through a large hole in the stem or knee of the head, alternately, and serving to bind the inner quarter of the bow- sprit close down to the ship's stem, in order to enable it the better to support the stays of the fore-mast : after all the turns are drawn as firm as possible, the opposite ones are braced together under the bow- sprit by a frapping Gammoning -hole, a hole cut through the knee of the head, and some- times one under the standard in the head, for the use of gammon- ing the bowsprit Garboard strake, the strake in the 199 bottom that is wrought into the rabbet of the keel of a ship Gardens. The ancient plans of gar- dens show that the Egyptians were not less fond than our ancestors of mathematical figures, of straight walks, architectural decorations, and vegetable avenues ; and that they as thoroughly entered into the idea of seclusion and safety suggested by enclosures within en- closures. It has been remarked, that in some old English places there were almost as many walled compartments without as apart- ments within doors : the same may be said of Egyptian country houses. This principle of seclusion, and an excessive love of uniform arrange- ment, are remarkably displayed in the plan of a large square garden given in Professor Rosellini's great work. As a subject for the painter, the materials which form the scenery of a garden are provided by Nature herself: the artist must therefore be satisfied with the degree of ex- pression which she has bestowed, and give the best possible disposi- tion to those scanty and intractable materials. In a landscape, on the contrary, the painter has the choice of the objects he intends to repre- sent, and can give whatever force or extent he pleases to the expres- sion he wishes to convey, as the whole range of scenery is before his eye. Gargoyle or Gurgoyle, a projecting spout used in Gothic architecture, to throw the water from the gutter of a building off the wall Garland, an ornamental band used in Gothic work Garnet, a hinge, now called a ' cross garnet ;' a red gem of various sizes Garret, an upper apartment of a house, immediately under the roof Garretting, small splinters of stone inserted in the joints of coarse masonry : they are stuck in after the work is built : flint walls are very frequently garretted GAS Gas. All substances, whether animal, vegetable, or mineral, consisting of carbon, hydrogen, and oxygen, when exposed to a red heat, pro- duce various inflammable elastic fluids capable of furnishing artificial light. The evolution of this elastic fluid may be perceived during the combustion of coalin a common fire. The coal, when heated to a certain degree, swells and kindles, and frequently emits remarkably bright streams of flame, and after a cer- tain period these appearances cease, and the coal glows with a red light. The flame produced from coal, oil, wax, tallow, or other bodies which are composed of carbon and hydrogen, proceeds from the pro- duction of carburetted hydrogen gas, evolved from the combustible body when in an ignited state. If coal, instead of being burnt in the ordinary way, be submitted to the temperature of ignition in close vessels, all its immediate -con- stituent parts may be collected: the bituminous part is distilled over, in the form of coal-tar, &c., and a large quantity of an aqueous fluid is disengaged at the same time, mixed with a portion of es- sential oil and various ammoniacal salts. A large quantity of carbu- retted hydrogen, carbonic oxide, carbonic acid, and sulphuretted hydrogen, also make their appear- ance, together with small quantities of cyanogen, nitrogen, and free hydrogen, and the fixed base of the coal alone remains behind in the distillatory apparatus, in the form of a carbonaceous substance called coJce. An analysis of the coal is effected by the process of destruct- ive distillation ; and the products which the coal furnishes may be separately collected in different vessels. The carburetted hydrogen, or coal-gas, when freed from the ob- noxious foreign gases, may be pro- pelled in streams out of small apertures, which, when lighted, 200 GAS. GAS form jets of flame, now called gas- lights. Mr. Croll has patented an in- vention for the purification of gas from ammonia, which is effected by means of dilute sulphuric acid applied between the condensers and the ordinary lime purifiers. The vessels are made either of wood or iron, and lined with lead, having a wash-plate similar to the wet-lime purifiers. The radiating bottom is formed of wooden bars, for the pur- pose of supporting the wash-plate and distributing the gas. In com- mencing the process, these vessels are charged with water and sulphu- ric acid in the proportion of 7 fts. of the latter to 100 gallons of the former. As the acid is neutralized by the ammonia contained in the gas passing through the vessels, the above proportion is kept up by a continuous dropping or running of acid, regulated according to the quantity of ammonia contained in the gas, from a reservoir placed on the top of the saturator. This mode of supplying the acid is con- tinued until the specific gravity of the solution is at 1170, or near the point of crystallization; after which the supply of acid is discontinued, and the liquor retained in the vessel until neutralized : it is then drawn off and evaporated, and yields a pure sulphate of ammonia. Gas (distribution of, through mains}. There is no branch of science con- nected with the subject of gas en- gineering so highly important as that which relates to its conveyance and distribution through pipes ; there is none in which theory af- fords more assistance, and there is hardly any branch to which so lit- tle attention has been paid. The interests of a gas company are not best served by simply increasing the quantity of gas from the same quantity of coal, or improving the lime machinery, &c. The laying of street-mains forms the most consi- derable item in the outlay; and by GAS GAS DISTRIBUTION. GAS a judicious arrangement in the first instance, much may be saved hoth at first and last. It is for the purpose of rendering this branch of the science, and that of the passage of gas through pipes, perfectly plain, that the following observations are here given. When it is proposed to light any town, or district of a town, with gas, the first step to be taken is to ascertain the number of lights, both public and private, that will be required, with as much accu- racy as circumstances will permit ; the length of time such lights will have to burn, and the quantity of gas consumed by them per hour, making allowances for the increase of lamps that will probably be re- quired by the extension of the town. The size of the works themselves may be easily ascertained from this calculation. It will then remain to fix upon a proper situation in w r hich to erect them : the best local position is upon the banks of a na- vigable river or canal, and at the lowest available level, and the near- est approach to such a situation is advisable for obvious reasons. A map of the town must be obtained, or a survey made of the different streets and thoroughfares : running levels must be taken through them at several points, and their respect- ive heights marked with reference to the level of the works as a da- tum : upon this map all the mains must be drawn, also their branches, valves, and governors. Their ar- rangement must be such as to allow of a perfect circulation of the gas, and a nearly uniform pressure at the highest and lowest point. All the pipes upon the same level should be joined into one another, and no valves used but such as are necessary to shut off the gas for repair of mains. To supply a higher level, a governor should be placed at the summit of the lower level, with the lower main leading into it. The pipe or pipes for supplying 201 the higher parts should proceed from the regulating vessel. A cel- lar may be appropriated for the reception of this vessel. One lead- ing main should be taken direct from the works to an equilibrium cylinder situated at some point from which several streets diverge, and no supply taken from this main until it has reached the cylinder. Branches suitable to the supply of each division of the district should lead from this cylinder. The supply of gas to the cylinder should be so regulated as to cause the gas to flow along the branches at an even pressure of about five- tenths of an inch. If the cylinder be at any considerable distance from the works, a smaller main, with increased pressure, may lead to it, its size being sufficient to equalize the discharge. Supposing a district to be lighted requiring 1000 public or street lamps, and 7000 private burners : it is usually considered that each lamp on an average will consume 5 cubic feet of gas per hour, there- fore 40,000 cubic feet will be re- quired to light the district for an hour; and the leading main must be capable of delivering that quan- tity into the equilibrium cylinder in that time. To determine the size of this main, the probable in- crease of lamps must be taken into consideration ; and as that will de- pend so much upon circumstances in every instance, the judgment of the engineer alone can serve to re- gulate the additional area. If the increase should be beyond that which was expected, the gas must be forced through the leading main at a greater pressure. In the above example, if the diameter of main for a present con- sumption be 12 inches, and to se- cure an adequate supply at any future period its diameter be in- creased to 15 inches, the present working pressure may be reduced to 1-5 of an inch instead of 3 inches; i 5 GAS GATES AND DOORS. GAT and as the leakage will also be decreased, the extra-sized main will not be found disadvantageous even in the first instance. Gasometer, a reservoir of gas, with conveniences for measuring its volume. The simplest and most general in use consists of an iron vessel, open at the bottom, and inverted into a tank of water below the surface of the ground, having perfect freedom to rise and fall, and guided by upright rods fixed at several points in the circumference. The diameters and numbers of the vessels will vary according to the magnitude of the works to which the gasometer is attached, and the space to be occupied by it. If the works are situated in a town, where the ground is too valuable to allow an increased extent, a 'telescope gaso- meter' is employed. Gas-tar, commonly called coal-tar. When the manufacture of gas from coal was in its infancy, great advantages were expected to be derived from the coal-tar which distilled over with the inflammable gas. It was considered to be a substance possessing even superior properties to the vegetable tar for the preservation of timber and other perishable materials exposed to the influences of the weather. In the year 1665 a German chemist proposed to distil coal for the sole purpose of obtaining this tar, and in 1781 the Earl of Dun- donald took out a patent for col- lecting the tar which appeared during the formation of coke. Nei- ther scheme answered. After a few years' trial, coal-tar as a sub- stitute for vegetable tar fell into disuse. It was tried in the navy, and was found to give the timber a considerable degree of hardness, but not of durability. Its smell is extremely offensive ; and since that time it has been used only in places where that is of little conse- quence. The exposed part of the machinery of a gas establishment 202 may be protected by being coated with coal-tar. Gasket, plaited cord fastened to the sail-yards of a ship, and used to furl or tie up a sail firmly to the yard, by wrapping it round both six or seven times, the turns being at a competent distance from each other Gatchers, the after-leavings of tin Gate-house, or park entrance, a struc- ture designed rather to produce an agreeable and picturesque effect, than to accord with any fixed rules or customs of art : such, indeed, was the practice towards the latter end of the sixteenth century, when it would appear, that most men wished to display their taste and learning in architecture. The gate- house also forms an entrance to a private mansion, to any public, municipal, or collegiate building, or to a palace, &c. In the early English architecture, gate-houses, now sometimes called Lodr/es, were large and imposing structures, of great elegance. Gates and doors are generally, whe- ther arched or square, twice their breadth in height. The former may be ornamented with columns, pilasters, entablatures, pediments, rustics, imposts, archivolts, &c. ; the latter with architraves round the sides and top of the opening, and crowned with a frieze and cor- nice. The cornice in this case is very frequently supported with a console on each side. Columns, pilasters, and other ornaments are also sometimes employed in the decoration of doors. Inside doors should not be nar- rower than 2 feet 9 inches, nor is it needful that they exceed 6 feet in height ; entrance doors, 3 feet 6 inches to 6 feet 6 inches broad in private dwellings : but in public buildings, where crowds assemble, they must be considerably enlarged. The smallest width for a gate should be 8 feet 6 inches. As some general rule for the pro- portion of the architraves of com- GAT GERMAN SCHOOL. GER mon dressings to doors may be useful, the following directions may be safely followed : Supposing the height of the aperture to represent the height of a column; then, if an architrave, frieze, and cornice, or the first only, he desired, take them in the proportion that would serve for the order itself, and return the architrave down the sides of the door. The whole entablature over a square-headed door should never exceed one-third the height of such aperture. Gauge (pronounced gage), a measure by which the capacity or contents of a cask or vessel may be ascer- tained. Gauging is a term used in mensuration, and applied by engi- neers in their several operations. The gauge, as applied to railways, became a familiar term during the antagonistic discussions respecting the proper distance between the lines of rail ; and the battle of the gauges, which raged fiercely and ex- pensively, ended, like many similar contentions, in both parties spend- ing enormous sums of money, with- out the result of victory on either side. Gauge, a mixture of fine stuff and plaster, or putty and plaster, or coarse stuff and plaster; used in finishing the best ceilings and for mouldings, and sometimes for set- ting walls Gauge-cocks, two or three small cocks fixed in front of the boiler of a steam engine, for the purpose of ascer- taining the height of the water Gauge-glass, in locomotive engines, a strong glass tube, connected with the boiler by two cocks attached to the gauge-cock pedestal. The water is admitted to this tube by the lower cock, the steam by the upper cock. It thus becomes an index to what is going on inside the boiler, exhibiting the height or agitation of the water in it. A small cock is placed below the glass for blowing out any sediment which may be deposited in it. 203 Gauge-lamp, in locomotive engines, a small lamp placed beside the gauge-glass at night, that the state of the water in the boiler may be seen by the engine-man Gauntlet, in heraldry, an iron glove : in challenges, the gauntlet was thrown down in defiance Gear, furniture, dress, harness : the term is also applied to the several working parts of a locomotive steam engine Generating surface, the heating sur- face of a boiler, or that on which heat is applied to generate steam Gentese, in early English architecture, cusps or featherings in the arch of a doorway Geometry, the science of quantity, extension, or magnitude Geoscopy, a knowledge of the different kinds of earth German School of Painting. In early times, a school of painting can hardly be said to have existed in Germany : it was merely a suc- cession of single artists, who de- rived their manner from different sources of originality and imitation. There were some German painters of emimence when the art, emerg- ing from its barbarous state, first began to be cultivated in Europe ; but as they were totally unac- quainted with the ancients, and had scarcely access to the works of their contemporaries in Italy, they copied Nature alone, with the exception of somewhat of that stiffness which forms the Gothic manner. This is by no means the case with their successors, some of whom were edu- cated in Flanders, and others in Italy. But if Mengs or Dietrich were comprehended in this school, there would be nothing peculiar to its manner discovered in their works. Albert Durer was the first German who corrected the bad taste of his countrymen : he ex- celled in engraving as well as in painting ; his genius was fertile, his compositions varied, his thoughts ingenious, and his colours brilliant. GEO GIRDERS. GIR His works, though numerous, were finished with great exactness. For an account of this great man and his productions, see the 'Works of Divers Ancient Masters/ in two vols. folio, 1846. Geology (a treatise or discourse on the earth) "is a term which admits of a very wide interpretation, and naturally suggests to the mind in- quiries, 1st, into the formation and original condition of the earth; 2ndly, into the successive modifica- tions which it has undergone, and the agencies by which they have been effected ; and Srdly, into its present condition, and the agencies by which changes in that condition are still effected. The first object of the geologist is to establish, on the principles of inductive reason- ing, the science as it depends on each of these inquiries, and then to apply it to the practical purposes of life. It may be premised that a science is practicably valuable just in proportion as its facts have been discovered, and its laws established and studied ; for so long as we are uncertain whether a known result has proceeded from a definite cause, we are unable to apply the fact or circumstance to the elucidation of other facts or circumstances ; and so long as we are unacquainted with the properties of any sub- stance under our examination, we cannot declare with certainty what share it may have had in the phe- nomena we have observed. This may be illustrated by a reference to gunpowder. Its explosive qua- lity is the result of its composition, and we can only depend upon the results when we know that the compound has been accurately formed: to insure, therefore, cer- tainty in the operations depending on it, we must take care that a proper standard of composition has been adhered to. In a similar man- ner we can only apply geology as a practical science when we have as- certained and made ourselves fami- 204 liar with those facts which prove the first principles on which it has been founded to be correct and stable." Gib and key, the fixed wedge and the driving wedge for tightening the strap which holds the brasses at the end of a connecting-rod in steam machinery Gimlet, a piece of steel of a cylin- drical form, having a transverse handle at the upper end, and at the other, a worm or screw, and a cy- lindric cavity, called the cup, above the screw, forming, in its trans- verse section, a crescent. Its use is to bore small holes : the screw draws it forward in the wood, in the act of boring, while it is turned round by the handle: the angle formed by the exterior and interior cylinders cuts the fibres across, and the cup contains the core of wood so cut : the gimlet is turned round by the application of the fingers, on alternate sides of the wooden lever at the top. Girders, the longitudinal beams in a floor. Girders are the chief sup- port of a framed floor: their depth is often limited by the size of the timber, but not always so ; there- fore the method of finding the scant- ling may be divided into more than in one case. Girders of wrought and cast iron are now extensively used for bridges, to girt railroads, canals, &c., many of which are of considerable span : the following will give a better explanation of the importance of testing their strength. Experiments on an open cast-iron girder. Figures 1 and 2, in the an- nexed diagrams, show the eleva- tion and section of a cast-iron open girder, which was intended to act as a bressummer between the co- lumns which supported an iron sheet roof of 40 feet span. These columns were 20 feet apart from centre to centre, and the principals of the roof being 6 feet 8 inches apart, two of them were of course supported GIR GIRDERS. by the iron girder at the points a and b. The maxi- Fig. 1. mum weight thus thrown <*"" on the girder, according to a calculation made at the time, would amount to 2 tons at each of the points where the principalbore upon it ; giv- ing a total pressure of 5 tons : this was on the sup- position that the weight of the roof it- self, and the action of the wind upon it, would prove equivalent to a weight of 40 fos. on the foot superfi- cial. The roof was erected by the con- tractor who furnished the plan, and had undertaken the work at his own risk. When it ar- rived on the ground, the slightness of the girders was such as to render it advisable to subject them to necessary proof before proceeding to place them in the work. Accordingly, two girders 205 f. \ Fig. 2. 4. 8 -> < - 5 > were placed at a short distance apart, and properly fixed ; baulks were then laid across from one to the other, at the two points a and l\ and upon these, planks were laid, which carried pigs of iron. They did not show much symptom of weakness until 4 tons were placed on the platform ; but with this load, which was less than one-half of what the two should have carried, the two vertical braces, c and d, were broken by a tendency of the under flange of the girder to rise at those points in a direction perpendicularto the curve, and the whole very soon gave way, and was completely smashed. In this case, not only was the metal too thin, but the connecting pieces be- tween the upper and lower flanges were too slight, and too far apart ; the top flange was made wider than the bottom, in order to give a bed for the shoe of the principal : had the openings been filled in, the girder might have stood the test, though even then it would have been but slight. Fig. 3 shows two links of a chain guy for supporting a pair of shears, erected for lifting heavy weights, such as boilers, &c. : these links were about 6 feet 6 inches long, and were made of 2-inch round iron : they were subjected to the following proof by means of an hydraulic press. With 35 tons, these "I t ,. . , two links stretched | ^ Ofanmch ' GIR GIRDERS. Gill With 40 tons, these! 3 , . , f i A i- j r T? i an men. two links stretched J e and had then a permanent set. "With 60 tons they stretched 3 inches and broke, the metal being clean and sound. In this case the breaking weight Fig. 3. was about double that which might have been fairly placed upon the chain, viz. about 31 tons, which would have been at the rate of 10 tons upon the square inch ; for although 35 tons did not ap- parently cause any set during the time the experiment lasted, yet it is impossible to say that that weight might not have caused such an ef- fect, if left for a sufficient length of time. The following formula is deduced from Mr. Hodgkin- son's experiments. " As the distance between the sup- ports in feet is to the depth in feet of the beam in the middle of its length, so is the area in inches of the bottom flange to a fourth quantity, which, when mul- tiplied by a constant number to be determined by experi- ment, will give the breaking weight in tons." This given number may be taken at 27'3 for common beams ; then half of this quantity will be the weight which the girder will bear, if distributed equally over its length. The ratio of the area of the middle section of the top flange to that of the bottom should be about 1 to 4, or 4 '5. The diagram (fig. 4) represents a girder of 18 -feet bearing: the maximum weight which would ever be thrown upon it, including the weight of a fire-proof floor, was considered to amount to about 200 ibs. on the foot, or 14 tons spread over its length: two of these girders were placed at but a short distance apart from each other, and 206 loaded uniformly over their whole surface with iron ballast ; a hori- zontal line was struck upon one of the girders, and the deflection measured when each weight was applied. Twenty tons of ballast gave a deflection of inch. 184 . Deflec- April Tons. Tons. tion. 13. 4 added, making 24 ; f . 15. 2 do. 26; f. 16. 2 do. 28; f. 17. 2 do. 30; }. 18. 2 do. 32; f. 20. 4 do. 36; T V April 23. Deflection still the same, the weight having remained undisturbed. April 29. No alteration had taken place in the deflection, and the weights being removed, the girder resumed its original form, showing no trace of a set or per- manent alteration. The section annexed shows the relative proportions of the upper and under flanges of the girder: the top and bottom of the girder were parallel, but the lower flange, being 8 inches broad at the middle, diminished to 4 inches at the point of support. The computed breaking weight, according to Mr.Hodgkinson's rule, would be 16 ^'^x 27-3 = 28-28 tons: half of this, viz. 14 tons, distributed GLA GLUE. GOL over the whole length, should be its maximum load; whereas it car- ried 18 tons, or 36 tons placed on two girders, without showing any symptoms of giving. The average weight of a large number of these girders amounted to about 16f cwt. Gland, the pressing piece of a stuffing- box of a steam-engine Glass: this artificial transparent sub- stance was introduced very early. Hollinshed says, an Englishman named Benedict Biscop, who had taken upon him the habit of a monk in Italy, came here with the Archbishop of Rome, in the year 670, and brought painters, gla- ziers, and other such curious crafts- men into England for the first time. Glasses superseded small drinking- bowls ; they were of Venetian manufacture, and probably first brought here in the 16th century. Earlier they do not appear to have been used in England ; nor to have come into much fashion till the time of Elizabeth. Glass water-gauge. See Gauge-glass. Glazing, the art of affixing glass to the sashes of windows, casements, &c., for the purpose of admitting the light of day ; anciently applied to the affixing to windows deco- rative, stained, and painted glass. A great many beautiful examples exist in this and other countries, of early designs, and of examples in the cinque-cento style : for the latter, see ' Divers Works of Early Masters,' 2 vols. folio, 1846. Glazing is also a term applied to the finishing of a drawing with some thin, transparent, and glossy tint, through which the first co- lours appear, and are heightened in their effect Glebe, turf, soil; land possessed as part of the revenue of an ecclesias- tical benefice Glist, a shining black or brown mine- ral, of an iron cast Glue, a tenacious viscid matter, which is used as a cement by carpenters, 207 joiners, &c. Glues are found to differ very much from each other in their consistence, colour, taste, smell, and solubility. Some will dissolve in cold water, by agitation ; while others are soluble only at the point of ebullition. The best glue is generally admitted to be trans- parent, and of a brown yellow co- lour, without either taste or smell. It is perfectly soluble in water, forming a viscous fluid, which when dry preserves both its tenacity and transparency in every part, and has solidity, colour, and viscidity, in proportion to the age and the strength of the animal from which it is produced. To distinguish good glue from bad, it is necessary to hold it between the eye and the light ; and if it appears of a strong dark brown colour, and free from cloudy or black spots, it may be pronounced to be good. The best glue may likewise be known by immersing it in cold water for three or four days, and if it swells powerfully without melting, and afterwards regains its former di- mensions and properties by being dried, the article is of the best quality. A small portion of finely levi- gated chalk is sometimes added to the common solution of glue in water, to strengthen it and fit it for standing the weather. A glue that will resist both fire and water may be prepared by mixing a handful of quicklime with four ounces of linseed oil, thorough- ly levigated, and then boiled to a good thickness, and kept in the shade, on tin plates, to dry. It may be rendered fit for use by boiling it over a fire in the ordi- nary manner. Glyphs, perpendicular flutings or channels used in the Doric frieze Gobbets, stones ; a measure or quan- tity, so called in the time of Ed- ward III. Gola, the Italian term for cyma Gold, a well-known valuable metal GOL GOVERNOR. GOV found in many parts of the world, but the greatest quantity of which is obtained from the coast of Guinea. The produce of California remains to be determined. Gold seems to be the most simple of all substances. It is spoken of in Scrip- ture, and the use of it among the ancient Hebrews, in its native and mixed state, and for the same pur- poses as at present, was very com- mon. The ark of the covenant was overlaid with pure gold ; the mercy seat, the vessels and utensils belonging to the tabernacle, and those also of the House of the Lord, as well as the drinking- vessels of Solomon, were formed of this metal. Gold occurs, in the metallic state, mixed with several metals, but more commonly with silver and copper, and sometimes pure. Golden sulphur of antimony, golden yellow,is the hydro-sulphuret of an- timony, of an orange colour, which is destroyed by the action of strong light. It is a bad dryer in oil, injurious to many colours, and in no respect an eligible pigment either in oil or water. Gold purple, or Cassius's purple preci- pitate, the compound oxide which is precipitated upon mixing the solu- tions of gold and tin. It is not a bright, but a rich and powerful colour, of great durability, varying in degrees of transparency, and in hue from deep crimson to a mur- rey or dark purple: it is princi- pally used in miniature painting, and may well be employed in ena- mel painting. Gondola, a Venetian barge much or- namented, used in the canals of Venice for the convenience of the inhabitants : the common dimen- sions are 30 feet by 4 feet : each end is terminated by a very sharp point, which is raised perpendicu- larly to the full height of a man Goniometer, an instrument for mea- suring angles and crystals Gorged, in heraldry, the bearing of a 208 crown, coronet, or the like, about the neck of a lion, swan, &c. Gossan, an imperfect iron ore, com- monly of a tender rotten substance, and of a red or rusty iron colour Gothic Architecture, usually so called. Both Mr. Britton and Mr. Pugin have treated of it by the name of ' Christian Architecture.' It had its rise from the Romanesque : this took its origin from Roman remains at the declension of that empire. It became Saxon, then Norman, and varied in its character with the maturity of years. It was Early English, Perpendicular, Decorated, Flamboyant, &c., till it lost its ec- clesiastical and monastic character in the Domestic, which prevailed in the Tudor style (Renaissance), followed by the Elizabethan, &c. Gouge, in carpentry, an instrument like a round hollow chisel Governor, the apparatus for regulating the supply of steam to the cylinder so as to give a constant velocity to the engine. It consists of two balls suspended from a vertical spindle, and revolving with it : the suspend- ing rods are connected by arms to a sliding-piece which fits the spindle and acts upon a lever attached to a throttle-valve in the steam-pipe : the balls rise by the centrifugal force as the velocity increases, and close the valve : when the velocity diminishes, the balls fall, and open the valve. Governor, a contrivance for equalizing the motion of mills and machinery, as well as being used as above de- scribed Governor balls, the solid metal balls fixed on the ends of the suspending rods of the governor Governor (gas). The governor is a machine for regulating and equal- izing the flow of gas from the gaso- meters to the street-mains, and is much more perfect in its action than any slide-valve applied for that purpose requiring attendance. Its use is no where sufficiently ap- preciated. Had it been a compli- GOW GRANITE. GRA cated piece of machinery, or ex- pensive in its first cost and after- application, objections to its adop- tion would not have been surprising, but it is perfectly simple, its ac- tion is certain and unvarying, and its first cost inconsiderable. The velocity of gas in the mains and pipes of supply is, in the first instance, as various as there are differences in their altitudes and extent. A main at one place will furnish, with a certain pressure of gas, a flame one inch high ; while at a different altitude it will furnish a flame double that height. If, again, in the direction of the main there are many bends, angles, or contractions in its diameter, the velocity of the gas through it will vary considerably more than if it were direct and uniform. If the pipe be of any great length, and of uniform bore, but unequally fur- nished with branches, the burners will be unequally supplied with gas : those which are near its head will be supplied with a fuller stream of gas than those which are situated towards its termination. Independently of these differ- ences, arising from diversity of local positions, there will always be one great variation in the velocity of the gas, occasioned by the va- riety of periods during which lights are required by different consumers supplied from the same main or system of pipes : for example, when a certain number of burners is to be supplied, and it happens that one-half are shut off sooner than the rest, the velocity of the gas in the mains will be materially in- creased, and the remaining lamps should be turned down ; but many would not be reduced, and much gas would be lost. Gowan, decomposed granite ; but the term is sometimes applied to the solid rock Gozzan, oxide of iron and quartz Grace is taken for beauty, graceful form or agreeableness of person; 209 for form, friendship, and kindness; for certain gifts of God, which He bestows freely, when, where, and on whom He pleases : such are the gifts of miracles, prophecy, lan- guage, &c. Grace principally consists in the turn that a painter gives to his objects, to render them agreeable, even those that are inanimate. It is more seldom found in the face than in the manner ; for our manner is produced every moment, and can create surprise. A woman can be beautiful but one way, yet she can be graceful a thousand. Grace is neither found in constrained nor in affected manners, but in a certain freedom and ease between two ex- tremes. Gradation, in painting and drawing, implies the gradual receding of objects into the remote distance, by a proper strength or due dimi- nution of light, shade, and colour, according to their different dis- tances, the quantity of light which shines upon them, and the medium of air through which they are seen Gradient, a deviation from a level surface to an inclined plane Graduation, the division of philo- sophical instruments into degrees and other minute parts Grain tin, the finest tin, smelted with charcoal ; also the ore of very rich tin sometimes found in the form of grains or pebbles Grange, a monastic farming establish- ment : in ancient times it was com- mon to attach farm-houses and granaries to the estates of religious institutions Granite, a natural stone of great strength, hardness, and durability ; much used in building: it is a primary and unstratified rock, con- sisting of quartz, mica, and felspar, each crystallized and cohering, but without any base or cement Grapnel, in navigation, a sort of small anchor with four or five flukes or claws, commonly used for boats and small vessels GRA GREGORIAN CHANT. GRE Gravel, a geological term applied to those sabulous soils, or assemblages of worn and rounded stones, which are found scattered on the surface of the earth Graver, the burin of an engraver ; a square piece of steel fixed in a handle, and bevelled diagonally at the end: an instrument used for turning iron, after it has been roughed out by the 'heel tool,' is so called Gravity is that power or force which causes bodies to approach each other. This universal principle, which pervades the whole system of nature, may be enunciated as follows : the mutual tendency of two bodies towards each other in- creases in the same proportion as their masses are increased, and the square of their distance is decreased ; and it decreases in proportion as their masses are decreased, and as the square of their distance is in- creased. Gravity is also the force wherewith a body endeavours to descend to- wards the centre of the earth : this is called absolute gravity when the bodytends downwards in free space, and relative gravity is the force it endeavours to descend with in a fluid. Terrestrial gravity is that force by which bodies are urged towards the centre of the earth, and it is measured by the velocity generated in a second of time. Ex- periments show that a falling body describes 16-^ feet in one second, and it has then acquired a velocity of 32 feet, which is therefore the true measure of the force of gravity. Gray colour is the third and last, being the nearest in relation of co- lour to black. In its common ac- ceptation, gray denotes a class of cool cinerous colours, faint in hue ; whence we have blue-grays, olive- grays, green-grays, purple-grays, and grays of all hues, in which blue predominates ; but no yellow or red grays, the predominance of such hues carrying the compounds 210 into the classes of brown and mar- rone, of which gray is the natural opposite. Graywacke, a coarse slate; in geo- logy, a secondary rock Grease-cock, a short pipe fixed in the cylinder cover of a steam engine, with two stop-cocks inserted at a short distance apart, and a funnel at the top for holding tallow. When the upper cock is opened, the tallow falls into the intermediate space ; the cock is then closed, and the lower one opened for the melted grease to enter the cylinder, and lubricate the piston without allow- ing the steam to escape. Green verditer is the same in substance as blue verditer, which is converted into green by boiling it Green ebony wood, imported from the West Indies, is used for round rulers, turnery, marquetry -work, &c. ; it is also much used for dyeing, and contains resinous matter Greenheart wood, from the West In- dies, resembles cocoa wood in size and bark, and is used for turnery and other works Grees, steps ; also a staircase Gregorian Chant: Cantus Gregoria- nus, Cantus Firmus, Cantus Plan us or Plenus, in Latin ; Canto Firmo, in Italian; Plein Chant, in French; Plain Chant, inEnglish; andChoral, in German. This species of music is the most ancient of all, and is still the only one properly adapted to the ritual services of the Chris- tian churches. The Gregorian chant consists of a few notes, on which the words of the Liturgies are recited. The earliest specimens in existence con- sist of only one or two notes, and were used by St. Ambrose, at Milan, in the fourth century. The origin of this chant is traced to the earlier churches of Egypt, Thebes, Pales- tine, Arabia, Phosnicia, Syria, &c., from whence it was introduced into the church of Constantinople by St. John Chrysostom. St. Ambrose is said to have brought it into use GRE GREGORIAN CHANT. GRI in Milan, " after the custom of the inhabitants of the East," and from Milan it came to Rome " long be- fore the time of St. Gregory." But as, in the course of time, various mutations had taken place, St. Gre- gory, in order to reform and settle the music for the church, made a compilation of such as was fit for its use, and formed the first ritual book of music, or Roman Anti- phonarium. From the order which he gave it, and in consequence of this work of Gregory being after- wards established in the other (the Western) churches, it received the name Gregorian. We have very little of the music ascribed to Gre- gory himself, a specimen of which is given by Mr. Spencer in his work on the church modes, and is very grand. A portion of the old Gre- gorian chant is still used in our cathedrals in the so-called 'intoning the service' by the minor canons, and also in the responses by the choir, but in a very mutilated form. But in the chanting of the prose Psalms, it is almost entirely aban- doned; the only specimen (and that somewhat mutilated) being the grand and well-known 'Tallis's chant.' There is a remarkable difference between the Gregorian melodies for the Psalter and Can- ticles (and which are called the eight tones) and those of a more modern date. No such thing as a double chant exists in Gregorian music, and the ' tones ' are formed on one general law ; i. e. a ' tone ' consists of one principal note, called the Dominant, i. e. the predominant or reciting note, upon which the principal part of each half-verse is chanted, the remainder being in- flected in cadences of one or several notes revolving (as it were) above and below the dominant, or ter- minating on the final of the mode ; and it is a law that the reciting parts are always (when the tone is regular) on the same note, viz. the dominant. There are very few instances of any deviation from this rule. In the modern system there seems to be a total absence of any rule of this sort, and the cadences, both in the middle of the verse and at the end, consist of a greater number of notes, and these of unequal value. Moreover, in the Gregorian chant no attention is paid to time ; it is regulated entirely by emphasis and syllabic quantity, not by time and accent, as in mo- dern chanting. On Sundays and the greater festivals it is a rule to commence the ' tone ' with a few preliminary notes, called the into- nation, which serve as an inchoa- tion, or induction to the dominant, or reciting note : on other occa- sions, these initial notes are not used. For specimens of the adap- tation of these Gregorian tones or chants to the Canticles, &c. of the English church, see the 'Hymnal,' by Mr. Spencer. Gregorian music requires a nobler and more rigid harmony than can be given in the modern system; and its effects in the divine offices, when properly harmonized and performed, are far superior to any other kind of church music. Greut, or Grit, a kind of fossil body, consisting of sandy, rough, hard, earthy particles Grey. See Gray. Griddle, a large wire sieve, used in- stead of a hurdle, for sifting and sorting copper ore as it rises from the mine Griffin, in heraldry, a fabulous animal, feigned to be between the lion and eagle, and to have the paws and head of the first, with the beak and wings of the last ** Grindstone, a cylindrical stone, on which, being turned round its axis, edge-tools are sharpened by apply- ing their edges to the convex surface Gripe, the lower part of the knee of the head that connects with the foremost end of the keel of a vessel Grit, coarse sand; rough hard par- ticles of sandstone GRO GROINS. GRO Groin, the angle formed by an inter- section of vaults : most of the vaulted ceilings of the buildings of the middle ages were groined, and therefore called groined ceilings. During the early part of the Nor- man style the groins were left pur- posely plain, but afterwards they were invariably covered with ribs. Groins, in coast engineering. A groin is a frame of wood-work, con- structed across a beach, between high and low water, perpendicular to the general line of it, either to retain the shingle already accumu- lated, to recover it when lost, or to accumulate more at any particular point ; also to break and check the action of the waves. The component parts of a groin are piles, planking, land-ties, land tie-bars, blocks, tail-piles, and keys and screw-bolts. The length of a groin depends on the extent, and the requisite strength of its component parts on the nature of the beach on which it is to be constructed. Those at Eastbourne, on the coast of Sussex, of which the following is more particularly a description, are from 150 to 250 feet in length, and the beach at that place being very rough, consisting of coarse heavy shingle and large boulders, they require to be composed of proportionably strong materials to resist its force. The piles are from 1 2 to 25 feet long, and 8 by 6^ inches scantling, shod with iron. The planking is in lengths of 8, 12, and 16 feet, 2| inches thick, and with parallel edges. The land- ties are of rough timber from 20 to 25 feet long, and large enough at the but-end to receive the bars. The land tie-bars are 13 ft. 6 in. long, and 12 by 5 in. scantling. The land tie-bar blocks are about 2 feet long, and of the same scant- ling as the piles. The land-tie tail-keys are about 212 2 feet 6 inches long, and 6 by 2 inches scantling. The above materials are of oak or beech. The screw-bolts are of inch round iron, 2 feet 9 inches and 2 feet 1 inch long, in equal proportions. The relative proportions of the component parts are, four piles, one land-tie with tail-piles and keys, one land tie-bar with two blocks, two long and two short bolts, about 180 square feet of planking, and about 140 six-inch spikes for every 16 feet in length ; and the expense of a groin, constructed with mate- rials of the above dimensions, may be calculated at about 30 for the same length. GENERAL RULES OBSERVED IN THE CONSTRUCTION. When the object, in constructing a groin, is to recover shingle, or accumulate more, the first pile is driven, at the high-water mark of neap-tides, leaving its top level with that of spring-tides. The next is driven at the point on the sands, beyond the bottom of the shingle, to which the groin is to extend, leaving about 4 feet of it out of the beach. The tops of these two piles may be taken for the general slope of the groin, unless the beach should be very steep, and much curved, in which case it becomes necessary to follow its curvature in some degree. From the high-water mark of neap-tides, the piles are carried back nearly level to that of spring- tides, and as much further as may be considered necessary. The piles are driven 4 feet asunder from centre to centre, and so as to admit the planking between them alternately, and they should be sunk about two-thirds of their length. The longest piles are placed be- tween the high-water mark of neap- tides and the bottom of the shingle, particularly from 20 to 40 feet below the former point. The planking is, if possible, car- GRO GUSSETS. GUS ried down to about two-thirds from the tops of the piles, and kept parallel with them. The land-ties are placed about one-third from the top of the plank- ing (supposing the latter to com- mence from the tops of the piles), and their tails are sunk to the level of the bottom of the planking, or as nearly so as possible. Grotesque. This term, which is now familiar among all the lovers of the art of painting, was by the Italians appropriated to that peculiar man- ner of composition and invention observed among the antique mo- numental paintings which were discovered in the subterraneous chambers that had been decorated in the times of the ancient Romans ; and as the Italians apply the word Grotto to express every kind of' cave or grot, all paintings which were in imitation of the antique designs discovered in those cham- bers, which for ages had been covered with ruins, are grotesqued or grotesque, which is now applied to English subjects of a quaint and anomalous character. Grotesque, a name given to the light and fanciful ornaments used former- ly to characterize persons and things Grotto, a natural or artificial cavern or cave Grouan lode, any tin lode which abounds with rough gravel or sand Ground-plate orffround-sill,the lowest plate of a wooden building for sup- portingthe principal and other posts Grounds, pieces of wood fixed to walls and partitions, with their surfaces flush with the plaster, to which the facings or finishings are attached Ground table stones, the projecting course of stones in a wall above the plinth Ground-ways, large pieces of timber laid across a ship or dock, and upon which the blocks are placed Grouping is the combining or joining objects in a picture for the satis- faction of the eye, and also for its repose; and although a picture may 213 consist of different groups, yet those groups of objects, managed by the chiaro-oscuro, should all tend to unity, and one only should predo- minate Guay, Cornish. Tinners, holeing into a place which has been wrought before, call it holeing in guag Gudgeon, the iron piers fixed in a beam or wooden shaft for bearings Gudgeons, in ship-building, are eyes driven into the stern-post, to hang the rudder 011 Guide-blocks, pieces of metal with parallel sides, fitted on the ends of a cross-head of a steam engine, to slide in grooves in the side frames, and keep the motion of the piston- rod in a direct line Guilloche, an ornament used in classi- cal architecture, formed by two or more intertwining bands Gules, in heraldry, a red colour Gulph of ore : a lode which throws up very great quantities of ore, and proves lasting and good in depth, is so called Gum wood, or blue gum wood, is the produce of New South Wales, sent over in large logs and planks simi- lar to dark Spanish mahogany : it is used in ship-building, &c. Gun-metal, a mixed metal, an alloy of copper and tin Gunnies, in Cornish, a term applied to breadth or width : single gunnies are 3 feet wide Gunter's chain, the chain in common use for measuring land: the length of the chain is 66 feet, or 22 yards, or 4 poles of 5 yards each ; it is divided into 100 links of 7 '92 inches each. See Acre. Gunwale, or gunnel, in ship-building, the piece of timber which reaches on either side of the ship from the half-deck to the forecastle Gunwale, the plank that covers the heads of the timbers between the fore and main drifts Gussets, as understood in mechanical construction, are brackets or angular pieces of iron, to strengthen, to keep steady, and support a structure. GUS HALF-TIMBERED HOUSES. GYP In the construction of the rect- angular covered openings of the Britannia and Conway iron bridges, gussets are used extensively in the interior, consisting of double tri- angular plates riveted to the bot- tom and sides of the plates of the bridge, as a series of brackets (and at the top and either sides also), to add to the strength and durability of these extraordinary works, and as a counter-effort to the tendency of strain on the lower sides to se- parate or open the joints, and on the upper side to force them closer together. Gusto, a term used by the Italians, signifying taste in the design of the attitudes, good arrangement, and composition of a picture Guttce, ornaments resembling drops, placed in the epistylium of the Doric order below the triglyphs. They occur likewise in the under HAD HADE, in mining, the underlay or inclination of the vein Half-pace, or Haute-pace, a raised floor in a bay window. Half-timbered houses: this mode of constructing domestic buildings was practised in England and on the Continent during the reigns of Henry VIII. and Elizabeth. It was peculiarly of a picturesque charac- ter ; the foundations and principal supports were of stout timber, and the interstices of the fronts were filled with plaster. In many cases the ornamental timber framing was of a dark colour, which, with the barge-board gable, gave the whole an exceedingly interesting appear- rance. There are yet remaining some very fine examples in England, particularly in the western and north-western counties. Half-timbers, in ship-building, those timbers in the cant bodies which are answerable to the lower fut- tocks in the square body 214 face of the mutules in the Doric corona. They are supposed to have originated from the intention to represent drops of water running off the roof, adhered to the under surface of the canterii or rafters of early buildings. Gybing, in navigation, the shifting of any boom-sail from one side of the mast to the other Gymnasium, a public building used by the Greeks for the practice and exercise of gymnastics, or mus- cular development ; also a place, according to Vitruvius, for amuse- ments and scientific recreation Gynceceum, in Greek architecture, the apartment of the females in the interior of the house ; the nursery Gypsoplaste, a cast taken in plaster of Paris or white lime Gypsum, sulphate of lime, called also plaster of Paris, selenite, and ala- baster HAM Hall, the principal apartment in the domestic houses of the middle ages; a place of assembly; a spacious building attached to inns of court Halliards, in navigation, the ropes or tackles usually employed to hoist or lower any sail on its respective mast Hallyings, the hangings of a hall Halvans, in Cornish, the refuse ore Ham, in Saxon, a house, farm, or vil- lage Hamburgh lake is a colour of great power and depth ; rather purpleish, or inclining to crimson : it dries with extreme difficulty, but differs in no other essential quality from other cochineal lakes Hammer-beams, horizontal pieces of timber, frequently used in the roofs of old English buildings, in pairs on the opposite sides of the same roof; often used also in the prin- cipals of Gothic roofs, to strengthen the framing and to diminish the lateral pressure that falls upon the walls HAN HAND-GEAR. HEA Hances, in architecture, ends of ellip- tical arches, which are arcs of smaller circles than the scheme or middle part of the arch Hand-brace, a tool for boring, con- sisting of a cranked spindle, at one end of which a broad head or breast-plate is attached by a swivel, so that it may remain stationary while the crank is turned ; at the other end is a socket, into which a drill can be fixed Hand-drilling machine, a small drilling machine turned by manual labour Hand-gear, in a locomotive engine, the handles of the working gear, placed conveniently to the foot- plate, so as to be within reach of the engine-man when he requires to use them for regulating the dif- ferent parts of the engine Hand-pump, in a locomotive engine, the pump placed by the side of the fire-box, to be worked by a hand- lever when the engine has to stand with steam up Hand-railing, in a locomotive engine, the railing along the sides of the engine, to protect persons passing to the front of the engine for any necessary purpose Hand-saw, a saw from 12 to 15 inches in length, fixed in an iron frame, with a handle at one end; used for cutting wood or metal Harmony is the general accordance of the objects in a painting with one another, and their subordination to the principal object ; so that all unite to constitute a pleasing whole. It is effected by a due combination of lights and shades, by the union and colour, or by such constrasts as are sufficient to relieve the dis- tant groups. Harmony of colours. Lessons in colouring have ever been given, notwithstanding it is a part so principal in painting, that it has its rules founded on science and reason. Without such study, it is impossible that youth can acquire a good taste in colouring, or un- derstand harmony. 215 Harpings, pieces of oak which hold the timbers of the fore-and-aft cant-bodies till a ship is planked Hatches, the coverings for the hatch- ways of a ship, made with ledges, and laid with oak or deal, and caulked Hatching is shadowing with a black- lead pencil or pen : it is done either in straight lines or zigzag strokes, such as are seen in pencil drawings, or in pencilled back- grounds. It is used by engravers in etching. Hatchment, in heraldry, an armorial escutcheon placed over a door in memory of a deceased person of rank Hatchways, places in the middle of the decks of a vessel, for the con- venience of lowering down goods Haul the wind, in navigation ; to direct the ship's course nearer to the point of the compass from which the wind blows Haunch of an arch, the part between the vertex and the springing Hawse, in navigation, the situation of the cables before the ship's stern when she is moored with two an- chors forward from the starboard and larboard bow Hawse-pieces, the timbers in the bow of a ship whose sides are nearly parallel to the middle line Hawthorn, a wood not much used, is hard, and of a whitish colour, with a tinge of yellow Hazel, a small underwood which is very elastic, used for turning, for the handles of blacksmiths' chisels, for the hoops of casks, &c. Head-ledges, the thwartship pieces which frame the hatch -ways or ladder-ways of ships Head-stocks, the frames which sup- port the centres of a lathe; viz. the mandril-frame and the poppet- head, or back centre frame Health of Toums, a phrase recently coined to express the general purpose of public sanatory measures. These measures are based upon the prin- ciples of animal physiology, but HEA HEAT. HEA had been recognized only in the curative policy of the physician, until the evils of their neglect were traced by statistical inquiries into the causes of disease ; and they are therefore now properly regarded as essential objects in the social eco- nomy of life. The human constitution is so formed that its health depends on an adequate supply of pure air, water, and light. Every circum- stance, therefore, which vitiates the quality, or reduces the due quan- tity, of these essentials, is injurious to health, and demands amendment or extinction. Thus the efficient supply of pure and attemperated air requires pro- per drainage and ventilation, warm- ing or cooling of all places in which human beings live or congregate : it also limits the minimum of size for the healthy habitations of men. The plentiful supply of pure wa- ter necessitates suitable provision for obtaining and treating it, and the proscription of all arrangements which limit the service or injure its purity. Equally important with these conditions is the third one enumerated, which suggests the ne- cessity of so arranging and con- structing streets and buildings, that abundance of light may at all times be admitted into them. As measures auxiliary to these objects, and of great importance in the combined arrangements of so- ciety, public exercising and plea- sure grounds, baths and wash- houses, cooking apparatus, medical and remedial establishments, street accommodations, &c., command adoption, and, when adequately carried out, will tend to complete the physical requisites of the health of towns. Heat, in the ordinary application of the word, signifies, or rather im- plies, the sensation experienced upon touching a body hotter, or of a higher temperature, than the part or parts which we bring 216 into contact with it : in another sense, it is used to express the cause of that sensation. To avoid any ambiguity that may arise from this double use of the same expres- sion, it is usual and proper to em- ploy the word caloric to signify the principle or cause of the sensation of heat. On touching a hot body, caloric passes from it, and excites the feeling of warmth : when we touch a body having a lower tem- perature than our hand, caloric passes from the hand to it, and thus arises the sensation of cold. Caloric is usually treated of as if it were a material substance ; but, like light and electricity, its true nature has yet to be determined. COMMUNICATION OF CALORIC. Caloric passes through different bodies with different degrees of ve- locity. This has led to the division of bodies into conductors and non- conductors of caloric : the former includes such bodies as metals, which allow caloric to pass freely through their substance ; and the latter comprises those that do not give an easy passage to it, such as stones, glass, wood, charcoal, &c. Table of the relative conducting power of different bodies. Gold. . . . 1000 Platinum . . .981 Silver . . .973 Copper . . .898 Iron . . . .374 Zinc .... 363 Tin . . . . 304 Lead . . .180 Marble ... 24 Porcelain . . . 12-2 Fire-brick . . . 11 Fire-clay . . . 11 '4 With Water as the standard. Water ... 10 Pine. ... 39 Lime ... 39 Oak .... 33 Elm .... 32 Ash . . . . 31 Apple ... 28 Ebony ... 22 HEA HEIGHT OF COLUMNS. HEI Relative conducting power of dif- ferent substances compared with each other. Hares' fur . . 1-315 Eider-down . . 1-305 Beavers' fur . . 1-296 Raw silk . . . 1-284 Wool . . . 1-118 Lamp-black . . 1*117 Cotton . . . 1*046 Lint B jyfa .: . . 1-032 Charcoal . . . : *937 Ashes (wood) . . '927 Sewing silk . . *917 Air . . . . > A * -576 Relative conducting power of fluids. Mercury . . . 1*000 Water ... *357 Proof Spirit . . -312 Alcohol (pure) . . '232 RADIATION OF CALORIC. When heated bodies are exposed to the air, they lose portions of their heat, by projection in right lines into space, from all parts of their surface. Bodies which radiate heat best, absorb it best. Radiation is affected by the na- ture of the surface of the body; thus black and rough surfaces ra- diate and absorb more heat than light and polished surfaces. Table of the radiating power of different bodies. Water . 100 Lamp-black 100 Writing-paper 100 Glass . 90 Indian ink 88 Bright lead 19 Silver . 12 Blackened tin 100 Clean do. 12 Scraped do. 16 Ice . 85 Mercury . 20 Polished iron 15 Copper . 12 Professor Leslie has proved, by a variety of experiments, that the heat which is propagated by radi- ation from different bodies varies 217 with the nature of their external surfaces ; the quantity which flows in a given time from a body with a polished surface being much less than would flow from the same body with a rough surface. It therefore follows that the external surfaces of the steam-pipes of steam engines and steam cylinders should be as smooth as possible, and should be covered with any body which is a bad conductor of heat. Heel tool, a tool used by turners for roughing out a piece of iron, or turn- ing it to somewhat near the intend- ed size : it has a very acute cutting edge and an angular base or heel Height of columns. The height of a column is measured by its diameter immediately above the base. Diameters high. The Tuscan column . 7 The Ionic ... 9 Corinthian and Composite 10 In the above heights are included the capitals and bases, which are esteemed parts of the columns with which they are used. Heights and Distances. Trigonometry receives its principal practical ap- plication in the operations of sur- veying, and measuring heights and distances; as, however, the methods of its application (depending on the peculiar circumstances of each case) are exceedingly various, no general rules can be specified. The instruments employed to measure angles are quadrants, sex- tants, theodolites, &c., the use of either of which may be sooner learned from an examination of the instruments themselves than from any description independently of them. For military men and for civil engineers, a good pocket sex- tant and an accurate micrometer (such as Cavallo's), attached to a telescope, are highly useful. For measuring small distances, as bases, 50-feet and 100-feet chains, and a portable box of graduated tape, will be necessary. For the purposes of surveying, it HEL HERALDRY. HIN is usual to employ a chain 66 feet in length, subdivided into 100 links, each 7'92 inches : the reason for using a chain of this length is, that ten of such square chains are equal to an acre, and therefore the acre- age of the several divisions of an estate is found with much greater facility when measured in chains and links, than when the measure- ments are taken in feet. Helix, the small volute under the abacus of a Corinthian capital Helix, any thing of a spiral form, whe- ther in one plane, as the spiral curve, or in different planes, as the screw Heptagon, in geometry, a figure with seven sides or angles Heraldry is a science intimately con- nected with the early history of Europe, its chivalry, its conquests, and the bearing of arms : it teaches how to blazon or explain in proper terms all that belongs to arms ; and how to marshal or dispose with extreme punctualness divers arms on a field. It is in its archae- ology and in precedent indisputable. It teaches whatever relates to the marshalling of solemn processions and other public ceremonies, at co- ronations, installations of Knights of the Garter, Knights Grand Cross of the Bath, Knights Companions, &c.; at the creation of peers, nuptials, christenings of princes, funerals, &c. It is, in fact, an important science, particularly in English history, in tracing the narrative of the families ef the nobility and commoners, their holdings, their distinguishing qualifications, in arms, in literature, and in the arts. Hermce, statues of which only the head is carved, and sometimes a portion of the bust : square or cu- bical figures of the god Mercury, without legs and arms, anciently placed by the Greeks and Romans at their cross-ways Herring-bone work, masonry in which the stones are laid aslant instead of being bedded flat 218 Herse, a portcullis ; a frame whereon lighted candles were placed at the obsequies of distinguished persons Heterogeneous, opposite or dissimilar in nature, as opposed to homogene- ous Hewns, in Cornwall, the sides of a calciner or burning-house furnace ; so called from their being formerly built with hewn moor-stone Hexagon, in geometry, a figure of six. sides or angles Hexahedron, in geometry, one of the five regular solids, being the same with a cube Hexastyle, a portico of six columns in front Hexastylos, a frontage of six columns Hexeres, a vessel with six banks of oars on each side Hiatus, an aperture, a breach or de- fect Hictfs mandril, an arbor for turning rings : at the centre of the arbor there is a cone, round which, at equal distances, wedges are fitted into dove-tailed grooves, and are expanded to the bore of the ring by a nut acting on a screw at the end of the cone Hickory, or white walnut, a native of America. The wood of the young trees is exceedingly tough and flex- ible, and makes excellent hand- spikes, &c. Hieroglyphic, an emblem, a figure by which a word is implied ; the Egyptian art of writing in picture High-pressure engine, a non-conden- sing steam engine, worked by the excess of the pressure of the steam upon the piston above the pressure of the atmosphere : in this engine, after the steam has acted upon the piston, it passes through the educ- tion-pipe into the air Hiling, the covering or roof of a build- ing Hinges, the joints on which doors, gates, &c., turn Hinges. The diversity of forms into which door furniture has been re- solved is almost endless. Many of the ancient hinges were not only HIP HORSE-POWER. HOR wrought into scrolls and other flo- rid devices, but occasionally further enriched with inscriptions. Hip, the external angle formed by the meeting of the sloping sides of roofs whichhave their wall-plates running in different directions Hip-knob, a pinnacle, finial, or other similar ornament, placed on the top of the hips of a roof or the point of a gable Hippodrome, a large plot of ground laid out for the exercise of horses ; among the Greeks, a race-course Hoggan, in Cornish, a hawthorn-berry, the tinner's pasty Hogging, in ship-building, the convex appearance resembling the back of a hog, given to a ship after being first launched, by the dropping of the two extremities Hogshead, a measure of 63 gallons Hoist, an apparatus for raising bodies from the ground floor of a building to a floor above Hollow newett, an opening in the mid- dle of a staircase, the steps only being supported at one end by the surrounding wall, the ends next the hollow unsupported; also a hollow groin, pier, of brick or stone, made behind the lock-gates of canals Holly is a very clean, fine-grained wood, the whitest and most costly of those used by the Tunbridge- ware manufacturers : it is used for painted screens and a great variety of fancy and tasteful purposes Holy-water vessel, the vessel which contains the consecrated or holy water carried in religious proces- sions : also the receptacle for holy water placed at the entrances of Roman Catholic churches Holy-water stone, the stoup on which the holy -water vessel is placed Homestall or Homestead, a mansion, house, or seat in the country; a farm, with the land adjoining Homogeneous, a term applied to va- rious substances, to denote that they consist of similar parts, or parts of the same nature and kind Hoodings-ends, the ends of planks 219 which fit into the rabbets of the stem and stern-post of a ship Hood-mould, a band or string over the head of a door, window, or other opening, in an ancient build- ing; so called from its enclosing, as within a hood, the inferior mould- ings and the opening itself Hood-moulding, a name given to the label-moulding Hornbeam, a very tough and stringy European wood, used by millwrights for the cogs of wheels, also for plumbers' dressers, or mallets, &c. Hornblende, a conspicuous ingredient in the composition of rocks, divided into common hornblende, horn- blende-schist, and basaltic horn- blende Horn-stone, a conchoidal and silicious mineral substance, allied in compo- sition to flint, but of a more earthy texture Horologium, a name anciently given to any instrument for measuring time Horse, a large round bar of iron fixed in the head of a ship Horse, in navigation, the name of a rope reaching from the middle of a yard to its extremity, on which the sailors stand when they are loosing or reefing the sails Horse-chestnut wood is one of the white woods used by the Tunbridge turners ; it is close and soft, even in the grain, and is much used for brush-backs, &c. Horse -power. Although horses are not all of one strength, yet there is a certain force now generally agreed upon among those who construct steam engines, which force is de- nominated a horse's power, and hence steam engines are distin- guished in size by the number of horses' power to which they are said to be equal. The measure of a mechanical effect equal to a horse's power has been much disputed: this, however, can be but a matter of little conse- quence, if the measure be generally understood, since there is no such thing as bringing it into any real IOR HOT-AIR BLAST. HOT measure. Some horses will perform double the work of others, and those of one country will work more than those of another. Desaguliers' mea- sure is, that a horse will walk at the rate of 2 miles per hour, against a resistance of 200 fts., and this gives, as a number for comparison, 44,000 ; that is, the raising of 1 ft. 44,000 feet in a minute, or, what amounts to the same, the raising of 44,000 Ibs. 1 foot in a minute. Emerson's measure is the same as Desaguliers', and Smeaton's re- sult is 22,9 1 6 fts. under the same circumstances. James Watt found from repeated experiments, that 33,000 fts. 1 foot per minute was the average value of a horse's power; but his engines were calculated to work equal to 44,000 fts. 1 foot per minute. //. P., the abbreviation for horse- power Hortus, a garden or a pleasure-ground Hose-pipes, in locomotive engines, elastic pipes made of canvas, satu- rated with a solution of Indian rub- ber, sometimes galvanized, and forming a good elastic connection between the engine and tender feed- pipes. They are now generally used in preference to ball and socket connections for conveying the steam to the tender. Hospitalia, anciently the doorways in the scene of a theatre on the right and left of the valvae regiae or prin- cipal doorway; so called because the moveable scenes, representing inns or places appropriated for the recep- tion of strangers, were placed near them Hospitals were originally designed for the relief of poor and impotent per- sons, and the entertainment of tra- vellers upon the road, particularly of pilgrims, and therefore they were generally built upon the road- side ; in later time they have always been founded for fixed inhabitants : before the spoliation, there existed in England above 358 of these houses of relief ... 220 Hostelry or Hostry, anciently an inn Hot-air blast. It was conceived that the presence of sulphur in the air was the cause of blast furnaces working irregularly, and making bad iron in the summer months. Subsequently it was stated that one of the Muirkirk iron furnaces, in Scotland, situated at a considerable distance from the engine, did not work so well as the others, which led to the conjecture that the fric- tion of the air, in passing along the pipe, prevented an equal volume of the air getting to the distant furnace as to the one which was situated close by the engine : it was considered also, that by heating the air at the distant furnace, its volume would increase in the ratio of the known law, that air and gases ex- pand to double their bulk at 448 temperature. Example: If 1000 cubic feet, say at 50 of Fahrenheit, were pressed by the engine in a given time, and heated to 600 of Fah- renheit, it would then be increased in volume to 2104'4, and so on for every thousand feet that would be blown into the furnace. In prose- cuting the experiments which this idea suggested, circumstances,how- ever, became apparent which in- duced a belief, that heating the air introduced for supporting combus- tion into air furnaces materially in- creased its efficiency in this respect; and with the view of putting these suspicions to the test, the following experiments were made. To the nozzle of a pair of common smith's bellows, a cast-iron vessel heated is attached from beneath, in the manner of a retort for gene rating gas, and to this vessel the blow-pipe, by which the forge or furnace was blown, was also at tached. The air from the bellows having thus to pass through the heated vessel above mentioned, was consequently heated to a high tem- perature before it entered the forge fire, and the result produced, in HOT HOUSE. HOU increasing the intensity of the heat in the furnace, was far beyond ex- pectation, and so evident as to make apparent the fallacy of the generally received opinion, that the coldness of the air of the atmosphere in the winter months was the cause of the best iron being then produced. In overthrowing the old theory, new principles in the process of iron-making were established. Experiments on the large scale, to reduce iron ore in a founder's cupola, were commenced at the Clyde Iron Works. These experi- ments were completely successful, and in consequence the invention was immediately adopted at the Calder Iron Works, where the blast, being made to pass through two retorts placed on each side of one of the large furnaces before entering the furnace, effected an instanta- neous change, both in the quantity and quality of iron produced, and a considerable saving of fuel. The whole of the furnaces at the Calder and Clyde Iron Works were filled up on the principle of the hot blast, and its use at these works continues to be attended with the utmost success; it has also been adopted at Wilsontown and Gart- shirrie Iron Works in Scotland, and at several works in England and France. The air as at first raised to 250 of Fahrenheit produced a saving of three-sevenths in every ton of pig iron made, and the heating appa- ratus having since been enlarged, so as to increase the temperature of the blast to 600* Fahrenheit and upwards, a proportional saving of fuel is effected; and an immense additional saving is also acquired by the use of raw coal instead of coke, which may now be adopted. By thus increasing the heat of the blast, the whole waste incurred in burning the coal into coke is avoided in the process of making iron. By the use of this invention, with three-sevenths of the fuel formerly 221 employed in the cold -air process, the iron-maker is now enabled to make one -third more iron of a superior quality. Were the hot blast generally adopted, the saving to the country in the article of coal would be immense. In Britain, about 700,000 tons of iron are made annually, of which 50,000 tons only are pro- duced in Scotland: on these 50,000 tons would be saved, in the process of manufacture, 200,000 tons of coal annually. In England the saving would be in proportion to the strength and quality of the coal, and cannot be computed at less than 1,520,000 tons annually; and taking the price of coals at the low rate of four shillings per ton, a yearly saving of 296,000 sterling would be effected. Nor are the advantages of this invention solely confined to iron- making : by its use the founder can cast into roods an equal quantity of iron in much less time, and with a saving of nearly half the fuel employed in the cold -air process ; and the blacksmith can produce in the same time one-third more work, with much less fuel than he for- merly required. In all the processes of metallur- gical science it will be found of the utmost importance in reducing the ores to a metallic state. Hot-water pump, the feed-pump of a condensing engine, for supplying the boiler from the hot well Hot well, the vessel which receives the water from the air-pump Hour-glass stand, a bracket or frame of iron for receiving the hour-glass. See* 'Papers on Architecture,' vol. iii., which contains a good example. " By the side of the pulpit still remains the ancient hour-glass and frame." House, a place of residence. The pur- pose of a house being for dwelling, and that of tents being the same, they are called by one name in the Hebrew; on the same principle, the HOU HOUSES. HOU Tabernacle of God, though only a tent, is sometimes called the Tem- ple, that is, the residence of God. The ordinary buildings or houses in the East have continued the same from the earliest ages, without the least alteration or improvement ; large doors, spacious chambers, marble pavements, cloistered courts, with fountains, &c., conveniences well adapted to the circumstances of these climates, where the summer heats are generally intense. The streets of these cities, the better to shade them from the sun, are usu- ally narrow, with sometimes a range of shops on each side. On enter- ing one of the principal houses, a porch or gateway will first be seen, with benches on each side, where the master of the family receives visits and dispatches business. In houses of better fashion, the cham- bers are hung with velvet or damask from the middle of the wall downwards, and covered and adorned with velvet or damask hangings of white, blue, red, green, or other colours. The ceiling is generally of wainscot, either very artistically painted, or else thrown into a variety of panels with gilded mouldings, and with scrolls of the Koran, &c. The stairs are some- times placed in the porch, some- times at the entrance into the court. When there is one or more stories, they are afterwards continued, through one corner or other of the gallery, to the top of the house, whither they conduct through a door that is generally kept shut, to prevent their domestic animals from daubing the terrace, and thereby spoiling the water which falls from thence into the cisterns below the court, &c. Such in general are the manner and contri- vances of the Eastern houses ; and if it may be presumed that our Saviour, at the healing of the para- lytic, was preaching in a house of this fashion, it may, by attending only to the structure of it, throw 222 some light on one circumstance of that history, which has given great offence to some unbelievers. The houses of the poorer class of people in the East are of very bad con- struction, consisting of mud walls, reeds, and rushes. In Constanti- nople every thing is sacrificed to outside decorative show : built prin- cipally of wood, conflagrations are frequent and extensive. In earlier history, magnificence and refined luxury were combined with the highest and most noble examples of decorative art. The interior of the domestic residences and public edi- fices of Herculaneum and Pompeii surpassed every existing example. The houses of the Roman citizens partook also of the refinement of an age of art ; and modern Europe has noble examples of domestic dwellings, coeval with the wealth of the country in which they are still to be found. In England, the domestic residence of the noble- man, the merchant, and the trader are, besides the elegances of their arrangements, models of comfort and health. Houses. Before a house is planned, the proprietor should describe the kind of house he wishes to be built. The architect is to consider what must be had, and what may be dis- pensed with. He ought to keep his plan as scrupulously within the expense proposed, as within the limits of the ground he is to build upon ; he is, in short, to enter into the views, the wishes, and the ideas of the gentleman who will inhabit the house proposed to be erected. Houses suitable to the different ranks of the community. Vitruvius in- structs us of those parts of private houses which are exclusively appro- priated to individuals of the family, and in what manner these ought to be connected with the apartments into which strangers are admitted; for there are several parts of a house which may not be approached by those who are not of the household, HOU HYDRAULIC BELT. HYD unless expressly invited ; such as the sleeping-rooms, triclinia, baths, and those apartments which are in general use. The parts which are accessible to all, and into which any person may enter uninvited, are the vestibule, cavaedium, peri- style, and whatever others are built for similar purposes. Houses. Of the proportions of private houses, Vitruvius says, " Nothing ought to engage the attention of an architect more than the pro- portions of all the parts in the houses he constructs : after having determined upon such proportions as the necessity for the commen- suration of the parts with the entire building seems to require, the great- est judgment must be exercised in adapting them to the nature of the spot, the use to which the edifices are designed, and the appearance they ought to assume ; and this must be done by making such addi- tions or deductions, that, although the proportions are not strictly what they ought to be, the eye may not be conscious wherein they fail. The same objects appear differently under dissimilar circumstances ; if near the ground or at a considerable elevation ; if in a confined space or an exposed situation. Under every peculiar circumstance, great judg- ment is necessary in calculating the effect which will be ultimately pro- duced. The impression made upon the sense of seeing is not always a correct image of the object ; for, in painting, columns, mutules, and statues are made to appear pro- jecting and detached, when, in fact, every object represented is in one and the same place. It becomes necessary, in the first place, to in- stitute laws of proportion, upon which all our calculations must be founded. According to these, the ground-plan, exhibiting the length and breadth of the whole work and the several parts of it, must be formed. When the magnitude of these is once determined, the parts 223 must be arranged so as to produce that external beauty which suffers no doubt to arise in the minds of those who examine it as to the want of proportion in any part." Houses of the Greeks. The Greeks had a different way of building from the Romans ; for, as Vitruvius says, "instead of making porticoes or galleries and halls, they made the entry to their houses very narrow, placing on one side the stables, and the porter's lodge on the other. From this first entry one passed into a court, which had piazzas on three sides, and towards that of the south they made anti, or abut- ments of pilasters, which supported the joists of the ceiling more in- wards ; because that leaving some space between the one and the other, they had very large places, which they appointed for lodging to the mistress of the house, and to the men and women servants. On the same floor with these abut- ments there were some rooms which maybe called ante-chambers, cham- bers and drawing-rooms, being every one just behind the other." Housing, a tabernacle, or niche for a statue, was formerly so called Huel, a work, a mine, as huel stones, a tin mine Hulk, in Cornwall, an old excavated working ; ' to hulk the lode ' Hulk or hull, the body of a ship Hungarian machine, an hydraulic en- gine, a very ingenious application of the Hero jet -d'eau principle Hydraletes, according to Strabo, a mill for grinding corn by water- power Hydraulic belt, an endless double band of woollen cloth, passing over two rollers, the lower part of the belt being immersed in water : it is driven with a velocity of not less than a thousand feet per minute, and the water contained between the two surfaces is carried up and discharged, as it passes over the upper roller, by the pressure of the band HYD HYDROSTATIC PRESS. HYD Hydraulic ram, a machine contrived to raise water by means of its own momentum Hydraulics. The science of hydraulics teaches the method of estimating the swiftness and force of fluids in motion. The science is dignified by the name of hydrodynamics, or the application of dynamics to the impulsion and flow of water and other liquids, as well as the forces with which they act upon bodies against which they strike, or which move in them. Hydrodynamics, the science of the laws of the motion of fluids, con- sisting of two branches. The science of hydraulics refers princi- pally to the machinery for conduct- ing fluids ; that of hydrostatics, to the pressure, equilibrium, and cohesion of fluids. Hydrogen. Hydrogen gas is com- monly obtained for experimental purposes by the decomposition of water : its name is derived from the Greek words meaning water and to generate. Hydrometer, an instrument for mea- suring the specific gravity of various spirits and other liquids, by floating in them Hydroscope, an instrument intended to mark the presence of water in air Hydrostatic or Hydraulic press, a machine adapted for acquiring great pressure in cases where little mo- tion is required. The contrivance of this apparatus is due to the ce- lebrated mechanician, Joseph Bra- mah, who obtained a patent for it on the 31st of March, 1796, under the title of ' certain new methods of producing and applying a more considerable degree of power to all kinds of mechanical apparatus and other machinery requiring motion and force, than by any means at present practised for that purpose.' The action of this press is founded upon the fundamental principle in hydrostatics, that " when a liquid mass is in equilibrium, under the action of forces of any kind, every ~~224 molecule or part of the mass sus- tains an equal pressure in all direc- tions." From this it follows, that a pressure exerted on any portion of the surface of a confined mass of fluid is propagated throughout the mass, and transferred undiminished to the entire surface in contact with the water. The first sugges- tion of the hydraulic press is con- sidered to have been made by Pas- cal in the middle of the 17th cen- tury ; but Bramah was the first to carry this suggestion into practice, by devising and applying apparatus in various forms for the purpose of producing pressure. . Since the date of its invention, the hydraulic press has been ex- tensively used in pressing goods of various kinds. Another of its most useful applications is to the testing Fig. i. HYD HYDROSTATIC PRESS. HYD of girders and beams of cast iron. (See article, Bramah's hydrostatic press.) Its latest and perhaps most remarkable duty is that of lifting the iron-work of tubular bridges en masse from the water level to their final altitude. Hydrostatic presses consist es- sentially of two distinct parts, viz. the press, or machine in which the force acquired is applied, and the pumping apparatus, by which the water is forced into the press ; these two parts of the entire machine being connected only by the pipe Fig. 2. through which the water passes from one to the other. Of the ac- companying figures, Nos. 1 and 2 225 show the main parts of the press, viz. the cylinder, into which the water is admitted; the ram, or solid plunger or piston; and the cross- head by which the pressure at the end of the ram is distributed over a lengthened surface for use. The figures show the cylinder as sup- ported in a frame upon girders, in a manner similar to that adopted in raising the tubes of the railway bridge recently erected at Conway. Fig. 3 shows the section of a portable forcing-pump as commonly used for proving castings with the hydraulic press, for which purpose the press is applied horizontally, and mounted on an iron carriage for portability. But, however va- ried in arrangement for particular purposes, the pump and the press consist of the same essential parts, as follows : the pump comprises a cistern or kind of pail, for contain- ing the water, and into which a barrel descends nearly to the bot- tom. The barrel is fitted with a plunger, by working which, the water is driven through a small tube or pipe into the press. The pump is furnished with a safety- valve, and also with a screw for letting off the water as required. The press consists of a strong hol- low cylinder of cast iron, close at one end, and of a solid ram work- ing through the other end, the water-pipe being inserted through the metal of the cylinder in a water- tight screwed aperture. Fig. 1 is an elevation of the press ; fig. 2, a vertical section of the press, taken at right angles to the elevation; and fig. 3, a vertical section of a pump : a is the cast-iron cylinder ; 6, the ram ; c, the casing or frame of the cylinder ; d d are two cast- iron girders supporting the casing ; e is the cast-iron cross-head ; //, two guide-rods ; g, the water-pipe from the pump, with a lever-valve - at h, by closing which the pressure will be retained, should the pipe burst. On fig. 3,.; shows the other K5 HYD HYDROSTATIC PRESS. HYD end of the water-pipe, which is at i screwed into a stuffing-box on the pump ; k is the lever of the safety- valve, a', which is cylindrical, and finished with a conical end, which fits a seating of similar form ; / is a standard bolted at m to the cover of the cistern, and having an eye- boss at n, for guiding the plunger ; o p is a link pinned to the plunger; q is the pail or cistern for holding the water; r, the barrel passing through an opening in the cover, and fixed to it with bolts and nuts ; .9, the lower valve-seat, and conical three-sided valve, the former being screwed into the end of the barrel; 226 t, a tube depending from the valve- seat s, and screwed upon it : this tube reaches nearly to the bottom of the cistern, and is perforated at the end with minute apertures, through which the water is ad- mitted without dirt or particles, which would injure the working of the pump ; u is the plunger, which works through a stuffing-box on the top of the barrel, and is made with a slot at v, to receive the link o p, which is pinned to it and also to the pump - handle ; w is the plunger-rod, screwed into the upper end of the plunger ; y, the pump- handle, jointed to the standard at x. During the first part of the action of the pump, while no great pres- sure is yet produced, the handle is pinned to the outer of these holes, as it makes a larger stroke with the piston, and thus saves time : the pin is after- wards removed to the inner hole, to have all the ad- vantage of the leverage, z is the upper or discharge valve, with a conical end : it is introduced from the top, and covered with a short screw, which likewise regulates the lift of the valve. This valve is formed by being simply filed flat out of the round. The rule for finding the increase of power commanded by the pump is derived, first, from the ratio of the areas of cross section of plunger of pump and ram of press ; and, secondly, from the ratio of the le- verage of the pump-handle. Thus suppose the plunger to be | inch and the ram 6 inches in diameter, and the arms of the lever or handle as 1 to 4, the power will be thus found: 5 2 : 6 2 multiplied by 1 : 4 25 : 144, that is, 1 : 576. And thus a power equal to 20fcs., applied on the end of the pump- handle, will produce a pressure HYD HYGROMETER. HYP equal to 11,520 fts. on the ram, or 5 tons 2 cwt. 3 qrs. 12 ibs. Each of the presses applied at Conway was worked by a steam engine having a horizontal cylinder 17 inches in diameter and 16 inches stroke, with piston-rods working through stuffing-boxes at both ends of the cylinder. The piston-rods worked two forcing-pumps, with plungers 1-Jg inch diameter and 16 inches stroke. The rams of these presses were each 5 feet 2 inches long and 18| inches in diameter, with a space nearly | inch wide around. The cylinders were 37^ inches diameter externally, and 20 inches internally, the metal being 8f inches in thickness: the orifice of the water-tubes f inch in diameter. Hydrostatic paradox. This may be explained upon the same principles as the mechanical powers ; and an explanation conducted in this man- ner strips it of its paradoxical ap- pearance. Hydrostatics, the science which treats of the mechanical properties of fluids ; strictly speaking, the weight and equilibrium of fluids. The weight and equilibrium of fluids at rest are the objects of this science. When the equilibrium is destroyed, motion ensues ; and the science which considers the laws of fluids in motion is hydraulics. Hygrometer : this instrument is used to ascertain the quantity of mois- ture held in the atmosphere. There are several kinds of hygrometers in use, namely, De Luc's, Saussure's, Leslie's, and Professor Daniell's. The latter is considered preferable. ICE ICE-HOUSE, a subterranean chamber for preserving ice free from mixing with the ordinary changes of tem- perature Ich Dien, in heraldry, ' I serve ' Ichnography, in drawing. The ichno- graphy of a building represents the plan or ground-work ; the ortho- 227 Hyp&thral, open above : in temples of this description the cella was in part exposed to the air: they had a double range of columns within the cella, dividing it into three alae, or aisles. The alae on either side were roofed, but that in the middle had no covering. Hypaetrum, a latticed window over the entrance-door of a temple Hyperbola, a section of a cone made by a plane, so that the axis of the section inclines to the opposing leg of the cone, which in the parabola is parallel to it, and in the ellipse intersects it Hyperthyrum, that part of the frame of a doorway which is over the supercilium Hyperthyrum, in Greek architecture, a frieze and cornice supported by friezes and consoles Hypocastamim, or chestnut brown, is a brown lake prepared from the horse-chestnut : it is transparent and rich in colour, warmer than brown pink, and very durable both in water and oil : in the latter it dries moderately well Hypocausis, among the Greeks, a fur- nace with flues running underneath the pavement of an apartment, to increase the temperature Hypocaustum, the stove-room of a bath, in which was placed the prae- furnium for heating the caldaria Hypogceum, in ancient architecture, a name common to all the under- ground parts of a building Hypotrachelium, that part of the ca- pital of a column which occurs be- tween the shaft and the annulets of the echinus IMP graphy the front ; and the sceno- graphy the whole building. Icosahedron, in geometry, a regular body or solid, consisting of twenty triangular pyramids Image, a term applied to a statue Imbowment, an arch or vault Impages, the horizontal parts of the IMP INDIAN ARCHITECTURE. IND frame -work of doors, commonly termed rails Impale, in heraldry, to conjoin two coats or arms, as a wife's with those of her husband Impetus, in mechanics, violent ten- dency to any point, violent effort, force, momentum, motion Impinge, in mechanics, to fall against, to strike against, to clash with Impluvium, the cistern in the central part of the court or atrium of a Roman house, to receive the rain- water Impost, the horizontal mouldings or capitals on the top of a pilaster, pillar, or pier, from which an arch springs : in classical architecture the form varies in the several orders. Sometimes the entablature of the order serves for the impost of an arch. Impost ,archivolt, and key-stone. The height of the impost should be from one-ninth to one-seventh of the width of the aperture, and the breadth of the archivolt not more than an eighth nor less than a tenth of it. The breadth of the under side of the key-stone should be the same as the breadth of the archivolt, and its sides, of course, concentric ; its length, once and a half its breadth, but not more than double its breadth. Impulsive force is that wliich acts during an extremely short time, and is so called because the forces that take place in any impulse, or impact, are speedily exhausted Incise, to cut ; to engrave ; to carve Inclined plane (the), in mechanics, is a plane which makes with the hori- zontal plane any angle whatever, forming one of the simplest me- chanical powers. The inclination of the plane is measured by the angle formed by two lines drawn from the sloping and the horizontal plane, perpendicular to their com- mon intersection. Increment, an increase ; produce Incrustation. If water, impregnated with calcareous matter, remains 228' long in contact with extraneous substances, an earthy incrustation takes place that soon encloses the encrusted substance, which is then said to be petrified. Indian Architecture consists of two distinct styles, the Buddhist and theBrahminical, the former being the earliest, and consisting of topes or tumuli, large domical buildings of brick or stone, either quite solid or containing one or more small chambers, in which are deposited relics, coins, and other similar ob- jects, which the greater number of them were erected to enshrine. The principal topes are now found in Ceylon and Affghanistan, but they also exist in Burmah and in other neighbouring countries. The next class of Buddhist buildings are the Chaitya halls, similar in plan and use to the early basilicae : these exist principally in caves in India. And lastly, viharas or monasteries, in which the monks attached to the Chaitya halls re- sided : these also exist principally as caves in India, and as structural buildings in all countries where Buddhism is still practised. Brahminical or Hindoo architec- ture consists mostly of temples, pro- perly so called. These in almost every instance are towers, square in plan, or nearly so, built over the cell or sanctum of the temple. In the south of India, the upper part forms a right-lined pyramid; in the north, the outline is curvilinear, sometimes tapering to a spire. To these towers are attached porches of greater or less dimen- sions. In the north there are generally square halls without pil- lars in the south, as universally pillared sometimes attached, at others detached from the temple itself: in the latter case, in the south, some of the porches possess from 500 to 1000 pillars, though this is never the case in the north. These temples are generally sur- rounded by a square court : in the IND INERTIA. INN south, three, four, and sometimes even seven such enclosures sur- round the principal cell, the outer one being, in many instances, some miles in circumference. These Hindoo temples exist sometimes, though rarely, as rock- cut temples ; but generally they are structural. Between these styles comes a third, the Jaina style, being a mix- ture of the two, possessing some of the characteristics of both, and frequently displaying more ele- gance than the first, and less taw- driness than the other. By the introduction of domes, whose use was thus brought to great perfec- tion, an element was added which was a great improvement on the other two styles, and from which that of Jaina originated. The absence of the arch in all constructions of every age is gene- ral throughout India, as the prin- ciple was quite unknown. The upper parts of the buildings were supported on square piers or pil- lars, and from all sides of their capitals brackets projected equal to their width, and leaving gene- rally a space equal to three diame- ters between their greatest projec- tion, thus leaving only one-half of the whole length of the architrave unsupported; but when a greater space was required, a succession of projecting brackets, placed above each other, was adopted, sometimes meeting in the centre, and thus having the effect of the horizontal arch. Indian Ink : the pigment well known under this name is principally brought from China in oblong cakes, of a musky scent, prepared for painting in water, &c. Indian red, a colour, is brought from Bengal, and is a very rich iron ore, or peroxide of iron. It is an ano- malous red, of a purple-russet hue, of a good body, and valued, when fine, for the pureness and lakey tone of its tints 220 Indian yellow is a pigment long em- ployed in India and subsequently introduced generally into painting in European countries. It is im- ported in the form of balls, is of a fetid odour, and is produced from the urine of the camel. It has also been ascribed, in like manner, to the buffalo, or Indian cow, after feeding on mangoes ; but the latter statement is incorrect. Indian yel- low resists the sun's rays with sin- gular power in water-painting. Indicator, the apparatus for showing the force of the steam, and the state of exhaustion in the cylinder during the stroke Indigo, or Indian blue, is a pigment manufactured in the East and West Indies from several plants, but prin- cipally from the anil or indigofera Inertia, the passiveness of matter: matter has not the power of putting itself into motion, neither has it the power of stopping itself when put into motion by the action of an ex- ternal force, as it requires as much force to stop a body as it requires to put it in motion Inflammable air, hydrogen gas Influx, in hydraulics, the act of flow- ing into any thing, as the tide into a bay or river Injection-cock, the stop-cock in the ejection-pipe, for shutting off the supply of cold water used for the condensation of steam Injection-pipe, the pipe through which the injection water passes to the condenser; in a steam vessel the injection-pipe is open to the sea, at the bottom of the vessel Inn or Hostel, anciently a lodging- house, or a house of lodging and refreshment for travellers : houses for lodging the collegians at Cam- bridge and Oxford were so called Inns of court, houses in which there are many lodgings for the accom- modation of students and practi- tioners at law Innate force, in physics, the vis inertia Inner-post, in ship-building, a piece brought in at the fore-side of the INS INTERCOLUMNIATION. INT main-post, and generally continued as high as the wing-transom, to seat the other transoms upon Insertum opus, according to Vitru- vius, a mode of building walls used by the Romans, in which the stones were small and unhewn, similar to what is now called rubble-work Insulated columns, in architecture, are those which are unconnected with any wall or building Intaglio, in sculpture, &c., any thing that has figures engraved on it, so as to rise above the ground Intense blue, indigo refined by so- lution and precipitation, in which state it is equal in colour to Ant- werp blue. By this process, indigo also becomes durable, and much more powerful, transparent, and deep. It washes and works well in water ; and in other respects it has the common properties of indigo. Inter -calumniation. The spacebetween two columns is called an interco- lumniation. When columns are at- tached to the wall, this space is not under such rigorous laws as when they are quite insulated ; for, in the latter case, real as well as apparent solidity requires them to be near each other, that they may better sustain the entablatures which it is their office to carry. DIFFERENT SORTS. The dif- ferent intercolumniations had the following names bestowed on them by the Greeks, and they still retain their ancient appellations : Pycnostylos, when the columns are once and a half of their diameter dis- tant from each other. Systylos . . when their distance from each other is two diameters. Eustylos . . when their distance from each other is two diameters and a quarter. Diastylos . . when their distance from each other is three diameters and a quarter. 230 Areeostylos. . when their distance from each other is four diameters. In the Doric, however, the in- tercolumniation is regulated by the disposition of the triglyphs in the frieze ; for the triglyph ought al- ways to be placed over the centre of a column^ and the metope should be square. In the Tuscan inter- val, the architraves being of wood, the space may be considerably ex- tended. A strict adherence to the above- named intervals between the co- lumns produces some irregularity in the arrangement of the modil- lions and dentils of the Corinthian, Ionic, and Composite cornices, which, though not offensive, is better avoided. Vignola therefore has, with some propriety, made his eustylos intercolumniation equal to two diameters and one-third in all but the Doric order. Intercolumniations. Columns maybe said to be either engaged or insu- lated : when insulated, they are either placed very near the walls or at some considerable distance from them. With regard to engaged columns, or such as are near the walls of a building, the intercolumniations are not limited, but depend on the width of the arches, windows, niches, or other objects, and their decorations, placed ^'ithin them. But columns that are entirely detached, and per- form alone the office of supporting the entablature, as in peristyles, porches, and galleries, must be near each other, both for the sake of real and apparent solidity. The ancients had several manners of spacing their columns, which are described by Vitruvius in his third and fourth books. Those practised in the Ionic and Corinthian orders were, the pycnostyle, the systyle, the eustyle/the diastyle, and the arseostyle. In the Doric order they used other intercolumniations, regulating them INT IONIC ORDER. ION by the triglyphs, of which one was always to be placed directly over the middle of each column, so that they were either systyle monotri- glyph, of one diameter and a half; diastyle, or araeostyle : the Tuscan intervals were exceedingly wide, some of them being above seven diameters, which, as the architraves were of wood, was practicable. Vitruvius intended the five inter- columniations, mentioned in his 3rd book, merely for the Ionic and Co- rinthian orders ; the latter of which, according to him, differed from the former only in its capital ; for, in the second and seventh chapters of his fourth book, he establishes other intervals for the Doric and Tuscan orders. Nevertheless, they have em- ployed these intercolumniations in different orders. Palladio has used the systyle in the Corinthian, and the araeostyle in the Tuscan ; by which means the Corinthian peri- style, of which the character should be extreme delicacy and lightness, becomes twice as strong and mate- rial as the Tuscan, of which the distinguishing characteristics ought to be extreme solidity. Interlignium, in ancient architecture, the space between the ends of the tie-beams Interpensiv(B, timbers in the roof of the cavaedium, extending in a dia- gonal direction from the angles made by the walls of the court to the angles made by the junction of the beams supporting the roof Intrados, the soffit or under-surface of an arch, as opposed to cxtrados In vacua, a void or empty space Invention, in painting, consists princi- pally in three things : first, the choice of a subject properly within the scope of art ; secondly, the sei- zure of the most striking and ener- getic moment of time for represen- tation ; and lastly, the discovery and solution of such objects, and such probable incidental circum- stances, as, combined together, may best tend to develop the story, or 231 augment the interest of the piece. The cartoons of Raphael furnish an example of genius and sagacity in this part of the art. Inverse, turned back or inverted ; op- posed to direct Inverse ratio, when more requires less, or less requires more Inverted arch, an arch of stone or brick, with the crown downwards, commonly used in the construction of tunnels Iodine scarlet is a new pigment, of a peculiarly vivid and beautiful colour, exceeding even the brilliancy of vermillion. It has received several false appellations, but is truly an iodide or biniodide of mercury, vary- ing in degrees of intense redness. It has the body and opacity of ver- million, but should be used with an ivory palette-knife, as iron and most metals change it to colours varying from yellow to black. Iodine yellow, ioduret of lead, is a precipitate from an acid solution of lead by an alkaline solution of iodine, of a bright yellow colour, which, from its active chemical affi- nities, and the little experience of its qualities in painting, is to be employed with doubt and caution Ionic capital. The Greek architects must have possessed much science in the formation of curves of every description. We cannot generate the curve of the volute of an Ionic capital but by approximation; but the inventors of the order must have known how to generate this and other curves in Greek architec- ture, on fixed principles ; so must the artist in vases, &c. Mr. Jopling is said to have discovered the true generic curve. Ionic Order: this, says Palladio, " had its origin in Ionia, a province of Asia; and we read that the famous tem- ple of Diana at Ephesus was built of that order. The column, with its capital and base, is nine modules high ; and by a module is under- stood the diameter of a column be- low. The architrave, frieze, or IRQ IRON. IRQ cornice, have the fifth part of the height of the column. When the columns are single, the inter-co- lumns are of two diameters and a fourth part, and this is the most beautiful and commodious manner of all inter-columns, which Vitru- vius calls eustylos." Amongst the ancients, the form of the Ionic profile appears to have been more positively deter- mined than that of any other order ; for in all the antiques at Rome, the temple of Concord excepted, it is exactly the same, and conformable to the description which Vitruvius has given of it. Modern artists have likewise been more unanimous in their opinions upon the subject ; all of them, ex- cepting Palladio and his imitators, having employed the dentil cornice, and the other parts of the profile, nearly as they are found in the Co- liseum, the temple of Fortune, and the theatre of Marcellus. In Palladio's works we meet with three different Ionic entablatures ; all of them very beautiful. The first is the true antique, which he has made use of at the palace of the Porti ; and in several doors and windows of the Thiene and Val- marana palaces, in Vicenza. The second is a very judicious imitation of the entablature in the temple of Concord, and is executed by him in the upper arcade of the basilica in the same city. The third, which is an invention of his own, being the same with that in his book, he has employed with some small dif- ference at the Chiericato palace, at the rotunda of Marchese Capra, and in various others of his build- ings in the Vicentine, or at Venice. Iron, the most useful and the most abundant of the metals, is found in various conditions of ore in most parts of the earth. Those ores which are principally worked for the production of the metal for manu- facturing purposes, are either oxides or carbonates, that is, they contain 232 the metal in a state of combination either with oxygen, or with oxygen and carbonic acid. The oxides are the best ores, and are found in vast beds in Sweden : the carbonates are inferior in point of strength and ductility, and therefore require an extensive reduction. They form the greater portion of the iron ores of Britain. The principal varieties of the ox- ides of iron are, the magnetic; the massive, found in the north of Eu- rope, and other parts of the world ; the micaceous, found in the lava of volcanoes, &c. ; and the red and brown haematites, found in Great Britain and Europe. The princi- pal varieties of the carbonates are, the massive, found in Great Britain and Ireland, Europe, and America ; and also the argillaceous, commonly known as clay iron-stone, found abundantly in beds and coal deposits in England, Wales, and Scotland. Besides the oxides and carbonates here enumerated, iron is found in large quantities in combination with sulphur; and the several compounds thus formed are known as pyrites, several varieties of which are found inNorway, Sweden, Germany, Ame- rica, and in many parts of England. Various artificial oxides of this metal are applied to medicine, dye- ing, and other purposes in the arts. The tenacity and strength of iron are impaired by its adulteration with foreign matters. Thus, of the oxides and carbonates, those are best in which the proportion of the metal is great. These qualities are further increased by fusion, and by the mechanical process of hammer- ing; and this fact points to the main distinction in the kinds of iron as applied for manufacturing purposes, viz. foundry iron, and forge iron. In the manufacture of iron, the first process is the reduction of the iron-stone or ore, technically called the mine, into the state of a metal. This is done by fusion in a furnace, with coke added to produce com- IRQ IRON. IRQ bustion, and limestone to act as a flux and assist the fusion of the ore. An artificial current of air is neces- sary to fuse the ore in these furnaces, which are therefore called blast fur- naces, and provided with tubes or tuyeres, through the tapered noz- zles of which, strong currents of air are delivered to the interior of the furnace, the required velocity of the blasts being sustained by steam or other power. Formerly the air was thus introduced at the same tempe- rature as that of the external atmo- sphere; but a plan has for many years been extensively adopted of previously heating the air for the blasts in separate vessels to a high temperature, by which the fusion of the ore is so powerfully assisted, that the saving of fuel in the furnace is many times greater than the quantity used for the preparatory heating of the air. Furnaces thus supplied are termed hot-blast fur- naces, and the product is called hot- blast iron, while that made with un- heated air is called cold-blast iron. The cost of the process of reduc- tion with the hot blast being so much less than of that with the cold blast, the ultimate value of the former is of course also partly de- pendent upon the quality of the produce. On this head much differ- ence of opinion has often been mani- fested, and with all the earnestness usually displayed in the advocacy of self-interest. The value of each process must, no doubt, arise from the completeness of the fusion pro- duced, and the separation effected between the iron and the impuri- ties combined with it in the ore. The hot-blast furnace effects the fusion more readily than the cold- blast, but admits a larger combina- tion of cinders with the ore ; and the advantage which has been taken of this facility of adulteration, in order to reduce the cost of pro- duction, has doubtless led to the introduction into the market of many qualities of hot -blast iron ~233~ which are inferior in strength to that made with the cold blast. The results of some of the most care- fully conducted experiments which have been made upon the strength of cast iron, and published in the 6th volume of the new series of 'Memoirs of the Literary and Phi- losophical Society of Manchester,' show that the transverse strength of the cold-blast iron tried was about 1\ per cent, greater than that of the hot-blast. The experi- ments here referred to were made upon rectangular bars 1 inch square, and 4 feet 6 inches long between the supports. The mean average breaking weights, placed at the middle of these bars, were R>s, In 21 samples of hot- blast iron .... 445-5714 In 22 samples of cold- blast iron .... 456-9090 The metal is allowed to flow from the furnace into rude channels formed on the surface of the ground, where it cools, and is taken up in the form of rough bars about 3 feet long, and each weighing nearly one cwt., which are technically called pigs. In the making of one ton of pig iron in Staffordshire, the fol- lowing materials are used : Coal, 2 tons 5 cwt. If coke is used instead of coal, 1 ton 17 cwt. Charred mine, or ore, 2 tons 5 cwt. to 2 tons 10 cwt. Limestone, 13 cwt. to 16 cwt. In the condition of pig iron, the metal forms the two staple de- scriptions of foundry iron and of forge iron, according to its quali- ties, and the proportion of carbon and oxygen which it contains. The several sorts of pig iron are consi- dered to be six in number, and are thus distinguished: Nos. 1, 2, and 3, foundry iron, of which the first two are never used for forge iron. No. 3, or dark grey, and also the fourth quality known as bright iron, are sometimes used for the foundry, IRQ IRON. IRQ and sometimes for the forge. The fifth and sixth sorts, known as mottled iron and white iron, are never used for the foundry. The order here observed corresponds with that of the proportion of car- bon and oxygen mixed with each kind of the iron, and also with that of the fluidity to which the metal is reducible : it also corresponds with the scale of their softness and toughness. Thus, No. 1 has the most carbon and oxygen, and the white iron has the least. No. 1 is the most fluid when melted, and the white iron the least so. Again, No. 1 is the softest, and the white iron the hardest ; and No 1 is the tough- est, while the white iron is the most brittle. But white iron is the best adapted for conversion into malleable iron, while Nos. 1 and 2, foundry iron, contain so large a pro- portion of carbon and oxygen, that they are totally unfit to be manu- factured into bars. The conversion of pig iron into malleable iron is effected by ex- tended processes, or subsequent to those by which the ore has been reduced to the form of pig. These processes are as follow : 1. Refining, 2. Puddling, ham- mering, and rolling, 3. Cutting up, piling, and rolling ; the 3rd series of operations being re- peated. The refining is for the purpose of separating a portion of the car- bon from the pig, and is performed in furnaces fitted with tuyeres for supplying a blast of air to the point of fusion. The metal run from the refining moulds is exceed- ingly brittle, and is then broken up into small pieces, and committed to the puddling or reverberatory furnace, to undergo a further puri- fication from the oxygen and car- bon which remain after the process of refining is accomplished. While in this furnace, the mass into which the pieces of refined metal become clustered is worked and stirred 234 about by the workman or puddler, until its thickness and tenacity are so far increased that it may be formed into lumps, or balls, which the puddler does with tools adapt- ed to the purpose. The hammering or shingling is performed upon the balls or blooms of puddled iron, with a very heavy hammer, worked by a cam-wheel, and has the effect of improving the solidity of the metal, and reducing the balls into an oblong form, by which they are better prepared for the action of the rollers. The rolls or rollers are fitted to- gether in pairs, and so formed in the periphery and arranged in size, that open spaces are formed be- tween them, through which the metal is passed while hot; and each succeeding pair of rollers present- ing a smaller space, the iron which is drawn through them becomes proportionately reduced in size and increased in length. The metal has thus been convert- ed from a hard brittle and readily fusible substance into a malleable bar, which is soft, tough, and very difficult of fusion ; but it is still far from fit for the smith's use, being to a great extent unsound in struc- ture, imperfect in tenacity, and irregular on the surface. The third set of processes is now commenced by cutting up the puddled bars into lengths with powerful shears. These lengths, of various dimensions, according to the sized bars to be produced, are carefully piled up and heated in another furnace similar to the pud- dling furnace, and which is called the balling furnace. In this the bars are simply heated to a degree which admits of their becoming welded together in the pile and adapted for reduction to the form of finished bars in the rolls. The rolling is the last operation in the making of bar-iron. The metal is drawn successively through a series of rollers, that is, between IRQ IRON. IRQ the peripheries of each pair of rollers, and thus gradually reduced in size, increased in length, and freed from the cinder and other impurities which remain after the puddle-rolling has been performed. The last set of operations is sometimes repeated in producing iron for superior purposes. The processes here described will give a general idea of the manufacture of iron from the native ore into the form of malleable bars; and it may be readily conceived how an exten- sion and variation of the process of rolling may be made to produce the several other forms in which this metal is prepared for the construc- tions of the engineer, the smith, and the machinist. As varieties of bar-iron may be mentioned, L, or augle-iron ; T, or tee-iron ; and H, or deck-beam iron ; which are prepared in several sizes, for the construction of roofs, iron vessels, &c. The malleable rails used for railways are also produced by an arrangement of rollers. Boiler-plate iron, sheet -iron, hoop-iron and nail rod-iron, are produced from the form of bars by the processes of heating and rolling, or hammering, as required. Boiler- plates require, according to the desired strength and size, several repetitions of heating, hammering, and rolling. Sheet-iron is distin- guished from boiler-plate by being thinner ; hoop-iron is rolled in the same manner as the bars, but be- tween rollers without grooves in their edges, the requisite thickness being effected by successive pass- ages through the rollers, which are brought nearer to each other at each process, by means of adjust- ing screws. Nail rod-iron is rolled in thin bars, which are, while still hot, passed between steel-cutters that slit them up into the form of small rods, which, although rough, are well fitted to be manufactured into nails. 235 A very useful form of sheet-iron, which should be noticed, is that of corrugated iron, which is produced by passing the sheets between rollers having grooved peripheries. By this form, the strength or stiff- ness of the sheet is so much in- creased, that sheet-iron thus formed may be usefully applied to a great variety of purposes, for which it is otherwise, owing to its thinness and pliability, utterly inadequate. By the combustion of charcoal with the coke, and the adaptation of a peculiar furnace in the process of smelting, Mr. Clay has succeeded in producing malleable iron direct from the ore, and thus materially reducing the series of processes here described. The results thus brought out are of a very interest- ing character, and promise to ac- quire a great practical value. Iron. Moses forbade the Hebrews the use of any stones to form the altar of the Lord, which had been in any manner wrought with iron ; as if iron communicated pollution. He says, the stones of Palestine are of iron, that is, of hardness equal to iron, or, being smelted, they yielded iron. "An iron yoke" is a hard and insupportable dominion. "Iron sharpeneth iron," says the Wise Man; "so a man sharpeneth the countenance of his friend:" the pre- sence of a friend gives us more confidence and assurance. God threatens his ungrateful and perfi- dious people with making the heavens iron, and the earth brass ; that is, to make the earth barren, and the air to produce no rain. Chariots of iron are chariots armed with iron, with spikes and scythes. Iron-stone, iron-bound stone, in colour of a blueish gray, and very hard to work: it contains but very little iron Iron-stone has the appearance of rusty black shale, and, when laid together in large heaps, is so com- bustible that it ignites, leaving a a calx of 60 per cent, of iron. It IRQ ITALIAN ARCHITECTURE. ITA abounds in Scotland. Common iron-stone is also very abundant in connection with coal, and in former times formed the principal supply, which induced the founda- tion of the Carron Iron Works. Iron wood is imported from the Bra- zils, the East and West Indies, and other countries, in square and round logs, 6 to 9 inches and up- wards through. Its colours are very dark browns and reds : some- times it is streaked, and generally straight-grained: used principally for ramrods, turnery, &c., and is extremely hard. Iron yellow, jaune de fer, or jaune de Mars, &c., is a bright iron ochre, prepared artificially, of the nature of sienna earth. The colours of iron exist in endless variety in na- ture, and are capable of the same variation by art, from sienna yel- low, through orange and red, to purple, brown, and black, among which are useful and valuable dis- tinctions, which are brighter and purer than native ochres. Isochronism, in mechanics, the per- forming of several things in equal times; such as the vibrations of the pendulum Isodomon, a building every way straight Isodomos, in Greek architecture, ma- sonry cut and squared to the same height, so that, when laid, the courses were all regular and equal Isometrical, projections and drawings so termed Isoperimetrical, in geometry, such figures as have equal perimeters or circumferences Isosceles, in geometry, a triangle that has only two sides equal Isothermal, in chemistry, equal heat Italian Architecture, a style now much appreciated not only in Italy, but in England and France, was first in- troduced at the revival of classical architecture, and was subsequently much improved and adapted to modern refinement. The architec- ture of Venice, Florence, Genoa, "236~~ Rome, and Sicily, afford to the architect a complete library of ex- amples, by the possession of the several works published of the ar- chitecture of the palaces and man- sions of these cities. Italian Architecture, Roman. Respect- ing buildings originally erected in Italy Mr. Jos. Gwilt has thus written : The Romans followed the Greeks in the general form of their temples, but added to their splendour by a greater richness of detail, and the employment of other orders. For the simple steps on which the Greek temple was elevated, they substitu- ted pedestals, and added a base to the Doric order. The climate pre- scribed a more elevated pediment ; but the luxury of the people was the cause of the preference given to the richer orders of architecture. TEMPLES, BRIDGES, AQUEDUCTS, COLUMNS, THEATRES, &C. The chief temples of Rome were the Capitol, built on the Tar- peian or Capitoline mount, by Tar- quinius Superbus. (See Capito- lium.} No traces of it at present remain. The edifice of the Capitol was about 200 feet square, and con- tained three temples, consecrated to Jupiter, Minerva, and Juno. On the Capitol were also the temples of Terminus and Jupiter Feretrius, and the cottage of Romulus. The Pantheon, built by Agrippa, the son-in-law of Augustus, and dedicated to Mars and Venus, or more probably, from its name, to all the gods. Pope Boniface IV. consecrated it in honour of the Vir- gin Mary and All Saints, A.D. 607. It is now generally known by the name of the ' Rotonda ;' its dia- meter between the axes of the columns is 147 feet: like most of the ancient buildings, it has fallen a prey to the spoiler. The Balda- chino in St. Peter's is indebted for its materials to the Pantheon of Agrippa. The temple of Apollo, on the Palatine hill, was built by Augus- ITA ITALIAN BUILDINGS. ITA tus : a temple of Diana stood on the Aventine. The temple of Janus was sup- posed to have been built by Romu- lus ; that of Romulus by Papirius. Of those to the Sun and Moon, Fortuna Virilis, Vesta, Minerva Medica, Neptune, Antoninus and Faustina, Concord, Jupiter Stator, and most particularly of the tem- ple of Peace, considerable remains are fortunately still in being. The three magnificent arches now stand- ing of that last named, though of themselves majestic, convey but a faint idea of its pristine splendour. Of the temple of Jupiter Stator, whose columns, capitals, and en- tablatures were a perfect example of the Corinthian order, only three columns are in existence. The re- mains of the temples of Antoninus Pius, Claudius, Hercules, Jupiter Tonans, Isis, Romulus, and Venus and Cupid, are still interesting. No vestiges exist of the temples dedicated to Saturn, Juno, Mars bis Ultor, in the forum of Augus- tus, nor of numberless others that adorned the city. The temples of Balbec and Pal- myra are the last of the ancient Roman works that can lay claim to the appellation of classic architec- ture. In these, invention seems to have found its limits. The repro- duction and new adaptation of their detail was all that has been done by following artists. The Romans, not content with the quadrilateral temple, made use of the circular form, as in the Pan- theon, temple of Vesta, and others at Rome, and that of the Sibyl at Tivoli. Except their theatres, and the little work generally known by the name of the Lantern of Demo- sthenes, the Greeks have left no buildings on a circular plan. After the time of Diocletian, a new style prevailed in Italy. The basilicse of Constantine, as they ex- isted previous to their restoration, and, in short, almost all the first 237 Christian churches, were built out of the materials which the old tem- ples afforded in abundance. The basilica of S. Paolo fuori le mura still contains a large portion of the columns which had originally be- longed to the mausoleum of Adrian. The style of these basilicse may with propriety be termed Roman- Gothic. This was followed by the Greek-Gothic, of which examples may be found in most of the cities of Italy, as in St. Mark at Venice, the cathedral at Pisa, (built by Buschetto da Dulichio, a Greek ar- chitect of the llth century,) and in the baptistery and leaning cam- panile of the same city : specimens abound also in Bologna, Sienna, Venice, Viterbo, Rome, &c. They are chiefly the works of Nicola da Pisa and his scholars. At the time that the famous ca- thedral of Milan, the perfection of the Lombard-Gothic style, was in hand, Brunellesrchi was advancing a step further, and had begun the restoration of classical architecture in the great cupola of Sta Maria del Fiore at Florence ; his prototype seeming to have been the temple of Minerva Medica, to which his work has sufficient resemblance to justify the allusion to it. He suc- ceeded in his enterprise, and thus gave a death-blow to the Italian- Gothic of all sorts. L. B. Alberti, Bramante, and Fra. Giocondo re- stored the use of the orders ; Michael Angelo, Raphael, Sangallo, Palladio, and Scamozzi completedthe change; the church of St. Peter rose, and every little city began to provide itself with a Duomo. The fora of the ancients were large squares surrounded by por ticoes, which were applied to dif- ferent purposes. Some parts of them answered for market-places, other parts for the public meetings of the inhabitants, still other parts for courts of justice. The forum also occasionally afforded accom- modation for the shows of gladi ITA ITALIAN BUILDINGS. ITA ators. Rome contained seventeen fora, of which fourteen were used for the show and sale of goods, provisions, and merchandise, and were called Fora Venalia ; the other three were appropriated for civil and judicial proceedings, and hence called Fora Civilia et Judicialia. Of the latter sort was the forum of Trajan. The forum of Julius Caesar was far more splendid than the Forum Romanum : it cost upwards of 800,000 sterling, and stood in the neighbourhood of the Campo Vaccino, to the east of the temples of Peace and of Antoninus and Faustina. In the vicinity of that last named was the forum of Augustus : the temple of Mars bis Ultor decora- ted the centre of it. The forum of Nerva, called also the Forum Transitorium, begun by Domitian, was decorated by Alex- ander Severus with colossal statues of the emperors, some of which w r ere equestrian. Parts of this forum are still in tolerable preser- vation. The forum of Trajan, which has lately been accurately traced by means of very extensive excavations, and the demolition of a great num- ber of houses, was by far the most magnificent. The Trajan column formed one of its ornaments : the architect was Apollodorus, and its situation was between the forum of Nerva and the Capitol. The basilica (a term now applied to the cathedrals of Rome) was originally a court of justice. Like the forum, it was furnished with shops for the merchants and bank- ers. In the place called the Comi- tium were four basilicas, viz. that of Paulus, the Basilica Opimia, Julia (built by Vitruvius), and Por- tia : besides these, the most impor- tant were those of Sicinius, Sem- pronius, Caius and Lucius, Antoni- nus Pius, and the Basilica Argen- tariorum, or of the goldsmiths. 238 Some of less consideration stood in the vicinity of the Forum Ro- manum. The modern halls of Italy in some respects answer the purpose of the ancient basilica. Those most worthy of notice are at Venice, Vicenza, Padua, and Brescia. Near the Tarpeian rock stood the famous prison built by Ancus Martius, which was afterwards cal- led Tulliana, from the additions thereto by Servius Tullius. The Curia Hostilia, where the senate frequently met, was the Comitium : at its entrance, close to the tem- ple of Saturn, was the Milliarium Aureum, the central point from which all the roads to the different provinces diverged, and near to which ran the gallery constructed by Caligula, which joined the Pa- latine and Capitoline hills. It was constructed with eighty columns of white marble. The porticoes of Pompey, Au- gustus, Domitian, and Nero were the most celebrated of Rome. The first -named afforded a refreshing retreat from the sun's rays. The portico of Augustus was construct- ed with columns of African mar- ble, and was ornamented with fifty statues of the Danaides. Those of Nero, three in number, each three miles in length, were called Milliariae, on account of their extraordinary dimensions, forming a part of his palace. The pyramidal form was gene- rally applied to tombs. In the he- roic ages, a cone of earth, whose base was of considerable extent, covered the ashes of the person to be commemorated. This was the practice of the early ages. Men were, however, desirous of triumph- ing over death, and the Pyramids, as well as numberless other monu- ments, the names of whose authors are now lost, have proved the vanity of their desires : the memory of man must depend upon " deeds done in the flesh." ITA ITALIAN BUILDINGS. ITA The pyramid of Caius Cestius, a trifle compared with those of Egypt, is yet enormous, considering the in- dividual to whose memory it was erected. The tower of Cecilia Me- tella, called the Capo di Bove, on the Appian way, is a beautiful speci- men of art. The Appian, Flami- nian, and Latin ways exhibit num- berless sepulchres of an interest- ing nature. Those which are found with the inscription D. M., or Diis Manibus, contain the ashes of the persons whose names they bear; but the others are mostly cenotaphs, the bodies having been deposited elsewhere. Triumphal arches may be reck- oned among the luxuries of the Romans. Nothing which could tend to perpetuate the fame of the con- queror was omitted in the design. Some of them were with two, some with three passages. The richest were on the Triumphal way. Those which also served as gates generally consisted of two openings, one for the carriages passing out of, the other for carriages passing into the city. With the Greeks, a trophy erected on the field of battle was held of equal importance with the triumphal arch of the Romans, and a breach was sometimes made in the walls to admit the entry of the conqueror. The Roman senate received the conqueror at the Porta Capena, near the Tiber, which was the en- trance to the city from the Appian way. The arch of Augustus at Rimini has but a single passage, about 33 feet wide : it was crowned with a pediment, contrary to the usual practice. This was a beautiful specimen, but it is much mutilated. That called the arch of the Gold- smiths at Rome is a curious example. It is very small, with a single open- ing, whose crowning is a flat lintel. The arch of Augustus at Susa, a small townjust on the Italian side of Mount Cenis, is extremely elegant. 239 Those of Aurelian and Janus are more singular than beautiful. The arch of Pola in I stria is only curious on account of its affording a justification of the use of coupled columns, were the authority of the ancients necessary for the purpose : it was erected by Salvia Posthuma in honour of Sergius Lepidus and his two brothers. The arch of Trajan at Ancona is still in tolerable preservation. It has long since been stripped of its bronze ornaments, but their absence has not impaired its elegant pro- portions. The arches of Titus at Rome and Trajan at Benevento bear con- siderable resemblance to each other. That of Gavius at Verona, called ' del Castel Vecchio,' no longer ex- ists. The precepts of Vitruvius have been confronted with his prac- tice in this arch ; but Vitruvius Cerdo, not Vitruvius Pollio, was the architect. The arches of Septimius Severus and of Constantine are with three openings. The latter is decorated with ornaments shamefully stripped off from the arch of Trajan, which, from their absurd application, ren- der the barbarism of the robber more disgusting. Rome formerly contained eight bridges. The Pons Sublicius, built by Ancus Martius near the Tiber, was of timber, so framed as to re- quire no iron bolts or ties for its security. It stood at the foot of the Aventine, and was that which Horatius Codes defended. It was replaced by one of stone by ^Emilius Lepidus, and then had the name of jEnrilianus. Tiberius afterwards repaired it. Finally, Antoninus Pius rebuilt it of marble, whence it obtained the name of Marmoratus. The Pons Triumphalis, near the Vatican, is in ruins : few vestiges of it exist. Those who triumphed passed over this bridge in their way to the Capitol. The Pons Fabricius led to an ITA ITALIAN BUILDINGS. ITA island in the Tiber : it is now called Quattro Capi. That which led from the island to the right bank of the river was called Pons Cestius or Esquilinus : it was rebuilt during the reigns of the emperors Valen- tinian, Valens, and Gratian. Pons Janiculi, so called because it led to the Janiculum, and now known by the name of Ponte Sisto, (from having been restored by Six- tus IV.) was of marble, and built by Antoninus Pius. Pons ^Elius, built by ^Elius Adri- anus, is still in existence. It is situated close to the mausoleum of Adrian. This having changed its name into that of Castel St. Angelo, the bridge has acquired a corre- sponding appellation. The Pons Mirvius, now Ponte Molle, is a little way out of the city, on the road to Florence. On this bridge Cicero arrested the ambas- sadors of the Allobroges, and in its vicinity Constantine defeated Max- entius. Pons Senatorius, or Palatinus, is partly remaining, close to the Pa- tine mount. Ponte Salaro is over the Teve- rone, about three miles from Rome. The spans of the arches are gene- rally but small; yet there are some few magnificent exceptions, as in the Ponte del Castel Vecchio at Verona. This consists of three arches, the largest of which is 170 feet span ; its two other arches are smaller: they diminish from the city, the left bank of the river being considerably lower than the right. The bridge built by Augustus over the Nar, near Narni, on the Flami- nian way, was a single arch of 150 feet span. In the later times of the city, bridges were decorated with trophies, colossal statues, triumphal arches, and the like. Such was the case with the Pons Julius and the bridge of Augustus at Rimini. The country round Rome is co- vered with the remains of aque- ducts, some of w r hich conveyed the 240 water to Rome from a distance of more than 60 miles. The first aqueduct (Aqua Appia) was built, according to Diodorus, by Appius Claudius, in the year of the city 441. The water which it supplied was collected from the neighbourhood of Frascati, and its summit was about 100 feet above the level of Rome. The second (Anio Vetus) was begun forty years after the last- named by M. Curius Dentatus, and finished by Fulvius Flaccus : it was supplied from the country beyond Tivoli. Near Vicovaro it is cut through a rock upwards of a mile in length, in which part it is 5 feet high and 4 feet wide. The water of this aqueduct was not good, and therefore only used for the most ordinary purposes. The third (Aqua Martia) was supplied from a fountain at the ex- tremity of the mountains of the Peligni. The water entered the city by the Esquiline gate. This aqueduct was the work of Quintus Martius. The fourth (Aqua Tepula) was supplied from the vicinity of Fras- cati. The fifth (Aqua Julia) was about six miles long, and entered the city near the Porta Esquilina. The sixth (Aqua Virginis) was constructed by Agrippa thirteen years after that immediately pre- ceding. Its summit, in the terri- tory of Tusculum, was about eight miles from Rome, which it entered by the Pincian gate. This water still bears its ancient appellation, being called Aqua Vergine. The seventh (Aqua Alsietina, called also Augusta, from the use to which Augustus intended to ap- ply it for supplying his Naumachia,) was brought from the lake whose name it bears. The eighth (Aqua Claudia), whose summit is about forty miles from Rome, was begun by Caligula, and completed by Claudius. It enters ITA ITALIAN BUILDINGS. ITA the city at the Porta Nevia, near the Esquiline mount. The quality of the water which this aqueduct supplies is better than that of any of the others. The ninth (Anio novus, to dis- tinguish it from the second-named water,) was begun and finished by the same persons as the last men- tioned. It is the water of the Anio, which, being exceedingly thick and muddy after the rains, is conveyed into a large resei-voir at some little distance from Rome, to allow the mud to subside. The Aqua Felice is modern, and was erected by Sixtus V. in 1581. The popes have, from time to time, been at considerable pains and expense in repairing and re- newing the aqueducts; but the quantity of water delivered is con- stantly diminishing. In the ancient city, the total sum of the areas of the different pipes (which were about an inch in diameter) through which the above immense quantity of water was delivered, amounted to about 14,900 superficial inches; but the supply was subsequently reduced to 1170. The waters were collected in re- servoirs called castella, and thence were conveyed through the city in leaden pipes. The keepers of the reservoirs were called castellani. Agrippa alone built thirty of these reservoirs during his aedileship. There are five modern ones now standing in the city: one at the Porta Maggiore, Castello dell' Ac- qua Giulia, dell' Acqua Felice, dell' Acqua Paolina, and that called the Fountain of Trevi. In later times, the bath was al- ways used by the Romans before they went to their supper. The rich generally had hot and cold baths in their own houses ; and it was not till the time of Augustus that the baths assumed an air of grandeur and magnificence. They were called Thermae, that is, hot baths, though the same pile of 241 building always contained cold well as hot baths. Different au- thors have reckoned as many as 800 public baths in Rome. The chief were those of Agrippa, Nero, Titus, Domitian, Caracalla, Anto- ninus, and Diocletian. Their ves- tiges indicate the amazing magnifi cence of the age in which they were erected. The pavements were mosaic, the vaulted ceilings were gilt and painted, and the walls in- crusted with the richest marbles. Some of the finest and best pre- served remains of ancient Greek sculpture have been restored to light from these edifices. It was from these that Raphael took the hint for his fantastic decorations of the Vatican, and the first restorers of art drew their resources. Dramatic entertainmentswere first introduced at Rome in the 391st year of the city. In ancient times the people stood during the per- formance. For a considerable pe- riod the theatres were mere tempo- rary buildings constructed of wood. The most splendid of these upon record was that of Marcus ./Emilius Scaurus : it was magnificently de- corated, and was capable of con- taining 80,000 persons. It was in Pompey's second con- sulship that the first stone theatre was erected : this accommodated 40,000 spectators. To avoid the animadversions of the censors, (for the magistracy did not yet sanction theatrical exhibitions,) he dedicated it to Venus. Several other theatres afterwards arose: that of Marcellus can still be distinctly traced, and part of the circular facade, in tolerable pre- servation, is singularly elegant. The theatre of Balbus was also of considerable celebrity. The theatres were open at top to the heavens ; but in times of rain or excessive heat, means were pro- vided for covering them with a species of cloth awning, by which the inclemency of the weather might ITA ITALIAN BUILDINGS. ITA be wholly or partially excluded. Their general form on the plan was that of the letter D. The seats (gradus) rose behind each other, like steps. The front row was as- signed for the use of the senators and the ambassadors of foreign states. Fourteen rows behind this were reserved for the equites, and the rest were open for the public generally. The beautiful Olympic theatre, by Palladio, at Vicenza, was formed on the model of the ancient Roman theatres, and gives one an excellent idea of their effect. Like the theatres, amphitheatres were at first constructed of wood, and were only temporary. The fii st amphitheatre of stone was built by Statilius Taurus, at the desire of Augustus. Of all the monuments of anti- quity, none is capable of creating such sublime sensations in the mind as the stupendous amphitheatre generally called the Coliseum. It was commenced in the time of Vespasian, and completed by Titus. The plan of it is oval, and its ac- commodation was for 87,000 spec- tators, who could enjoy the exhibi- tions therein without crowding each other. That part in which the gladiators fought was at the bottom, and was called the arena, from being usually covered with sand to absorb the blood spilt in the savage conflicts for which it was used. The arena was encircled by a wall, called the podium, which projected at top. Thr podium was fifteen or sixteen feet in height : immediately round it sat the senators and foreign am- bassadors. As in the theatres, the seats rose at the back of each other: fourteen rows in the rear of the podium being allotted to the equites, and the remainder to the public generally, w r ho sat on the bare stone; but cushions were pro- vided for the senators and equites. Though open to the sky, the build- ing was occasionally covered by 242 means similar to those used in the theatres. The amphitheatre at Verona is still in excellent preservation. The Naumachise, or buildings for the exhibition of sham naval com- bats, were somewhat similar on their plans to the circi, to which purpose also sometimes these latter were appropriated. The amphithe- atres were, moreover, occasionally used for the same sort of display. Those of Augustus and .Domitian were the most magnificent. The circus was a long narrow building, whose length to itsbreadth was generally as five to one : it was divided down the centre by an or- namented barrier, called the spina. These buildings were used for the celebration of games, racing, &c. ; and sometimes also for making ha- rangues to the people. The first circus of stone is attri- buted to Tarquin, and was situated between the Palatine and Aventine mounts. The Circus Maximus was much improved and altered by Julius Caesar, who supplied it with water for the purpose of occasionally using it as a naumachia. Augustus made great additions to it, decorating it with the famous obelisk which now stands in the Piazza del Popolo, where it was placed by Fontana in the year 1589, during the pontificate of Sixtus V. Being much dilapidated, it was repaired under Antoninus, and afterwards embellished with a second obelisk, which has found a resting-place in front of the church of St. John Lateran, where it was set up by the same Fontana. No vestiges of this circus remain. The circus of Flaminius, in the vicinity of the Pantheon of Agrippa, was of considerable dimensions, and very magnificent. The Circus Agonalis occupied the site of what is now known by the name of the Piazza Navona. The circus of Nero, upon a part ITA ITALIAN BUILDINGS. ITA whereof some portion of the basilica of St. Peter is seated, was a splen- did building. The obelisk now standing in the open circular piazza before St. Peter's belonged to this circus. Those of Florus, Antoninus, and Aurelian, are no longer even in ruins ; but that of Caracalla is suf- ficiently perfect to trace its plan and distribution. It was 738 feet in length. The streets, in the time of Au- gustus, were narrow and irregular. After the great fire in Nero's reign, the city was rebuilt with greater splendour. The streets were then set out straight, and considerably broader than before. Those houses wherein several families dwelt were called insula. Domus w r as the ex- pression of a house occupied by one family only. We know little of the form of the Roman houses, though Vitruvius has described at sufficient length the different apartments of which they consisted. The small houses discovered in the ruins of Pompeii can bear but little if any resemblance to the houses of the opulent inhabitants of Rome. The most celebrated were those of the Gordians, P. Valerius Publicola, Caesar, Sallust, Mecaenas, Cicero, Verres, Augustus, and Lucullus. The Domus aurea of Nero was probably the most magnificent in Rome. The villa of Adrian, at Tivoli, was so extensive, that it al- most deserved the name of a city. Immense ruins of the palaces of the Caesars are still to be seen. Rome was decorated with num- berless pillars. The most remark- able are fortunately in an excellent state of preservation, namely, those of Trajan and Antoninus. The column of Trajan stood in that emperor's forum : it is about 12 feet in diameter at its base, and (including the pedestal) is about 125 feet in height. The ascent to the gallery on the top of the abacus of its capital is by 185 steps, each 2 feet 9 inches long, winding round the column, and lighted by 40 open- ings. A colossal statue of Trajan formerly crowned the top ; but St. Peter has long since deposed the emperor. The column of Antoninus is 176 feet high, its number of steps 106, with 56 openings for the admission of light. Sixtus V. caused its pe- destal to be cased, when, in 1589, the pillar was under repair. It was this pontiff who elevated St. Peter to his situation, as well on this as on the Trajan column. The great sewers of Rome are reputed to have been the work of Tarquinius Priscus. The Cloaca Maxima, which still carries some of the filth and waste water of Rome into the Tiber, was the work of Tarquinius Superbus. The public ways were not only some of the most stupendous, but also the most useful of the Roman works. The first road which the Romans paved was the Via Appia, so called because it was executed by order of Appius Claudius. He carried it as far as Capua, whence it was af- terwards continued to Brundusium in all, a distance of 350 miles. It is still entire in many places, though more than twenty centuries have elapsed since its construction. It was properly called ' Regina Viarum.' The Via Numicia led to Brindis (Brundusium) ; the Via Flaminia to Rimini and Aquileia; the Via Aurelia was along the coast of Etruria ; the Via Cassia ran to Mo- dena, between the Flaminian and Aurelian ways ; the Via ^Emilia extended from Rimini to Piacenza, The smaller ways were, the Via Praenestina to Palestrina (the an- cient Praeneste) ; Tiburtina to Ti- voli; OstiensistoOstia; Laurentina to Laurentum, south of Ostia ; Sa- laria, &c. The cross-roads were called Diverticula. ITA ITALIAN ARCHITECTURE. IVO Italian architecture comprises so many diversities that it is hardly possible to affix to it any thing like a precise character, except by limit- ing it to a particular epoch or school, or to one special class of . buildings ; and even then the ex- ceptions may be more numerous than the examples referred to as a standard. With many vices and defects, it possesses many excel- lences and recommendations, and a variety of resources, which render it capable of being turned to far greater account than hitherto has been done. But if on the one hand it affords much scope to the architect, it calls on the other for the exercise of discriminating taste ; one that not only rejects what is positively bad, but is capable of re-combining all the better ele- ments of the style, so as to impart to them originality and freshness, without forfeiting what is valuable in and characteristic of the style itself; so that, instead of appearing contrary to its genius, the novel forms and effects that may be pro- duced shall seem to be beauties, which have merely been lying la- tent, and waiting for a discoverer to bring them to light. A style is to be judged of, not only retro- spectively by what it has produced, but prospectively also, according to what it is capable of supplying. Nevertheless, so far from being at all encouraged, such view of the subject is kept out of sight as much as possible ; and precedent is al- JAC JACK, an instrument for raising a heavy weight through a short dis- tance ; it consists of a strong piece of wood, with an iron rack which is moved, by wheels fixed inside the wood, from a handle outside Jack, in navigation, a flag or colour ; a small union flag Jak wood, a native of India, is im- ported in logs from 3 ft. to 5 ft. 244 lowed to usurp such sway, that any departure from it, no matter in what spirit, is liable to be con- founded with and reprobated as capricious innovation, although the one proceeds quite in an opposite direction to the other. Italian church (the), in the front or facade, is never true to the internal structure ; it is always divided into two apparent stories, by two heights of pillars, or pilasters, and by win- dows, or alcoves ; but the greater number of churches in Rome have the outward look of large dwelling- houses, a highly ornamented centre and wings less so, with two or three ranges of windows, not differing from a habitable house Ivory is first mentioned in the reign of Solomon : ivory was used in de- corating those boxes of perfumes whose odours were employed to exhilarate the king's spirits. It is probable that Solomon, who traded in India, first brought thence ele- phants and ivory into Judea. Ca- binets and wardrobes were orna- mented with ivory by marquetry- work. These were called ' houses of ivory/ "Eighty more chests of ivory, for your use and pleasure," are enumerated in the letter which accompanied the very remarkable tribute of the Ethiopian queen, Candace, to Alexander the Great. Ivory-black and bone-black, ivory and bone charred to blackness by strong heat in closed vessels ; if skilfully prepared, they are eligible for oil and water painting JAM diameter; the grain is coarse and crooked: used in cabinet-work, marquetry, and turning, and also for brush-backs Jamb, in building, a supporter on either side, as the posts of a door Jambs, the side pieces of any open- ing in a wall, which bear the piece that discharges the superincumbent weight of such wall JAN JUSTICE, COURTS OF. JUS Janta, a machine extensively used in Bengal and other parts of India, to raise water for the irrigation of land. It consists of a hollow trough of wood, about 15 ft. long, 6 inches wide, and 10 inches deep, and is placed on a horizontal heara lying on bamboos fixed in the bank of a pond or river : one end of the trough rests upon the bank, where a gutter is prepared to carry off the water, and the other end is dipped in the water by a man standing on a stage, plunging it in with his foot. Janua, among the Romans, the street- door of a private house Japanning, the art of painting and varnishing on wood, leather, metal* or paper, after the manner of the Japanese Jaune Minerale. This pigment is a chromate of lead, prepared in Paris. The chrome-yellows have obtained other names from places or per- sons from whence they have been brought, or by whom they have been prepared, such as Jaune de Cologne, &c. Jesse (the root of), a term applica- ble to the genealogy of Christ, as affording subjects for the painter, sculptor, or embroiderer Jet d'Eau, a French expression, sig- nifying a fountain that throws up water to some height in the air Jetty, a part of a building that pro- jects beyond the rest, and over- hangs the wall below, as the upper stories of timber-houses, bay-win- dows, pent-houses, small turrets at the corners, &c. Jetty, a projecting erection into the sea, partaking something of a pier, mostly constructed of timber, with open spaces for the sea to play Jewry, a district, street, or place or locality, in which Jews formerly resided Jib, the overhanging part of a crane, or a triangular frame with a pulley at the end, for the chain to pass over which leads from the crane Jib, in navigation, the foremost sail of a ship 245 Jib-boom, a spar run out from the bowsprit Jigger, a machine consisting of a piece of rope about 5 feet long, with a block at one end and a sheaf at the Other, used to hold on the cable when it is heaved into the ship by the revolution of the windlass Jigging, in Cornwall, a method of dressing the smaller copper and lead ores, by the motion of a wire sieve in a kieve or vat of water Joggle, a term in the business of ma- sonry, the art of joining and fitting the stones together Joinery, the art of joining, compre- hends all the fixed wood-work in- tended for ornament or convenience in the interior of a house Joint, the interstices between the stones or bricks in masonry and brick-work are so called Joists, in carpentry, the secondary beams of a floor; those pieces of timber framed into girders and summers, on which the boards of the floor are laid Journal, a bearing of a shaft when it is between the points where the powers and resistance are applied ; a bearing subject to torsion Jube, anciently, the rood-loft or gal- lery over the entrance into the choir of a cathedral or church Jugumentum, the lentil of a door Jumper, a long borer used by one person Jumper wood, an aromatic and very durable kind of wood Junk -ring, a ring fitting a groove round a piston, to make it steam- tight. The ring is turned accu- rately to the diameter of the cylin- der, and slightly hammered all round on the inside to increase its elasticity ; it is then cut open, and put in its place : springs are some- times used for pressing it outward. Justice (Courts of). These places (according to Palladio) were an- ciently called basilicas, where the judges attended to administer jus- tice, and where, sometimes, great and important affairs were trans- KAG KEY-STONE. KIN acted : whence we read, that the tribunes of the people caused to be taken away a column that inter- rupted their benches, from the Ba- KAG KAGE, anciently applied to chantry chapels enclosed with lattices or screen-work Kaolin, aluminous earth ; the porce- lain earth of the Chinese Kazer, in Cornwall, a sieve Kedging, in navigation, a term used when a vessel is brought up or down a narrow river or over a bar Keel, false, in ship-building, a strong thick piece of timber bolted to the bottom of the real keel, which is very useful in preserving it Keels, in navigation, small vessels that carry coals down the river Tyne Keelson, in ship-building, the piece of timber attached to a ship's keel Keep, the chief tower or dungeon of a Norman castle Keeping, in painting, is the observance of a due proportion in the general light and colouring of a picture, so that no part be too vivid or more glaring than another, but a proper harmony and gradation be evident in the whole performance Kept down is a term implying gloomi- ness of tint, or an object so shaded with fuscous colour that its form can scarcely be determined ; which object is not intended to be seen by the spectator until he has re- gularly observed all the other parts of the painting, but which is ne- cessary to the composition Kermes lake, an ancient pigment, per- haps the earliest of the European lakes : the name is probably derived from the alkermes of the Arabians, from Kerman, the ancient Carma- nia, on the borders of Persia Kerned, a term applied to a heap of mundic or copper ore hardened by lying exposed to the sun Ketch, in navigation, a vessel with with masts and sails Kevels, in ship-building, answer the 246 silica Portia ; which was at Rome, near the temple of Romulus and Remus, and is now the church of St. Cosmus and Damianus. KIN purpose of timber-heads, and are sometimes fixed to the spirketing on the quarter-deck, when the tim- ber-heads are deficient Key, a term applied to a painting when one object, generally the prin- cipal one, is so worked up to its proper tone, strength of colour, &c., that the painter is compelled to finish the whole piece in a mas- terly manner : this is said to have been the practice of Titian Key-grooving machine, a machine for cutting the grooves or key-ways in the boss of a wheel to be fixed on a shaft Key-screw, a lever used for turning screws Key-stone, the stone in an arch which is equally distant from its springing extremities. In a circular arch there will be two key-stones, one at the summit and the other at the bottom thereof: in semi-circular, semi-elliptical arches, &c., it is the highest stone, frequently sculp- tured on the face and return sides. Kiabooca wood, or Amboyna wood, imported from Sincapore, is very ornamental, and is used for small boxes and writing-desks, and other ornamental works Kibbal, a bucket in which ore is raised from the mines Kieve, a vat or large iron-bound tub for washing of ores Kilkenny marble, a fine black marble, full of shells and corolloid bodies Killas, a clay slate occurring in dif- ferent parts of a mine Kil/epe, anciently a gutter, groove, or channel Kilogramme (pronounced Kilo), a French weight, equivalent to 2 fts. 3 oz. 5 drs. 13 grs. avoirdupois King -at -arms, in heraldry, a principal KIN KYANIZING. KYA officer at arms, of whom there are three : Garter, Norroy, ajid Claren- cieux King-post, the middle post of a roof, standing in the tie-beam and reach- ing up to the ridge ; it is often formed into an octagonal column with capital and base, and small struts or braces, which are slightly curved, spreading from it above the capital to some other timbers Kingston's valve, a flat valve form- ing the outlet of the blow-off pipe of a marine engine : it opens from the side of the vessel by turning a screw King wood, called also violet wood, is imported from the Brazils : it has violet-streaked tints, and is used in turnery and small cabinet-work Kirk, church, a term still used in Scotland, formerly so in England Klinometer, or Climometer, an instru- ment contrived to measure the in- clinations of stratified rocks, the declivity of mountains, and the dip of mineral strata Knee, a term sometimes used for the return of the drip-stone at the spring of an arch Knees, in ship - building, are the crooked pieces of oak timber, or iron, which secure the beams to the side of the ship Knight-heads or bollard-timbers, the timbers on each side nearest the stern, and continued high enough to secure the bowsprit Knits, small particles of lead ore Knockings, lead ore with spar, as cut from the veins Knot or Knob, a boss; a round bunch of leaves or flowers, or other orna- ment of a similar kind Knuckle -timber, the foremost top timber in the ship that forms the buck-head; the timbers abaft it, as far as the angle is continued, may be called knuckle-timbers Krems, Crems, or Kremnitz white, a white carbonate of lead, named from Crems or Krems, in Austria ; also called Vienna white Kyanizing and Burnettizing. Kyan- 247 izing is a simple process by means of w r hich timber, canvas, and cord- age, &c. may be preserved from the effect of dry-rot, and seasoned in a very short time. It was in- vented by Mr. Kyan, who obtained a patent for it, which was purchased by a company called the ' Anti- Dry-rot Company,' constituted and empowered by Act of Parliament. The timber is prepared as fol- lows : a wooden tank is put together so that no metal of any kind can come in contact with the solution when the tank is charged. The solution consists of corrosive sublimate and water, in the pro- portion of 1 tb. of corrosive subli- mate to 10 gallons of water as a maximum strength, and 1 ft. to 15 gallons as a minimum, according to the porosity or absorption of the timber subjected to the process. Oak and fir timber absorb nearly alike, but the domestic woods, such as beech, poplar, elm, &c. are more porous. An hydrometer will mark accu- rately the strength of the solution, waterbeing (vide diagram) ; then, when the hydrometer sinks to 6, - Water. lib. of cor. sub. to 15 gal. of water. 10 _ - 1 lb. to 10 gal. do. -- 1 ft. to 5 gal. do. KYA KYANIZING AND BURNETTIZING. KYA it denotes that the solution con- tains lib. of sublimate to 15 gallons of water ; when it rises to 1 7, 1 ft. of sublimate to 5 gallons. As a general rule, when it stands midway between 5 and 10, the solution will be the proper strength. The corrosive sublimate will dis- solve best in tepid water. The period required for satu- rating timber depends on its thick- ness : 24 hours are required for each inch in thickness, for boards and small timbers. The timbers, after saturation, should be placed under a shed or cover from the sun and rain, to dry gradually. In about 14 days, deals andtimber not exceeding 3 inches in thickness will be perfectly dry and seasoned, and fit for use. Large timbers will require a proportionate time, ac- cording to their thickness. The solution may be used ad infinitum, as its strength is not diminished ; but it will be advisable to ascertain occasionally by the hydrometer that it contains the re- quired proportions of corrosive sub- limate and water. Professor Faraday and the late Dr. Birkbeck have, with many other scientific men, testified in the strongest manner to the efficacy of this solution. The former says, with respect to the penetration of the solution by steeping, without pressure, that it may be tested by the application of a drop of hydro- sulphuret of ammonia, which will turn black on meeting with the mercury. In the cube of elm, the corrosive sublimate may be traced by the above test to the depth of from to of an inch ; by the test of voltaic action, from f to 1 inch. In the cube of oak, with the same test, it was found at of an inch, but irregular, and apparently fol- lowed the fissures of the wood ; by voltaic action, not quite so far as in the elm. 248 In the cube of fir, the penetra- tion was the least by the common test, -| to of an inch ; by voltaic action, ^ of an inch, the turpentine in the wood probably being the obstruction to penetration. From this testimony it is evident that when pressure is not used, the timber should be worked up into the form required before immersion. The patentees or company, who have also the means of saturating with hydraulic pressure at their establishment, similar to that at Portsmouth Dockyard, under Sir William Burnett's process, grant licenses at the rate of 5*. per cubic foot internal dimensions of the tank, and sell corrosive sublimate at 4s. per ft. Hft. is sufficient to saturate a load of timber of 50 cubic feet, at the rate of 1 ft. of sublimate to 15 gallons of water. The process has been for several years extensively used for sleepers on railroads. Several of the sleepers on the South Western Railway, which had been subjected to this process, were taken up, owing to their being decayed, particularly in the chalk districts. It was, however, stated by the engineer that they had been steeped at the company's works in a hasty manner, and that he did not consider it conclusive against the process ; that he had never seen any wood decayed that had been steeped by the patentees. It is also said that neither Kyan's, Burnett's, nor Payne's process, can resist the combined effects of mois- ture and great heat, say 80 Fahr. BURNETTIZING. Burnettizing is the process by means of which timber, felt, can- vas, cordage, cottons, and woollens, may be preserved from dry-rot, mildew, moth, and premature de- cay. It takes its name from its inventor, Sir William Burnett, M.D., K. C.B., F. R. S., of the Navy, who took out a patent for it in 1837. :YA KYANIZING AND BURNETTIZING. KYA It consists in immersing the various substances above enume- rated in a solution of chloride of zinc and water in a wooden tank, in the proportion of 1 tb. of chlo- ride of zinc to 4 gallons of water for wood, and 1 tb. of the chloride to 5 gallons of water for the re- mainder of the articles, with the exception of felt, which requires 1 ft. of the chloride to 2 gallons of water. Three-inch deals require to re- main in the tank or cistern six days, and all other woods in the same proportion, or two days per inch. They are then taken out and put under a shed, on their ends, to dry, and require for this purpose from fourteen days to three months, according to the thickness of the wood, when they are fit for use. The timber should be reduced to the scantling required for use before it is subjected to this process. Canvas, yarn for cordage, cottons, and woollens, require to be sus- pended in the solution for forty- eight hours. The process, however, with re- spect to timber, is much more ex- peditiously and effectively done by hydraulic pressure in Her Majesty's dockyard at Portsmouth, where large quantities of timber, &c., are prepared for the use of the Royal Navy at the various dockyards in England, particularly for ships' magazines. There is a large wrought-iron tank, 52 feet in length and 6 feet in diameter, with a door 2 feet 6 inches x 2 feet at each end for loading. Timber of all sizes and descrip- tions is put into this cylinder, which contains about twenty loads. As soon as it is filled, and the doors well secured both against external and internal pressure, the air is ex- hausted in the cylinder, and also in the timber, by means of an air- pump worked by a small rotatory engine of 10-horse power, on the Earl of Dundonald's principle, un- til the barometer stands at 27: the valve leading to the air-pump is then shut, and the cock of a pipe leading from the tank, filled with the solution, to the cylinder, is turned: the solution rushes into the cylinder to fill up the partial vacuum, and about half-fills it, when the cock is turned, and the air- pump again set to work until the barometer stands at 27i, when the same process is repeated, and the cylinder nearly filled with the so- lution. A pressure of 150tbs. per square inch is then obtained by means of a Bramah forcing-pump, connected with an iron copper or reservoir, filled with the solution, and com- municating with the cylinder by means of a pipe. This is worked by hand until a valve placed on the top of the cylinder, and loaded to the required gauge, begins to lift. The timber is then left in the cylinder, subject to this pressure for eight hours, which is considered sufficient for the largest logs, even in a rough state. The solution being then drawn off into the tank and the timber taken out of the cylinder, it is re-loaded, and the process repeated: the same solu tion is used for two months, when fresh is prepared. The same process for drying the timber thus saturated is adopted as before stated. Canvas, felt, anc yarn, &c. are not subjected to pressure. The felt is used as a lining to th magazines of men-of-war, between two thicknesses of wood ; also to cover over the steam boilers o steam ships : it is said to be ren dered much less liable to combus tion by the process. It is stated that in tropical cli mates, more especially in Africa the saturated canvas has stood th climate, when the unprepared, unde similar circumstances, has rapid! decayed. 219 L 5 LAB LAKE, COLOUR. LAC Both Burnettizing and Kyan- izing offer great advantages to the engineer : 1st. Wood of every kind is ren- dered more durable, and is rapidly seasoned. 2ndly. It brings into general use larch, poplar, and a variety of other indigenous woods, as well as American pine, &c., which, with- out the process, from being liable to rapid decay, and being much inferior to Baltic timber, are sel- dom used in public buildings. To the military engineer, these inventions offer still greater advan- tages. He is frequently called on, LAB LABURNUM, a small dark-greenish broom-wood, is sometimes used in ornamental cabinet-work Labyrinth, a series of hedges, mounds, or walls, with numerous winding passages; intricate and winding walks in a garden Lacing, a piece of compass or knee- timber, fayed to the back of the figure and the knee of the head of a ship, and bolted to each Lacker, a varnish applied upon tin, brass, and other metals, to preserve them from tarnishing, and to im- prove their colour Lac lake is prepared from lac, an Indian drug. It resembles cochi- neal and kermes, being the produc- tion of a species of insect. Its co- lour is rich, transparent, and deep, less brilliant, and more durable than those of cochineal and kermes, but inferior in both these respects to the colour of madder. Laconicum, among the ancients, the semicircular end of a bath ; a cir- " cular stove, for the purpose of heating the sudatories, or sweating- rooms of a bath : the use of the diy bath is said to have been pre- valent among the Lacedaemonians Lacquer. See Lacker. Lacunaria, the ceiling of the ambu- 250 in distant colonies, to construct block-houses, stockades, bridges, and barracks, where the only ma- terial to be had in abundance is the tree standing in the forest : to him a few pounds of either ingre- dient would be invaluable, by en- abling him to season and render durable the timber a few days after it was cut down, and thus provide him with the ready means of ren- dering a distant post tenable in a short time by a small body of men, with the additional satisfaction of knowing that the work thus hastily erected would be found to be of a permanent nature. LAC latory around the cella of a tem- ple or of the portico. The beams, which extended from the walls to the entablature, were intersected by others ranged longitudinally : the square spaces made by these inter- secting beams were contracted to- wards the top, and were sometimes closed with single stones, which might occasionally be removed. Lacunars, in architecture, are panels or coffers in the ceilings of apartments, and sometimes in the soffits of the corona of the Ionic, Corinthian, and Composite orders Lady-chapel, a chapel dedicated to the blessed Virgin Lake (colour), a name derived from the lac or lacca of India, is the cogno- men of a variety of transparent red and other pigments of great beauty, prepared for the most part by pre- cipitating coloured tinctures of dye- ing drugs upon alumine and other earths, &c. The lakes are hence a numerous class of pigments, both with respect to the variety of their appellations and the substances from which they are prepared. The colouring matter of common lake is Brazil wood, which affords a very fugitive colour. Superior red lakes are prepared from cochineal, lac, LAM LANDSCAPE GARDENING. LAN and kertnes ; but the best of all are those prepared from the root of the rubia tinctoria, or madder -plant. See Lac lake. Lama, in mining, slime or schelm Laminae, the extremely thin plates or layers of metal which compose the solid metal Laminable, a term applied to metal which maybe extended by passing it between steel or hardened (chilled) cast-iron rollers Laminated, disposed in layers or plates. When metal can be readily extended in all directions, under the ham- mer, it is said to be malleable, and when in fillets under the rolling- press, it is said to be laminable. Lamp-black is a smoke-black, being a soot of resinous woods obtained in the manufacturing of tar and tur- pentine. It is a pure carbonaceous substance of a fine texture, intensely black and perfectly durable, which works well, but dries badly in oil Lance wood, imported in long poles from 3 to 6 inches in diameter, from Cuba and Jamaica, is of a paler yellow than box wood : it is selected for elastic works, as gig shafts, archery bows and springs, surveyors' rods, billiard cues, &c. Landscape. In landscape we find Na- ture employing broken colours in enharmonic consonance and variety, and equally true to picturesque re- lations : she employs also broken forms and figures in conjoint har- mony with colours, occasionally throwing into the composition a regular form or a primary. Landscape Gardening. The outline of a wood may sometimes be great, and always beautiful, but the first requisite is irregularity. That a mixture of trees and underwood should form a long straight line, can never be natural; and a suc- cession of easy sweeps and gentle rounds, each a portion of a greater or less circle, composing altogether a line literally serpentine, is, if pos- sible, worse ; it is but a number of regularities put together in a disor- 251 derly manner, and equally distant from the beautiful, both of art and of nature. The true beauty of an outline con- sists more in breaks than in sweeps ; rather in angles than rounds ; in variety, not in succession. The outline of a wood is a continued line, and small variations do not save it from the insipidity of same- ness : one deep recess, one bold prominence, has more effect than twenty little irregularities ; and that one divides the line into parts, but no breach is thereby made in its unity : a continuation of wood al- ways remains, the form of it only is altered, and the extent increased: the eye, which hurries to the ex- tremity of whatever is uniform, de lights to trace a varied line through all its intricacies, to pause from stage to stage, and so lengthen the progress. The parts must not, however, on that account, be multiplied till they are too minute to be interesting, and so numerous as to create con- fusion : a few large parts should be more strongly distinguished in their forms, their directions, and their situations : each of these may afterwards be decorated with sub- ordinate varieties, and the mere growth of the plants will occasion some irregularity: on many occa- sions more will not be required. Every variety in the outline of a wood must be a prominence or a recess ; breadth in either is not so important as length to the one and depth to the other : if the former ends in an angle, or the latter di- minishes to a point, they have more force than a shallow dust or a dwarf excrescence, how wide so- ever : they are greater deviations from the continued line which they are intended to break, and their effect is to enlarge the wood it- self. Every variety of outline hitherto mentioned may be traced by the underwood alone; but frequently LAN LANDSCAPE PAINTING. LAT the same effects may be produced with more ease, and much more beauty, by a few trees standing out from the thicket, and belonging or seeming to belong to the wood, so as to make a part of its figure. The materials of natural land- scape are ground, wood, and water, to which man adds buil dings i and adapts them to the scene : it is therefore from the artificial con- siderations of utility, convenience, and propriety, that a place derives its real value in the eyes of a man of taste : he will discover graces and defects in every situation ; he will be as much delighted with a bed of flowers as with a forest thicket, and he will be as much disgusted by the fanciful affecta- tion of rude nature in tame scenery as by the trimness of spruce art in that which is wild. Landscape Painting. The best paint- ers in landscape have studied in Italy or France, where the verdure of England is unknown : hence arises the habit acquired by the connoisseur, of admiring the brown tints and arid foregrounds in the pictures of Claude and Poussin; and from this cause he prefers the bistre sketches to the green paint- ings of Gainsborough. One of our best landscape painters studied in Ireland, where the soil is not so yellow as in England ; and his pic- tures, however beautiful in design and composition, are always cold and chalky. Autumn is the fa- vourite season of study for land- scape painters, when all nature verges towards decay, when the foliage changes its vivid green to brown and orange, and the lawns put on their russet hue : but the tints and verdant colouring of spring and summer will have su- perior charms to those who de- light in the perfection of nature, without perhaps ever considering whether they are adapted to the painter's landscape. Land Steward. A person solely occu- 252 pied in the management and culti- vation of an estate should see to the production, advancement, and value of the land ; should be well acquainted with the pursuits and interests of country life ; should un- derstand the qualities of the soil and the proper manuring of the same, as well as the different com- binations of sand, gravel, loam, clay, chalk ; he should be able to show what stock the pasture will maintain, what quantity of grain the arable land will produce, and what quantity of hay may be ex- pected from the meadows : with other requisite knowledge pertain- ing to farming, he will be able to form a fair estimate of the produce of the farm, to keep accounts, and ultimately acquire a taste for the erection of farm buildings and la- bourers' rural cottages, and also the arrangement of landscape, flower, and vegetable gardens. Laniard, in navigation, a stout piece of line or cord used to fasten and secure the shrouds, stays, or buoys Lantern, in architecture, a small struc- ture on the top of a dome or in similar situations for the admission of light, and the promotion of ven- tilation. It is generally made or- namental, arid was much used in Gothic and Tudor architecture. Lapidarius, a lapidary, a stone-cutter Lapis lazuli, a mineral which fur- nishes the valuable pigment called ultramarine Lapis lydius, a variety of touch-stone ;. the schistose jasper of Brongniart r containing silica, iron, alumina, and charcoal Laque Miner ale is a French pigment, a species of chromic orange. This name is also given to orange oxide of iron. Larboard, in navigation, the left-hand side of a ship, standing with face to the head : now the word ' Port ' is used Lardrose, a screen at the back of a seat behind an altar Later, a brick or tile. Besides the LAT LATHE. LAY Greeks and Romans, other ancient nations employed brick for build- ing to a great extent, especially the Babylonians and Egyptians. Lathe, a machine for turning metals or wood by causing the material to revolve upon central points, and be cut by a tool fixed in a slide-rest, or held by hand. The lathe is very ancient, and seems to have been known to the Greeks and Romans, but, till within the last half century, was a very rough and almost powerless ma- chine compared with the elegant, very powerful, and well constructed machine now in use. It is used for turning either metal or timber, and varies in size and construction, ac- cording to the nature of the work required. The construction of the present lathe is as follows : a long frame, called the lathe-bed, having a per- fectly planed surface, and a slot or mortise from end to end, is fixed at each end upon two short standards, and upon one end of it a frame, called the head-stock or mandril- frame, is bolted: this frame carries the short shaft or mandril, upon which are the driving pulleys. The end of the mandril stands through the inner side of the frame, and is screwed so that a socket or centre chuck may be fixed on it: this chuck acts as a centre for the work to rest upon, and has a projecting arm or driver to carry it round with it. Another frame, called the back centre frame, capable of being fixed upon the lathe-bed at any distance from the front centre, has a cylin- der, with a pointed end or centre, at precisely the same height as the other, with two set-screws, one to adjust the centre piece, the other to fix it. The work is placed be- tween these two centres, and caused to revolve by a band passing over a pulley on the mandril, if the lathe is large, and by a treddle and band- wheel, if the lathe is small. In small lathes, the rest, upon 253 which the tool is held, is fixed in a socket cast on a small slide by a set-screw: the slide is for adjust- ing its position, and is capable of being fixed at any part of the lathe- bed between the centres. In large lathes the slide-rest is always used. See Slide-rest. Lathe-bed, that part of a lathe on which the ' poppet-head ' slides forward or backward to its required position Latitude, breadth, width, extent ; in geography, the distance, north or south, from the equator, a great circle, equally distant from the poles, dividing the globe into equal parts, north and south Latten, a mixed metal resembling brass. The monumental brasses in churches are called latten. Lattern-sail, in navigation, a long triangular sail used in xebecs, &c. Launders, in mining, tubes and gut- ters for the conveyance of water in mines, &c. Lavatory, a cistern or trough to wash in, used formerly in monasteries Laver, brazen. Moses was directed to make, among other articles of furniture, for the services of the ta- bernacle, a laver of brass, borne by four cherubim, standing upon bases or pedestals, mounted on brazen wheels, and having handles belong- to them, by means of which they might be drawn and conveyed from one place to another, as they should be wanted. These lavers were double, composed of a basin which received the water that fell from another square vessel above it, from which the water was drawn by cocks. The whole work was of brass : the square vessel was adorned with the heads of a lion, an ox, and a che- rub. Each of the lavers contained forty baths, or four bushels, forty- one pints, and forty cubic inches of Paris measure. Lay figure, a figure made of wood or cork, in imitation of the human body. It can be placed in any po- sition or attitude, and moves at LAZ LEVELLING. LEV every joint, on the principle of the ball and socket. It serves, when clothed, as a model for drapery and for fore-shortening. The dress of the person is generally placed on the lay-figure after the head is taken, by which the painter finishes his entire portrait at leisure, with- out requiring the person to sit. Lazaretto, an hospital ship for the reception of the sick Lead is a very heavy metal, suffici- ently well known. The mode of purifying it from the dross which is mixed with it, by subjecting it to a fierce flame, and melting off its scoria, furnishes several allusions in Scripture to God's purifying or punishing his people. It was one of the substances used for writing upon by the ancients Leader, a branch, rib, or string of ore, leading along to the lode Lead spar, sulphate of lead Leading springs, the springs fixed upon the leading axle-box of a lo- comotive engine, bearing the weight above Leading wheels, the wheels of a loco- motive engine, which are placed before the driving wheels Leaf, a water-course, or level for conveyance of water Leaves, a term applied to window- shutters, the folding-doors of clo- sets, &c. Leaving (in Cornish), or casualties, in tin, is the same as hanaways of copper or lead ore Lectern or Lettern, the desk or stand on which the larger books used in the services of the Roman Catholic church are placed. In modern Protestant churches they are now often used, and are very ornamental in appearance, and far more ap- propriate than the cumbersome reading-desk. Lecterns are made sometimes of stone or marble, but usually of wood and brass, and generally are extremely well exe- cuted. Lectus, a bed or couch Ledger, a large flat stone laid over a 254 tomb : horizontal timbers used in forming scaffolding are also called ledgers Ledyment, a string-course, or hori- zontal suite of mouldings, such as the base-mouldings of a building Lee, in navigation, the side opposite to the wind ; as the lee-shore is that on which the wind blows Lembus, according to Plautus, a skiff or small boat, used for carrying a person from a ship to the shore Lemon yellow, a beautiful light and vivid colour. In body and opacity it is nearly equal to Naples yellow and masticot, but much more pure and lucid in colour and tint, and at the same time not liable to change by damp, sulphurous or impure air, or by the action of light, or by the steel palette-knife, or by mixture of white lead or other pigments, either in water or oil. Levecel, anciently a pent-house, or a projecting roof over a window, door, &c. Level, an instrument for determining the heights of one place with re- spect to another Levelling, the art by which the rela- tive heights of any number of points are determined. The height of a point is the vertical distance to which it is ele- vated or depressed, as compared with the true general surface of the earth. The earth is in form a spheroid. On land we can nowhere trace its true geometric surface ; but the sea, when at rest, presents every where a very near approximation to it, and hence the level of the sea has been assumed as the stand- ard to which all heights are to be referred. The absolute height, then, of any point is its vertical distance from the level of the sea : the relative height of two or more points, com- monly called their difference of level, is the difference of those ver- tical distances. A true level is anv surface or LEV LIGHT. LIG line which is parallel to the true geometric surface of the earth; every true level must, therefore, necessarily present a curve every where perpendicular to the direc- tion of gravity. It is a beautiful property of fluids that in every situation, when at rest, their sur- face will present a true level. All points situated within the same true level are evidently at the same height. One point is said to be higher or lower than another, according as a true level traced through it passes above or below that point ; and the vertical distance at which it so passes is the measure of its relative height. In theory, levelling is extremely simple. It consists in tracing through space a series of level sur- faces, and finding their intersec- tions with vertical lines passing through the points whose relative height we wish to ascertain. Level, Road, a triangular frame of wood with a long straight base, and a plummet suspended by a thread from the vertex of the triangle. When the ground to which it is applied is level, the thread will co- incide with a line perpendicular to the base. A tool similar in principle to the above-mentioned is used by fitters, and is made of a plate of sheet- iron, two sides of which form a right angle, and the thread which suspends the plummet is parallel to the vertical side when the base is level. Level, Spirit, a glass tube, closed at the ends, and nearly filled with water or spirits, fixed in a piece of wood or metal, with a flat base, to which the tube is perfectly parallel. When placed upon a level surface, an air-bubble will be at the centre of the tube. Lever, the first mechanical power, being an inflexible straight bar, supported in a single point on a fulcrum or prop, called its centre 255 of motion : it is used to elevate a great weight Lever-valve, a safety-valve kept in its seat by the pressure of a lever with an adjustable weight. In locomo- tive engines a spring is used at the end of the lever, instead of the weight ; and the pressure is regu- lated by a screw, and indicates on a brass plate. Levigation, the process of reducing hard bodies into subtile powder by grinding upon marble with a muller Lewis, an instrument used by masons for hoisting, consisting of thin wedges of iron, forming a dovetail, which is indented into a large stone for the purpose of moving it Ley, a standard of metal ; contents in pure metal Libella, a small balance ; a level used by carpenters and masons, to test flat surfaces Libra, a pound weight ; a balance, or a pair of scales : one of the twelve signs of the zodiac Library, a room or rooms appropri- ated for the arrangement and keep- ing of books, fitted up with shelves to hold them, or furniture called book-cases, to which shelves are af- fixed for the same purpose Lifts, in navigation, the ropes at the yard-arms, used to make the yards hang higher or lower, as required Lifting-gear, the apparatus for lifting the safety-valves from within a boiler : it consists of levers con- nected to the valve and to a screw workedby ahandle outside the boiler Light. The meteorological pheno- mena induced by the action of light are, chiefly, atmospheric refraction, i. e. the temperature of the different strata of the atmosphere ; the tints which at certain times spread over the disc of the sun, the moon, and the stars; the various aspects of the waters of the ocean, of seas, and of lakes; the Fata Morgana, the mirage, and all those varied optical appearances which both celestial and terrestrial objects pre- sent when seen through atmosphe- LIG LIMESTONE. LIM ric strata of different degrees of elasticity. Light red is an ochre of a russet- orange hue ; principally valued for its tints. The common light red is hrown ochre burnt; but the prin- cipal yellow ochres afford this colour best ; and the brighter and better the yellow from which this pigment is prepared, the brighter will this red be, and the better flesh-tints will it afford with white. Lignum vitee, or Guaiacum, is a very hard and heavy wood, shipped from Cuba and other adjacent islands. When first cut, it is soft and easily worked; but it speedily becomes much harder on exposure to the air. It is cross-grained, covered with a smooth yellow sap, like box, almost as hard as the wood, which is of a dull brownish green, and contains a large quantity of the gum guaiacum, which is extracted for the purposes of medicine. The wood is used in machinery, and for rollers, presses, mills, pestles and mortars, sheaves for ships' blocks, skittle-balls, &c. Limber boards, short pieces of plank fitted from the limber strake to the keelson of a ship, butting at the sides of all the bulk-heads, that they may be easily taken up Limber strake, the strake of wood waleing nearest the keelson, from the upper side of which the depth in the hold of a vessel is measured Lime or Quicklime. When required perfectly pure, lime is obtained by heating to whiteness, in an open platinum crucible, precipitated car- bonate : most marbles yield it mo- derately pure ; but as prepared for ordinary purposes, by the calcina- tion of common limestone in a fur- nace with coal, it is far otherwise Limestone becomes lime on being de- prived of its carbonic acid and of the water it contains, whether hy- grometrically or in combination. The agent employed to effect this is heat. With the same heat, the calci- 256 nation is effected with more ease and rapidity, in proportion as the stone is of a less compact texture than the smallness in bulk of the fragments into which it is reduced, or to its being impregnated with a certain degree of humidity. The contact of the air is not in- dispensable, but it exercises a useful influence, especially in regard to argillaceous limestone. Moreover, no limestone can be converted into lime in a vessel so close as to ren- der the escape of the carbonic acid impossible. Limestone which is pure, or nearly so, supports a white heat without inconvenience. Under the intense heat of the hydro-oxygen blow-pipe this substance affords the brilliant light, the beautiful appli- cation of which to the microscope is now so well known. The com- pound limestone, on the other hand, alloyed in the proportions necessary to form hydraulic or eminently hydraulic lime, fuses easily. Its calcination demands certain pre- cautions : the heat ought never to be pushed beyond the common red heat, the intensity being made up for by its duration. The compound limestone, when too much burnt, is heavy, compact, dark-coloured, covered with a kind of enamel, especially about the an- gular parts ; it slakes with great difficulty, and gives a lime carbon- ized and without energy: some- times it will not slake at all, but becomes reduced, after some days- exposure to the air, to a harsh powder altogether inert. The pure and compound lime- stones, when insufficiently burnt, either refuse to slake, or slake only partially, leaving a solid kernel, a kind of sub-carbonate with excess of base. The calcining of calcareous mi- nerals constitutes the art of the lime-burner. According to situa- tion, either fire-wood, fagots, brush- wood, turf, or coal is used. LIM LIMESTONE. LIM Lime-kilns of various kinds have have been suggested or tried. The forms of interior most generally adopted are, 1st, the upright rect- angular prism; 2nd, the cylin- der ; 3rd, the cylinder surmounted hy an erect cone slightly trun- cated ; 4th, a truncated inverted cone ; 5th, an ellipsoid of revo- lution variously curvated, or egg- shaped kiln. The rectangular kilns are in use in Nivernais, and in the south of France, in which are burnt, at the same time, limestone and bricks. The limestone occupies very nearly the lower half of the capacity. The upper is filled with bricks, or tiles, laid and packed edgewise. The cylindric kilns are princi- pally employed upon works which consume a large quantity of lime in a short time. They are termed 'field-kilns;' their construction is expeditious and economical, but precarious. Above a pointed oven- shaped vault, is raised, in the form of a tower, a high stack of lime- stone, which is enclosed by a cur- tain of rammed earth, and supported outwardly by a coarse wattling, in which care is taken to leave an opening to introduce the fire be- neath the vault. The kilns of the third kind are constructed in a solid and durable manner, like the four-sided kilns : no bricks are burnt in these; the largest stones occupy the lower part of the cylinder ; the smaller pieces and fragments are thrown into the cone which surmounts it. The kilns of the fourth and fifth kind are specially intended for the burning with coal. The interior wall of the kiln is generally built with bricks, or other material unalterable by heat, ce- mented throughout a thickness of from 12 to 15 inches with a mix- ture of sand and refractory clay, beaten together. In the flare-kilns fed by logs or brush-wood, the charge always rests 257 upon one or two vaults built up dry with the materials of the charge itself. Underneath these vaults a small fire is lighted, which is gradually increased as they retire, in proportion as the draught esta- blishes itself, and gains force. On reaching the exterior, the aperture at the eye of the kiln is suitably adjusted, and then kept constantly filled with the combustible. The air which rushes in carries the flame to a distance over every point of the vaults: it insinuates itself by the joints, and is not long in extending the incandescence by degrees to the highest parts. There are some kinds of stone which the fire, however well re- gulated, seizes suddenly, and causes to fly with detonation : they can- not, without the risk of spoiling the charge, be used for the con- struction of the vaults and piers in loading the kiln. In such a case, materials which are free from this inconvenience are employed. Practice can alone indicate the time proper for the calcination. It varies with a multitude of circum- stances, such as the more or less green, more or less dry quality of the wood; the direction of the wind, if it favour the draught, or otherwise, &c. The master-burners usually judge by the general settling of the charge, which varies from 5- to ^. In a kiln of the capacity of from 211-8 to 264'75 cubic feet, the fire lasts from 100 to 150 hours. In the coal-kilns by slow heat, the stone and coal are mixed. Of all the methods of burning lime, this is certainly the most precarious and difficult ; more especially when applied to the argillaceous lime- stone. A mere change in the du- ration or intensity of the wind, any dilapidation of the interior wall of the kiln, a too great inequality in the size of the fragments, are so many causes which may retard or accelerate the draught, and occasion irregular movements in the descent LIM LIMES, HYDRAULIC. LIM of the materials, which become locked together, form a vault, and precipitate at one time the coal, and another the stone, upon the same point : hence an excess oFdeficiency in the calcination. Sometimes a kiln works perfectly well for many weeks, and then all at once gets out of order without any visible cause. A mere change in the quality of the coal is suf- ficient to lead the most experienced lime-burner into error. In a word, the calcination by means of coal, and the slow heat, is an affair of cautious investigation and prac- tice. The capacity of a furnace con- tributes, no less than does its form, to an equable and proper calcina- tion. There are limits beyond which they cannot be enlarged without serious evils. The bulk of coal burnt to pro- duce a cubic foot of lime neces- sarily varies with the hardness of the limestone used, but within narrow limits. The calcination of limestones presents other important problems, which can only be solved by expe- riment. Limes, hydraulic (artificial). Already the artificial limes have been ap- plied to a number of important works. In the canals ofSaint Martin and Saint Maur they have almost exclusively been used. Nearly a thousand cubic metres have been employed within five years at the harbour of Toulon. These limes have served for the fabrication of the mortar for the foundations of several bridges, and |their con- sumption is increasing daily in Paris and its environs. The artificial hydraulic limes are prepared by two methods : the most perfect, but also the most expen- sive, consists in mixing with rich lime, slaked in any way, a certain proportion of clay, and calcining the mixture : this is termed ' arti- ficial lime twice kilned.' 258 By the second process, any very soft calcareous substance is sub- stituted for the lime (such, for ex- ample, as chalk, or the tufas), which it is easy to bruise and reduce to a paste with water. From this a great saving is derived, but at the same time an artificial lime, perhaps of not quite so excellent a quality as by the first process, in conse- quence of the rather less perfect amalgamation of the mixture. In fact, it is impossible, by mere me- chanical agency, to reduce calca- reous substances to the same degree of fineness as slaked lime. Never- theless, this second process is the more generally followed, and the results to which it leads become more and more satisfactory. By a proper regulation of the proportions, a degree of energy may be given to the factitious lime, which will render equal it if not superior to the natural hydraulic limes. It is usual to take twenty parts of dry clay to eighty parts of very rich lime, or to one hundred and forty of carbonate of lime. But if the lime or its carbonate should already be at all mixed in the natural state, then fifteen parts of clay will be sufficient. Moreover, it is proper to determine the proportions for every locality. In fact, all clays do not resemble one another to such an extent as to admit of their being considered as identical: the finest and softest are the best. There is at Meudon, near Paris, a manufactory of artificial lime, set on foot by Messrs. Brian and St. Leger. The materials made use of are, the chalk of the country and the clay of Vaugirard, which is previously broken up into lumps of a moderate size. A millstone set up edgewise, and a strong wheel with spokes and felloes, firmly at- tached to a set of harrows and rakes, are set in movement by a two- horse gin, in a circular basin of about six feet and a half radius. LIM LINK MOTION. LIN In the middle of the basin is a pillar of masonry, on which turns the vertical arbor to which the whole system is fixed: into this basin, to which water is conveyed by means of a cock, four measures of chalk are successively thrown, and one measure of clay. After an hour and a half's working, about fifty-three cubic feet (English) of a thinpulp is obtained, whichis drawn off by means of a conduit, pierced horizontally on a level with the bot- tom of the basin. The fluid descends by its own weight ; first into one excavation, then into a second, then a third, and so on to a fourth or fifth. These excavations communicate with one another at top. When the first is full, the fresh liquid, as it arrives, as well as the super- natant fluids, flow over into the second excavation ; from the second into the third, and so on to the last, the clear water from which drains off into a cesspool. Other excavations, cut in steps like the preceding, serve to receive the fresh products of the work, whilst the material in the first series ac- quires the consistency necessary for moulding. The smaller the depth of the pans in relation to their superficies, the sooner is the above-mentioned consistency ob- tained. The mass is now subdivided into solids of a regular form by means of a mould. This operation is executed with rapidity. A moulder, working by the piece, makes on an average five thousand prisms a day, which will measure 2 11 -8 cubic feet. These prisms are arranged on drying shelves, where in a short time they acquire the degree of desiccation and hardness proper for calcination. At Paris a mixture of coke and coal is employed, and the common mode of burning by slow heat rendered necessary by that kind of combustible. The artificial hydraulic limes are 259 intended to supply the place of the natural ones in those countries where the argillaceous limestone is entirely wanting, and which are commonly sold in Paris. Lime-tree (the) is common in Europe, attains considerable size, is very light-coloured, fine and close in the grain, and is used in the con- struction of piano-fortes, harps, &c.: it is particularly suitable for carving, from its even texture and freedom from knots. The works of Gibbons at Windsor Castle, and St. Paul's, London, are of the lime-tree. Limning, a term formerly applied to portrait - painting, is drawing or painting the body and limbs of the human figure Linch-pin, the small pin in carts, &c., that is put at the ends of the axle- tree to confine the wheels on them steadily Linear perspective is that which de- scribes or represents the position, magnitude, form, &c. of the se- veral lines or contours of objects, and expresses their diminution, in proportion to their distance from the eye Link-motion, a new apparatus for re- versing steam engines : it is used in locomotive engines instead of the reversing forks, and consists of a link with a slot from end to end, into which a guide-block fits, and is connected to the slide-valve rod : the rods of the two eccentrics are connected one to each end of the link, which is raised or lowered, or held in a central position by appa- ratus attached to the centre of it, moved by the reversing lever. When the link is in a central po- sition with regard to the slide- valve rod, the guide-block remains stationary, as it is then at the centre upon which the link vibrates. When the link is up, the guide-block is at the lower end, and the slide receives motion from the backward eccen- tric. When the link is down, it receives motion from the forward eccentric. LIN LOCKS FOR CANALS. LOC Links, in locomotive engines, are flat or round pieces of iron with round holes at each end: they are used to connect together, by bolts, dif- ferent parts of the mechanism of the engine Lintel, a piece of timber or stone placed horizontally over a door- way or window, to support the superincumbent weight Lintel. " And ye shall take a bunch of hyssop, and dip it in the blood that is in the basin, and strike the lintel and the two side-posts with the blood that is in the basin ; and none of you shall go out at the door of his house until the morn- ing." Exodus xii. 22. Liquid rubiate, or Liquid madder lake, is a concentrated tincture of mad- der, of the most beautiful and per- fect rose colour and transparency. It is used as a water colour only in its simple state, diluted with pure water, with or without gum ; it dries in oil, by acting as a dryer to it. Mixed or ground with all other madder colours, with or with- out gum, it forms combinations which work freely in simple water, and produce the most beautiful and permanent effects. Lithography, the art of drawing on and engraving on stone, and taking impressions from the same at press, similarly to copper-plate printing, but differing in manipulation Little winds, in mining, an under- ground shaft, sunk from the hori- zontal drift, by which the top of the winds communicates with the side or bottom of the great work- ing-shaft Load water-line, the mark on a ship which the water makes when she is loaded Loam, a natural mixture of sand and clay : in the neighbourhood of London, loam consists of fine red- dish-gray sand 87 parts, allumina 13 parts = 100 Local colours are such as faithfully imitate those of a particular object, or such as are natural and proper 260 for each particular object in a pic- ture ; and colour is distinguished by the term trial, because the place it fills requires that particular co- lour, in order to give a greater character of truth to the several colours around it Lock, a mechanical contrivance to fasten a door, gate, or any place or thing for security. A vast deal of ingenuity has been exercised to prevent false openings : keys of va- rious kinds are made to fit the wards (interior contrivances), and prevent what is called picking, the key being made only to suit that belonging to the possessor. Lock, in inland navigation, a portion of a canal confined between a sluice- gate and a flood-gate, to facilitate the passage of boats in ascending or descending planes Lockrand, a course of bond stones, or a bonding course, in masonry Locks for canal and river navigation. The earliest approximation to what is now known by the name of lock consisted of a simple dam formed across the bed of a river, so as to raise the water to such a height as to allow vessels to float along it. Where the river had a considerable fall with a strong current, it was necessary to have these dams at short distances from each other, otherwise the requisite depth of water could not be obtained. As the whole space between two of these dams was in fact the lock, it was necessary, in passing from one level to another, to run down the water for the whole of that distance, thereby causing consider- able delay, and a waste of water that would now be considered a serious evil. In China these dams are common, and they have also been used on the Continent. Lock with a double set of gates, but no chamber walls, are now of ordi- nary construction. The evils at- tendant on the dams formerly constructed were in a great mea- sure removed by the introduction LOG LOCKS WITH SIDE PONDS. LOG of double sets of gates or sluices ; the upper set being constructed so near to the lower as only to leave room enough for the vessel or ves- sels to float between them. Framed gates were also used instead of se- parate beams and planks, because the space to be emptied or filled was so small that a very short time was required to pass the water, and there was no stream of suffi- cient strength to prevent their being easily opened. Where these locks are intended for rivers, it is usual to make a side cut or arti- ficial canal for the purposes of the navigation, and to leave the river course for the passage of the sur- plus water. A quick bend of the river is generally chosen for one of these cuts; and to keep the water in the upper part of the river to a sufficient height for navigation, a dam or weir is made across the old river course at or below the point where the artificial cut quits it. The lock is then built at the most convenient part of the cut, and its fall made equal to the difference in the levels of the water at the top and at the bottom of the dam or weir. When a vessel is going up the river, she floats along the cut, and passes between the lower gates into the lock ; the lower gates are then closed, and the valves or paddles of the upper gates being opened, the water flows into the lock, and rises to the level of the upper part of the river ; the upper gates are then opened, and the vessel floats out of the lock. The reverse of this operation conducts a vessel down the river. The abutments for the gates have been made of timber, brick-work, and masonry; but when the double set of gates was first introduced, it was usual to leave the space be- tween the upper and lower gates unprotected by either timber or any kind of building. Of course the agitation of the water in the lock was constantly washing away 261 the earthen banks, thereby causing a risk of their being broken down by such continued weakening ; and by enlarging the space between the two sets of gates, it occasioned a loss of time in emptying and filling, as well as a waste of water. Lock (common modern canal). The difference of altitude between the upper and lower levels, where the locks are constructed, varies ac- cording to local circumstances. Where the ground is longitudinally steep and water plentiful, the locks are generally made of greater lift or fall than where the ground is comparatively flat and water scarce. It is evident, that where the super- ficial area of locks is the same, one having a rise of 12 feet would re- quire twice the quantity of water to fill it that would be requisite for one of 6 feet. Having many locks, however, of small lifts instead of a few of greater, increases the ex- pense, as well as the time for pass- ing them. For narrow canals these locks are generally made about 80 feet long, and 7 to 8 feet wide in the chamber. On the Caledonian canal they are 180 feet long, 40 feet wide, and 30 feet deep. Locks are also constructed of every intermediate size. Lock-gates have till lately been made of timber; but in consequence of the difficulty of procuring it of sufficient size for those on the Caledonian canal, cast iron was partially adopted for the heads, heels, and ribs. Iron gates, cast in one piece, have been used on the Ellesmere canal, as well as others with cast-iron framing and timber planking. Locks with side ponds. When water is scarce, it is common to construct side ponds, by which a considerable portion (in general one -half) is saved. The usual number of these ponds is two ; for it has been de- termined by experience, that when a greater number has been made LOG LOCKS, PARALLEL DOUBLE -TRANS IT. LOC use of, the loss occasioned by leak- age and evaporation has sometimes been more than equal to the ad- ditional quantity of water thus re- tained. Locks for the transit of vessels of different sizes. Where vessels of different sizes have to pass the same locks, three pairs of gates are sometimes placed instead of two, the distance between the upper and lower pairs being sufficient to admit the largest vessels, and that between the upper and middle pairs being adapted to the smaller class. By this contrivance, when a small vessel is to be passed through, the lowest pair of gates is not used ; and when a large vessel goes through, the middle pair of gates is not worked. Thus it is evident that the quantity of water contained between the middle and lower pair of gates is saved when a small ves- sel passes, compared with what would be required were the middle set of gates omitted. Locks (parallel double - transit}. Where the transit is great, much time and water may be saved by a double-transit lock, which is two locks placed close to arid parallel with each other, with a communi- cation between them, which can be opened or cut off at pleasure by valves or paddles. As one of these locks is kept full and the other empty, a vessel in descending floats into the full one : the upper gates are then closed, and the water is run, by means of the connecting culvert, into the empty lock (the gates of which were previously closed), till the water in the two locks is on the same level, which will be when each is half-full : the connecting paddles are then closed, and the remaining half of the water in the descending lock is run into the lower canal. The next descending vessel has to be floated into the lock which remains half-filled, and which consequently requires only half a lock of water to be run from the upper pond to raise it to the proper level, and then that half is transferred to the lock previously used, to serve the next descending vessel; but supposing a vessel to be ascending after the first descent, it will enter the empty lock, and receive a quarter-lock of water from that which remained half-filled : of course, three-quarters of a lock of water is now required from the upper canal to complete the filling. If a descending vessel next follows, it enters the full lock, and its water is run into the lock which was previously left a quarter-full; and when both have arrived at the same level, it is evident they will be each five-eighths full, and the succeeding descending vessel will require only three-eighths of a lock of water from the upper pond or canal. From these observations, it will be seen that the double -transit lock saves nearly one-half of the water which a common single lock would require. Sometimes the two parallel locks are made of different sizes, to suit the various descriptions of vessels that may have to pass. Locks connected longitudinally, com- monly called a Chain of Locks. When loss of water is of no conse- quence, a considerable expense is sometimes saved by placing the locks close together, without any intermediate pond ; for by passing from one immediately into the other, there is only required one pair of gates more than the number of locks so connected, besides a proportionate saving of masonry. Thus, eight connected locks would only require nine pairs of gates ; whilst, if they were detached, they would require sixteen pairs. But to show that these cannot be adopt- ed with propriety excepting where water is abundant, it is necessary to observe, that every two alternate ascending and descending vessels will require as many locks-full of LOC LOCOMOTIVE STEAM ENGINES. LOC water as there are locks: for in- stance, if a vessel has just ascended, it has left all the locks full ; a de- scending vessel then enters the upper lock, and when its gates are closed, the water is run down ; but all the locks below being previously filled, they cannot contain it, and it consequently passes over the gates or weirs of all of them into the lower canal : the vessel has by this means descended to the level of the second lock, the water in which must abo be run into the lower canal, for the same reason as al- ready stated. When the water of all the locks has thus been run down, an ascending vessel will re- quire all these locks to be filled from the upper canal, which, how- ever, will be retained in the locks ready for the succeeding vessel to pass down. From this it will be evident, that where eight locks are connected, a descending vessel draws no water from the upper canal, because the locks are pre- viously all filled, but it empties eight locks of water into the lower canal : an ascending vessel, on the contrary, empties no water into the lower canal, because all the locks were previously emptied, but it draws eight locks-full from the upper canal, in order to fill them : consequently, the passing of one ascending vessel, and one descend- ing, requires eight locks -full of water. Other modes of passing vessels from one level to another, by sub- stituting machinery, either wholly or in part, have been adopted ; but these have either failed entirely, or have not been brought into general use. Locomotive Steam Engines, a class of travelling machines adapted either for railways or common roads, were originally designed for the latter, but did not succeed; and roads were then made for them, called railways, on which they have been most successful. The principle 263 of action being the same in both kinds, a description of the railway variety will explain the manner in which progressive motion is obtain- ed by the agency of steam. Locomotion or progression is the combined effect of a number of parts in each engine performing separate duties. The principal of these parts and the plan of their co-operation may be thus classed : 1st. The parts which generate the steam. 2nd. The parts which regulate the employment of the steam. 3rd. The parts by which the driver controls the action of the engine. 4th. The parts immediately con- cerned in producing locomotion. 5th, The parts which excite the rapid combustion of the fueL 6th. The parts which supply water to the boiler. 7th. The parts which support the engine on the rails. 8th. The manner in which loco- motion is produced by these parts. In explaining them and their effect as thus arranged, we have 1st, The parts which generate the steam, called the boiler, con- taining internally a fire-box,varying according to the dimensions of the engine from 25 (as in the 'Rocket') to 303 small tubes (as in the broad- gauge engines), a regulator, and a steam-pipe. Externally, a chim- ney and two safety-valves are fixed to the boiler. 2ndly, The parts which regulate the employment of the steam are, two slide-valves (covering the passages to andfromthe cylinders), attached to two sets of 'valve-gear,' worked by two eccentrics for the 'forward* and two other eccentrics for the 'backward' motion of the engine ; but only two of them work at one time, the other two being what i called * out of gear.' Four rods called eccentric-rods, encircling the eccentric-sheaves at one end, and jointed to the slide-valve gear at the other end, complete the con- LOG LOCOMOTIVE STEAM ENGINES. LOG nection of the slide-valves to the eccentrics fixed on the axle of the driving wheels. 3rdiy, The parts by which the dri- ver controls the action of the engine are, three sets of levers and rods connected to the slide-valve, eccen- tric-rods, regulator-valves, andfeed- pipe cocks, whereby he can ' put on' or ' shut off' steam to the cy- linders, water to the boiler, or place the slide-valves in a ' for- ward' or 'backward' position at his pleasure. These arrangements are usually called the ' hand-gear. ' 4thly, The parts immediately con- cerned in producing locomotion are, two cylinders, on which work two steam-tight pistons, fixed on the end of the piston-rods. On the open end of the piston-rods are also fixed T- pieces, called cross- heads, which slide between or round guide-bars, called motion- bars, fixed parallel with the cylin- ders. By this means the pistons can only move in a right line with the cylinders. Two strong rods, called connecting-rods, attach the cross-heads to the driving wheels, or to a cranked axle when there is one used. "Whether the pistons are connected to a cranked axle or to the arms of the driving wheels, this connection is always made at an angle of 45 degrees to each other ; therefore the one piston is in the centre of the cylinder exert- ing its greatest power during that part of the stroke when the other piston is at the end of the cylinder exerting no power. (This excel- lent arrangement was amongst the first improvements introduced by the late Mr. G. Stephenson, in 1814, who thus placed the locomo- tive in the same high position, as to efficiency, as was previously done for fixed engines by Watt.) The connection being thus completed between the pistons and the driv- ing wheels, it is evident that any movement of the one must imme- diately act upon the other. 264 5thly, The parts which excite the rapid combustion of the fuel re- quired in locomotive engines are, the chimney and a pipe called the blast-pipe, so made as to cover the exhausting passages from both cy- linders, and terminating in the centre of the chimney, near the level of the top of the boiler. It is the escape through this pipe of each succeeding cylinder-full of steam, or that portion of it allowed to escape by the slide-valves, which causes the 'beats' or 'pulsations' so distinctly audible when the locomotive is at work. 6thly, The parts which supply water to the boiler are, two force- pumps, connected by two feed- pumps to the boiler, and to a re- servoir of water. The pumps are worked either from the cross-head, or from eccentrics on the axle of the driving wheels. 7thly, The parts which support the engine are, 2, 4 or 6 wheels, besides the driving wheels, a set of springs, and a strong frame on which the boiler and machinery are securely fixed. Sthly, The manner in which lo- comotion is produced from the co- operation of these several parts is as follows. The boiler is filled with water until it completely sur- rounds all the tubes and inside fire- box. Fire is then applied, and in due time steam is generated from the water and collected between the surface of the water and the top of the boiler, until it has reached the pressure required. On the regulator being then opened, and the slide-valves placed in their working position by the driver, the steam passes from the boiler through the steam-pipe to the cylinders, where its force moves the pistons, which, being attached to the driv- ing wheels (as has been explained), causes them to revolve, and thus produces locomotion. The slide- valves and pumps being wrought from some part set in motion by LOG LOCOMOTIVE ENGINES. LOG the piston, regulate the admission of steam to the cylinder, and of water to the boiler. When the steam has moved the piston to the end of the cylinder, a passage is opened for its escape to the atmo- sphere through the blast-pipe, and the velocity of this escaping steam creates a partial vacuum in the chimney, causing a rush or ' blast ' of air through the fire to fill this vacuum ; which blast excites the rapid combustion of the fuel, and consequent rapid generation of steam. This completes the duties of one admission of steam to the cylinders, until its escape to the atmosphere ; and when this escape has taken place, another admission of steam, to the opposite side of the piston, forces it back to the other end of the cylinder ; and by the medium of the crank, the re- ciprocating motion of the piston is converted into a rotatory one, and the locomotion begun by the first admission of steam to the cylinders is continued by the second and succeeding admissions. The repetition of these simple operations has amazed and gratified the world, by safely conveying heavy passenger trains at upwards of 70 miles an hour, and merchan- dise trains of 600 tons weight, at 25 miles per hour ! the mere idea of which, not many years since, would have been regarded as purely fabulous. Such is the modern railway loco- motive, an illustrative example of the genius of man ; but, like other important inventions, it is the joint production of many minds, and many more are still directed to its further improvement. The records of the Patent Office show, that from January, 1840, to the end of September, 1849, no less than 226 patents were enrolled, all of them more or less applicable to the steam engine and its ap- pendages. Of these 226 patents, 45 were enrolled during the first 265 nine months of 1849. It has been remarked that steam engines and railways were too matter-of-fact subjects for poets and painters; but from the above record it is evident that they deeply impress them- selves upon the inventive intellect of the world ; and if the prodigies performed by steam remain un- sung or unportrayed, they dare, if not realize, the very sublimity of both poetry and painting ; for what more interesting scene to delineate than one of these stately machines moving safely along, at eagle-speed, the very elite of the land, (including even the Royal Family,) through districts rich in the historical as- sociations of past ages, and still teeming with the works of nature and of art ! Surely it cannot be that the subject is too lofty a one for poetical or pictorial illustration, for in greatness of idea lies the success of both. A brief review of the progress of locomotive engines is all that can be here given. It is now (1849) about 2000 years since the powers of steam were recorded by Hero of Alexandria, but it is only 200 years (in 1650) since it was first usefully employed by the Marquis of Wor- cester. The first idea of using it for propelling carriages is generally ascribed to Dr. Robison, in 1759, when it was suggested by him to Watt, who included a steam carriage in his patents of 1769 and 1784, but never carried them out. In 1786, Oliver Evans, of Philadelphia, had clear perceptions of the advantages of applying steam to waggons, boats, and mills ; but the want of friends and means compelled him to confine his exertions to steam mills. From 1802 to 1805, Trevi- thick applied steam carriages to both common roads and railways, with considerable success for first experiments ; and his engine, with Stephenson's improvements, is now the modern locomotive. About the year 1803, it appears that a Mr. LOG LOCOMOTIVE ENGINES. LOC Fredericks also made a steam en- gine for a silver mine in Hanover, which, in 1811, was employed to convey their Majesties and suite of Westphalia over the mineral rail- way at considerable speed. This was probahly the first royal trip on a railway. From 1805 up to 1814, invention was directed to insure the adhesion of the wheels upon the rails; and many ingenious plans were tried, some of which succeeded well at slow speeds, but were not calculated for high velocities. In 1814, however, Mr. Blackett, of the Wylam Railway, reverting to Trevithick's plan, fully established the FACT, that on a level, or mo- derately inclined railway, the ad- hesion of a smooth iron wheel upon a smooth iron rail was sufficient to draw heavy loads. He tried both six and eight wheeled engines. In 1814, Mr. Stephenson introduced two cylinders, or two complete steam engines, to one locomotive. From this time up to 1829, the powerful opposition of the owners of other modes of conveyance greatly retarded the progress of the locomotive engine ; and so strong was the feeling that they were not economical, that both Mr. Walker and Mr. Rastrick re- ported against them, in 1829. These reports, and one of a doubt- ful character by Telford, led to the offer of a prize of 500, in 1829, by the directors of the Liverpool and Manchester Railway, for the best locomotive engine, whose weight was not to exceed six tons. This proceeding gave an important impulse to locomotives, and ended in establishing their superiority over all other existing systems of travelling. Five competitors ap- peared, namely, Messrs. Stephen- son, Erickson, Hockworth, Burstal, and Brandreth. The machinery of the two last were not suitable, and did not proceed to trial. Mr. Stephenson's ' Rocket,' Mr. Erick- son's ' Novelty,' and Mr. Hock- 266 worth's ' Sanspareil,' were all tried, and the prize was fairly won by the ' Rocket,' which, after the trials were over, reached a speed of 35 miles per hour, and the ' Novelty' about 24 miles per hour. The ' Rocket ' embraced the fire- box, tubes, and blast-pipe of the modern locomotive. The 'Novelty' embraced the plan now much used on short lines, of carrying engine, fuel, and water, all on one frame. The ' Sanspareil ' embraced the blast-pipe of the modern engine, with the single returned tube of the older locomotives. From this it will be seen that this competition at once brought put the leading features which have since rendered the locomotive engine so popular throughout the world. From 1830, upto the introduction of the 7-feet gauge on the Great Western Railway, in 1838, no marked improvement took place in the locomotive, but the rivalry which sprung up between the gauges served greatly to develop their capabilities. Engines of a novel construction, having the boiler on one frame, and the machinery on another frame, were tried on the Great Western Railway; also engines embracing Trevithick's plan of working the driving wheels by toothed wheels, fixed on a separate cranked axle, were tried, but all abandoned for engines modelled from one of Stephenson's ; and the last new Great Western engines only follow up his latest improvements and Gray's expansive slide-valve motion on a large scale. A number of patents have been enrolled for improving the loco- motive engine, but a few only have been reduced to practice. Amongst the more conspicuous of them are, Mr. Stephenson's im- provements in the slide-valve mo- tion ; Mr. Gray's expansive mo- tion ; Mr. Crampton's arrangement LOG LOCOMOTIVE ENGINES. LOC of wheels ; Mr. Bodmer's arrange- ment of four pistons in two cylin- ders; Mr. M'Connell's tank engine; Mr. Samuel's express engine ; and Mr. Adam's steam carriage. The improvements in the mechanism of the slide-valve motion, by Messrs. Stephenson and Gray, have been widely adopted. Mr. Crampton has engines of his plan at work both in England and on the Con- tinent, which enable high driving wheels to be used on the narrow gauge, without raising the centre of gravity. (For an illustration of these and other examples, see the new edition of ' Tredgold on the Steam Engine.') Mr. Bodmer's plan is to admit the steam between two pistons in one cylinder acting on two cranks, so as to compensate the strain on the frame and machinery. His engines work steadily, and are in- genious in construction. The Tank engine carries on the Bame frame water and fuel, its tank for water being placed on the top of the boiler. This is the plan adopted on the Great Western Rail- way ; but on narrow-gauge lines the tank is usually placed below the boiler and framing, a better arrangement, where the machinery permits it to be done. Mr. Samuel's express engine weighed only 25 cwt., and con- veyed seven passengers at the rate of 30 miles per hour on the Eastern Counties Railway. Mr. Adam's steam carriage is on this plan, with a very handsome carriage for passengers, all on one frame, and has been tried on some of the branch railways of both gauges. Having thus briefly glanced at the progress of the locomotive engine, it only remains as briefly to notice some important discussions which have agitated the mechanical world regarding them. From the earliest introduction of 1 ocomotives, four, six, or eight wheels 267 appear to have been used, according to the designs of the makers ; but about 1840-1-2, an animated dis- cussion of the respective merits of the four and six wheeled engines was carried on in the columns of the railway press. Both classes have their merits, and both classes had able advocates, but public opinion evidently tended in favour of the six-wheeled engine as the safer of the two under all contingencies : hence the greater proportion of the present locomotives have six wheels. The gauge controversy of 1845- 6-7-8 led to the re-introduction of eight -wheeled engines on both gauges, weighing about 36 tons each, which realized speeds of about sixty and seventy miles per hour. The weight of these monster en- gines, it will be observed, is more than eight times that of the 'Rocket' (4 tons), which won the prize in 1829, whilst the speed is only twice that of the ' Rocket' (thirty-five miles) at that time. It is worthy of remark, that in 1829 the exist- ing engines of 10 to 16 tons were considered as far too heavy, and the Liverpool and Manchester directors bound competitors not to exceed six tons weight. In 1849, the same feel- ing prevailed, and the injury done to the railway by these 36 tons engines is much complained of, and tank engines and steam carriages embody this feeling in practice. A description of the locomotive can scarcely be closed without no- ticing the death of its great im- prover, Mr. G. Stephenson, who died in 1848, aged 68 years. He found the locomotive a very imperfect machine ; he left it in that efficient state that even the daring genius of a Brunei could only copy his plans for the 7-feet gauge. This is another testimony to that far- seeing intellect which so early grasped the principal requisites for an efficient locomotive, and whose genius coped with and overcame the leading engineers of England, LOG LOGARITHMS. LOG in 1829, by establishing both loco- motives and the Liverpool and Manchester Railway against all op- position, and from which sprung that system of railways which has added so immensely to the resources of the nation ay, of the world. Civil services, military services, naval sendees, and no services, have at all times been liberally reward- ed by the Crown and Legislature; but there are no such rewards, no ORDER OF MERIT for such men as Stephenson, Watt, Arkwright, &c., who are the mainstays of our pro- gress, our greatness, and our power. This is wrong very wrong, and ought to be amended. However, if the Crown forget, and the Legis- lature neglect such men, it is con- solatory to know, that their names will be embalmed in the hearts of the people, whilst the profligacy of honours and rewards to those hav- ing no real claim on the gratitude of the nation is universally con- demned. Upon the Taunus Railway, an apparatus is in use, invented by Mr. Thorman, which, from its simplicity and efficiency, cannot easily be excelled. It is attached to the hinder part of the tender, and is used in case of emergency, as well as being constantly used when at the stations, where it is necessary to uncouple the engine and tender from the train, thereby saving great trouble, and with less danger to engine-men and fire-men, as they can disconnect at any speed or at any time, whether the engine and train are in motion or not. (For a better elucidation of this simple and ingenious contrivance, see Thorman's work on the ' Taunus Railway,' 4to, 1846.) Locker, a small closet or cupboard: lockers were used in churches to hold sacred relics Locust-tree (the) of North America is of a greenish yellow ; is tough and durable, and used for treenails for ships, for posts, stakes, paling, &c. 268 Lode, a metallic vein Loft, a room in the roof of a build- ing ; a store-room in a theatre ; a depository for hay and corn in a stable : a music loft ; a singing loft ; a rood-loft in a church Lofty tin, rich, massive, and rough tin Log, in navigation, a small triangular piece of board balanced by a thin plate of lead so as to swim perpen- dicularly, and, being fixed to a bine, measures the ship's way Logarithms are the artificial numbers used to facilitate or abridge arith- metical calculations, and may be considered as expressing the rela- tion between an arithmetical and geometrical series of terms, or between ratios and the measures of ratios, and are the indices or ex- ponents of a series of numbers in geometrical progression. The ori- gin and nature of logarithms may be easily explained. In arithmetical series the quan- tities increase or decrease by the same difference, but in a geome- trical series they increase or dimi- nish by a common measure. The first of the following lines exhibits an arithmetical progression; all the other lines are examples of geome- trical progression. 10, 1,2,3,4, 5, 6, 7,8,9. 21, 2, 4, 8, 16, 32, 64, 128, 256, 512. 31, 3, 9, 27, 81, 243, 729, 2187, 6561, 25683. 41, 10, 100, 1000, 10,000, &c. Here consider the upper line as the index to all the rest ; every term of it is the logarithm of a corresponding term in each of them ; and it is evident that an infini- tude of other lines, or any one of the same lines, varying the point of commencement, and containing numbers in geometrical progression , might be added, to all of which the same arithmetical series might fur- nish logarithms. Logeum, the pulpitum or wooden stage of a theatre, placed upon the proscenium or permanent stage. LOM LOMBARDIC SCHOOL. LYS In the Greek theatre the pulpitum extended into the orchestra beyond the proscenium. Logwood, from Campeachy, Jamaica, Honduras, &c., is largely used as a purple or dark red dye-wood Lombardic Architecture, a style which immediately succeeded the decline of the Roman style Lombardic School of Painting. The distinguishing characteristics of this school are, grace, an agreeable taste for design, without great correc- tion, a mellowness of pencil, and a beautiful mixture of colours. An- tonio Allegri, called Correggio, was the father and the greatest orna- ment of this school : he began by imitating nature alone, but as he was chiefly delighted with the graceful, he was careful to purify his design; he made his figures elegant and large, and varied his outlines by frequent undulations, but was not always pure and cor- rect, though bold in his concep- tions. Correggio painted in oil, a kind of painting susceptible of the greatest delicacy and sweetness ; and as his character led him to cultivate the agreeable, he gave a pleasing, captivating tone to all his pictures. London and Nottingham whites. The best of these do not differ in any essential particulars materially, nor from the white leads of other ma- nufactories. The latter, being pre- pared from flake-white, is gene- rally the grayest of the two. The inferior white leads are adulterated with whiting or other substances, which injure them in body and brightness, dispose them to dry more slowly, to keep their place less firmly, and to discolour the oil with which they are applied. All the above are carbonates of lead, and liable to froth or bubble when used with aqueous, spiritous, or acid preparations. Longitude, length; the distance of any part of the earth, east or west, from London, or any other given place 269 M 3 Long timbers, in ship-building, thos timbers in the cant bodies which reach from the dead-wood to th second futtock-head Loobs, tin slime or sludge Loof, in navigation, pronounced luff a term applied when a ship going large before the wind, is brough close by the wind ; to put the helm towards the lee -side Loop-hole, a narrow opening or cre- nelle used in the battlements of the castles of the early English Lord of the land or tree, in Cornwall the person in whose land the mine is ; therefore the part which he re- serves to himself for liberty to work a mine in his land is the one-sixth, one-seventh, one-eighth, or any other proportion, free of expense, and called the ' dues' dish' Louvre, a lantern ; a turret on the roof of an ancient hall or kitchen for the escape of smoke and for ventilation, now made an orna mental and pleasing object Lozenge, in geometry called a rhomb, and when the sides are unequal, a rhomboid ; in heraldry, a four-cor nered figure, resembling a pane of glass in old casements. Lozenge moulding, a name given to the Norman style of mouldings and ornaments, which are shaped like lozenges Lubricate, to make smooth or slippery Lubricator, an oil-cup or other con- trivance for supplying oil or grease to rubbing surfaces, in order to diminish friction Lucerna, an oil -lamp. The Greeks and Romans originally used can- dles; but in later times these were chiefly confined to the houses of the lower classes Lugsail, in navigation, a small sail hoisted occasionally on the mast of a boat or small vessel Lychnus, a lamp suspended, or a pen- dent light Lysis, some member above the corona of a podium, introduced in temples, and in the scene of a theatre MAC MACHINERY. MAC MAC MACHINES ORGANA, defined by Vi- truvius, in his 10th book, as con- trivances for the concentration and application of force, which are known by the names of instru- ments, mechanical powers, ma- chines, engines, &c. Machinery, a general term applied to mechanical combinations of parts for creating power, or producing works which may otherwise be, more or less perfectly, made with the hands. The first class of these combinations is -usually distin- guished by the name of engines ; the second, by that of machines. Engines, or machines for creat- ing or accumulating and applying power, are distinguished from each other according to the material employed in the creation of their power, as air-engines, water-en- gines, gas-engines, steam-engines, electric-engines, &c. Machines employed in the ma- nufacturing arts are named accord- ing to their .products, as lace-ma- chinery, rope-machinery, paper- machines ; or to the processes they perform, as spinning -machinery, printing -machinery, sawing-ma- chinery, &c. The materials of which machine- ry is composed are, wood of various kinds, iron, brass, copper, and other metals, with flexible materials for bands, cords, &c., as wool, caoutchouc, and leather. The several parts of machinery are, frames, plummer-blocks, car- riages, bolts and nuts, pins, shafts, wheels, pinions, levers, cranks, springs, screws, pulleys, riggers, bands or belts, and cords, &c., studs, tappets, wedges, rods, cylin- ders, tubes, pistons, valves, buckets, floats, weights, beams,racks, chains, clutches, winches, &c. The power of engines, as distin- guished from machines, depends upon the nature of the material 270~ MAC from which their power is gathered. The mere mechanical effect of every piece of machinery is calculable upon its combinations of certain elementary forms, commonly term- ed the mechanical powers, with deductions from the effect of these for friction between the parts, for rigidity of parts which are theore- tically supposed to be perfectly flexible, and for the elasticity of parts which are supposed to be perfectly rigid. The mechanical powers, some- times described as six in number, viz. the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and the screw, are reduci- ble to two only, viz. the lever and the inclined plane, in each of which the effect produced is just as many times greater than the power em- ployed, as the space through which the power moves is greater than the space through which the effect is continued. Thus, if with a lever a weight be raised ten times greater than the weight or power by which it is raised, this weight or power will have to move through ten times as much space as the height through which the greater weight is raised. Propriety of form in the detail of machinery depends upon two circumstances. The first is, that the parts subject to wear and tear, and influenced by strains, should be capable of motion or adjustment : the second, that every portion should be equally strong, and pre- sent to the eye a uniform figure, or one that is consistent with its degree of action : theory, practice, and taste, all must combine to produce such. A great extent of beauty is attainable in all the details, but mathematical reasons cannot be given why a certain arrangement of lines should be preferable to another, provided MAC MANDRIL. MAN they are equally strong. Truth does not strike us without the as- sistance of custom ; but so great is the force of custom, that unassisted by truth it has worked the great- est miracles ; and it certainly must be this universal Mentor which gives us the power to choose be- tween forms. Macellum, a market-place for all kinds 'of provisions Maceria, a rough wall Machicolations, openings formed for the purpose of defence at the top of castles and fortifications, by set- ting the parapet out on corbels, so as to project beyond the face of the wall Madder carmine, or Field's carmine, is, as its name expresses, prepared from madder. It differs from the rose lakes of madder principally in texture, and in the greater rich- ness, depth, and transparency of its colour, which is of various hues, from rose colour to crimson Madder orange, or Orange lake, is a madder lake of an orange hue, va- rying from yellow to rose colour and brown Madder purple, Purple rubiate, or Field's purple, is a very rich and deep carmine, prepared from mad- der. Though not a brilliant pur- ple, its richness, durability, trans- parency, and superiority of colour, have given it the preference to the purple of gold purple, and to burnt carmine. Madder yellow is a preparation from the madder root. The best is of a bright colour, resembling Indian yellow, but more powerful and transparent, though hardly equal to it in durability of hue ; metallic, terrene, and alkaline substances acting on and reddening it as they do gamboge : even alone, it has by time a natural tendency to change in appearance. Mamiana, seats in the upper porticoes of the Roman forum, from whence spectators witnessed the combats of gladiators 271 Magnase black is the best of all blacks for drying in oil without ad- dition, or preparation of the oil : it is a colour of vast body and tingeing power Mahogany is a native of the "West Indies and the country round the Bay of Honduras. It is said to be of rapid growth, and so large that its trujik often exceeds 40 feet in length and 6 feet in diameter. Spanish mahogany is importedfrom Cuba, Jamaica, Hispaniola, St. Do- mingo, and some other of the West India Islands, in logs from about 20 to 26 inches square and 10 feet long. It is close-grained and hard. There is also African mahogany. All the species are used for many purposes, more particularly for su- perior household furniture. Main links, the links in the parallel motion which connect the piston- rod to the beam of a steam engine Malleable, in metallurgy, capable of being spread by heating or by rolling, a distinguishing character of metals, but more especially of gold. When flattened, it is said to be laminable ; when drawn as wire, ductile. Manacaybo is a furniture wood of moderate size, hard, as good as ma- hogany, and in appearance between that and tulip wood Manchineel, a large tree of the West Indies and South America : it possesses the general character of mahogany, but has a poisonous and unwholesome sap Mandril, the spindle which carries the centre-chuck of a lathe, and communicates motion to the metal to be turned : in small lathes it is driven by a pulley Mandril-frame, the head-stocks or frame bolted to the end of a lathe- bed, for the purpose of supporting the mandril Mangrove, an aquatic tree, straight- grained, hard, and elastic: much used for ship-building Man-hole, in locomotive engines, an opening in the top of a boiler, used MAN MARINE ENGINE. MAR as an entrance when the boiler re- quires cleaning : it is covered by a strong plate bolted to the boiler plating, so as to be steam-tight Man-hole cover, inlocomotive engines, a strong plate of iron, bolted over the man-hole so as to be remove- able when required Manipulation, in mining, the manner of digging silver or other metals ; a term now generally applied to the means by which materials or effects are produced Manner is that habitude which paint- ers have acquired, not only in the management of the pencil, but also in the principal parts of painting, invention, design, and colouring. It is by the manner in painting that a picture is judged to be by the hand of Titian, Tintoret, Guido, the Caracci, and others. Some masters have had a variety in their manners at different periods of life, and others have so constantly adhered to one manner, that those who have seen even a few of them will imme- diately know them, and judge of them without any risk of a mistake. The variety observable among ar- tists in their manner and taste arises from the practice of the dif- ferent schools in which they have received their instruction, or of the artists under whom they have stu- died. Yet there are many instances of great artists who have divested themselves of that early partiality to a peculiar manner, and have altered it so effectually as to fix on one abundantly more refined and better adapted to their peculiar genius, by which means they have arrived at excellence. Thus, for instance, Raphael proceeded, and acquired a much more elevated manner after he had quitted the school of Perugino. Mannerist, a term applicable to a painter whose pictures have no re- semblance to the beautiful varieties of nature,but discover an unpleasing and tasteless sameness Manometer, an instrument intended 272 to measure the rarefaction and con- densation of elastic fluids in confined circumstances, whether occasioned by variation of temperature or by actual destruction, or generation of portions of elastic fluids Mansard roof, of French origin, from the name of the inventor ; a curb roof Manse, a parsonage-house Mantel-piece, a beam across the open- ing of a fire-place, serving as a lintel or bressummer to support the masonry above, which is called the chimney-breast Maple wood is considered to be allied to the sycamore or the plane- tree; its colour is pale: much used for picture frames and Tunbridge ware Marble, a kind of stone found in great masses, and dug out of pits or quarries Marcus, a large iron-headed hammer Market. The market or forum in the cities of antiquity was different from the market in our English towns, where flesh meat, merchan- dise, &c., are usually sold. The Apostle Paul disputed with philo- sophers in the market at Athens : this and other evidences prove it to have been also a place of dispu- tation and public resort. Margin or Lock-rail, the flat part of the stile and rail of framed work Marine engine, a steam engine to propel a ship. There are various kinds of them, the beam, direct- acting, oscillating, &c. (See Tred- gold's work.) Marline, a small line used for winding round ropes and cables Marone is of a class of impure colours, composed of black and red, black and purple, or black and russet pigments, or with black and any other denomination of pigments in which red predominates Marone lake is a preparation of mad- der, of great depth, transparency, and durability of colour : it works well in water, glazes and dries in oil, and is in all respects a good MAR MASONRY. MAT pigment : its hues are easily given with other pigments, but it is not much used Marquetry, chequered or inlaid work ; work inlaid with variegation, a sort of veneering, representing flowers, birds, and other figures Masonry. The early Roman archi- tecture, both in public and private buildings, was of far more durable materials and of more accurate masonry than such as was executed in the decline of the empire. It began to be uncemented blocks of stone, passed into the reticular work of the republic, thence into the travertine, and descended into the mixture of tufo, and brick, and stucco facing. Masonry. Marble is polished by being first rubbed with grit-stone, after- wards with pumice-stone, and lastly with emery or calcinedtin. Marbles, with regard to their contexture and variegation of colour, are almost in- finite : some are black, some white, and some of a dove colour : the best kind of white marble is called statuary, which, when cut into thin slices, becomes almost transparent, which property the other kinds do not possess. Other species of mar- ble are streaked with clouds and veins. The texture of marble is not altogether understood, even by the best workmen ; but they generally know upon sight, whether it will receive a polish or not. Some mar- bles are easily wrought, some are very hard, other kinds resist the tools altogether. Artificial marble, or Scagliola, is real marble pulver- ized and mixed with plaster, and is used in columns, basso-relievos, and other ornaments. The chief kind of stone used in London is Portland stone, which comes from the island of Portland, in Dorsetshire ; it is used for build- ings in general, as strings, window- sills, balusters, steps, copings, &c., but under great weight or pressure it is apt to splinter, or flush at the joints. When it is recently quar- 273 ried, it is soft and works easily, but acquires great hardness in course of time. St. Paul's cathedral and Westminster bridge are construct- ed of Portland stone. Purbeck stone comes from an. island of the same name, also in Dorsetshire, and is mostly employed in rough work, as steps and paving. Yorkshire stone is also used where strength and durability are requisites, as in paving and coping. Ryegate stone is used for hearths, slabs, and covings. Mortar is used by masons in ce- menting their works. (See Brick* laying, Cements, Mortars, &c.) In setting marble or fine work, plaster of Paris is used, and in water-works, tarras is employed. Tarras is a coarse mortar, durable in water, and in most situations. Dutch tarras is made of a soft rock- stone, found near Cologne, on the Rhine. It is burnt like lime, and reduced to powder by mills, from thence carried to Holland, whence it has acquired the name of Dutch tarras. It is very dear, on account of the great demand for it in the construction of aquatic works. An artificial tarras is formed of two parts of lime and one of plaster of Paris : another sort consists of one part of lime and two parts of well-sifted coal ashes. Mast curlings, in ship-building, large timbers at the side of the mast rooms that are left deep enough to receive the cross-chocks Mastic, a cement used for the plaster- ing of walls Mastic varnish is easily prepared by digesting in a bottle, during a few hours, in a warm place, one part of dry picked resin with two parts or more of the oil of turpentine Materiatio, according to Vitruvius, the timber-work of a roof Mathematics, a science which teaches to number and measure whatever is capable of it, comprised under lines, numbers, superficies, or solids Matter and Motion. Quantities of MAU MEASUREMENT. MEA matter in all bodies are in the com- pound ratio of their magnitude and densities ; for if the magnitudes are equal, the quantities of matter will be as the densities ; and if the den- sities are equal, the quantities of matter will be as the magnitudes : therefore, the quantities of matter are universally in the compound ratio of both. Mausoleum, a pompous funereal mo- nument, a costly sepulchre Maximum and minimum. The ex- tremes of temperature are no less important to the meteorologist than interesting to the general observer. They are obtained by the self-re- gistering thermometer. The first instrument of this kind was sug- gested by John Bernpuilly. Several forms of thermometers were com- municated to the Royal Society by Lord Charles Cavendish. The next in point of time were the contri- vances of Fitzgerald and Crighton. Six, Rutherford, Keith, Blackadder, and Dr. Trail, greatly added to the Fig. stock of self-registering thermo- meters. There are two kinds in general use ; Mr. Six's, which is placed vertically, and Dr. Ruther- ford's, which is suspended horizon- tally. The latter is preferable on land, and, from its simplicity, has to a certain extent superseded the former. Mear, thirty-two yards of ground in a vein of ore Measurement of earth-work. There are many works and tables pub- lished to facilitate the admeasure- ment of earth-work, which may be reduced in practice to the follow- ing geometrical forms, in one or more chains in length, as the case may be. The two chains marked B and c in the section will reduce to the forms in the diagrams that follow. The dotted lines, fig. 1, show the section at the largest end, next to B in the section ; and the dotted line, fig. 2. shows the sec- tion at the smallest end, next to A in the section. The bottom piece, c, being re- duced to a parallel throughout, is measured by multiplying the area of Slopes 2 to 1. the end by the length : the two banks being equal, it will measure thus : 15' 0" x 57' 0" x 132' 0". 274 The piece B, the middle or wedge piece, being parallel horizontally only, is measured by taking one- Fig. 2. half the vertical height : thus, 3' 6" x 87' 0" x 132' 0". MEA MEASUREMENT. MEA The two pieces B B form the two halves of a right-angled pyramid, and are measured by multiplying the area of the end by one-third the height : therefore 7' 0" x 14' 0", the slope being 2 to 1, is equal to 98' 0" ; the area of the two bases then, 1' 0" x 98' 0" x 44' 0", gives the cube quantity in the two. Measurement of shipping for tonnage (called the 'new measurement') was regulated in the 5th and 6th of George IV. By this Act certain rules were established for ascer- taining the tonnage of ships, as well on shore as afloat, and of ves- sels propelled by steam ; and the account of such tonnage, whenever the same shall have been ascer- tained according to the rules herein prescribed, (except in the case of ships admeasured afloat,) it is en- acted, shall be deemed the tonnage of such ships, and shall be repeated in every subsequent registry of such ships, unless any alteration shall have been made in their form and burthen, or unless it be disco- vered that the tonnage had been erroneously computed : and it is considered that the capacity of a ship is the fairest standard by which to regulate its tonnage ; that inter- nal measurements will afford the most accurate and convenient me- thod of ascertaining that capacity, and that the adoption of such a mode of admeasurement will tend to the interests of the ship-builder and the owner. It was enacted that the tonnage of every ship or vessel required by law to be registered shall, previous to her being registered, be mea- sured and ascertained while her hold is clear, and according to the following rule : Divide the length of the upper deck between the after-part of the stem and the fore- part of the stern-post into six equal parts. Depths : At the foremost, the middle, and the aftermost of those points of division, measure in feet and decimal parts of a foot the 275 depths from the under side of the upper deck to the ceiling at the limber strake. In the case of a break in the upper deck, the depths are to be measured from a line stretched in a continuation of the deck. Breadths : Divide each of those three depths into five equal parts, and measure the inside breadths at the following points : at one-fifth and at four-fifths from the upper deck of the foremost and aftermost depths, and at two-fifths and four-fifths from the upper deck of the midship depth. Length : At half the midship depth measure the length of the vessel from the after-part of the stem to the fore- part of the stern-post, then to twice the midship depth add the foremost and the aftermost depths for the sum of the depths ; add to- gether the upper and lowerbreadths at the foremost division, three times the upper breadth and the lower breadth at the midship division, and the upper and twice the lower breadth at the after division, for the sum of the breadths ; then mul- tiply the sum of the depths by the sum of the breadths, and this pro- duct by the length, and divide the final product by three thousand five hundred, which will give the num- ber of tons for register. If the vessel have a poop or half-deck, or a break in the upper deck, measure the inside mean length, breadth, and height of such part thereof as may be included within the bulk- head; multiply these three mea- surements together, and dividing the product by 92'4, the quotient will be the number of tons to be added to the result as above found. In order to ascertain the tonnage of open vessels, the depths are to be measured from the upper edge of the upper strake. To ascertain the tonnage of steam vessels, it was also further enacted, that in each of the several rules prescribed, when applied for the purpose of ascertaining the tonnage ME A MECHANICS. MEN of any ship or vessel propelled by steam, the tonnage due to the cu- bical contents of the engine-room shall be deducted from the total tonnage of the vessel as determined by the rules, and the remainder shall be deemed the true register tonnage of the said ship or vessel. The tonnage due to the cubical contents of the engine-room shall be determined in the following manner : measure the inside length of the engine-room in feet and de- cimal parts of a foot from the fore- most to the aftermost bulk-head, then multiply the said length by the depth of the ship or vessel at the midship division, as aforesaid, and the product by the inside breadth at the same division at two-fifths of the depth from the deck taken as aforesaid, and divide the last product by 92-4, and the quotient is deemed the tonnage due to the cubical contents of the engine-room. Measurement of standing timber. Measure from the tree ten, twenty, thirty, &c., feet, and then plant the theodolite level: direct the tele- scope to the bottom of the tree, and observe the degree and tenth of depression ; and to the top of the tree, the degree and tenth of elevation. When the timber has been previously felled, it is custo- mary, in measuring, to girt a string round the middle of the tree, and fold it twice, which will give the fourth part of the girt, and which is considered the true side of the square ; then the length is mea- sured from the but-end of the tree, so far up as the tree will hold half a foot girt, or, more properly speaking, quarter-girt ; that is, the line six inches when twice folded. Various tables are published, to assist the timber-measurer in the performance of his duty. All tim- ber is bought and sold by the load, and a load is estimated at forty feet of unhewn or rough timber, and fifty feet of hewn timber, which is supposed to weigh one ton, or twenty hundred weight. Mechanical powers are contrivances by which we are enabled to sustain a great weight or overcome a great resistance by a small force. (See Machinery.} Mechanics, that branch of practical science which considers the laws of equilibrium and the motion of solid bodies ; the forces by which bodies, whether animate or inanimate, may be made to act upon one another ; and the means by which these forces may be increased so as to overcome those which are more powerful. The term mechanics was originally applied to the doc- trine of equilibrium. It is now, however, extended to the motion and equilibrium of all bodies, whe- ther solid, fluid, or aeriform. The complete arrangement of mecha- nics is now made to embrace, be- sides, the pressure and tension of cords, the equilibrated polygon, the catenary curve, suspension bridges, the equilibrium of arches and the stability of their piers, the construc- tion of oblique arches, the equili- brium of domes and vaults with revetments, the strength of mate- rials, whether they be of wood or iron, dynamics, or the science of moving bodies, with hydrostatics, pneumatics, and hydraulics. Medallion, in architecture, any cir- cular tablet on which figures are embossed; busts, &c. Mediaeval, relating to the middle ages Member, a moulding; either as a cornice of five members, or a base of three members, and applied to the subordinate parts of a building Mensuration is the application of the science of arithmetic to geometry, by which we are enabled to discover the magnitude and dimensions of any geometrical figures, whether solid or superficial. To enable us to express this magnitude in deter- minate terms, it is necessary to assume some magnitude of the same kind as the unit, and then, by 276 END OF PART II. MER MERE, HAARLEMMER. MER stating how many times the given magnitude contains that unit, we obtain its measure. The different species of magni- tude which have most frequently to be determined are distinguish- able into six kinds, viz. 1. Length. 2. Surface. 3. Solidity, or ca- pacity. 4. Force of gravity, com- monly called weight. 5. Angles. 6. "Time. Mere, or Meer, a name frequently given, in England and the Nether- lands, to inland lakes or sheets of fresh water, such as Windermere, Whittleseamere, Ugg-mere, So- ham-mere, in England, and the Egmonder meer, Purmer meer, and Haarlemmer meer, &c., in the Ne- therlands. The term is most fre- quently used in the latter country, where, prior to 1440, there were more than 150 meers, of which 85 occupied an area of 177,832 acres, since drained and reclaimed, in the provinces of North and South Hol- land; and where also the Haarlem- mer meer, covering an area of 45,230 acres, is now in course of drainage. As the meers, in fen-lands, serve as reservoirs to hold a portion of the surplus rain-water falling on the district of which they form a part, their being dyked off and drained, where of considerable ex- tent, has most important effects on the neighbouring lands, by con- tracting the area of the reservoir or catch -water basin of the district. But as these drainages generally oblige improvements in the out- falls, their result is mostly benefi- cial to the other lands. The beds of the Dutch meers are from 10 to 20 feet below the level of the lowest point of the natural outfall in their districts ; consequently they are always drained by mechanical means. Wind-mills have been employed to drain the land, in the Netherlands, from time immemorial; but the drainage of the meers was not com- 277 ~ menced until 1440, about which period wind-mills and draining machinery were considerably im- proved; and as late as 1840, wind- mills for draining purposes conti- nued in favour with the Dutch engineers, in preference to steam engines; and at that date, 12,000 wind-mills were employed to drain the polders, in the Netherlands, and only five small steam engines, the largest not exceeding 30-horse power: the average consumption of fuel was 20 ibs. of coal per horse power per hour. In the English fens, steam had in a great measure superseded wind- mills for drainage purposes ; but the consumption of fuel was nearly as great as in the Dutch engines. In 1839, the Dutch States-Ge- neral decreed the drainage of the Haarlemmer meer, and voted eight millions of florins for that purpose, to which two millions more were subsequently added, making the total sum of 834,000. The Haarlemmer meer forms part of the great drainage district of Rhynland, which has an area of 305,014 English acres: prior to 1848, this area was occupied by 56,609 acres of meers and water- courses, nearly all in communica- tion with each other, forming what is called the boezem, or catch-water basin of the district ; the surface of the water being maintained at the lowest level of natural sluiceage, by sluices at Katwyk into the North Sea, and at Sparndam and Halfweg into the Y, or the southern end of the Zuyder Zee. Above the boezem are 75,357 acres drained into it by natural level ; and at depths from 2 feet 6 inches to 4 feet below it are 170 polders covering an area of 135,850 acres; and 37,198 acres, divided into 28 polders which were for- merly meers, but are now drained, and whose beds are on an average 14 ft. below the level of the boezem. The surplus rain and infiltration MER MERE, HAARLEMMER. MER waters from the 173,048 acres of polder-land are lifted into the boe- zem by the united action of 261 large wind-mills, with an average force of 1500-horse power. The drainage of the Haarlemmer meer, which forms part of the boezem or basin, will deduct45,230 acres from its area, and reduce it to 11,379 acres, or th part of its former size ; whilst the land surface drained into it will be increased from 229,657 to 293,735 acres. The average level of the boezem is 10 inches below the ordinary low water, and 27 inches below high-water mark in the Y or Zuy- der Zee ; and 7 inches above low water, and 57 inches below ordi- nary high water, in the North Sea. The bed of the Haarlem Lake is 14 feet below the winter level of the boezem ; and when drained, the maximum lift will be 16 feet 6 inches to 17 feet, according to the state of the wind, which raises or depresses the surface of the wa- ter in the canals very considerably. The water contents of the Haar- lemmer meer to be pumped out, including the additional quantity arising from the surplus rain and infiltration during the draining, are estimated at 800,000,000 cubic metres or tons. The greatest quantity of monthly drainage when the meer is pumped out is estimated at 36,000,000 tons, and the annual average sur- plus of rain-water, &c. at 54,000,000 tons to be lifted, on an average, 16 feet high. The Dutch engineers were gene- rally in favour of wind-mills, or a combination of wind-mills and steam engines, for pumping out the meer; but in 1841, the late king, William II., by the advice of a commission, decreed that steam engines only should be employed for the purpose; and in 1842, at the suggestion of two English en- gineers, Mr. Arthur Dean and Mr. Joseph Gibbs, it was determined to 278 erect, and they were directed to prepare the designs for, three steam engines upon the high-pressure, expansive, condensing principle, of the ordinary force of 350-horse power each, but capable of being worked on emergencies up to 500- horse power. The consumption of fuel was limited to 2 fts. of coal per horse power per hour. The three engines were named the ' Leeghwater,' ' Cruquius,' and 'Lynden/ after three celebratedmen who had at different periods pro- posed plans for draining the Haar- lemmer meer. The ' Leeghwater ' was the first erected, to work eleven pumps of 63 inches diameter, with 10-feet stroke in pumps and steam cylin- ders; and the ' Cruquius' and 'Lyn- den/ were afterwards constructed, to work eight pumps each, of 73 in. diameter, and with 10-feet stroke ; each engine is calculated to lift 66 cubic metres or tons of water per stroke. The accompanying sketch is a representation of the interior of the ' Lynden ' engine and engine- house, on the upper floor : the ' Cruquius ' is on the same model ; but the ' Leeghwater ' has the inner ends of its eleven pump-beams ar- ranged under the great cross-head, instead of over it. Each engine has two steam cy- linders, placed concentrically, the one within the other, the outer of 12 feet diameter, and the inner one of 7 feet diameter : both are secured to one bottom, and covered by one cover, but the inner cylin- der does not touch the cover within 1^ inch : there are two pistons, 26 inches deep, the com- partments of which are fitted with cast-iron plates : the outer piston is annular, and has a packing on both sides : beneath this annular piston a constant vacuum is main- tained when working : the two pistons are connected by five pis- ton-rods, as shown in the sketch, to a great cross-head or cap, the whole mass weighing about 85 tons, andby eight connecting-rods the cap 279 pistons are suspended from the in- ner ends of eight cast-iron balance- beams, to the outer ends of which are hung the eight pump-pistons ; MER MERE, HAARLEMMER. MER the action of the engines is therefore very simple: the steam being ap- plied under the inner piston, lifts both the pistons, the great cross- head, and inner ends of pump ba- lance-beams simultaneously, andthe pump-pistons descend at the same time : by an hydraulic apparatus attached to the great cross-head, the dead weight of the pistons, &c. is arrested at the point to which it has been thrown up by the steam, and time is given for the valves of the pump-pistons to close before the down -stroke of the steam- pistons is made ; then, the equili- brium-valve being opened, the hy- draulic apparatus is liberated at the same moment, and the steam passing from beneath the small piston, above both pistons, the pressure on both sides of the small one is equalized, whilst nearly two- thirds of the steam acts upon the annular piston against a vacuum, and in aid of the dead weight helps to make the down-stroke in the steam-cylinder, and the up- stroke in the pumps. The use of the two cylinders enables the en- gine-man, by judiciously altering the expansion in the small cylinder, to command his work at all times, without stopping the engine to take out, or put in, dead weight, as would be necessary for a single- acting one-cylinder engine, where dead weight only is used for lifting the water. It has frequently oc- curred that the load of an engine has been added to or diminished by 10 or 12 tons in the course of half an hour, by the action of gales of wind on the surface of the meer and boezem. Each engine has two air-pumps of 40 in. diameter, and 5-feet stroke. The steam is cut off in the small cylinder at from one-fourth to two-thirds of the stroke, according to the load ; and after expanding through the remainder of the stroke, it is still further expanded in the large cy- linder. 280 The anticipated economy in con- sumption of fuel has been realized : when working with the net power of 350 horses, the average con- sumption is 2 tbs. of best Welsh coals, or 75 millions duty with 94 its. of coal ; and on a late trial, the ' Cruquius ' and ' Lynden ' en- gines were found to do a duty of 87 millions. The whole cost of machinery, buildings, coals, and wages, to pump out the lake, will not exceed 150,000, whereas, by wind it would have cost 308,000, being a saving of 158,000; and there will also be a further economy upon the works in the bed of the lake, amounting to 40,000 more, so that the total saving by steam over wind will be 200,000, and three years' time. To compensate the district of Rhynland for the loss of 45,230 acres of the boezem or catch-water basin, a steam engine of 200-horse power, driving 10 large scoop- wheels, has been erected at Sparn- dam to lift the boezem water over the tide in the Y, or base of the Zuyder Zee, where the rise is on an average only 17 inches. This engine has discharged 30,000,000 tons of water in fifteen consecutive days. When the state of the boezem permits the ' Leeghwater,' ' Cru- quius/ and 'Lynden 'engines to work freely, they discharge on an aver- age 2,000,000 tons in twenty-four hours, and they are capable of doing this down to their full depth. In the month of June, 1849, the three engines discharged 60,000,000 tons water, and lowered the meer one foot; between the 1st of May and 1st of December they had lowered the lake 5 feet, and by the autumn of 1850, it is calculated the dry land will appear. (See Table.) The 'Leeghwater,' ' Cruquius' and ' Lynden ' engines were contracted for jointly by the Hayle and Per- ran Foundry Companies, Cornwall, and were manufactured and erected MERES, DRAINAGE OF. Table, arranged chronologically, showing the Lakes, Meers, and Water-placet which have been drained by mechanical means, and converted into Fertile Lands, in the Provinces of North and South Holland, in the Netherlands. NORTH HOLLAND. 82 SOUTH HOLLAND. !" Date of Name of Lake, l Name of Lake, l*b Drain- Meer, or Water- Location near. ^fl Meer, or Water- Location near. gw age. place. place. << B 1440 Nesch Meer Wervershoofd 59 1460 Burghornder Do. Burghorn 684 1553 1555 The Zyp Egmonder Meer Schagerbrug Egmond 19026 10080 n Berger Do. Bergen 1394 1560 Daal Do. Koedyk 285 1561 Vrooner Do. St. Pancras 246 1566 Achter Do. Alkmaar 78 Kooi Do. Do. 33 1567 Zwyns Do. Oudorp 38 1580 Boekeler Do. Akersloot 745 1607 Wog Do. Spierdyk 1541 1608-12 The Beemster Purmerend 16369 The Weiring- \ erwaard J Colkom 3979 1614 .. .. Soetermeeriche \ Meer / Soetermeer 12S5 1616 1618-22 Tjaarlinger Meer Purmer Do. Warmenhuizen Purmerend 98 6260 1622 The Lisserpoel Lisse 533 1624 Baarsdorper Do. Berkhout 401 Hem Meer Sassenheim 149 TheEngeWor-"! Near Worme-\ 241 ** mer J meer / 1625 The Hr. Huo gowaard J Langendyk 6904 M Broeker Meer -f Broek&Wa- \ ter-land J 638 1625-28 Belmer Do. Monnikendam 310 Buikslooter Do. Buiksloot 772 1626 The Groot Waal Berkhout 138 }j Wormer Meer Gisp 3786 1626-29 Diemer Meer Diemen 1575 1630 Benning Do. Abbekerk" 245 Harger & Pet- 1 temer Polder J Petten 987 1631 The Tien Meeren Haring Garspel 4647 M TheDrie Do. Oud Garspel 730 Kley Meer Koedyk 147 Kerk Do. Do. 48 Deble Do. Warmenhuizen 31 Greb Do. Do. 201 The Vier 1 Meertjes J Medenblyk 680 Braak Meer Eerstwoude 69 Veenhuizer Do. Veenhuizen 718 Schals Do. Knollendam 145 1632 Schermer Do. N.&S. Schermer 12938 1633 The Vier 1 Meertjes J Obdam 142 1636 Berk Meer Veenhuizen 596 1640 Kolk Do. { Lambert Scha- > gen 220 1642 .. Slooter Meer 190 1643 Star Do. Oostgrafdyk 1447 1644 Noordeinder Do. Graft 409 1645 Sap Do. TheRyp 52 1646 The Wilde \ Veenen J Moerkapel 1322 1650 .. Stom Meer Aalsmeer 409 281 MERES, DRAINAGE OF. Date of Drain- age. NORTH HOLLAND continued Area drained in Eng. acres. SOUTH HOLLAND continued Area drained in Eng. acres. Name of Lake, Meer, or Water- place. Location near. Name of Lake, Meer, or Water place. Location near. 1666 .. Wassenarsche ", Polder J Rhynsaterwoud 2488 1668 .. The Driemans \ Do. J Soetermeer 2013 1674 . . . . Horn Meer Aalsmeer 441 1700 .. Binnenweg- \ sche Polder J Zegwaard 2247 ^ . . H. Geest Polder Leyminden 384 1715 Goger Do. Alkernade 607 1/27 . . Katjes Do. Zevenhuizen 772 1736 .. The Starre- > vaarts Do. J Stompwyk 443 1736-44 .. The Vier Am- 1 bachts Do. / Esselykerwoude 518 1741 Vrieskoophche \ Vriezekqop 1325 1754-62 .. Endragts Do. Zevenhuizen 2473 1758-59 . Damhouder Do. Stompwyk 949 1759-65 . . Novider Plas Hazerswoude 8415 1760-62 .. Palenternsche \ Polder ; Zegwaard 1279 1763-66 .. .. Ouwendvksche \ & Boe Do. / Esselykerwoude 806 1764 .. .. Bovenkerker Do. Amstelveen 3412 Great and Lit- 1 1767-68 ... tie Kalko- J. Oudshoorn 1318 vensche Do. J The Groote Do. Soetermeer 1686 1768-71 . . Do. Do. Stompwyk 1178 1772-77 Berkelsche Do. Berkel 2171 1772-82 .. Bleiswyksche T Drainage J Bleiswyk 8299 1773-80 Schiebroksche \ Polder J Schiebroek 1457 1781-84 .. Veender en "i Lyker Do. J Alkemade 1373 1782-89 .. Pynakerscke Do. Pynacker 1270 1786-88 .. Aarlander- \ veensche Do. / Aarlanderveen 1171 1788-91 .. .. . % Zestienho- \ vensche Do. / Overschie 1064 1/88-99 .. Schieveensche \ Do. / Overschie 654 17901 1810/ .. Mydrechtsche 1 Do. J Mydrecht 2622 1797-1 1809/ .. .. : :"~ .'" Niewekoopsche ") en Zevenho- > venesche Do. J Niewekoop 1571 1798-99 .. .. Gnephoek en \ Vrowe Do. / Oudshoorn 254 1799-1 1801 J Bieslandsche Do. Nootdorp 333 1810 Kleine Slarre- \ vuartsche Do. J Leydschendam 23 1820 .. .. Bylmer Meer Weesp 1470 1828-40 . . The Zuid Plas Rotterdam 4820 1842 .. .. Nootdorpsche \ Plas Delft 2500 Haarlem Lake"! Amsterdam, "\ 1840-50 .. . . (not yet com- > Haarlem and > 45230 pleted) J Leyden J 98557 In South Holland, acres 124505 In North Do. Do. 98557 ! Total Acres 223062 282 MER MERIDIAN. MES under the direction of Mr. Arthur Dean ; they have all worked during nearly three months with only twelve hours' stoppage. It may be said in this instance, the Dutch have realized the fable of the ' Hare and the Tortoise:' in 1840, the erection of a steam engine of 30 or 40-horse power, for drainage purposes, was thought to be a bold step, whereas, under the guidance of English engineers, they have dared, between 1840 and 1849, to erect the most gigantic steam machinery in the world. The low lands of the Nether- lands are divided into large drain- age districts, which have been em- banked against the inroads of the tides and river floods ; and the va- rious parts of a district are con- nected by what is called the doezem, or water-basin, or reservoir, formed by the rivers, lakes, meers, or water- places having their origin in the district, and serves to receive the water drained either naturally or artificially from the surrounding lands. The boezem is put into communication with the exterior waters of the rivers or sea by locks and sluices. All lands in a given drainage district above the level of the boezem, and draining naturally into it, are called boezem lands.' All lands lying below the boezem, and drained into it by machinery, are called polders. Of polders there are two kinds : the first are seldom more than 2 or 3 feet below the level of the boezem, which is em- banked above the natural surface of the land : of such polders there are upwards of 1000 in the pro- vince of South Holland only ; and they are kept dry by the aid of an immense number of wind-mills. Of the second class of polders there are 43 in North Holland and 43 in South Holland, as recorded in the precedingTable,and these are works of a formidable character, being, for the most part, the beds of lakes, or permanent sheets of water, varying 283 in depth from 5 to 20 feet below the boezem, and requiring powerful machinery to pump them out in the first instance, and to maintain them dry afterwards ; and as these lakes, &c., always form part of the boezem, or reservoir, of a much larger tract of land, their drainage frequently involves the construction of immense works, and seriously affects the prosperity of the whole district in which they are situate. The preceding Table will, as an apt illustration of the subject of draining large districts, be found important in engineering history. By the Table it will be seen that the North Hollanders had effected the drainage of nearly all their lakes, &c., as early as 1645, and they had then recovered 98,557 acres of land forming their beds ; whereas the South Hollanders had in 1645 only drained five small lakes, whose area was only 3741 acres. It must be observed that the South Holland drainages are of a much more extensive character than those of North Holland, and the difficulties to be overcome were much greater; and last, but not least, the North Hollanders were much richer than their neighbours. Of the 223,000 acres of lakes, &c., recorded in the Table, upwards of 50,000 acres were formed artifi- cially, by dredging the peat pulp to the depth of 10 or 20 feet, to serve as fuel for domestic pur- poses, &c. Meridian, in astronomy, the line drawn from the north to the south, through the zenith, nadir, and poles, which line the sun crosses at noon Merlon, the solid part of an embattled parapet, standing up between the embrasures Merits, the plain surface between the channels of a triglyph Mesaula, a passage, gallery, lobby; an entry or court Mestlinff, brass ornaments; candle- sticks ; sacred utensils used in An- glo-Saxon times MET METALS. MET Metallurgy, the art of working me- tals, invented by Tubal-Cain, B. c. 3608. " And Zillah also bare Tubal- Cain, an instructor of every arti- ficer in brass and iron." (Gen. iv. 22.) In the earliest periods of his- tory, mention is made of the ex- cellence in working metals among the Egyptians. Some specimens of metal-work of an early date exist, and modern fashion has also pro- duced some very elaborate ex- amples. Metals are elementary bodies capable of combining with oxygen ; and many of them, during this combi- nation, exhibit the phenomenon of combustion. Seven metals only were formerly known ; but recently a much greater number has been been added. Metals are distin- guished by their great specific gra- vity, considerable tenacity, and hardness, opacity, and property of reflecting the greater part of the light which falls on their surface, giving rise to metallic lustre or brilliancy. Metals are the best conductors of caloric : their expan- sibilities are various, and are pro- bably nearly in the order of their fusibilities. Mercury melts at so low a temperature, that it can be obtained in the solid state only at a very low temperature ; others, as platina, can scarcely be melted by the most intense heat which we can excite. Metals employed in the mechanical arts : ANTIMONY is of a silvery white colour, brittle, and crystalline in its ordinary texture : it fuses at about 800 : its specific gravity is 6-712. BISMUTH is a brittle, white metal, with a slight tint of red : its specific gravity is 9-822 : it fuses at 476, and always crystallizes on cooling. COPPER is the only metal, with the exception of titanium, which has a red colour: it has much lustre, is very malleable and ductile, and 284 exhales a peculiar smell when warmed or rubbed : it melts at a bright red or dull white heat, or at a temperature intermediatebetween the fusing points of silver and gold = 1996 Fahr. : its specific gravity varies from 8*86 to 8-89, the for- mer being the least density of cast copper; the latter, the greatest of rolled or hammered copper. GOLD is of a deep and peculiar yellow colour : it melts at a bright red heat, equivalent, according to Daniell, to 2016 Fahr., and when in fusion, appears of a brilliant greenish colour: its specific gra- vity is 19-3 : it is so malleable, that it may be extended into leaves which do not exceed the S8i ^ 000 th of an inch in thickness, or a single grain may be extended over 56 square inches of surface. LEAD in colour is blueish white : it has much brilliancy, is remarka- bly flexible and soft, and leaves a black streak on paper. When han- dled, it exhales a peculiar odour : it melts at about 612, and by the united action of heat and air, is readily converted into an oxide. Its specific gravity, when pure, is 11*445 ; but the lead of commerce seldom exceeds 11 '3 5. Lead is used, in a state of comparative purity, for roofs, cisterns, pipes, vessels for sulphuric acid, &c. MERCURY is a brilliant white metal, having much of the colour of silver. It has been known from remote ages. It is liquid at com- mon temperatures, solid and mal- leable at 40 Fahr., and contracts considerably at the moment of con- gelation : it boils and becomes va- pour at about 670 : its specific gravity at 60 is 13-5. In the solid state, its density exceeds 14. The specific gravity of mercurial vapour is 6-976. NICKEL is a white, brilliant metal, which acts upon the magne- tic needle, and is itself capable of becoming a magnet. Its magnetism is more feeble than that of iron, MET METALS. MET and vanishes at a heat somewhat below redness. At 6-30 it is duc- tile and malleable : its specific gra- vity varies from 8-27 to 8-40 when fused, and after hammering, from 8-69 to 9'00. It is not oxidized by exposure to air at common tempe- ratures; but when heated in the air, it acquires various tints, like steel: at a red heat, it becomes coated by a grey oxide. PALLADIUM is of a dull white colour, malleable and ductile. Its specific gravity is about 11 '3, or 11 '86 when laminated. It fuses at a temperature above that required for the fusion of gold. PLATINUM is a white metal, extremely difficult of fusion, and unaltered by the joint action of heat and air. It varies in den- sity from 21 to 21-5, according to the degree of mechanical compres- sion it has sustained. It is ex- tremely ductile, but cannot be beaten into such thin leaves as gold and silver. RHODIUM, discovered in 1803 by Dr. Wollaston, is a white metal, very difficult of fusion. Its specific gravity is about 11; it is extremely hard. When pure, the acids do not dissolve it. SILVER is of a more perfect white than any other metal : it has considerable brilliancy, and takes a high polish. Its specific gravity varies between 10 - 4, which is the density of cast silver, and 10'5 to 10*6, which is the density of rolled or stamped silver. It is so mallea- ble and ductile, that it may be ex- tended into leaves not exceeding a ten-thousandth of an inch in thick- ness, and drawn into wire much finer than a human hair. Silver melts at a bright red heat, estimated at 1873 Fahr., and when in fusion appears extremely brilliant. TIN has a silvery white colour, with a slight tint of yellow : it is malleable, though sparingly ductile. Common tin-foil, which is obtained by beating out the metal, is not 285 N5 more than 1 ^o O th of an inch in thickness, and what is termed 'white Dutch metal* is in much thinner leaves. Its specific gravity fluctuates from 7*28 to 7*6, the highest being the purest metal. When bent, it occasions a peculiar crackling noise, arising from the destruction of co- hesion amongst its particles. When a bar of tin is rapidly bent back- wards and forwards several times successively, it becomes so hot that it cannot be held in the hand. When rubbed, it exhales a peculiar odour. It melts at 442, and by exposure to heat and air is gradu- ally converted into a protoxide. ZINC is a blueish white metal, with considerable lustre; rather hard ; of a specific gravity of about 6'8 in its usual state; but when drawn into wire, or rolled into plates, its density is augmented to 7 or 7*2. In its ordinary state, at common temperatures, it is tough, and with difficulty broken by blows of the hammer: it becomes very brittle when its temperature ap- proaches that of fusion, which is about 773; but at a temperature a little above 212, and between that and 300, it becomes ductile and malleable, and may be rolled into thin leaves, and drawn into moderately fine wire, which, how- ever, possesses but little tenacity. When a mass of zinc which has been fused is slowly cooled, its fracture exhibits a lamellar and prismatic crystalline texture. The pipes of the great organ in the town-hall at Birmingham, and in that of York cathedral, are made principally of sheet zinc. Meteorology, the term now used for the purpose of designating the sci- ence which observes, registers, clas- sifies, and compares the various and varying phenomena of our atmo- sphere. It remarks, at the same time, the connection of those phe- nomena with the heavenly bodies, and with the solid and liquid ma- terials of the earth, in reference to MET MILESTONES. MIL their reciprocal and combined in- fluence in determining the character of different climates, and with the view of learning the meteoric his- tory of every region of our globe, of ultimately investigating the laws of atmospheric change, the plan of meteoric action ; the theory, in fact, of meteorological phenomena, on which depend essentially the fit- ness of the various portions of the earth's surface for the production of distinct vegetable and other sub- stances, and for the support of ani- mal life. Meteorological phenomena are not con- fined to the inferior regions of the atmosphere, but extend as far as observations have reached. It is possible their influence may extend universally, and therefore it is de- sirable to know whether there exists throughout space a medium, or con- ductor, or whether there is such a thing in matter as vacuum. Some have, it is true, endeavoured to re- concile opinions so diametrically opposed to each other, by suggesting that the universe, though infinite, is a plenum and a void ! This (the doctrine of Leucippus) a recent au- thor declares to be really true; and some conceive that the New- tonian theory necessarily implies the reality of a metaphysical void, although the astronomical calcula- tions of that theory were made without any allowance for the re- sistance to the motions of the planets, which might be experienced from such a medium. Metoche, the intervals between two denticuli in the Ionic entablature Metope, the spaces between the triglyphs of the Doric frieze, which in the Parthenon, for instance, were filled in with sculpture; but in modern porticoes that are said to be after the Parthenon, they are mere blanks Metre, a French measure, equal to 39-3702 English inches. Mezzanine, a low intermediate story between two higher ones ~~286 Mezzo-relievo, projection of figure between alto- and basso-relievo ; demi-relievo Mezzotinto, a kind of engraving nearly resembling painting, effected by scraping and burnishing the copper Mezuzoth, a name given to certain pieces of parchment which were anciently fixed on the door-posts of houses Mica, an important ingredient in the composition of rocks, consisting of silica, alumina, oxide of iron, and potash : it is easily divided into laminae, even to the 6oo l 00 O th part of an inch, and is distinguishable from talc by its elasticity : in Russia it is used instead of window-glass Micrometer, an instrument for mea- suring small spaces Microscope, an optical instrument for rendering visible minute objects : the single microscope has one lens only, and magnifies by permitting a near view of the object ; in the compound microscope, a focal image is again magnified by other lenses Middle-ground is a term used, not to express the middle of a picture, but generally perspectively so ; some- times it is the highest part of a picture, and sometimes the second degree of shade. Pictures are di- vided into three parts : fore-ground, middle-ground, and back-ground. Middle-rail, the rail of a door which is upon a level with the hand when hanging freely : the lock of the door is generally fixed in this rail Midship signifies the middle of a ship Midship-bend, the broadest frame in the ship, called the 'dead-flat' Milestones. Pliny says, the miles on the Roman roads were distinguished by a pillar, or a stone, set up at the end of each of them, and which was marked with one or more figures, signifying how far it was from the Milliarium Aureum, a pillar in the forum near the temple of Saturn, which had on it the figure I., so that the next pillar to it, which was marked II., was but one mile from the standard pillar, and consequently MIL MINES. the XIV. and XL stones were but thirteen and ten miles from the forum. Millennium, a thousand years; the term applied to that period of the Christian Church described in Re- velation, during which, according to many commentators, it is supposed that Jesus Christ will reign person- ally on the earth, that the bodies of martyrs and other eminent Christians will be raised from the dead, and in this renewed state con- stitute the subjects of His glorious kingdom Milliare, a Roman mile, consisting of 1000 paces of 5 feet each, and therefore = 5000 feet : taking the Roman foot at 11-6496 English inches, the Roman mile would be 1618 English yards, or 142 yards less than the English statute mile. Milk for the grinding of grain into flour are of several kinds : wind- mills, with sails to be impelled by the action of the wind, over- shot and under-shot; and the horizontal, or turbine water-wheels. Mill machinery is used for the grinding of tobacco into snuff, impelled by wind, particularly in Holland, where stupendous structures can be seen on the road from Rotterdam to the Hague. Mills are also used,propelled by steam or water, for the grinding of bark, preparing of flax, sawing of timber, and for the many and varied purposes in manufacture. In the ' Papers on Engineering,' vol. vi., will be found an interesting paper by Mr. Fairbairn on 'Water- Wheels with Ventilated Buckets.' Millwrights' Planing Machine. This machine is similar in principle to the ordinary planing machine (see Planing Machine), except in cases where heavy work is required to be planed, when a machine with a moveable tool and fixed table is used. The advantage of this ar- rangement is, that very large and heavy castings are planed, which could not be moved to and fro, as , in the ordinary machines, without 287 great loss of power. It is placet over a pit made for the purpose with steps to descend into it. Th two side frames are bolted to th ground, and the table has a serie of apertures for bolts to fix thi work upon it, and can be raised o lowered to any required height bj four strong screws, one at each corner. The horizontal and ver. tical slides are placed over the work in the usual manner, and are at- tached to a light frame, which when the tool is adjusted to the work by the vertical slide, is moved to and fro, carrying with it the slides and tool, and at the end ol each backward stroke a lappet, or other contrivance, sets the vertical slide and tool a little further across the table, until the entire surface is planed. Minaret, in Mohammedan architec- ture, a spire or steeple Mineral Black is a native and impure oxide of carbon, of a soft texture, found in Devonshire Mineral Green is the commercial name of green lakes, prepared from the sulphate of copper Mineralogy forms one of the three great divisions into which natural history or the knowledge of natu- ral objects has been classified ; the other two being botany, devoted to plants, and zoology, to animals. Mineralogy is also distinguished from geology, inasmuch as it re- gards the characters of minerals in detail, without regard to their formation and general distribution in the crust of the earth, which belong to geology. If the compo- sition of a mineral substance is to be considered, then mineralogy forms a portion of chemistry ; but in its more limited sense, mine- ralogy is the art of distinguishing mineral substances from each other, and the science of accurately de- scribing and arranging them, by what may be termed a natural clas- sification. Mines. Water-springs in mines are MIN MITRE-WHEEL. MIX wrongly considered to be of great injury. It is true, the lifting of water by machinery from the deep mines is attended with expense, when they are so situated that no level, drift, or water-course can be obtained for that purpose ; but, on the other hand, they are so abso- lutely necessary in mining, that in the very first process, a judicious miner, in boring down to his mine, previous to his sinking to or work- ing it, even in this simple act, cannot proceed very deep without water to work his bore-rod in ; and if the strata of the earth passed through does not produce it, he must pour it down the bore-hole, or he cannot proceed. When all his pits or shafts are sunk, and his mine opened, and ventilation is re- quired to expel inflammable air, fire, or black damp (as it is termed), nothing is superior to water. When this can be obtained, and made to run with facility through the mine and its various workings, it is found superior to air-furnaces of any kind for expelling the fulminating va- pours so destructive to the health and lives of the workmen employed. Mines in Scotland. The general cus- tom of Scotland provides for yield- ing to the landlord a royalty pro- portioned upon the net amount of sales at the colliery, in conjunction with a certain or sleeping rent pay- able half-yearly. The royalty pro- portion is sometimes so high as one-quarter the amount of sales, but generally one-eighth ; of late years many collieries have been let at one-twelfth and at one-four- teenth the amount of sales. Mining. There is an essential differ- ence between civil and military mining : in the former, the works are frequently carried on at consi- derable depths below the surface of the earth, and sometimes in solid rock; whereas military mining is what may be termed superficial, and consequently the miner works through the more recent formations 288 of earths and sands, which, from their little tenacity, he has to sup- port as he advances. For the bet- ter ventilation of military mines, a machine has been invented by Ser- geant Lewis, of the Royal Sappers and Miners ; and it has been con- jectured that Mr. Haig's patent pneumatic engine, invented for the purpose of purifying the holds of vessels, might also be successfully employed in mining operations." Minster, a cathedral, anciently a large church. (See Westminster Abbey.) Minute, a proportionate measure in architecture, by which the parts of the orders are regulated ; the six tieth part of the lower diameter of the shaft of a column, written thus, 10', i.e. ten minutes; in geography and astronomy, the sixtieth part of a degree Miserere, projecting brackets in the under side of the seats of stalls in churches ; they are always more or less ornamented with carvings of leaves and grotesque subjects Mitre, an episcopal crown. In carpen- try, the line formed by the meeting of mouldings or other surfaces which intersect each other. If two pieces of wood be formed to equal angles, or if the two sides of each piece form equal inclinations, and thus be joined together at their common vertex, so as to make an angle double to that of either piece, they are said to be mitred together, and the joint is called 'the mitre.' Mitre-wheel, a wheel having teeth formed so as to work at an angle of 45 to the centre line of the shaft on which it is fixed, to move with another wheel of equal size, fixed on a shaft at right angles to the former one Mixed Citrine. There are two prin- ciples of combination, of which the artist may avail himself in pro- ducing these colours; the one being that of combining two original se- condaries, green and orange in pro- MIX MONASTERY. MON during a citrine; the other, the uniting the three primaries in such a manner that yellow may predomi- nate in the case of citrine, and blue and red be subordinate in the com- pound. Mixed Grays are formed by the compounding of black and white, which yields neutral grays, and of black and blue, black and purple, black and olive, &c. Mixed Greens, compounds of blue and yellow pigments, which may be formed by compounding them in the several ways of working, or by blending them in the proportions of the various hues required Mixed Olive is compounded by unit- ing green and purple colours, or by adding to blue a smaller proportion of yellow and red, or by breaking much blue with little orange Mixed Orange. Orange being a colour compounded of red and yellow, the place of original orange pigments may be supplied by a mixture of the two latter colours, by glazing one over the other; by stippling, or other modes of breaking and inter- mixing them in working, according to the nature of the work and the effect required. Mixed Purple. Purple being a se- condary colour, composed of blue and red, it follows of course that any blue and red pigments which are chemically at variance may be used in producing a mixed purple of any required hue, either by compounding or by grinding them together ready for use, or by com- bining them in the various modes of operation in painting. Mixed Russet. Orange, vermillion, and madder purple afford a com pound russet pigment of a good and durable colour. Mizen-mast, in ship-rigging, the mast next the stern Mock lead, wild lead, Hack lead, or black jack, a ponderous black mi- neral, which does not readily in corporate in the fire ; a zinc ore Model, a pattern used for moulding 289 a machine or building executed in miniature Modillion, a projecting bracket under the corona of the Corinthian and Composite orders, and sometimes of the Roman Ionic Module, a measure of proportion by which the parts of an order or of a building are regulated in classical architecture; considered generally as the diameter or semi-diameter of the lower end of the shaft of the column ; in other words, semi-dia- meter of the column, or 30 mi- nutes Molecule, synonymous with atom, in physics, a very small mass or por- tion of any body Molybdenum, a brittle and white glo- bulous metal Momentum, in dynamics, is the force of a body in motion. When the motion of a body is considered with respect to the mass, or quantity of matter moved, as well as its ve- locity, it is called its momentum, or quantity of motion. The mo- mentum of a body is therefore in the compound ratio of its quantity of matter and velocity. Monastery, an establishment for the accommodation of a religious fra- ternity, who made it the receptacle of benevolence and charity for th poor and the way-worn. A con- siderable portion of the land was formerly occupied by the monas teries and other religious houses which existed in Britain, and th< endowments of these establish ments subsequently became th< foundation of the great wealth o some of the early aristocracy in England. Of the ample means enjoyed by the inmates of these cloistered sane tuaries, some idea may be former from the following historical state- ment, translated from the preface to the ' Ely Cartulary,' preserved in the Public Library at Cambridge After the defeat and death o Harold, many of the leading mei of the realm, who had strenuous! MON MONASTERIES. MON opposed the Bastard, fled for re- fuge to Ely Monastery, together with their friends, " laden with their richest treasures," and with- stood, for seven years, the im- petuous threatenings of the Nor- mans, until they were unexpectedly surprised. " Then a council being held, it seemed advisable to implore the royal mercy ; upon which some were despatched to the king's court, at that time at Warwick, carrying rich treasures to the king, the gift of atonement and compen- sation of their misconduct; with which the king was satisfied, but on these terms and conditions, that, during his pleasure, forty royal officers should be lodged at the expense of the monastery. * * The knights are sent for, they arrive, and are present with their household, every one of whom has under him a monk of the first order, as an officer under his earl, or a guest under his host. But the king ordered that the cellarer should dispense provisions to the officers and monks promiscuously in the public hall of the convent. In short, the officers with their earls, the guests with their hosts, the knights with their monks, the monks with their knights, were most grateful to each other; for each and all of them mutually afforded each other the offices 01 humanity." Afterfive years passec in this way, the knights were re- called by the Conqueror, to assist in punishing the unnatural wicked- ness of his son Robert ; and " they departed with grief; and our monks, wonderful to relate, lamented the departure of these most illustrious companions, heroic knights, and most pleasing guests, not only in tears, but in dismal bowlings and exclamations, and struck their breasts in despair, after the man- ner of a bride whose husband is unseasonably hurried from her sweet embraces to arms." All the monks accompanied the knights as far as Hadenham, with hymns, crosses, thuribals, processions, and every solemnity, and, when re- turned, took care to paint the arms of each knight on the walls of the refectory, to the perpetual remem- brance of the uncommon humanity of their military guests." In the cartulary the names of the knights, forty in number, with their com- panions, are given ; and their arms are emblazoned on the margin. In addition to the monasteries and nunneries enumerated in the following alphabetical list, no less than 131, which are unnoticed in the Books, are said to have been scattered over England and Wales. NAME. Amesbury . . . Ankerwyke . . . Arden .... Arklow .... Armethwaite . . Arthington . . . Ashbridge . . . Austin Canons . . Austin Cell . . Austin Cell . . ofCasham on Tweed of Taversbam of Halywell . Austin Nunnery of~l Legh . . . . / Aylesford .... 290 ORDER. Benedictine Benedict.Nuns Do. Benedictine Nunnery Do. Augustine Do. Do. Do. Do. Do. Do. Do. Carmelite DATE. 980 1257 1150 Wm. Rufus 1254 1283 1147 1126 1256 1296 1162 1325 Henry II. 1240 COUNTY. Wiltshire Buckinghamshire Yorkshire Wicklow Cumberland Yorkshire Buckinghamshire Huntingdon Norfolk Norfolk Northumberland Oxfordshire Warwickshire Devonshire Kent MON MONASTERIES. MON NAME. Badlesmere .... Barking Basselech .... ORDER. Augustine Nunnery Do. Benedictine Carthusian Benedictine Do. Carmelite Cistercian Nunnery Cist. Nunnery Nunnery Do. Do. Nun Priory Nunnery Augustine Do. Nunnery Do. Do. Do. Carthusian Nunnery Do. Do. Do. August. Nun. Cistercian Nunnery Cist. Nunnery Do. Nunnery August. Nun. DATE. Edward II. 630 1101 1200 1113 1347 1349 1150 1200 1321 Henry I. 1295 Richard I. Edward II. 1115 1268 1262 1160 1148 1161 1142 1140 1146 1190 Richard I. 1348 980 1183 1264 1100 1195 616 Henrv II. 1260 1185 1100 1461 1181 1355 1153 1160 1184 Wm. Conq. 1285 650 Edward I. 1078 1140 651 Wm. Rufus COUNTY. Kent Essex Monmouthshire Somersetshire Hertfordshire Nottinghamshire Cambridge Cheshire Norfolk Norfolk Westmoreland Staffordshire Warwickshire Staffordshire Shropshire Nottinghamshire Shropshire Berkshire Yorkshire Suffolk Staffordshire Derbyshire Staffordshire Somersetshire Norfolk Essex Northamptonshire Staffordshire London Cambridgeshire Hertfordshire Cheshire Middlesex Meath Carnarvonshire Yorkshire Worcestershire Lincolnshire Essex Devonshire Norfolk Kent Kent Derbyshire Worcestershire Somersetshire Oxford Norfolk Yorkshire Bedfordshire Staffordshire Northumberland Suffolk Beaulieu Beauvale Benedictine Cell . . Birkenhead .... Blackborough .-<'. Blakeney . . * . Bleatarn . . . . Blythebury . . 4 ; . Bretford . . . ' . Brewood . . . . firewood . . i . Brodholm .... Bromfield .... Brorahale . . i } . Brunham . . 4 Bungay . . .... Calewich CeU . . , . Calke . . . ; : * Cauwell . . . Canyngton . . * '. Carow . i Castle Hedingham Catesby . . V ' Cell of Lees . . . Charter-house . . . Cheshunt .... Chester Clerkenwell . . . Clonard Clynnock Vaux . . Codenham .... Cokehill Cokwelle .... Coin Cornworthy . . . Crabhouse .... Dartford . . . . : . Davington . . u Nunnery Benedict. Nun. N unnery Dodford Dunster ..... Cell Premonst. Benedictine Ed n - of Monks 3ist. Nunnery sf unnery Durham College . . East Dereham . . Ellerton Elstow Fairwell Farne Island . . . Felixtow ..... Benedictine Do. Do. 291 MON MONASTERIES. MON NAME. ORDER. DATE. COUNTY. Flamstead .... Benedict. Nun. 1220 Hertfordshire Floxton Nunnery 1258 Suffolk Folkestone .... 630 Kent Fosse Cist. Nunnery Henry III. Lincolnshire Gloucester College, "1 or Hall . . . J Benedictine 1260 Oxford Godeland .... King John Yorkshire Godestow .... Nunnery 1138 Oxfordshire Goring t Do. Henry II. Oxfordshire Grany . . . Benedict. Nun. 1200 Kildare Greisley Augustine Henry I. Derbyshire Grimesby .... Benedictine 1185 Lincolnshire Haliwell Nunnery 1127 Middlesex Handale 1133 Yorkshire Kenwood .... Do. 1228 Warwickshire Heyninges .... Cist. Nunnery 1180 Lincolnshire Hinchingbrook . . Nunnery Wm. Conq. Huntingdonshire Hode Cell 1138 Yorkshire Holystan .... Nunnery 1255 Northumberland Horewelle .... Cistercian 1291 Warwickshire Home 1226 Suffolk Ikelington .... Nunnery 1140 Cambridgeshire Ilchester Hospital . . Do. 1217 Somersetshire Inch Colme . . . Augustine 1133 Fife shire Ivingho Nunnery 1160 Buckinghamshire Jarrow Benedictine 684 Durham Kaylend Premonstrant Northamptonshire Kells and Inistioge . Augustine 1183 Kilkenny Kilburn Nunnery 1191 Middlesex Kirklees . . Cist. Nunnery 1291 Yorkshire Lacock Nunnery 1232 Wiltshire Lakeburn .... Cist. Nunnery 1150 Lincolnshire Lambly upon the Tyne Nunnery 1292 Northumberland Lammana .... Benedictine 1200 Cornwall Langley Nunnery King Canute Leicestershire Lestingeham . . . 648 Yorkshire Letteringham . Augustine Suffolk Liming 633 Kent Lindisfarne .... 1082 Northumberland Littlechurch . . . Nunnery 1151 Kent Little Marcis . . . Benedict. Nun. 1163 Yorkshire Little Marlow . . . Nunnery 1230 Buckinghamshire Littlemore .... Benedict. Nun. 1177 Oxfordshire Llanlorgan .... Cist. Nunnery 1239 Montgomeryshire Lymbroke .... 1036 Herefordshire Mailing Nunnery 945 Kent Cluniac Henry I. M onmouthshire Marham Cistercian Nun 1249 Norfolk Marrick Nunnery 1171 Yorkshire Marton Augustine temp. Steph. Yorkshire Mergate Benedictine 1145 Bedfordshire Middleburgh . . . Benedictine 1120 Yorkshire Middleton .... Do. 933 Dorsetshire 292 MON MONASTERIES. MON NAME. ORDER. DATE. COUNTY. Molesby . . Nunnery 1167 Yorkshire Monkton 1268 Yorkshire Neddrum Benedictine 1177 Devon Newcastle . Black Friars 1260 Northumberland Nun-Appleton Cistercian K. Stephen Yorkshire Nun-Cotun . Do. Lincolnshire Nun-Kelynge Nunnery 1152 Yorkshire Oxney . . Northamptonshire Peykirk . . 714 Northamptonshire Pinley . . Benedictine 1195 Warwickshire Pinwortham Do. Wm. Conq. Lancashire Polslo . . Nunnery 1169 Devonshire Reculver . . ' . 669 Kent Redburne . ; Nunnery 1178 Hertfordshire Redlinglield . Do. 1120 Suffolk Reinton, St. Michael . Do. 1274 Wiltshire Rosedale . . . . Do. 1310 Yorkshire Roth well August. Nun. 1305 Northamptonshire Rowney Nunnery 1164 Hertfordshire Rumsey Benedictine 967 Hampshire Rusper . . . '" . Nunnery 1291 Sussex Scarthe . . . ;<-' ; Augustine Henry I. Yorkshire Sciily, in the Isle of\ Trescaw / 1346 Cornwall Selsey 711 Sussex Seton . . Benedict. Nun. 1227 Cumberland Sewardesley . . Cisterc. Nun. Henry II. Northamptonshire Shepey . . . . Nunnery 675 Kent Sinningthwaite . . Cistercian 1160 Yorkshire Snelleshall . . . Black Monks 1219 Buckinghamshire Sopwell . . . . Nunnery 1140 Hertfordshire Stanfeld . . Do. 1278 Lincolnshire Stanford Benedict. Nun. 1156 Northamptonshire St Anne Ocirtliusitin. 1381 Warwickshire St. Bartholomew . . Nunnery 1086 Northumberland St. Bernard's College. Cistercian 1437 Oxford St. Clement . . . Nunnery 1130 Yorkshire St. Dogmael . . . Wm. Conq. Pembrokeshire St. Edmund's Bury . 633 Suffolk St. German's . . . Benedictine 614 Cornwall St. Helen . . . -.* Nunnery 1212 London St. Ive (Cell of) . . Benedictine 1001 H untin gdonshire St. John Baptist . . Do. Edward I. Cork St. Martin's .... Do. 1100 Yorkshire St. Mary de Pre . . Do. 1190 Hertfordshire St. Mary Magdalen . 1170 Bristol St. Mildred's . */iv Nunnery 670 Kent St. Nicholas . .- i* Benedictine 1103 Exeter St. Rategund . ; ,~ Benedict. Nun. 1130 Cambridgeshire St. Sepulchre's . w Nunnery 1100 Canterbury St. Syriae .... Cluniac Richard I. Cornwall Stodely . . . . * Nunnery 1184 Oxfordshire Stratford at Bow . . Benedictine Wm. Conq. Middlesex 293 MON MOORISH ARCHITECTURE. MOO NAME. Stykoswold . Swaffham . Syon . . . Tarent . . Thicked . . Trentham . Wallingwell . Wherwell . Whiston . . Wilberfosse . Wilton . . Winchester . Winteneye . Wroxhall . , Wyckham . , Wykes . . , Wyrthorp . . Yarmouth . ORDER. Cisterc. Nun. Nunnery Do. Cisterc. Nun. Nunnery Augustine August. Nun. Nunnery Cisterc. Nun. Nunnery Benedictine Nunnery Cisterc. Nun. Benedictine Cisterc. Nun. Do. Nunnery Benedictine Monkey-wrench, a spanner with a moveable jaw, which can be adjusted by a screw or wedge to the size of the nut which it is required to turn Monogram, a cipher composed of two or more letters interwoven as an abbreviation of a name : monograms were common as distinctive marks on ancient coins, and were also used as seals Monolithic, consisting of a single stone : statues, columns, and pillars were formed by the ancients out of large blocks of stone or marble Monopteral, a temple which has no cella, but consists of columns dis- posed in the form of a circle, co- vered with a conical roof Monota, a vase with one handle Monotriglyph, the interval observed between the columns of a Doric portico, where a space is left suf- ficient for the insertion of one tri- glyph only between those immedi- ately over two contiguous columns Monstrance, sometimes called Remon- strance, the vessel in which the consecrated wafer or host is placed while the congregation are blessed with it, in the Roman Catholic Church. In the ' Divers Works of Early Masters,' 2 vols. folio, will be found two of the rarest and most 294 DATE. K. Stephen 1255 1414 Richard I. 1214 Henry I. K. Henry 986 1255 1153 773 900 1200 Wm. Conq. 1153 Henry II. 1357 1101 COUNTY. Lincolnshire Cambridgeshire Middlesex Dorsetshire Yorkshire Staffordshire Northamptonshire Hampshire Worcestershire Yorkshire Wiltshire Hampshire Hampshire Warwickshire Yorkshire Essex Northamptonshire Norfolk elaborate examples of tabernacles or canopies, in a compartment of either of which the casket or vessel containing the sacred vessel is de- posited. Monton, a heap of ore ; a batch under process of amalgamation, varying in different mining districts Monument, a mausoleum or tomb. Sepulchral monuments of the mid- dle ages still exist to a considerable extent, both here and on the Con- tinent. Monuments and tombs of modern date are designed from Classical and Gothic architecture, and in many instances are beautiful models of modern art. Moor, in Cornish, a root, or quantity of ore in a particular part of a lode, as a ' moor of ore,' a ' moor of tin' Moorish, Mohammedan, or Saracenic Architecture, is a combination of Egyptian, Grecian, and Roman de- tails; first established by the Arabs about the tenth century, and for oriental scenery of a pleasing cha- racter: its complicated ornament and lattice-work are rich and pecu- liar. Many existing examples are interesting ; but the style is wholly unfit for European usages and re- quirements. Moot-hall, or Moot-house, in Saxon times, a building appropriated to MOR MORTAR. MOR assemblies on public affairs; a. guild- hall or town-hall,- hotel de mile, &c. Mora wood. This tree is 100 feet high, and abundant; it is close- grained, like teak, and superior to oak ; esteemed for ship-building. Moresque, a kind of painting, carving, &c., in the arabesque and grotesque styles of ornament Mortar. The materials which are added to lime, in the formation of mortars or calcareous cements, are, 1st, The different kinds of sand, properly so called ; 2nd, arenes ; 3rd, psammites; 4th, clays; 5th, volcanic or pseudo-volcanic pro- ducts ; and 6th, artificial products arising from the calcination of the clays, the arenes, and the psam- mites ; and the rubbish and slag of manufactories, forges, &c. INGREDIENTS OF MORTAR. SAND. The granitic, schistose, and calcareous rocks, free-stones, &c., reduced to the state of hard and palpable grains, either by the agitation of water, or by spontane- ous disaggregation, give birth to the various kinds of sand. We dis- tinguish them from powders by their falling at once to the bottom, when thrown into limpid water, and that without altering its trans- parency in a sensible degree. The disaggregation of rocks is often accompanied by a decomposi- tion which produces a powder : this powder renders the sand 'rich/ or, in other terms, susceptible of a certain cohesion, when tempered with water. Washed by rains and currents of water, it is soon freed from the pulverulent particles, and is deposited pure in the beds of rivers. This purity is often changed near the mouths of streams, and in the small rivulets whose tributaries flow over a bed of clay or mould : the sand mixes with vegetable de- bris and animal matters, and be- comes ' loamy.' The particles com- posing sand faithfully represent those of the rocks whence they are 295 derived. The granitic regions fur- nish quartz, felspar, and mica; and the volcanic regions, lavas of all kinds. The tabular-shaped sands, whose particles are tender, are fur- nished by the schistose mountains. It is difficult for them to be trans- ported far without being reduced to powder. The calcareous sands are the least common, probably arising from the fact that rivers generally take their rise from primitive sum- mits, or such as are composed of primitive elements. The calcareous rocks, besides, are not susceptible of that kind of disaggregation which can be called granitic ; for if they be of a soft kind, they produce powder ; if hard, scaly splinters. The partial and secondary revo- lutions of the globe have occasioned immense deposits of sand in situa- tions where now neither brooks nor rivers flow : these are the fos- sil sands; and they should be care- fully distinguished from the virgin sands, which are still in their origi- nal site, and have not been operated on by the waters. The fossil sands generally exhibit a more angular grain than the sea or river sands ; but in other re- spects they are the same elements, sometimes pure, sometimes coloured by ochres, &c. Among the fossil sands is one very remarkable, the arene. Its properties entitle it to attention. ARENES is a sand, generally quartzose, with very irregular, un- equal grains, and mingled with yellow, red, brown, and sometimes white clay, in proportions varying from one to three-fourths of the whole volume. The arene almost always occu- pies the summits of the rounded and moderately-elevated hills : it sometimes constitutes entire hil- locks; frequently it interposes it- self in large veins and seams in the clefts of calcareous rocks : it be- longs essentially to alluvial soils. MOR MORTAR. MOR PSAMMITES is a term applied to an assemblage of the grains of quartz, schist, felspar, and particles of mica, agglutinated by a variable cement. The varieties of these are very numerous : those which in ap- pearance strongly resemble the free-stones and silicious breccias belong to the class of rocks whose disaggregation furnishes sand, pro- perly so called. But the psam- mites, which are slaty, of a yellow, red, or brown colour, fine-grained, unctuous to the touch, producing a clayey paste with water, form a distinct species, and one which merits attention. These last belong to the primi- tive schistose formations : they do not and cannot exist except in situ: they are found in beds or veins, forming part of the schist of which they are merely a decomposition. CLAYS are earthy substances va- riously coloured, fine, soft to the touch, which diffuse in water with facility, forming with it a paste, which, when kneaded to a certain consistency, possesses unctuosity and tenacity, and may be drawn out and kneaded in every direction without separating. The clayey paste, when dried, retains its soli- dity, hardens in the fire, &c. Clays are essentially composed of silica and alumina: these two substances are adulterated by the presence of the oxide of iron, the carbonates of lime and magnesia, sulphuret of iron, and of vegetable combustible matter partly decom- posed. The clays are separated into four classes : viz. the refractory, which resist, without melting, the heat of the porcelain furnaces (140 Wedg- wood) ; the fusible clays ; the ef- fervescing or clayey marls; and, lastly, the ochrey clays, coloured red or pure yellow by oxide of iron. The position of clays is very va- ried : they are found as veins in pri- mitive formations ; in hillocks, on the confines of the primitive chains; 296 in horizontal beds, or layers, in the secondary formations; in threads, thin veins, or infiltrations, in chinks and hollows of calcareous masses ; lastly, in volcanic regions, where their formation is attributed to the decomposition of the compact lavas, and perhaps also, with some proba- bility, to miry eruptions. Mortar. Considered as a plastic material, mortar fit for moulding may be made to take every pos- sible form in moulds or shapes. To give it the appearance of stone, it should be made with fine colour- less sand, or rather with fine calca- reous powders derived from hard stones. Mortar contained in a mould may be beaten or rammed in the manner of pise, "a mode of building for- merly in use, whereby walls were formed by ramming and beating down earth, clay, &c., between up- right planks," and acquires by that means great compactness ; but an increase of resistance does not always result from this In order that any material be beaten with effect, it is necessary that it should possess a certain de- gree of consistency, which is a mean between complete pulverulence and that state of ductility which con- stitutes a firm paste. No compres- sion is possible when the material escapes from under the rammer; and this is still practised by the builders in pise, who never employ any but earth slightly moistened. Mortar may always be prepared in this way, leaving it, after it has been worked in the ordinary manner, to undergo desiccation to a proper extent. The successive approximation of the particles of the compressed material to one another neces- sarily determines a foliated struc- ture, which, though it may not be perceived, is nevertheless real. Analogy will lead to the conclusion, that, in every possible case, a body thus formed ought to oppose a MOR MORTISE AND TENON. MOR greater resistance to a tractile force in proportion as its direction forms a smaller angle with the plane of the laminae; however, experience shows that this in general does not take place. The following has been determined in this respect: 1st, Beating has the effect of augmenting the absolute resistance of mortars of rich limes and pure sand in every case, but in an un- equal manner. The greatest re- sistance assumes a direction per- pendicular to the planes of the Iamina3 when the mortars are buried in a damp soil immediately after their fabrication. It remains par- allel to these same planes when the mortars have been exposed to the atmospheric influence. 2nd, The effect of beating is not constantly useful to mortars of hydraulic or eminently hydraulic limes, and calcareous or quartzose sands or powders, except in the case when these mortars are used under a damp soil. The greatest resistance is then in a direction perpendicular to the planes of these laminae, as with the mortars of rich limes ; but in the air, the superiority of the mortars which have been beaten over those which have not is only exhibited in one direction, and that is parallel to the plane of the laminae. 3rd, Beating becomes injurious in every case when the hydrates of the hydraulic or eminently hydraulic limes are employed without admix- ture, and subjected to the influence of a damp soil ; and is favourable to it only in the direction parallel to the laminae when the stuff dries in the air. Considered as a plastic substance, the numerous casts which have been moulded, both in bas-relief and alto- relievo, prove that mortar receives and retains impressions well : their hardness is continually on the in- crease, and a kind of varnish, with which time covers them, gives them a strong resemblance to stone. 297 One problem remains to be solved, viz. to discover a means of hastening the set of mortar with- out injuring its future qualities ; and this, in order to avoid being obliged to multiply moulds indefi- nitely for the same casting. This last desideratum appears to be dif- ficult. The natural cements, which harden almost instantly in the air and in the water, when worked up like plaster of Paris, are subject to the inconvenience of being tinged brown. Such as are fabricated artificially, by calcining mixtures of lime and clay free from iron, do not stand the weather. Mortar of hydraulic lime may be employed as a plastic substance in a multitude of cases, in which the number of moulds is no inconve- nience. Such is the case in the pre- paration of artificial stones bearing mouldings, vases, or ornaments of any kind susceptible of formation by the rectilinear or circular move- ment of a profile. It is evident that it will then answer to set the mould in a trench, and run the profile along the clayey paste, pre- pared and arranged for that pur- pose. The economy which such a process would introduce into ornamental constructions is indeed incredible. Mortise, in carpentry, a hole cut in a piece of wood, to receive a corre- sponding projection formed upon another piece Mortise and Tenon. The following rules may be referred to as data for the workman in ordinary practice. The tenon, in general, may be taken at about one -third of the thickness of the wood. When the mortise and tenon are to lie horizontally, as the juncture will thus be unsupported, the tenon should not be more than one-fifth of the thickness of the stuff, in order that the strain on the upper surface of the tenoned piece may not split off the under-cheek of the mortise. MOR MOULDINGS. MOU When the piece that is tenoned is not to pass the end of the mor- tised piece, the tenon should be reduced one-third or one-fourth of its breadth, to prevent the necessity of opening one side of the tenon. As there is always some danger of splitting the end of the piece in which the mortise is made, the end beyond the mortise should, as often as possible, be made considerably longer than it is intended to remain ; so that the tenon may be driven tightly in, and the superfluous wood cut off afterwards. But the above regulations may be varied, according as the tenoned or mortised piece is weaker or stronger. The labour of making deep mor- tises, in hard wood, may be lessened, by first boring a number of holes with the auger in the part to be mortised, as the compartments be- tween may then more easily be cut away by the chisel. Before employing the saw to cut the shoulder of a tenon in neat work, if the line of its entrance be correctly determined by nicking the place with a paring chisel, there will be no danger of the wood being torn at the edges by the saw. As the neatness and durability of a juncture depend entirely on the sides of the mortise coming exactly in contact with the sides of the tenon, and as this is not easily performed when a mortise is to pass entirely through a piece of stuff, the space allotted for it should be first correctly gauged on both sides. One half is then to be cut from one side, and the other half from the opposite side ; and as any irregularities which may arise from an error in the direction of the chisel will thus be confined to the middle of the mortise, they will be of very little hindrance to the exact fitting of the sides of the mortise and tenon. Moreover, as the tenon is expanded by wedges after it is driven in, the sides of the mortise 298 may, in a small degree, be inclined towards each other, near the shoul- ders of the tenon. M-roofj a roof formed by the junction of two common roofs with a vallum between them Mosaic-work, the art of picturing with small pebbles and shells of various colours, pieces of glass, marble, &c. cemented on a ground of stucco Mosque, a Mohammedan temple Motif, that which suggests ahint or idea to an artist ; also the hint itself Motion. The cross-head, cross-head guides, and blocks, in a locomotive engine, taken as a whole, are called ' the motion.' Motion (laws of). A body must con- tinue for ever in a state of rest, or in a state of uniform and rectili- neal motion, if it be not disturbed by the action of some external cause. The alteration of motion produced in a body by the action of any external force is always proportional to that force, and in the direction of the right line in which it acts. The action and re- action of bodies on one another are equal, and are exerted in op- posite directions. Motion of bodies on inclined planes. The force of an inclined plane bears the same proportion to the force of gravity as the height of the plane bears to its length ; that is, the force which accelerates the motion of a body down an inclined plane, is that fractional part of the force of gravity which is repre- sented by the height of the plane divided by its length. Mould, the model or pattern used by workmen as a guide in working mouldings and ornaments, in the casting of metal, and models of machinery Mouldings, a term applied to all the varieties of outline or contour given to the angles of the various subor- dinate parts and features of build- ings, whether projections or cavi- ties, such as cornices, capitals, bases, door or window jambs, and MOU MOULDINGS. MOU heads, &c. There are eight sorts of regular mouldings, yiz. the Ovolo, the Talon, the Cyma, the Cavetto, the Torus, the Astragal, the Scotia, and the Fillet. These mouldings are not to be used at hazard, each having certain situ- ations adapted to its reception, to which it must always be applied. Thus the ovolo and talon, from their peculiar form, seem intended to support other important mould- ings or members; the cyma and cavetto being of weaker contour, should only be used for the cover or shelter of other parts ; the torus and astragal, bearing a resemblance to a rope, appear calculated to bind and fortify the parts to which they are applied ; the use of the fillet and scotia is to separate one mould- ing from another, and to give a variety to the general profile. The ovolo and talon are mostly placed in situations above the level of the eye; when below it, they should only be applied as crowning mem- bers. The place for the scotia is universally below the level of the eye. When the fillet is very wide, and used under the cyma of a cor- nice, it is termed a corona ; if under a corona, it is called a band. The curved contours of mould- ings are portions of either circles or ellipses. The principal mouldings, and the difference of their profiles in the Grecian and Roman styles, are here exhibited. Echinus or Ovolo. Cyma Recta. Cyma Re- versa. Scotia. Torus. Moulding, the process of forming a cavity in sand or loam, in order to give its form to metal which is ap- 299 plied in a fluid state ; an ornamental cavity in wood, stone, or other suitable material MOU MUSIC. MUS Mountain-blue. A. very beautiful sub- stance of this kind, a carbonate of copper, both blue and green, is found in Cumberland. None of these blues of copper are, however, durable ; used in oil, they become green, and, as pigments, are pre- cisely of the character of verditers. Mountain-green is a native carbonate of copper, combined with a white earth, and often striated with veins of mountain-blue, to which it bears the same relation that green ver- diter does to blue verditer; nor does it differ from these and other copper-greens in any property es- sential to the painter M. S., an abbreviation commonly used on tomb - stones or monumental tablets, for the Latin words Me- moria Sacrum, ' Sacred to the Me- mory': the letters J.H.S. are often similarly applied in sacred edifices, for Jesus Hominum Salvator, 1 Jesus the Saviour of Men.' Mud-holes, the covered openings in the bottom of a boiler for discharg- ing the dirt and sediment Mud-plugs, in locomotive engines, tapered screw-plugs fitted into con- venient parts of the boiler, to admit of its being washed out by these plug-holes when necessary Mulberry-tree, awood of great variety, principally from Rio Janeiro, and very suitable for furniture Mullion, the division between the lights of windows, screens, &c. in Gothic architecture : the styles or upright divisions in wainscoting are also sometimes called mullions Mule-jenny, a machine used in the manufacture of cotton thread Mun (Cornish), any fusible metal Mundick, an exceedingly ponderous mineral, whitish, beautiful and shining, but brittle. It is abundant in Cornish and Irish mines. Muniment-house, a strong, properly fire-proof apartment in public or private buildings, for the preserva- tion of charters, deeds, seals, &c. Munnions, pieces that part the lights in a ship's stern and quarter-gallery 300 Munnions, in house-building, upright posts that divide the lights in a window-frame Mummy, or Egyptian-brown, is a bituminous substance, combined with animal remains, brought from the catacombs of Egypt, where liquid bitumen was employed three thousand years ago in embalming, in which office it has been com- bined, by a slow chemical change, during so many ages, with sub- stances which give it a more solid and lasting texture than simple as- phaltum; but in this respect it varies exceedingly Mural, pertaining to a wall ; a monu- mental tablet affixed to a wall is a mural monument Murometer, an instrument to measure small spaces Murus, the wall of a Greek city, in contradistinction to Paries, the wall of a house, and Maceria, a boundary waU Music. This word is derived from the Latin musica, and this again from the Greek adjective mousi&os, which signifies, of or belonging to the Muses. As a substantive, the word mousikos, or in Latin musicus, a musician, means also a poet or an orator; and in the feminine gender signifies the liberal arts, but especially music, poetry, and elo- quence. The ancients, therefore, understood by music far more than has been attributed to it for some ages past. Music is now considered as the language of agreeable sounds, and is both a science and an art. As a science, it teaches the theory of musical sounds, their production by the vibrations of the air, the ratio of these vibrations, and also their times; likewise the various phenomena connected with musical sounds, the causes of discords,beats, &c., as well as the lengths of mu- sical strings and pipes. The ma- thematical theory of music is part of the science of acoustics, or phonics, and is therefore one of the high mechanical sciences. As an MUS NAOS. NAP art, music teaches the practical use of the science ; the scales or gamuts of sounds in a fixed succession, at fixed intervals from each other ; the permutations of their sounds; form- ing an immense variety of melodies. It .teaches also the combination of these sounds according to certain received laws, forming thereby the most agreeable sensations on the ear, by producing a great variety of chords, composed of concordant sounds alone, or of a judicious ad- mixture of concordant and dissonal sounds. Practical music teaches also the use and performance of the several instruments of music, as also their peculiar functions ; and herein is embraced the human voice, the most perfect and beautiful of all musical instruments. Music, therefore, is divided into two grand parts, viz. theoretical or scientific, and practical ; the former treating of the purely philosophical branch mathematically, the latter being confined solely to the production of musical compositions, and their per- formance. Practical music consists of several species, the highest of NAI NAILS, used in building, are small metallic spikes serving to bind or fasten the parts together. There are several kinds of nails, called by numerous names. In the middle ages, nails were frequently used much ornamented, of which there are several very beautiful existing specimens, particularly in church doors and the gates of large man- sions. Naked, of a column or pilaster, the surface of the shaft where the mouldings are supposed to project Naked, of a wall, the remote face whence the projectures take their rise. It is generally a plain sur- face, and when the plan is circular, the naked is the surface of a cy- linder, with its axis perpendicular to the horizon. 301 which is the ecclesiastical ; then follow the oratorio, opera, military, chamber, and ball-room species; and is divided into vocal and instru- mental music, each of these being variously subdivided. Musnud, in Persia, a throne or chair of state Mustaib, a wood from the Brazils, inferior to rose wood, but harder ; used at Sheffield for the handles of glaziers' and other knives, &c. Mutule, a projecting block \vorked under the corona of the Doric cor- nice, in the same situation as the modillions in the Corinthian and Composite orders ; it is often made to slope downward towards the most prominent part, and has usually a number of small guttae or drops, worked on the under side Mynchery, the Saxon name for a nun- nery : nuns were sometimes called Mynchies Myoparo, a small piratical craft, em- ployed by the Saxon corsairs Myriad, the number of 10,000 ; pro- verbially any great number Myriametre, a French measure of 10,000 metres NAP Naked flooring, in carpentry, the whole assemblage or contignation of timber-work for supporting the boarding of a floor on which to walk. Naked flooring consists of a row of parallel joists, called floor- joists. Naos, the chamber or enclosed apart- ment of a Greek temple. The part of the temple which stood before the naos, comprehended between the wall and the columns of the portico, was called the pronaos ; while the corresponding part be- hind was called the posticum. Naples yellow is a compound of the oxides of lead and antimony, an- ciently prepared at Naples under the name of Grallolina ; it is sup- posed also to have been a native production of Vesuvius and other NAP NASMYTH'S MACHINES. NAT volcanoes, and is a pigment of de- servedly considerable reputation. It is not so vivid a colour as patent yellow and turbith mineral, but is variously of a pleasing light, warm, golden-yellow tint. Like most other yellows, it is opaque, and in this sense is of good body. It is not changed by the light of the sun, and may be used safely in oil or varnish, under the same man- agement as the whites of lead ; but like these latter pigments also, it is liable to change even to black- ness by damp and impure air when used as a water-colour, or unpro- tected by oil or varnish. Naphtha, a species of mineral oil or fluid bitumen, now commonly used for lamps Narthetr, a division in the early Christian churches in which the catechisms were said, and peni- tents admitted; it was near the entrance, and separated from the rest of the church by a railing or screen Nasmyth's patent direct-actionsteam- hammer is employed instead of the old helves or lift-hammers, and is worked by a connected high-pres- sure steam engine, which raises the hammer to any required height within its vertical range of motion, and in which it is guided by two planed guides. On the escape of the steam, when the valve of the cylinder is opened, the hammer falls on the work that lies on the anvil with the full force due to gravity, without scarcely any loss from friction. The instant the hammer has given its blow, the steam is again let in under the piston, and the same action is re- peated with ease and rapidity. Nasmyth's steam pile-driving engine. There are two grand or important features of novelty in this pile- driving engine, compared with all former contrivances for the like purpose. In the first place, by the employment of the steam-hammer action, the steam is made to act '302 direct in raising up and letting fall the hammer, or monkey, without the intervention of any rotatory mo- tion ; while, in the second place, another grand feature consists in the employment of the pile about to be driven, or raised up and planted in its situation by the ma- chine, by means of a windlass worked by a small detached steam engine. Some conception of the rapidity with which piles are driven by this machine may be formed, when it is stated that a pile measuring 60 feet in length, and 14 inches square, can be driven 45 feet into stiff soil, down to the rock below, in four minutes; and such is the good effect resulting from the blows by being given by a great mass of 30 cwt. striking quickly, but with small velocity of actual impact, that the head of the pile requires no hoop, and presents, after being driven, a neater appearance than it had when it was first placed under the hammer. Natural beds of stone are the surfaces from which the laminae are sepa- rated. It is all important for the duration of stone walls, that the laminae should be placed perpendi- cular to the face of the work, and parallel to the horizon. Natural Philosophy takes an exten- sive range, embracing the study of the collection of created beings and objects, and of those laws by which they are governed, all of them expressed in the term Nature. Natural objects are separated into two grand classes, the organic and inorganic; the former being dis- tinguished by vital power or life : organic bodies admit of a marked distinction into animals and plants ; the science of Zoology describing and classifying the one, and that of Botany the other. These sciences admit of many subdivisions, and collectively with Mineralogy, that of Natural History : 1. Geology, the science which has NAT NAVE. NEB for its object the observation and description of the structure of the external crust of the globe ; Mine- ralogy taking account only of the separate items of which the earth's crust is composed. 2. Chemistry, which may be regarded as atomic anatomy, its object being to de- compose bodies, to study the proper- ties of their elements, and the laws of combination. 3. Physics, or Natural Philosophy, which considers the general properties of all bodies. Natural philosophy is again sub- divided into many distinct sciences. The mutual action of forces and masses of matter produces in the latter either equilibrium or motion, and hence arise those two divisions of sciences, called Statics and Dy- namics, which are again divided into Stereo - statics and Stereo- dynamics, as applied to solids ; Hydrostatics and Hydrodynamics, as applied to liquids; Electro-statics and Electro-dynamics, as applied to Electricity. The application of statics and dynamics to air and other gaseous fluids is called Pneumatics. The application of dynamics to the arts of life has led to the composition and arrange- ment of the various machines for assisting the labour of man : this branch is called Mechanics. The construction and performance of the various machines to raise water, or which are driven by the motion of that fluid, belong to hydronamics, while the construction of works de- pending on the equilibrium of liquids belongs to hydrostatics. Those machines which are driven by the wind depend on the application of pneumatics ; and all the varied phenomena of the atmosphere arising from the action of heat, light, electricity, and moisture, form the science of Meteorology. The phenomena of heat and elec- tricity also form separate sciences; the latter admitting of five divisions, viz. electricity, magnetism, galvan- ism or voltaic electricity, thermo- 303 electricity, and animal electricity. The phenomena of light, although included in the term Optics, are varied ; namely, perspective, catop- trics, dioptrics, chromatics, physical optics, and polarization ; to which may be added actino-chemistry. Naumachia, among the Greeks, a sea-fight; a spectacle. The term was also applied to a circus encom- passed with seats and porticoes, the pit of which, serving as an arena, was filled with water by means of pipes, for the exhibition of sea-fights. Naupegus, a shipwright Nautical, pertaining to ships or sailors Naval Architecture, the art of de- signing and constructing ships and vessels for the purposes of naviga- tion Navale, a ship-dock or dockyard Navalia, ship-building docks at Rome, where also ships were laid up and refitted Navarchus, among the ancients, the name of a commander or admiral of a fleet Nave, the body of a church west of the choir, in which the general congregation assemble. In large buildings it consists of a central division, with two or more aisles ; and there are frequently, in foreign structures, several small chapels on the sides beyond the aisles. In mechanics, the central part of a wheel. Navel-hoods, in ship-building, pieces of plank, or thick stuff, wrought above and below the hawse-holes Navis, in church furniture, a metal dteh or vessel to contain frankin- cense Neap, low, decrescent; a term applied to the tides which happen when the moon is in the middle of her second and fourth quarters. The highest spring-tide is three days after the full or change ; the lowest neap-tide is four days before the full or change. Nebule moulding, an heraldic term. In architecture, an ornament of the NEC NICHE. NOG zigzag form, but without angles : it is chiefly found in the remains of Saxon, architecture, in the archi- volts of doors and windows. Neck of a capital, the space between the channelures and the annulets of the Grecian Doric capital. In the Roman Doric it is the space between the astragal and the an- nulet. Neck-mould, in architecture, a small convex moulding surrounding a column at the junction of the shaft and capital Necrology, an obituary formerly kept in churches and monasteries Needle, or Nail, in mining, a long taper piece of copper or iron, with a copper point; used when stamp- ing the hole for blasting, to make by its insertion an aperture for a fusee or train Needle-work, a term anciently used for the frame-work of timber and plaster in old houses Neo, a Greek term, to spin or twist a number of separate fibres of wool or flax into a single thread Ne plus ultra (Latin), the extreme of any thing Nervures, nerves or branches, a term applied by Prof. Willis, of Cam- bridge, to the ribs of a vaulted roof which bound the sides of any groined compartment Net, or Neat, in commerce, that which is pure and unadulterated; the weight of any package after the tare has been deducted : most com- monly, but improperly, written nett Newel, the central column round which the steps of a circular stair- case wind; the principal post at the angles and foot of a stair- case. In the Tudor and Elizabe- than residences very beautiful ex- amples exist, adding much to the beauty of the staircase. Niche, in architecture, a cavity or hollow place in the thickness of a wall, in which to place a figure, a statue, vase, or ornament. Niches are made to partake of all the seg- ments under a semicircle : they are 304 sometimes at an equal distance from the front, and parallel or square on the back with the front line, in which case they are called square recesses, or square niches. Occasionally small pediments were formed over them, supported on consoles, or small columns or pi- lasters placed at the sides of the niches. Anciently they were used in ecclesiastical buildings for sta- tues and shallow square recesses. The ruins of Palmyra exhibit niches of various kinds. Within the por- tico of the temple of the Sun there are two niches, &c. Niche, angular, one formed in the corner of a building Niche, in carpentry, the wood-work to be lathed-over for plastering. The usual constructions of niches in carpentry are those with cylindrical backs and spherical heads, called cylindro-spheric niches, the execu- tion of which depends upon the principles of spheric sections. Niche, ground, that which, instead of bearing on a massive base or dado, has its rise from the ground, as the niches of the portico of the Pantheon at Rome : their ordinary proportion is, two diameters in height, and one in width. Round or square niches are also formed. Nigged ashlar, stone hewn with a pick or pointed hammer, instead of a chisel ; used principally at Aber- deen for the hewing of the hard granite Nitrate of lime, nitric acid in combi- nation with lime for a base, abound- ing in the mortar of old buildings Nitrates, compounds, or salts, formed by the combination of nitric acid with alkalies, earths, and metallic oxides Nitre, common saltpetre; in chemistry, nitrate of potash Nodus, anciently, in our cathedrals, a knot, key-stone, or boss Nog, in ship-building, a treenail driven through the heel of the shores which support a ship on the slip Nogs, blocks of wood cut to the form NOG NORMAN ARCHITECTURE. NOR and size of bricks, and inserted in the interior walls of apartments as holds for the joinery Nogs or Nays, in mining, square pieces of wood piled on each other to sup- port the roof of a mine Nogging, a kind of brick-work carried up in panels between quarters Nogging-pieces are horizontal boards placed in brick-nogging, nailed to the quarters, in order to strengthen the brick-work Nomades, in antiquity, wandering, rude, or savage tribes Nomenclature, the art of naming ; a vocabulary or dictionary of techni- cal language peculiar to any art or science Nonagon, a figure of nine sides and of as many angles Non- condensing Engines are those made without that part of the ma- chine called a condenser, and with- out those contrivances essential to the ordinary construction of en- gines that condense the vapour into fluid. In non-condensing engines the steam escapes into the atmo- sphere, after having acted upon the piston. The effect is measured by the excess of the pressure of the steam upon the piston, less the friction of the engine above the pressure of the atmosphere. Non-conductors, substances through which the electric fluid passes with considerable difficulty or not at all ; such as glass, resin, sulphur, silk, hair, wool, the air, &c. ; but these become electric by friction Nones, in the Roman calendar, the fifth day of January, February, April, June, August, September, November, December; and the seventh of March, May, July, and October Noria, an hydraulic machine, com- mon in Spain for raising water. The engine consists of a vertical wheel of 20 feet diameter, on the circum- ference of which are fixed buckets, for the purpose of raising water out of wells, &c., communicating with a canal below, and emptying it into a 305 reservoir above, placed by the side of the wheel. The buckets have a lateral orifice, to receive and dis- charge the water. The axis of the wheel is embraced by four small beams, crossing each other at right angles, tapering at the extremities, and forming eight little arms. This wheel is near the centre of the horse-walk, contiguous to the ver- tical axis, into the top of which the top beam is fixed ; but near the bottom it is embraced by four little beams, forming eight arms similar to those above described, on the axis of the water-wheel. In the movement of the horse or mule, these horizontal arms, acting on cogs, take hold, each in succession, of those arms which are fixed on the axis of the water-wheel, and keep it in rotation. Norma, a square for measuring right angles, used by carpenters, ma- sons, and other artificers, to make their w r ork rectangular Normal line, in geometry, a phrase used for a perpendicular line Norman Architecture. In Normandy, in the tenth century, when the Normans occupied Neustria, the churches in other parts of France were in imitation of the Roman style. The plan of the buildings came from Rome, and the round arches, the pillars, and the mould- ings, which were employed in their construction, had the same origin. But the corrupt taste of a less civilized people covered the capitals and the portals with a crowd of such appalling images as a wild fancy was likely to suggest, and* a rude hand to portray. The Normans, adopting the habitual plan and the established style, rejected the meretricious ac- cessories, and resolved to trust for success to the two great principles of size and elevation. The oldest of the Norman churches are the plainest, but even these aspire to dimensions which could not fail to command admiration. Their cha- NOR NORMAN ARCHITECTURE. NOR racter is severe but sublime. At the same time, the Normans had the boldness to insist upon an addition to their churches, which is admitted to be the grandest feature and the chief ornament of ecclesiastical buildings the central tower. Towers had, for- tunately, become an integral part of churches before the Normans began to build in Neustria, but the few towers which at that time ex- isted in other parts of France only adorned the western end. Size, elevation, simplicity, and strength, together with the central tower, are the architectural peculiarities to which the Normans, as contra- distinguished from the Franks, pos- sess undeniable claims. Norman workmanship was, at first, remarkable only for its solidity. The walls were often built of rub- ble, faced with small squared stones, a manner of building which had been copied from the works which the Romans had left behind them in France. The pillars were, of course, composed of larger blocks. By degrees, and in buildings of importance, larger blocks were em- ployed in the walls ; but the joints were wide, and the mortar w r as coarse. In the time of William the Conqueror, greater neatness was accomplished ; the stones were squared, and the courses regular; but the joints were still rather wide, and the mortar unsifted. Another mode of construction was with long, narrow stones, which were placed, not in hori- zontal courses, but alternately in- clined to the right and left. This, from the appearance it presented, was called the herring-bone fashion. It did not remain in use much after the eleventh century. The Norman walls were of great thickness, and were filled up with small stones, amongst which mortar was poured in hot. This was called grouting; and in time the whole mass so hardened together as to 306 acquire the consistence and strength of a solid rock. Such walls stood in no need of buttresses, through the means of which more advanced science afterwards obtained an equal amount of power at less labour and less expense. Buttresses, however, appear on the exterior of early Nor- man buildings, but seem to have been introduced only to relieve the baldness of the surface. They pro- ject so slightly that they can add but little support. In early Nor- man buildings the buttresses never rise above the cornice. The plan of the early Norman churches is always that of the basilica, with a semicircular recess at the end, which recess formed the choir. The larger churches have transepts and side aisles which are divided from the nave by ar- cades. The small churches have often neither side aisles nor tran- septs. The arches of the nave either rest on piers, to which half- pillars are attached, or on single pillars, but hardly ever on those huge cylindrical piers which are commonly seen in the Norman churches of England. Indeed, the thick cylindrical piers of England are scarcely to be met with in all France, except in one or two crypts, where the known superincumbent weight justifies the preference of strength to beauty. In the churches of France, single pillars preceded piers; the exact reverse of w ? hat might have been expected, were it not recollected to what an extent and degree France had become Roman, previous to the inroad of the Northern con- querors. The pillars have always capitals, which, at first, were per- fectly plain; but, from the begin- ning of the eleventh century, were enriched with different kinds of foliage, to a certain degree depart- ing from, but still seeking to imi- tate, the Roman models. The half- pillars, which are attached to the ends of the piers, are always set NOR NORMAN ARCHITECTURE. NOR back in recesses, or sinks; the same is the case with the small pillars on the outside of the windows, as also with those of the portals. This is a characteristic between the Nor- man style and the Roman the Norman pillars are recessed; the Roman project. The windows are always round- headed, and undivided ; and, exter- nally, have on each side a small recessed pillar, which supports an impost and moulding. In the gable, over the entrance door of churches, a small circular window is sometimes introduced. The windows of castles and of domestic buildings are usually di- vided by a single shaft. The portals are round-headed, and were gradually enriched by an increasing number of semicircular mouldings. The most common mouldings are the billet, the nail- head, the chevron, the zigzag or embattled frette, hatchet, nebule, star, rope, beak-head, dog-tooth, and, occasionally, different sorts of foliage, as the vine, the bay, the ivy, &c. (See Frontispiece.) The external cornice, under the eaves of churches, was sometimes a moulding describing a series of semicircles, under a projecting course, and sometimes a series of blocks. The ornamented corbels, on the exterior of churches, were adopted by the Normans before imagery was admitted into the in- terior of the edifice. The roofs of the early Norman churches were of wood, except the part over the semicircular chancel, which from the first was vaulted with stone. The side aisles were also vaulted with stone ; as were, sometimes, the comparatively small naves of village churches. The vaulting was composed either of small stones let into a bed of mor- tar or of tufa, or of a light calca- reous stone, which is found in many parts of Normandy. The most ancient vaulting is without ribs, 307 and the most ancient ribs are with- out mouldings. The dome vaulting over the side aisles of the abbey church atBernay is the only specimen of the kind in Normandy. The first and purest Norman style prevailed till the latter part of the reign of William the Con- queror, from the early part of the tenth till nearly the end of the eleventh century. The abbey church of Bernay, begun in the first half of the eleventh century, is the oldest Norman building of any conse- quence which remains in its pri- mitive form. The architecture of the interior is plain to baldness, but the dimensions are imposing. The abbey churches of Jumieges and Cerisy were begun in the first half of the eleventh century. The Norman portions of the cathedral, and of the church of St. Taurin, at Evreux, as also of the church of Mont St. Michel, belong to the same period. St. Georges de Boscherville, and the two great churches at Caen, arc splendid examples of the ar- chitecture of the time of William the Conqueror. In all these buildings the cha- racter of simplicity is preserved, but some ornament in the details begins to make its appearance be- fore the close of the Conqueror's reign, as, for instance, in the em- battled frette moulding round the arches of the nave of Matilda's church at Caen, in some parts of St. Georges de Boscherville, and other places. The florid Norman was already developed in the early part of the twelfth century. Of this style a rich specimen is afforded in the arcade of the nave at Bayeux. The arches are ornamented with a multiplicity and variety of mould- ings of intricate design and elabo- rate execution. Another specimen of the florid NOR NORMAN (ANGLO) ARCHITECTURE. NOR Norman exists in the neighbour- hood of Bayeux, in the church of St. Gabriel* built by Robert of Gloucester (1128). The abbey church of Monti- villiers (1117), and the church at Graville, are instances of the florid style in all its exuberance. Norman Architecture in England. Of the architecture which existed in this countiy previous to the intro- duction of the Norman there are no certain vestiges. The most competent authorities have decided that hardly any thing which can be proved to be Saxon remains in existence. Parts of a few churches, which have all the marks of a very remote antiquity, and of which the style differs materially from the Norman, may be suspected to be Saxon. Their distinguishing fea- tures are a ruder imitation of the Roman, projecting, instead of re- cessed pillars, and the combination of diagonal with perpendicular forms in the external ornaments of towers. Such is the case at the old church of Barton, in Lincoln- shire, and at Earl's Barton, in Northamptonshire. Some persons have imagined that the generality of the Saxon churches were merely timber build- ings, but this appears to be a mistake; for in Domesday Book, which takes note of 1 700 churches, one, and only one, is specified as being built of wood ; and Henry of Huntingdon, speaking of a parti- cular church, says, " It was not built of stone, but of wood, and covered with reeds, as is the custom in Scotland;" demonstrating that it was not the custom in Eng- land. Not only were the Saxon churches not merely timber buildings, but some of them were constructed at a considerable expense, and with much architectural ornament. In the seventh century, a church was built at Lincoln, which Bede says was of stone, and of good 308 workmanship. The church of the monastery of Wearmouth was erected in 675, by Abbot Benedict Biscopius, a noble Northumbrian, who, at twenty-five years of age, detached himself from the service of King Oswy, and embraced a re- ligious life. He brought over masons from France to build his church in the Roman manner, and, [ when the building was nearly finished, he procured artificers from the same country, skilled in the mystery of making glass, to glaze the windows. The conventual church of Ripon, and the cathedral church of Hex- ' ham, were both built by Wilfrid, Bishop of York, in the second half of the seventh century ; and were both constructed of stone, and supported by pillars and arches. Wilfrid also imported builders and artists from abroad from Rome, Italy, France, and other countries. In the eighth century, the mo- nastery of Croyland was built by Ethelbald, King of Mercia; and the church of St. Peter at York was rebuilt by Archbishop Albert, and consecrated just before his death, which took place in 780. Alcuiu describes this church as having pillars, arches, and porticoes. In the ninth century, the pro- gress of the arts was interrupted by the constant incursions of the Danes. All that had been done was destroyed; and little more than repairs, and military works, could be undertaken till the peace- able reign of Edgar, in whose time the abbey of Ramsey was founded, and the church built by Ailwin, then alderman of all England. This church was built in six years, and finished in 974. It was in the form of a cross, and had pillars, arches, and two towers, one of which was supported by four pil- lars, or piers, in the middle of the building. This appears to have been the first English church that NOR NORMAN (ANGLO) ARCHITECTURE. NOR had a tower so situated, or that was huilt in the form of the cross. From these descriptions of the Saxon churches, preserved in the early chronicles, it appears that the Saxon style was, like that of every other country, an imitation of the Roman. The abbey church of Ramsey, which was one of the latest, and one of the most cele- brated of the works of the Saxons, was completed in six years. The last Saxon work of importance was the abbey church of Westminster, built by Edward the Confessor, and finished and consecrated in 1065, one year before the Conquest. This church is represented to have been of a different character from that of any preceding structure in Eng- land; and this difference undoubt- edly consisted in an approximation to the Norman method of building. Edward the Confessor had been brought up in Normandy, and was almost reproached for his incessant endeavours to introduce Norman customs and manners. The churches and monasteries which arose after the Conquest were constructed after a new manner of building. From all this it appears that there must have been a marked difference between the Saxon and the Norman fabrics. But, as both were an imitation of the Roman, the difference must have consisted in the dimensions and the superior workmanship and magnificence of the new structures. It must have been the same style on a grander scale, and executed in a more sci- entific manner. At the time of the Conquest the Anglo-Saxons were in every respect a ruder and less civilized race than the Normans had by that time be- come. The earliest work of the Nor- mans which exists in this country was conducted by Gundulph, who, after rebuilding his cathedral at Rochester, was employed by Wil- liam to superintend the construc- 309 o 5 tion of the White Tower, in the Tower of London, which contains within its walls perhaps the only ecclesiastical remnant of the Con- queror's time at present in ex- istence. In the course of the Conqueror's reign, several cathedrals, abbeys, and castles were built, none of which remain in their original state. A remnant of the Con- queror's time existed at Canter- bury till within these few years, the northern tower, at the west end of the cathedral . This was a part of the work of Lanfranc. The stones of which it was built were irregular, and the joints between the courses were wide. Several castles have the reputa- tion of being of the Conqueror's time, but, on a close investigation, will be found to have been rebuilt in after years. Such is the case with the castles of Norwich, Ro- chester, the keep at Conisborough, and many others. Within less than a century after the Conquest almost all the ca- thedrals and abbey churches of England, besides innumerable par- ish churches, were either wholly rebuilt or greatly improved by the Normans, on whom William and his successors conferred all the best ecclesiastical preferments. By the introduction of these Norman pre- lates, the Norman style w r as rapidly diffused, at first, however, so much affected by the state of art in this country, as to give to the English building the character of a Norman building of much greater antiquity. Rufus was a great builder; his principal work was the great hall of his palace at Westminster. This hall, as it now exists, was altered by Richard II., but much of the original work was left, and during the late repairs, portions of this were visible. The lower part of the walls was faced with rubble; the courses were irregular; the joints wide. Remains of a tri- NOR NORMAN (ANGLO) ARCHITECTURE. NOR forium or gallery were discovered, \vhich had been carried along the sides of the hall, half-way up. The capitals of the pillars on which the round arches of this gallery rested were plain cubes. The whole of the workmanship was coarse. The plan of the churches erected about this time was the same as in Normandy. All were built with the semicircular chancel, which in England afterwards fell into such general disuse that few traces of its existence are to be found in this country. It is, however, to be traced in that of St. Bartholomew- le-Grand, in London, (begun in 1123,) in the minster at York, at East Ham, Essex, and in other places. The arches of the nave usually rested on those heavy cylindrical piers which in French churches are ever hardly to he found, except in crypts. Their prevalence in England must be ascribed to the inexpertness of the native work- men, and the probability is, that they had previously been adopted by the Saxons from their inability to imitate the Roman style in a more satisfactory manner. Some- times,to adorn the cylindrical piers, the Anglo-Normans introduced the spiral groove winding round them, with the net or lozenge - work spreading over them. The windows and the doors were the same as in Normandy, and the Norman mouldings were gradually introduced with little alteration. The walls are remarkably thick, and without prominent buttresses. Specimens of the time of Rufus are to be seen in the choir, side aisles, and middle transept at Dur- ham ; in the walls of the lower part of the western facade of Lin- coln ; the towers and transept of St. Alban's; the oldest remaining parts of Winchester ; and the east end and cross aisle of Worcester. The walls in this reign were 310 irregularly built, and the joints continued to be wide, as may be seen at Durham, Lincoln, Winches- and, other places. The style prevailed in the early part of the reign of Henry I., as may be seen by the ruins of St. Botolph's priory, Colchester, which was built by Ernulph, a Norman monk, in the first years of that prince. Here are the same heavy cylindrical piers, the same stumpy proportions, the same poverty of mouldings. But in the course of this reign an impulse was given to architecture by one of those men of genius who affect the character of the age in which they live. Roger Poor, Bishop of Salisbury, a Norman by birth, and combining in himself the offices and the qua- lities which, in those times of constant commotion, were often united, was much distinguished as a prelate, a warrior, a statesman, and an architect. William of Malmsbury relates, that the walls which were built under the super- intendence of Roger of Salisbury were so smooth, and had such fine joints, that they seemed to be made of a single stone. Had fine joints been in use before, their appearance in the works of this prelate would not have been so much extolled. The admiration with which they are mentioned gives us the date of the first introduction of fine joints in the walls of English buildings. From this time progressive im- provement took place in other parts of the fabric. Something like decoration was added. The portals began to be enriched. The architecture of England ascended to the level of the architecture of Normandy in the time of William the Conqueror. Examples of the style of this reign may be seen in the naves at Gloucester, Norwich, Ely, Durham and Southwell ; also in the latera towers of Exeter cathedral, built by Bishop Warlewast; in St. James's NOR NORMAN (ANGLO) ARCHITECTURE. NOR tower, Bury St. Edmund's; in the ruins of the chapter-house at Ro- chester, built between 1114 and 1125, by the same Ernulph who built St. Botolph's at Colchester, and who, on the death of Gundulph, was promoted to the see of Roches- ter ; in the portal of the round church at Cambridge ; in the nave of the church at Dunstable ; in Saint Bartholomew -le- Grand, London, which was begun in 1 123 ; in St. Sepulchre's, Northampton, built by Simon de Liz, second earl of Northampton, on his return from the Holy Land, and who died in 1 127 ; and in the abbey church of Tewkesbury, begun by Robert Fitz-Hamon, (who died in 1 107,) and consecrated in 1 1 23. EXAMPLES. Portal of the chap- ter-house at Durham, built by Bishop Galfrid Rufus, between 1133 and 1143 ; church of Castle Acre priory, Norfolk, consecrated in 1148; church of St. Cross, Hamp- shire ; Ripon minster ; St. Frides- wide, (now Christchurch,) Oxford, begun not later than 1150, and finished in 1180. About this time, or a little later, Domestic architecture began to make its appearance in England, though, from the dimensions and arrangement of some of those build- ings which have come down to our time, it is difficult to determine whether all of them were destined for dwelling-houses, or were only halls for public occasions, or for the courts of the feudal lords. Of these buildings the invariable plan is a parallelogram of two stories ; sometimes a double pa- rallelogram. The lower story was vaulted, as we have seen to have been the custom in Normandy, and it had no internal communication with the upper story. The upper story was approached by an exter- nal stab-case, which probably was moveable. The only fixed Norman staircase now extant is the one at Canterbury. 311 The probability is that the lower story was occupied by the servants, and the upper story by the masters ; but in none of the buildings of this time now extant do there exist any traces of subdivisions. An example of Normal Domestic architecture existed in Southwark till within these few years. It was the hostelry or town residence of the priors of Lewes. The church of St. Olave, Southwark, was confirm- ed to the prior and convent of Lewes by William, second Earl Warren and Surrey, the son of the founder. Earl William died in 1138. It appears, however, that the priors of Lewes rented a build- ing in 1170 and 1186, for their oc- cupation in London ; from whence it may be concluded, that the hos- telry in question was not built till after that period. The general features of the portion of the hos- telry which remained till lately nearly resembled those of the manor-house of Boothby Pagnel, Moyse'sHall, at Bury St. Edmund's, and the building which is called the Pythagoras School at Cambridge. In 1826 was still existing at Barneck, in Northamptonshire, a Norman manor-house, which was not built for defence. In this in- stance the hall, which was the principal feature, was on the ground floor, and had no vaults underneath. The hall consisted of a centre and two side aisles. The fine joints of the walls of this building denoted that it could not have been built much before the middle of the twelfth century. At Bury St. Edmund's is a Nor- man domestic building, which goes by the name of Moyse's Hall. At Boothby Pagnel, in Lincoln- shire, is a Norman manor-house on nearly the same plan. In this are a fire-place and a chimney, which indicates that the building of which it forms a part cannot be older than the second half of the twelfth cen- tury. This edifice has windows in NOR NORMAN (ANGLO) ARCHITECTURE. NOR the ends as well as the sides, a circumstance which makes it evi- dent that to this building no others could have been attached. It is surrounded by a moat. At Christchurch, Hants, is a Nor- man remnant which has also a chimney. At Lincoln is a Norman domestic building which goes by the name of ' John of Gaunt's Stables,' but which, in fact, was the public meet- ing-house of a guild. It is so much enriched as to be placed late in the reign of Henry II. These examples prove that about the middle of the twelfth century, mansions, distinct from castles for defence, began to be erected in England; and that, independent of colleges, abbots' lodgings, arid the habitable parts of convents, in- stances existed of Domestic archi- tecture. But it was long before dwelling-houses acquired a charac- ter bearing any relation to the qua- lity of the proprietor, or were con- structed with much regard to con- venience. Examples of the Norman style of the time of Henry II. are to be seen in the abbey gateway, Bristol ; in the Galilee, or chapel, at the west end of Durham, built by Bishop Pudsey (1154 to 1197), together with the lateral portals of the nave ; in the new nave and great west portal of Rochester, &c. It was in the latter years of the reign of Henry II. that the struggle between the Round and the Pointed styles, which is called the Transi- tion, began to take place in this country. Kirkstal abbey, in Yorkshire, was built in the thirty years preceding 1183. The nave arches are pointed, but the pillars are massive, and the windows and portals are round. The church at Roche abbey, though equally in the Transition style, and having round - headed windows above pointed arches, Norman mouldings and capitals, yet is of a 312 less heavy character. Both build- ings, however, denote that during those years the new style was only just beginning to be received in England. About the same time (1170), Archbishop Roger employed the Pointed style in the new crypt of York minster. But the early examples of the Transition, of which the dates are known with the most undoubted certainty, are the round part of the Temple church, London, which was consecrated in 1185, and the choir of Canterbury cathedral, which was rebuilt after the fire in 1175, and in which the Pointed style was introduced by John of Sens, a French architect. Other instances are to be found in the great tower at the w r est end of Ely, built by Bishop Ridel, who died in 1189; in the county hall of Oke- ham, Rutlandshire ; in the abbey church of Glastonbury, &c. But the nave of Rochester and the nave of Peterborough, rebuilt between 1170 and 1194, are proofs that the old fashion was not at once superseded by the new. Simultaneously with the intro- duction of the Transition style, hewn stone vaults appear to have been first thrown over the wider parts of English churches, w 7 hich till then had been habitually roofed with wood. A stone vault was thrown over the new choir of Can- terbury, in 1 1 74. It was customary before that time, to roof narrow spaces with plain cross-vaulting, but not to vault wide spaces with stone. Plain cross-vaulting of rub- ble, with and without ribs, had been adopted before in crypts, side aisles, and chancels. Barrel-vault- ing, we have seen, w r as introduced in the time of William the Con- queror. From the time that the choir of Canterbury was built, which was not long after, it became com- mon to throw stone vaults over the naves of the larger churches of NOR NOZZLES. NOZ Normandy, anil hewn stone vaults, plain at first, and gradually en- riched, became habitual in Eng- land. Prominent buttresses and flying buttresses, as in Normandy, followed in the train of the stone roofs. From this time, the Round style fell gradually into disuse; but at Fountain's abbey, the foundations of which were laid in 1204, and which was in progress during the forty subsequent years, the win- dows and portals are still round- headed ; and an instance of a round portal is to be found at Ketton, in Rutlandshire, so late as 1252. During the reign of Henry III. the Early Pointed style attained its most perfect condition. Fine ex- amples of this style are to be seen in the chapter-house, the transepts, and part of the choir of Westmin- ster abbey ; in the choir of St. Al- ban's ; in the nave of Lincoln ; east end of Durham ; nave of Wor- cester, 1224 ; nave and spire of Lichfield ; south transept of York ; and the older part of the choir of Southwell; and in Salisbury ca- thedral, which was begun in 1221, and carried forward, without inter- ruption, till it was completed. The establishment of the Pointed style was attended with one re- markable difference in England and Normandy. In Normandy, the semicircular chancel became, ge- nerally speaking, polygonal; in England, generally speaking, it be- came square. Polygonal chancels are as rare in England as square chancels are in the larger churches of Normandy ; and this difference of shape in England afforded the opportunity of those magnificent east windows, which are so princi- pal and so splendid a feature of our cathedrals. Another difference to be remarked, is the battlement, which usually forms the parapet of English churches, and which never occurs in the ecclesiastical build- ings of France. 313 It may be said, 1. That the supposed existence of the Pointed style in Normandy, in 1056, is imaginary. 2. That the Normans, adopting the corrupt Roman style, gave it a character of their own. 3. That the Normans greatly con- tributed to the advancement of the arts in England. 4. That archi- tecture performed exactly the same revolution in England and France, France having, in all the changes, a certain precedence. Norroy, or North roy, in heraldry, one of the two provincial Kings at Arms, whose jurisdiction lies on the north side of the Trent, as does that of Clarencieux to the south Northampton Tables, Tables made at the county town of Northampton, formed from the registers of burials of that locality, from which calcu- lations were made of the value of life, for the purpose of its insurance. (See article Assurance.} Nosing, the prominent edge of a moulding or drip; the projecting moulding on the edge of a step Nosing of steps, the projecting parts of the tread-board or cover, which stand before the riser. The nosing of steps is generally rounded, so as to have a semicircular section; and in good staircases a hollow is placed under them. Notch - board, a board notched or grooved out, to receive and sup- port the ends of the steps of a stair- case Notching, the cutting of an excava- tion throughout the whole breadth of a substance : by this means tim- bers are fastened together, or their surfaces, when joined at angles, are made to coincide Nozzles, those portions of a steam en- gine in which are placed the valves that open and close the communi- cation between the cylinder and the boiler and condenser, in low- pressure or condensing engines; and between the cylinder and boiler and atmosphere, in high-pressure or non-condensing engines NUC OAK. QBE Nucleus, the internal part of the floor- ing of the ancients, consisting of a strong cement, over which was laid the pavement, which was hound with mortar Nuisance, any thing tending to hurt, to annoy, or to endanger health. (See the excellent work by Mr. Gibbons on this subject.) Nullah, in India, a natural canal, or small branch of a river Nunnery, a Roman Catholic building for an association of nuns or females devoted to a life of religious seclu- sion. Previous to the Reformation, there existed in England 127 edi- fices for the convenient lodging of such pious women, 2 in Wales, and 20 in Scotland; in the whole in Great Britain, 149. But there were many convents and religious OAK OAK. There are two kinds of this timber common in England, on the Continent, and in America. Oak of good quality is more durable than any other w T ood which attains the same size : its colour is a well- known brown. Oak is a most va- luable wood for ship-building, car- pentry, frames, and works requiring great strength or exposed to the weather. It is also much used for carved ornaments, panelling of rooms, pulpits, stalls, and stand- ards for churches. It is likewise used in the construction of all kinds of buildings, for strength and sta- bility. English oak is one of the hardest of the species : it is consi- derably harder than the American, called white and red Canada oak. African oak is well adapted to the construction of merchant vessels. Italian oak is much purchased for our dockyards, to the prejudice of that which is proudly standing in our several forests. Obelisk, in architecture, a quadran- gular pyramid : those of Egypt may be described as large stones, qua- drilateral, diminishing from the 314 houses not specially named nun- neries, but which were receptacles also for such purposes. Nunnery, a term sometimes applied to the triforium or gallery between the aisles of a church and the clere- story ; so called from the situation of the nuns' choir in some convents. At the present time, the roomy galleries over the aisles in West- minster abbey are called nunneries, probably from having been used by the nuns of Kilburne, when they visited the abbey, to which they were subordinate. Nut, a short internal screw, which acts in the thread of an external screw, and is employed to fasten any thing that may come between it and a flange on the bottom of the external screw or bolt OBE base upwards, till, within about a tenth of the height, the sides con- verge to a point. The width of the base is usually about a tenth of the height, to that part where the sides begin to converge : they are commonly formed from a single stone, mostly of granite. There are, however, two small obelisks in the British Museum, formed of basalt, and one at Phike, of sand- stone. When obelisks were first made in Egypt, it was customary with the patriarchs of the Jews to set up stones to perpetuate the memory of great events. Strabo calls such stones 'books of history;' an epithet which might be applied with propriety to the inscribed Egyptian obelisks. The date of the Flaminian obelisk, which is covered with hieroglyphics, is by some writers supposed to be be- tween 1580 and 1600 B.C. The first obelisk was raised by Rameses, King of Egypt, in the time of the Trojan war : it was 40 cubits high, and employed 20,000 men in build- ing. Phins, another king of Egypt, raised one of 45 cubits, and Ptolemy OBL ODONTOGRAPH. ODO Philadelphns another of 88 cubits, in memory of Arsinoe, &c. The Romans also erected many, which are well described in Roman history. Oblate, flattened or shortened; in geometry, a term applied to a sphe- roid, produced by the revolution of a semi-ellipsis about its shorter diameter. Of this figure is the earth, and probably all the planets, having the equatorial diameter greater than the polar. Oblique, in geometry, aslant ; not di- rect ; not perpendicular nor parallel Oblique angle, one that is greater or less than a right angle Oblique-angled triangle, one that has no right angle Oblique arches, or Oblique bridges, are those which conduct high roads or railroads across a river, canal, &c., in an oblique direction: they are also called 'skew arches Oblique line. When one straight line stands upon another, and makes unequal angles therewith, the an- gles are said to be oblique, the one being greater than a right angle, and the other less : hence a line is only oblique as it relates to another line ; otherwise the word would be destitute of meaning. Oblique sailiny occurs when a ship, being in some intermediate rhumb between the four cardinal points, makes an oblique angle with the meridian, and continually changes both its latitude and longitude Oblong, a rectangle of unequal dimen- sions ; in geometry, longer than broad Observatory, a building erected for the purpose of making observations on the motions of the heavenly bodies. More particularly with re- ference to the study of Terrestrial Magnetism, observatories have been erected by the British Government in Canada, St. Helena, the Cape of Good Hope, and Van Dieman's Island; by the East India Com- pany at Madras, Singapore, Simla, and Trevandrum ; and by the Rus- sian Government at St.Petersburgh 315 and other places, in connection with those at Gottingen, &c. The most munificent example of private de- votion to the science of Astronomy is the splendid observatory erected by Lord Rosse at Pensantown, in Ireland. Obtunding, the blunting or taking away a sharp corner Obtuse, in geometry, blunt ; in oppo- sition to acute or sharp Obtuse angle. In geometry, if the contained angle be less than aright angle, it is called an acute ; if greater, it is called an obtuse angle. Obtuse -angled triangle, a triangle which has an obtuse angle Obtuse section of a cone, the hyper- bola of ancient geometricians, be- cause they considered it only such a cone whose section through the axis was an obtuse-angled triangle Occus, the banqueting - room of a Roman house. There were several kinds of occi, viz. Corinthian, tetra- style, Cyzicene, and Egyptian. In the Greek houses the occi were spacious apartments, in which the mistress of the family employed herself and servants at the loom Ochre, brown, a clay coloured brown by the oxide of iron Ochre, red, a clay coloured red by the oxide of iron Ochre, yellow, a clay coloured yellow by the oxide of iron Octagon, a figure of eight sides and as many angles : when all the sides and all the angles are equal, the figure is called a regular octagon Octahedron, in geometry, one of the five regular bodies, consisting of eight equal and equilateral triangles Octostylos, a portico which has eight columns in front Odeum, a small theatre for the reci- tation of musical compositions generally in the neighbourhood of the theatre : the odeum at Athens was contiguous to the theatre 01 Bacchus; the odeum at Pompei also joined the theatre Odontograph, a very ingenious instru- ment, invented by Professor Willis (EC ORATORY. ORA of Cambridge, to enable the mill- wright, workman, and engineer to measure, draw, and design infinitely in extent, the teeth of wheels (Ecus, according to Vitruvius, apart- ments near or connected with the dining-room Offices, as connected with the domes- tic purposes of large mansions, palaces, &c., consist of kitchens, sculleries, pantries, breweries, wash- houses, &c. ; frequently detached or out-houses, and sometimes, in cities, underground and vaulted places beneath the same roof Offices, as connected with business, are apartments for the accommo- dation of clerks or accountants ; merchants' counting-houses, &c.; for law clerks, law agents, &c. Offing, in navigation, that part of the sea distanced from the shore where there is deep water, and no neces- sity for a pilot Offset, or Set-off, the splay or narrow slanting course of stone or brick, serving to connect two portions of a wall, the uppermost of which re- cedes from the face of that beneath Ogee, a moulding consisting of two members, the one concave, the other convex ; the same with what is otherwise called cymatium. In Gothic architecture, ogees are very much employed. The term ogee is also applied to a pointed arch, the sides of which are each formed of two contrasted curves. Ogives, arches or branches of a Gothic vault, which, instead of being cir- cular, pass diagonally from one angle to another, and form a cross with the other arches which make the side of the squares, whereof the ogives are diagonals. The middle, when the ogives cut or cross each other, is called the key, sometimes carved in the form of a rose. The members or mouldings of the ogives are called nerves, branches, or veins ; and the arches which separate the ogives, double arches. Oillets, or Oylets, small openings or 316 loopholes, sometimes circular ; ex- tensively used in the fortifications of the middle ages Oliver, a small lift-hammer, worked by the foot. The hammer head is about 2 5 inches square and 10 inches long, with a swage tool having a conical crease attached to it, and a corresponding swage is fixed in a square cast-iron anvil- block, about 12 inches square and 6 deep, with one or two round holes for punching, &c. The ham- mer handle is about 2 to 2i feet long, and mounted in a cross- spindle nearly as long, supported in a wooden frame between end- screws, to adjust the groove in the hammer face to that in the anvil- block. A short arm, 5 or 6 inches long, is attached to the right end of the hammer axis; and from this arm proceeds a rod to a spring- pole overhead, and also a chain to a treadle a little above the floor of the smithy. Olympiad, a period of four years, by which the Greeks reckoned their time. The first Olympiad corre- sponds with the 775th year before the birth of our Saviour, and 22 years before the building of Rome. Oolite, the Portland stone used in ar- chitecture, called also freestone and roestone Opa, according to Vitruvius, a bed or cavity in which the head of a tie- beam rests Opaque, cloudy, not transparent Ophites, a black marble Opisthodomos, the enclosed space be- hind a temple : the treasury at j Athens was so called, because it stood behind the temple of Minerva Oppidum, according to the Romans, a mass of buildings ; an entrance to a town ; the facade to a public building ; not unlike to the termini on the principal lines of railway Opposite angles, those which are formed by two straight lines cross- ing each other, but not two adja- cent angles Opposite cones are those to which a ! ORA ORDNANCE SURVEY. ORD straight line can be every where ap- plied on the surface of both cones Opposite sections, those made by a plane cutting two opposite cones Optics, the science of direct vision, including catoptrics, dioptrics, and perspective. Optostrotum, according to the Greek, a brick-paved flooring Opus, Roman reticulated masonry ; a mode of workmanship Or, in heraldry, gold : it is denoted in engraving by small points all over the field or bearing Ora, a Roman hawser Oratory, a small private chapel or closet for devotion Orb, a mediaeval term for a blind window Orbs, in Gothic ornament, bosses and knots of foliage, flowers, or other ornament in cornices Orbiculus, according to Vitruvius, a roller or a pulley revolving upon an axis, and having a groove in its circumference for the rope to fit into; employed as a mechanical power for raising or drawing Orchestra, the area in the Greek theatre comprised between the lower range of seats and the pro- scenium. In the Roman theatre, the orchestra was appropriated to the senators ; but in the theatres of the Greeks it was- the scene of action of the dancers. Orders of Architecture, usually named the 'five orders,' without reference to other styles of architecture, are thus enumerated by most writers : 1. Tuscan. 2. Doric. 3. Ionic. 4. Corinthian. 5. Composite. (For their proportions, see Architec- ture.} Ordinates, in geometry and conies, lines drawn from any point of the circumference of an ellipse, or other conic section, perpendicularly across the axis, to the other side Ordnance Survey of Great Britain and Ireland : a work of great import- ance in ascertaining the true geo- graphical position of our islands and of their varied superficial fea- 317 tures. This survey originated in the mutual desire on the part of English and French philosophers to determine the precise difference of longitude between the meridi- ans of the Greenwich and Paris observatories. In the pursuit of this object, a meeting was arranged at Dover between three members of the French Academy, MM. Cas- sini, Mechain, and Legendre, and General Roy and Dr. Blagden, to arrange plans of operation. In the course of the subsequent survey, the Officers of the Royal Artillery, to whom the superintendence of the work was intrusted, extended their views and operations, and, under the patronage and at the expense of the Board of Ordnance, proceeded to determine the length of as many degrees on the meridian as came within the limits of the survey. The rules by which the main lines for this and all other extended surveys are obtained, are derived from the principles of trigonometry, or the properties of triangles. By these principles we are enabled to compute the exact form and dimensions of any triangle from the actual measurement of one side only, and of the angles formed at its extremities by the other sides. Upon these principles the true figure and size of our globe have been determined upon the relative lengths of degrees of a meridian in different latitudes. The exactness of the results of these operations depending upon the correct measurement of the one side, or base line, and of the angles at its ends, formed by the two imaginary sides which have a common meeting point in some distant and conspicuous object, the apparatus for measuring this side and the angle is required to act with extreme delicacy and exact- ness. For measuring the length, rods of various materials have been used, and endeavours made to obviate the effect of changes of ORD ORDNANCE SURVEY. ORD temperature in altering the length of the rods themselves. General Roy commenced the measurement of a base line on Hounslow Heath with rods of deal, each twenty feet long. But these rods, although prepared in the most careful man- ner, of the best seasoned timber, perfectly straight, and effectually secured against bending, were found to suffer such changes of length, from the varying dryness and moisture of the air, as ren- dered them utterly unfit for the purpose, and glass tubes were eventually substituted, each of them twenty feet long, and en- closed in a frame of wood, allow- ing only expansion or contraction in length from heat or cold ac- cording to a law ascertained by experiments. With these rods a base of about 5 miles in length was measured so exactly, that a remeasurement by Colonel Mudge several years afterwards, made with a steel chain constructed by the celebrated Ramsden, differed only from the original line to the extent of 2|- in. Steel chains are jointed similar to a watch-chain, and are always used with uniform tension, the differences in length due to temperature being calculated upon the observed fact, that each degree of heat above 62 Fahr. extends the chain -0075 of an inch. For determining the angles, the English Officers used an excellent theodolite by Ramsden, having both an altitude and an azimuth circle, and a telescope of great power. This instrument, com- bining the powers of a theodolite, a quadrant, and a transit instru- ment, is capable of measuring hori- zontal angles to fractions of a second. It is recorded among the proofs of the accuracy attained in this triangulation, that a testing line, or base of verification, as termed in geodesic operations, measured on Salisbury Plain, of which the length exceeded seven 318 miles, differed only one inch from the computation carried through the series of triangles from Houns- low Heath to Salisbury Plain. When the primary triangulation had been thus carefully completed, a further subdivision of each of these great triangles was perform- ed, and each of these again was subdivided into others, so that the entire plot of the country was re- presented by a complete net-work of triangles. Each of these divi- sions and subdivisions being form- ed independently of the others, and yet the exact accordance of the whole being insisted on and effected, accuracy is secured in all these principal operations, and the filling in of each of these spaces is intrusted to a different class of operators, whose labours in pro- ducing the final plan are so divided and arranged that the work of each is a check upon the exactness of his predecessor. Thus the sur- veyors measure the lines and angles on the ground, but another class of assistants (the plotters) produce the plan from the records of the surveyors, and a third class (ex- aminers) test the plan, thus pro- duced, by subsequent comparison in the field. One effect of this system, by which the range of ope- rations confided to each operator is thus limited, and the fidelity of these thus severely scrutinized, is, that the bulk of the work after the triangulation may be safely confided to an inferior and cheaply engaged class of assistants, and great comparative economy thus attained. The Ordnance Survey of Great Britain and Ireland is plotted to different scales. Thus the whole of Ireland is plotted on a scale of six inches to a mile, and is con- tained on 1907 sheets of maps, which may be purchased at 2*. 6d. and 5*. each. The Survey of Eng- land and Wales is plotted on a scale of one inch to a mile, and ORD ORGAN. ORG comprised in 110 sheets (of which ninety are already published), at 25. each ; about half of these are published in quarter-sheets at 6d. each. Portions of Lancashire and Wigton shire are plotted at six inches to a mile, price 2s. 6d. and 5*. each; and the towns of Dublin, Wigan, Blackburn, Chorley, and Liverpool, .upon the large scale of five feet to a mile, from 2,s. to 3s. &d. each. It is only the one-inch survey which has the hills shaded. A Geological Survey, which besides giving the one-inch maps geolo- gically coloured, shows horizontal and vertical sections of the country, is also in progress, and is com- pleted over some of the south-west- ern counties. The estimate for the recently completed Ordnance Survey of London was as follows: "That a block-plan of the metropolis, and of the suburban districts included within a radius of eight miles from St. Paul's, may be executed, with a proper system of levels, for 24,215, and that the cost of engraving the block-plan, upon a scale of five feet to the mile, and upon 901 plates of double elephant size, would be (including 3,604 for the copper) 12,614., making together 36,829." The plan has been produced at a cost within this estimate, and the engraving will probably be executed considerably below the estimate. Organ. This word is derived from the Greek organon: organum in Latin, organo in Italian, orgue in French, orgel in German. It signi- fies, generally, an instrument ; but is now used for the name of the grandest and most worthy of mu- sical instruments. The tones of an organ are pro- duced from the pipes only; of these some are of wood, others of various kinds of metal, and even of glass. An organ of full compass may contain all the sounds recog- nized in the science of music, from 319 the lowest appreciable to the very highest. The largest pipes pro- duce the lowest sounds, and some few are made as long as about 32 feet, while the smallest are about the size of the pipe of a very small key. Organs are of various kinds, viz. for the church, the concert- room, and for the private drawing- room. The church organ should be of a full, deep, and solemn cha- racter ; while the concert-room organ should be of a lighter and more brilliant kind, with every va- riety of stop, in order to imitate, not only the full orchestre, but also certain ' solo' instruments. Hence we have the flute-stop ; the haut- boy, the cremona, or krum-horn ; the vox-humana, &c. stops; ac- cording to the extent of the instru- ment. These solo, or fancy stops, belong only to the concert-room or drawing-room organ, and are wholly unbecoming in one for the church. We have not space to give any thing like a description of this the noblest of instruments ; and it must suffice to say that it consists of a bellows which supplies the pipes with wind by means of a wind chest; the wind being con- veyed therefrom, through channels, under the different ranks, or rows of pipes, and thence into the pipes by means of pallets, or valves, opened at the pleasure of the per- former, by pressing the proper lever or key. The organ is a very ancient in- strument of the church, and must have been very unwieldy, since we are told of one in the cathedral church at Halberstadt, which had only a few large pipes, and the keys were more than a hand- breadth in width, and were beaten or pressed down by the fist, or elbow ; the wind being supplied by several small bellows. We are also told of the Winchester organ which required seventy men to supply it with wind ; its compass was of ten ORG ORRERY. OSC notes only, although it had 400 pipes, i. e. forty to each note ; it was so loud that it could be heard all over the city. The organ is usually described as being of three kinds ; the great, or full chorus organ ; the swell organ, and the choir organ : the latter is used to accompany the softer parts of the music, and is such an instrument as was carried in the ancient pro- cessions, in the rogation days, and other seasons, to accompany the priests with wiiile chanting the litanies; the performer, or, more properly speaking, the minister at the organ, being carried also with the instrument, and seated : hence this organ was called the chair- organ, now corrupted into choir- organ, from the difference in its employment. The swell organ is used chiefly to accompany solos ; for interludes, and such like fanci- ful music, and takes its name from being able to swell out its sounds by openings made by turning a series of boards, on their centres, similar to a Venetian blind, these boards being connected by levers under the control of the per- former's foot. The key-board, or row of keys of an organ, are like those of a piano-forte, only they require to be pressed down, (not struck like those of the latter instrument,) so as to open the pallets before mentioned, and cause the pipes to speak. A complete church organ contains three rows of keys, one for each of the above-mentioned organs ; and most organs have also a row of keys called pedals, to enable the organist to play the bass-notes with his feet. In organs that are played by means of a wind, or handle, the part of the organist is perform- ed by a cylinder, on which are placed a number of wires so con- trived as to press upon the levers, and open the pallets or valves ; and hence those instruments are called 320 barrel organs. They are of little or no use for the purposes of the church. It has been the fashion for some time, to make one organ do the w r ork of two, namely, the full organ and the choir organ : but it is at best but a sorry con- trivance ; for in such an organ there can be no good choir organ mixture ; and the full organ is ge- nerally too noisy, the fullness being made up of loud-voiced pipes, in- stead of their being round, mellow, and full -toned. These kinds of organs have not the dignified and solemn character necessary for real church music. Organ screen, an ornamental stone wall or piece of timber frame-work, on which a church organ is placed, and which in English cathedrals and churches forms usually the western termination of the choir Oryanum, a name given to a machine or contrivance in aid of the exercise of human labour in architecture and other arts Oriel window, a projecting angular window, mostly of a triagonal or pentagonal form, and divided by mullions and transoms into differ- ent bays and other proportions. The word oriel has been discussed by many writers, but there cannot be conceived an architectural charm more cheerful to the interior, or more decorative to the exterior of a building, than an oriel window. Orlop, in shipping, the middle deck Ornithon, an aviary or poultry-house, or the appurtenance to a farm villa Orrery, in mechanics, a machine which by many complicated move- ments represents the revolutions of the heavenly bodies Orthography, in architecture, the ele- vation of a building, showing all the parts thereof in their true pro- portions : the orthography is either external or internal. The external is the delineation of the outer face or front of a building; the internal is a section of the same. Oscillating Engine, a marine engine, osc PAGODA. PAG with a vibrating cylinder, having the piston-rod connected to the crank, and the cylinder supported by the trunnions projecting from the sides at or near the centre, cast hollow and connected to the steam and eduction pipes Oscillation, or vibration, in mechanics, the act of moving backward and forward like a pendulum Oscillation, the axis of, in mechanics, a right line parallel to the apparent horizontal one, and passing through the centre, about which the pen- dulum oscillates Osterly House. " The opulence and gallantry of Sir Thomas Gresham rivalled the wonders of romance. Queen Elizabeth had visited that superb mansion, and on quitting the window to seek her bed, had remarked aloud, ' How much more gracefully the court yard would appear if divided in two by a wall.' The words were caught up by Sir Thomas, who instantly, on quitting the royal presence, sent hastily to his masons and bricklayers, assisted them with innumerable labourers, worked all the night, and completed the wall according to the Queen's wishes before she had risen from her bed. The courtiers were chag- rined at the knight's abruptness, and one of them consoled himself with a conceit, 'that it was noway strange that one who could build a PAC PACK, a quantity of material, either wood or coals, placed or piled up to support roofs, or for other pur- poses Paddle-shaft, the shaft upon which the paddle-wheel is fixed, placed centrally with, and connected to, the crank-shaft Paddle-wheel, the wheel fixed upon the paddle-shaft, for propelling a vessel through the water by the action of a number of paddle-boards fixed at the circumference 321 'change could exchange a build- ing.' " Ostium, an inner door, the door of a chamber Outward angle, the same as a salient angle Ova, in architecture, ornaments in the form of eggs, carved on the contour of the ovolo, or quarter- round, and separated from each other by anchors and arrow-heads Oval, a figure in geometry, bounded by a curve-line returning to itself. Overshot -wheel, a wheel driven by the weight of water conveyed into buckets, disposed on its circumfer- ence so that one part of the wheel is loaded with water while the other is empty Over story, the clear story or upper story of a building Ovolo, a convex moulding, mostly used in classical architecture ; in the Roman examples it is an exact quarter of a circle ; in Grecian it is more flat and quirked at the top. It is frequently used in the deco- rated Gothic style. Oxidation, rusting; the process of converting metals and other sub- stances into oxides, by combining a certain portion of oxygen with them Oxygen, in chemistry, a gaseous ele- ment, of great importance in the economy of Nature : it is essential to the maintenance of organic life : hence its original name, ' vital air.' PAG Pagoda, in architecture, a name ap- plied by the Europeans to Hindoo temples and places of worship, but not by the Hindoos themselves, who have no such appellation; they are square stone buildings, not very lofty, crowned with a cupola : the pagodas of China are, however, lofty houses, which sometimes rise to the height of nine stories, of more than twenty feet each. The buildings are depositories of their idols, and used for their worship. PAI PAINTING. PAL Painted and Stained Glass, formerly used exclusively for ecclesiastical purposes, displaying devotion and spiritual bearing. Latterly painted and stained glass have been used for domestic purposes. The art of painting on glass was known as early as the sixth century, and was applied to the enrichment of the basilica of St. Sophia, and other churches in Constantinople ; and in the reign of Charlemagne some progress was made in enrich- ing and beautifying glass with colours. In the tenth century it was much admired, and advanced rapidly : Henry II. patronized this art. In France it progressed in all the magnificence of colour and ex- ecution, andwas extensively diffused in England. In Canterbury and York some beautiful examples re- main, for the admiration and ex- ample of modern practice. Of the unique cento style, the revival of art under the immortal Albert Durer, some very fine specimens of the period, picturesquely drawn, are to be found in fine preservation in St. Jacques, at Liege ; and of ra- ther a later time, those of the Crabeths, at Gouda, in Holland, are magnificent executions of this art by these brothers. One of these windows, upwards of 70 feet high, was executed by Theodore Crabeth, by command and at the expense of Queen Mary of England, consort of Philip II. : a portion of the picture is magnificently painted, the sub- ject of which is the Queen, with her husband, kneeling at the Lord's table. The upper part of this win- dow has been destroyed by a storm, but the subject referred to remains perfect, and exhibits correct like- nesses of these sovereigns. (See ' Divers Works of Early Masters/ in 2 vols.) Painting. The art of painting gives the most direct and expressive re- presentation of objects ; and it was doubtless for this reason employed by many nations, before the art of 322 writing was invented, to commu- nicate their thoughts, and to con- vey intelligence to distant places. The pencil may be said to write a universallanguage,for everyone can instantly understand the meaning of a painter, provided he be faithful to the rules of his art: his skill enables him to display the various scenes of nature at one view, and by his delineations of the striking effects of passion, he instantaneously af- fects the soul of the spectator. In- vention in painting consists prin- cipally in three things : first, the choice of a subject properly within the scope of the art ; secondly, the seizure of the most striking and energetic moment of time for re- presentation ; and, lastly, the dis- covery and selection of such objects, and such probable incidental cir- cumstances, as, combined together, may best tend to develop the story or augment the interest of the piece. Architects will often find deco- rations of a room and its furniture well worthy of their study. In houses recently built, both in town and country, the taste of the archi- tect has been called in, to give designs for the arrangement of curtains, for grates, pier tables, chairs, and sofas ; and in many in- stances the superior chasteness of the designs, and the harmony of the whole with the architectural style of the rooms, may be seen, conformable with the different uses to which the rooms are appro- priated. Painter, in. navigation, a sea term for a rope employed to fasten a boat to the ship, wharf, &c. Palaestra, a building appropriated to gymnastic sports Palaces of Persia (the royal country) are at this day castellated, and many villages have towers of defence Pale, in heraldry, the third and middle part of the escutcheon Palisander, a name used on the con- tinent for rose-wood PAL PARABOLA. PAR Pall, in heraldry, denotes a sort of cross, representing the pallium or archiepiscopal ornament sent from Rome to metropolitans Palls, in ship-building, strong short pieces of iron or wood, placed near the capstan or windlass, so as to prevent their recoiling Palladium, a metal found with platina, but in small quantity Palladium, in antiquity, a wooden image of the goddess Minerva or Pallas, the possession of which involved the fate of Troy Pallium or Pall, in church rituals, a pontifical ornament worn by popes, patriarchs, primates, and metropo- litans of the Roman church, in the form of a fillet of black silk, over the shoulders, with four red crosses Palm-trees, wood of great variety, imported from the East and West Indies, but sparingly employed in England for cabinet and marquetry work, and sometimes for billiard- cues, &c. Palette (French), in painting, a light board on which the colours are held Palsgrave, in heraldry, a count or earl, who has the overseeing of a palace Pane, the light of a window ; for- merly applied also to the sides of a tower, turret, spire, &c. Panel, in carpentry, &c., a square piece of any matter inserted be- tween other bodies ; sunken com- partments of wainscoting, ceilings, &c., principally employed in Gothic and Domestic architecture for in- terior fittings Panel, a space or compartment in a wall, generally of English or Flemish oak, and on a ceiling, enclosed within a raised margin Panel, in mining, a heap of ore dressed and ready for sale Panemore, in mechanics, a globular wind-mill, proposed to be erected in the centre of a ship, for turning wheels and paddles. Panoply, in heraldry, complete armour Panorama (Full view), in painting, a picture drawn on the interior 323 surface of a large cylinder, repre- senting the objects that can be seen from one station when the observer directs his eye successively to every point of the horizon Pantheon, a temple dedicated to all the gods ; one of the most cele- brated edifices of Rome Pantograph, in mechanics, an instru- ment contrived for the purpose of copying drawings, so that the copy may be either similar to or larger or smaller than the original. (See Pentagraph.} Para, in Cornish mining, a gang or party of men Parabola, one of the conic sections formed by the intersection of a plane and a cone when the plane passes parallel to the side of the cone Parabolic Pyramidoid, a solid gen- erated by supposing all the squares of the ordinates applicable to the parabola so placed that the axis shall pass through all their centres at right angles, in which case the aggregate of the planes will form the solid called the para- bolic pyramidoid, the solidity of which is equal to the product of the bases and half the altitude Paraboloid or Parabolic Conoid, the solid generated by the rotation of parabola about its axis, which remains fixed. A frustrum of a pa- raboloid is the lower solid formed by a plane passing parallel to the base of a paraboloid. Parabolic spindle, the solid gene- rated by the rotation of a parabola? about any double ordinate Paradise, a private apartment, a study, the private appurtenances to a con- vent Paradromides, hypaethral walks, at- tached to the Greek palaestra. The Romans called these walls xysta ; whereas the xysta of the Greeks were covered porticoes, in which the athletae exercised in winter Parallel, in geometry, is applied to lines, figures, and bodies which are every where equidistant from each PAR PARTRIDGE WOOD. PAR other, or which, if ever so far pro- duced, would never meet Parallel bars, the rods parallel to the centre line of a beam, joining the connecting links at the lower ends. Parallel motion, the connection be- tween the top of the piston-rod and the beams : a name given to a con- trivance, invented by James Watt, for converting a reciprocating cir- cular motion into an alternating rectilinear motion Parallel ruler, an instrument consist- ing of two wooden, brass, or steel rulers, equally broad throughout, and so joined together by the cross blades as to open to different inter- vals, and accede and recede, yet still retaining their parallelism Parallelogram, in geometry, a quad- rilateral right-lined figure whose opposite sides are parallel Parallelogram of forces is a phrase denoting the composition of forces, or the finding a single force that shall be equivalent to two or more given forces when acting in given directions Parallelopiped, in geometry, a regular solid, contained under six parallelo- grams, the opposite of which are equal and parallel; or it is a prism whose base is a parallelogram : it is always triple to a pyramid of the same base and height Parament, the furniture, ornaments, and hangings of an apartment for a room of state Parameter, a constant right line in each of the three conic sections, and otherwise called latus rectum, be- cause it measures the conjugate axes by the same ratio which has taken place between the axes them- selves, being always a third pro- portion of them Parapet, the upper part of a house, which is above the springing of a roof, and guards the gutter; the upper part of a wall, a bridge, a terrace, or balcony, &c. Parapets around the flat roofs of houses in the East are of the most ancient date. " When thou buildest a new 324 house, then thou shalt make a bat- tlement for thy roof, that thou bring not blood upon thine house, if any manfall from thence. Ztew^.xxii. 8. Parascenium, in ancient theatres, a place behind the scenes to which the actors withdrew to dress and undress themselves Parastalce, square columns, or antse ; called also parastacles and parasta- licae. Vitruvius uses the term to signify the square posts placed be- hind the columns of the basilica, for the support of the floors of the upper porticoes Pargeting, parge-work, plaster-work, employed exteriorly for timber houses, as an ornament; used also in plain and ornamental work, for both the exterior and interior Paries, the walls of a Grecian house, in contradistinction to the wall of a city ; a small enclosure, such as a court yard Parlour, a private apartment in a dwelling, usually on the ground floor ; a speaking-room in a con- vent. In the time of Henry VIII. parlours and privy rooms summer parlours, winter parlours were well, comfortably, and conveniently furnished ; a proof that the gentry of that period were not quite so far behind the present race as might be supposed. Parsonage-house, a residence of the incumbent of a parish, a building in the vicinity of a church Patera, a round dish, plate, saucer, or goblet Patina, a basin or bowl of earthen- ware, rarely of bronze Parthenon, in architecture, the tem- ple of Minerva at Athens Particle, the minute part of a body, or an assemblage of several atoms of which natural bodies are composed Partners, in naval architecture, are thick pieces fitted into a rabbet in the mast carlings, to receive the wedges of the mast ; likewise tem- porary pieces nailed on the deck round the pumps Partridge wood is the produce of the PAR PATENTS FOR INVENTIONS. PAT Brazils and the West India Islands: it is sent in large planks, or in round and square logs. It was formerly employed in the Brazils for ship -building, and is known in dockyards as cabbage-wood. Party-walls are partitions of brick made between buildings in sepa- rate occupations, for preventing the spread of fire. These are made thicker than the external walls; and their thickness, and the neces- sity of their use, are regulated by Act of Parliament, and specified in some of the clauses of the Buildings Act passed in the reign of the present Queen. Parvise, a porch ; an open area be- fore the entrance of a church Paschal, a stand or candlestick, of a large size, used in Roman Catholic worship Pasigraphy, the art of universal writing Passant, in heraldry, a term applied to an animal in a shield appearing to walk leisurely : for most beasts, except lions, the word tripping is frequently used instead of pas- sant Passion, in painting, implies an emo- tion of the body, attended with certain expressive lines in the face, denoting an agitation of soul Pastici, or Imitations in Paintings. Teniers understood the union of colours extremely well, yet Bassan was superior to him in the sweet- ness and vigour of his tints. De Pile recommends it to all persons who would not wish to be deceived by pastici, to compare the taste of design, the colouring and the cha- racter of the pencil, with the ori- ginals. Teniers, Giordano, and Bon Boulloque are those who have appeared with the greatest reputation for imitating other great masters ; and, beside these, many other artists have employed them- selves in painting pastici. Pastoral staff, the official staff of an archbishop, a bishop, or mitred abbot 325 Patand, the bottom plate or sill of a partition of a screen Paten, a small plate or salver used in the celebration of the eucharist Patents for Inventions are public grants to the inventors of new and useful machinery and processes in the arts, and by which cer- tain privileges are secured to the inventors, for the exclusive use and exercise of their inventions during a limited period. Patents are therefore monopolies of a de- finite character; but being de- signed as a security for the reward of those whose ingenious faculties and practical skill have produced inprovements of general utility and value, these monopolies, if justly granted and honestly exercised, are not to be decried as injurious to the public interests, but should be conceded with willingness, and command the liberal protection of the community, which is destined to reap a continual and permanent advantage from the improvements thus fostered in their infant de- velopment. Patents for inventions should therefore be admitted as bargains between the inventor on the one hand, and the public on the other ; and the abuses to which these bargains are liable arise from the common causes of official cor- ruption and individual cupidity and jealousy. The laws under which patents are granted vary in their form in the several European and American States, and are all, in some degree, imperfect, and ineffective of their proper object. In Great Britain and Ireland, Letters Patent (founded on statutes from the 18th of Henry VI., but mainly on the 21st of James I. c. 3) are granted by the Crown, on behalf of the public, to the inven- tor of any manner of new manufac- ture, for the sole privilege to make, use, exercise, and vend his said in- vention, during the term of fourteen years ; and an inventor, as thus PAT PATENTS FOR INVENTIONS. PAT privileged, may be the first inventor absolutely, the first publisher if others have also made the same invention, or the first importer from abroad, into these realms, of an invention not previously herein used and exercised. British patents are granted as matters of course, pro- vided certain legal forms are duly complied with, certain official fees (which are very high) are duly paid, and the legal advisers of the Crown (the Attorney or Solicitor General) are not required by op- posing parties to discover that the privilege sought will interfere with any contemporary application. The several processes in solicit- ing a British patent are as follow : The inventor has to petition the Crown to grant letters patent for his invention, of which, at this stage, he states only the title ; and he accompanies his petition with a declaration of the grounds of his request, and the provinces in which he wishes to secure his patent right. These documents are lodged at the office of the Secretary of State for the Home Department, whence they are referred to the Attorney or Solicitor General, the selection of either of these officers being with the inventor. If no opposition occur there from caveats, (which are formal notices that any one may enter, to be informed of applications for patents,) one of those officers makes a report on the petition, and recommends that letters patent be granted thereon, provided the petitioner enrol the necessary specification, &c. within the time limited by the statute. This report is taken to the Secre- tary of State's office, for the Royal warrant, directing the bill to be prepared for the Royal signature. The warrant is committed to the Attorney-General, and if not op- posed, he prepares the bill, which is signed at the Secretary of State's office. Under Royal warrant, sealed with the Royal signet, the bill re- 326 ceives the privy seal, and is then directed to the Lord Chancellor for letters patent to be made out and sealed with the great seal. From this practice, that of soliciting patents for Scotland and Ireland differs only in minor details, the common feature of the arrange- ment being that of a multiplicity alike of forms and fees, which en- hance the trouble and expense, without promoting the efficiency or security of the system. Having obtained the great seal, the patentee is allowed a period of six months to complete his experi- ments, and to have his specifica- tion (and drawings, if required,) prepared. For this purpose, great care and judgment are needed, based on a knowledge of former patents, to frame the specification so that it shall explain with suffi- cient clearness the precise nature of the improvements, and have that value as property, which a good specification of a patent always has. On or before the last day of the allotted six months, the specification must be duly enrolled, and the patentee receives an official certificate of its enrolment. The patent is now complete, and the patentee can safely proceed to practise under it. By a comparatively recent statute (5 and 6 William IV. c. 83), a patentee is now enabled, under the authority of the Attorney or So- licitor General, to amend his title and specification subsequently ; if necessary, to correct one, to make it consistent with the other, and, in fact, to disclaim part or parts of his claims, which he may have since found to be untenable. Under the same statute also, the inventor may petition for a prolongation of his term of fourteen years ; which petition is referred to the Judicial Committee of the Privy Council, who grant the same if the petitioner makes out a case, satisfactory to them, of extraordinary losses, de- PAT PATENTS FOR INVENTIONS. PAT lays, or other special reasons for the prolongation. The property in a patent can be defended from infringement by a bill in equity, or action at law. It may be assigned, in whole or part, by the patentee to any number not exceeding twelve persons. It may be mortgaged to any number of persons ; and a patentee can also grant licences for the use of his patent, in a variety of modes, to an unlimited number of persons. The cost of obtaining a patent, including fees for agency, if un- opposed, is for England, 110; for Scotland, 80 ; and for Ireland, 135. If the patent be granted to two or more persons jointly, which it may be, extra fees are charged for the additional names ; and if the Channel Islands of Guernsey, Jersey, Alderney, Sark, and Man, and the British Colonies and Plantations abroad, are in- cluded, a further expense of about seven guineas is incurred. To these items should be also added the cost of preparing and copying spe- cification and drawings, the charges for which are of course very variable, according to length, intricacy, &c. The expenses and regulations under which the foreign patents are granted vary considerably. The following brief epitome must suffice in this place. In the United States of America, patents are granted only to the absolute inventor, always for four- teen years, and are granted or withheld at the option of the Go- vernment Commissioners of Pa- tents. The amount of official fees payable depends upon the country of which the applicant is a native. Thus, a citizen of the United States, or a foreigner who has resided in the States one year next preceding the application, and has made oath of his intention to be- come a citizen, pays a fee of 4^30 ; a subject of the Sovereign of Great Britain, =8*500 ; and any other 327 foreigner, 4^300. If the applica- tion for a patent be rejected by the Commissioner, two-thirds of the fees paid are returnable. In France, patents for inventions are granted alike to natives and foreigners, and the duration of the privilege may be fixed by the pa- tentee at five, ten, or fifteen years, the amount of tax being propor- tional to the term, namely, 500 francs for five years; 1000 francs for ten years ; and 1500 francs for fifteen years ; payable by annual in- stalments of 100 francs. The pa- tentee thus enjoys the power of relinquishing his invention, if found unprofitable, at any time during the intended term, by ceasing to pay the annual instalment of fees. In Belgium, patents are granted for five or ten years : imported in- ventions are patentable, and the whole of the Government tax, which is not heavy, may remain unpaid until the expiration of two years from the grant. In Holland, patents are granted for five, ten, or fifteen years, and may be had for foreign as well as native inventions. The fees for a patent for five years are 150 guilders, or 12. 10s.; and for terms of ten or fifteen years they vary from 300 to 750 guilders, or from 25 to 62. 10*. In Prussia, Russia, &c., the Go- vernments exercise a discretionary power in granting or refusing pa- tents, and the laws are of a strin- gent and arbitrary character. In Austria, patents are granted for terms from five to fifteen years ; the taxes must be paid when the application is made, and the in- vention put in practice within one year from the date of the grant. The German and Italian States have patent laws peculiar to them- selves, but generally similar to those already described. Patent yellow, Turner's yellow, or Montpellier yellow, is a submuriate or chloride of lead, which metal PAT PEDIMENT. PED is the basis of the most opaque yellow pigment : it is a hard, pon- derous, sparkling substance, of a crystalline texture and bright yel- low colour, hardly inferior, when ground, to chromic yellow. It has an excellent body, and works well in oil or water, but is soon injured, both by the sun's light and impure air; it is. therefore little used, ex- cept for the common purposes of house-painting, &c. Patera, a circular flat ornament, used in Classical architecture ; used also in Gothic and Italian architecture Paul, the catch which holds a ratchet- wheel, allowing it to turn in one direction only Pavilion, in architecture, a detached building ; an insulated turret, con- tained under a single roof, some- times square and sometimes dome- formed ; named from its resem- blance to the roof of a tent. The late palatial monstrosity at Brighton was called a pavilion. Pax, a small tablet, having on it a representation of the crucifixion, or some other Christian symbol, of- fered to the congregation in the Romish church, to be kissed in the celebration of the mass : it was usually of silver, or other metal, with a handle at the back, but was occasionally of other materials ; sometimes it was enamelled, and set with precious stones Peach- stone, a blueish - green soft stone Pearl white. There are two pigments of this denomination : one, falsely so called, prepared from bismuth, which turns black in sulphuretted hydrogen gas or any impure air, is employed as a cosmetic: the other is prepared from the waste of pearls and mother-of-pearl, is exquisitely white, and of good body in water, but of little force in oil or varnish; it combines, how- ever, with all other colours, with- out injuring the most delicate, and is itself perfectly permanent and innoxious. 328 Pear-tree, a native European wood; its colour is a light brown, some- thing of a pale mahogany or cedar : it is employed by the Tunbridge turners Pea-stone, or pisolite, in mineralogy, pisoform limestone Peat, in mineralogy, a substance con- sisting of the twigs, leaves, and roots of trees, mixed with grass, straw, plants, and weeds, that have laid long in water, and become con- verted into a blackish-brown mass that may be cut with a spade, and dried for fuel Pedestal, in architecture, the lower member of a pillar, named by the Greeks stylobates and stereobates ; also the basis of a statue. In Clas- sical architecture it consists of three divisions : the base, or foot, next the ground, the dado, form- ing the main body, and the cor- nice, or sur-base moulding, at the top. Pediment, the triangular plane or sur- face formed by the vertical ter- mination of a roof consisting of two sloping sides ; consequently it so far corresponds with the gable, but in other respects differs widely from it. One material difference be- tween them is, that whereas the gable has no cornices, the pediment is bounded by three, viz. a horizon- tal one, beneath it, forming its base, and two sloping or raking ones, as they are technically termed; and the triangular space or surface included within them is distinguished by the name of the tympanum of the pediment. Another marked differ- ence between them is, that the gable may be of any pitch ; and being merely a continuation of the wall below, instead of being, like the pediment, separated from it by any horizontal mouldings, its pro- portions do not at all depend upon the height or width of the front or compartment of the front which it terminates, but may be an equila- teral triangle, or even considerably more, as to height, and is, besides, FED PEDIMENT. FED iu nowise governed by the height of what is beneath it. The pediment, on the contrary, must be propor- tioned to the height of the order which it crowns ; consequently its pitch must be decreased in some- what the same ratio as its length or base is increased, or, in other words, the greater the number of columns beneath a pediment, the lower must the pitch of the lat- ter be. Hence it is hardly pos- sible to place more than eight, or, at the utmost, ten columns be- neath a pediment, without making the pediment either too low in itself, or else too lofty and heavy a mass in comparison with the columns beneath it; thereby not only overloading them the co- lumns being proportioned to their entablature alone but also di- minishing their importance, and causing the order itself to look almost puny and meagre, while the pediment looks heavy and clumsy. There has been a good deal of mystification about determining the proportion of pediments, and special methods have been devised for that purpose, which, however ingenious in themselves, as such, are any thing but artistic, or cal- culated to secure pleasing pro- portions. Discarding all such methods, it may be laid down as a safe general rule, that the height of the tympanum should accord pretty nearly with that of the enta- blature beneath the pediment, and not greatly exceed it, under any circumstances. Such is the pro- portion which Wilkins appears to have observed for the pediment of the London University College ; and although that building has a decastyle portico, the pediment does not appear too low, whereas that of the National Gallery is so, the height of the tympanum being there less than that of the entabla- ture, notwithstanding that the por- tico is octastyle. The ancients generally made the 329 pediment contribute largely to the embellishment of the structure, by sculpturing its tympanum with figures in high relief, and in some instances by setting it back, and placing entire statues against it ; and for such display of sculpture the pediment eminently recom- mends itself, both by its conspicu- ous situation, and by offering a far ampler surface for such purpose than any other part of the edifice ; one, moreover, which not only re- quired a higher decoration, for the sake of consistency, but an in- creased degree of it, in order to produce artistic climax and com- pletion. Yet it must be confessed that if its situation marks out the pediment as a very proper place for making a display of decoration, its shape is by no means well adapted for a composition of figures, ex- cept it be that it compels them to be arranged symmetrically, and the principal one to be directly in the centre. Be the subject what it may, the figures must always be disposed in nearly the same man- ner, and not only very convention- ally but very forcedly, particularly towards the extremities, an incon- venience that might be easily over- come by confining the figures to the centre of the tympanum, putting there a group of three or five, and either leaving the rest of the tri- angular space to be quite plain, or else filling it up with mere orna- ment. While this would certainly be a rather less expensive mode than that now practised, and an equally rational one, its not having been adopted before ought to be itself some recommendation of it, as being a laudable infringement of copyism, conventionalism, and routine. Besides sculpture within them, pediments are frequently surmount- ed at their angles and apex with acroteria, namely, low pedestals, upon which are placed either single figures or groups, or else vases, FED PEDIMENT. FED trophies, or other ornaments ; an example of which is furnished by Spencer House, in the Green Park, and still more strikingly by the portico of the East India House. The practice of placing statues upon pediments appears to have origi- nated with the Romans, and is somewhat analogous in taste to that of putting them on the summit of monumental columns; for in such situations human figures show only in their general mass as sculptural accessories to the structure, and at a little distance, or as seen in a ge- neral view of the building, produce scarcely more effect than so many pinnacles, which last are infinitely more characteristic of Gothic ar- chitecture than in accordance with the character of a classical portico. In Italian and modern architec- ture generally, the pediment is em- ployed as mere decoration in com- positions for the dressings of both doors and windows, which prac- tice, like that of applying columns for the same purpose, has been condemned by some in the most unqualified manner; and one writer has vituperated, and endeavoured to bring it into disgrace, by com- paring pediments over doors and windows to cocked hats ! The resemblance which he perceives, or fancies, between a cocked hat and a pediment is not a particu- larly flattering one ; but if it exists at all, the injurious comparison holds equally good with regard to a large pediment as a small one ; therefore, whether it be that over a portico or over a window, the shape itself is, in either case, the most unfortunate one of a cocked hat ; yet, as cocked hats are now gone quite out of fashion, the unlucky resemblance to them is not at all likely to be detected. In matters of decoration, some latitude some little departure from strict archi- tectural logic is allowable; other- wise a very great deal in Italian or 330 modern architecture must be pro- nounced decidedly faulty. If it be a solecism to place pediments whose form is derived from that of a roof, over windows, or where no roof exists, the same objection lies against applying entablatures whose cornices resemble the horizontal ones of a roof, to mere openings in the wall ; and in like manner, if it be a gross impropriety to flank windows with small columns, it must be as great, if not a greater one, to introduce, merely for the sake of decoration, a large order whose columns are partly buried in the wall, and support nothing but an entablature, or pieces of it, wholly unnecessary in themselves, and put there only that the columns may appear to support something. Again, as to the objection which has sometimes been urged against pediments over doors within a building, namely, those intended to throw off rain, they should be introduced only in external situa- tions, it partakes of the same kind of hypercriticism as the other ; or, if strict rationality is to be uni- formly enforced in architectural design, we must condemn a great deal in the Gothic style as being exceedingly licentious and irra- tional ; for in that we find a great many members and features origi- nating in forms invented for pur- poses of actual service externally, converted into mere interior de- coration ; for instance, emhattle- ments on the tops of screens, minia- ture buttresses for ornament instead of strength, miniature spires, and miniature blank windows in orna- mental panelling. Pediments are generally placed only over the windows of the principal floor of a building, to which they serve to give distinc- tion and importance. Window pediments are either angular or curved (L e. segmental), and both forms are frequently introduced together, and placed alternately, FED PENTELIC MARBLE. PEN in which case it is usual to place an angular pediment over the centre window. Sometimes the centre window alone is, for the sake of distinction, crowned with a pediment. When, as is generally the practice, all the pediments to a series of windows are alike, they are almost invariably made angular ones, although there are instances of the contrary, one of them being Bridgewater House, where Mr. Barry has given segmental pedi- ments to all the windows of the principal floor, and has even put them over the centre openings of the triple windows; and it de- serves to be further remarked, that he has enriched their tympanums with sculptured ornament a de- gree of decoration very rarely in- dulged in. A far more remarkable instance perhaps an unique one of the application of segmental pe- diments, may be seen in the house just erected for Mr. Hope, in Pic- cadilly, large pediments of that form being there placed over win- dows consisting of two openings, consequently forming square, or nearly square, instead of upright compositions ; owing to which, the pediments cause them to look far more heavy than elegant. In that instance, too, the pediments are filled in with sculpture; the figures, however, are not exactly confined to the pediments, but come some- what lower down, the horizontal cornice being partly suppressed for that purpose. Pedometer, in mechanics, an instru- ment in the form of a watch, con- sisting of various wheels, with the teeth catching in each other, and which, by means of a string fastened to any thing in motion, numbers the paces gone over from one place to another Peek, in navigation, a name given to the upper corners of sails extended by a gaff, or by a yard crossing the mast obliquely, as the mizen-yard of a ship. The upper extremity of 331 those gaffs and yards is also called the peek. To ' peek the mizen' is to put the mizen-yard perpendicular to the mast. Peek-halyards, the ropes or tackles by which the outer end of the gaff is hoisted Peg-tankard, an ancient species of wassail-bowl, used in the time of Queen Elizabeth. Itheldtwoquarts, and had generally a row of seven pegs, dividing the height into eight equal parts, each containing half a pint. Pendant, an ornament suspended from the roof of a Gothic or Tudor build- ing; the hanging pendants of a vaulted ceiling, uniting solidity with ornament. The most remarkable are those in King Henry the Seventh's chapel at Westminster - abbey. Pendentive, the portion of a groined ceiling supported and bounded by the apex of the longitudinal and transverse vaults. In Gothic ceil- ings of this kind the ribs of the vaults descend from the apex to the impost of each pendentive, where they become united. Pennyweight, the 20th part of an ounce Pentagon, a figure of five angles and five sides : when these are equal, it is called a regular pentagon, but otherwise, it is irregular Pentagraph, an instrument whereby designs, prints, &c. may be copied, in any proportion, without a person being skilled in drawing. (See Pantograph.} Pentangular, in geometry, five-cor- nered or angled Pentastyle, in architecture, a work in which there are five rows of co- lumns Pentelic marble, in statuary, a beau- tiful and glossy variety of Parian and Carrara marble, named from Mount Pentelicus, near Athens, where it was quarried. Pentelic marble, from the smallness of the grain, is mistaken for the Parian ; but, of the two, the former is of a PEN PERICLES. PER finer quality. The Pentelic quar- ries display in a remarkable man- ner the energies of the ancient Athenians : whole sides of the mountain have disappeared, and present uniformly cut perpendicular cliffs; and holes, still to be traced on the slope of the quarries, made for the insertion of capstans, mark the place of the mechanical de- scent of the marble ; whilst a da- maged and rejected cylinder, appa- rently intended for a part of a 'column of the Parthenon, interests the traveller on the ascent. Penthouse, a projection over a door, an entrance, a window, or a flight of steps, &c., for protection from weather Peperino marble, in mineralogy, a calcareous stone, something of the nature of travertino. It is supposed to be the ancient Saxum Albanum, of which the foundations of the capitol at Rome (still to be seen) were built. Perambulator, in surveying, an in- strument for measuring distances ; named also the Pedometer and Sur- veying wheel Perch, a small projecting beam, cor- bel, or bracket, near the altar of a church Perch, or Pole, a linear measure of 5^ yards Perclose, an enclosure, a railing ; sometimes used to protect a tomb, or to separate a chapel from the main body of the church Percussion, in mechanics, the striking of one body against another, or the shock arising from the collision of two bodies Periacti, the revolving scenes of the theatre, called scena versatilis by the Romans : they were placed be- fore the itinera versurarum, or those entrances to the stage which were in the returns of the perma- nent scene Periactos, a theatrical machine, con- sisting of three scenes placed in the form of a triangle on a revolv- ing platform ; so that, by simply 332 turning the machine, the scene could be changed Pericles, at Athens, executed the i famous statue of Minerva, of gold and ivory. Pausanias says, it was standing erect, her garments reach- ing to her feet ; she had a helmet on, and a Medusa's head; in one hand she held a spear, and on the other stood a Victory, of 4 cubits high. Pliny tells us the statue was 26 cubits high (37 ft. 8 in.), in which he perhaps included the pedestal, whereon they both say the birth of Pandora was repre- sented. We are not told whether the ivory was painted; but by what Strabo says, that Pansenus, the brother or nephew of Phidias, as- sisted him in colouring the statue of Jupiter at Elis, which was like- wise of ivory and gold, it probably was. The reason why ivory was used in statues of this kind, ra- ther than wood, seems not to have been on account of its colour, but because wood is apt to crack, and to be destroyed by worms : but ivory is not of uniform colour, being yellow near the outside of the tooth, and white in the middle ; it therefore would require painting on that account, and likewise to hide the joining of the pieces. Thucy- dides says the gold about it weighed 40 talents, which, according to the value of gold at that time, was worth about 120,000 sterling. Peridromus, in ancient architecture, the space of an aisle in a peripteron , between the columns and the wall, used for walks by the Greeks Perimeter, the boundary of any figure, being the sum of all the sides in right-lined figures, the same as cir- cumference or periphery in those of a circular form Periphery, the circumference of a circle or ellipse Peripteral, a temple which had its cella surrounded by columns Peristylium, a continued row or series of rows of columns all round a court or building, in contradistinc- PER PERPENDICULAR STYLE. PHA tion to porticoes, in which the pillars did not surround a space, but were arranged in one or more parallel lines Peritrochium, in mechanics, a wheel or circle concentric with the hase of a cylinder, and moveable toge- ther with it about an axis : the axis, with the wheel and levers fixed in it, to move it, constitute that me- chanical power called axis in peri- trochio Perpendicular, in geometry, a line crossing or cutting the horizon, or another line, at right angles Perpendicular, formed of one line meeting another, so as to make the angles on each side of it equal to each other Perpendicular Style of Gothic Archi- tecture, derived from the Decora- tive about the end of the fourteenth century, and continued till the middle of the sixteenth: it is so called from its tracery consisting of perpendicular lines, and forming one of its most striking features. Many fine examples yet exist in England. The perpendicular cha- racter of the style is exhibited in the window tracery, where the transoms cross the mullions at right angles ; and in large windows these are occasionally repeated several times : bands, quatrefoils, and other ornaments are more frequently employed than in the other styles', and are often carried across the panellings and vertical lines, cre- ating a rectilinear arrangement, pervading most of the subordinate parts, that gives a peculiar air and stiffness. Panelling is used most abundantly on w r alls, both inter- nally and externally, and also on vaulting. Some fine examples of this style are drawn in Mr. Parker's ' Glossary,' in 2 vols. Perpent -stone, a bond-stone ; a large stone reaching through a wall so that it appears on both sides of it Perpetual motion is that which pos- sesses within itself the principle of motion Perron, in architecture, a staircase outside of a building, or the steps in front of a building leading up to the first story Persian Wheel, a name given to a machine for raising water, which may be turned by means of a stream acting on and turning round the wheel. The buckets, instead of being firmly fastened, are hung upon the wheel by strong pins, fixed in the side of the rim, which must be made as high as the water is intended to be raised above the level of that part of the stream in which the wheel is placed. Persians, in ancient architecture, male figures employed to support entablatures ; the female figures were named Caryatides Perspective, in painting, &c., the science by which all things are ranged on a plane surface, as in a picture, according to their appear- ance in their real situation Pew, an enclosed seat in a church, in- troduced since the Reformation. Previous to the Reformation the nave was occupied by the congre- gation. Pews are fixed seats, se- parated from each other by wains- coting, and varying in height. Peivter, in metallurgy, a mixed metal, consisting of tin variously alloyed with lead, zinc, bismuth, or anti- mony. Common low-priced pewter contains 20 parts tin, 3 lead, 1 brass; best pewter, 17 parts antimony, 100 parts tin, and a little copper. Pewter dishes and wooden tren- chers were the ordinary services of our ancestors till the time of Elizabeth, when " by reason of sharpelawsprovidedin that behalf," pewter was compounded of purer metal than before. The splendid services of gold and silver were only used on occasions of ceremony and on festivals. Pharos or Pharus, a lighthouse. The most celebrated lighthouse of an- tiquity was that situated at the entrance of the port of Alexandria, 333 p5 PHI PILES. PIL built by Sostratus on an island, by the direction of Ptolemy, at a cost of 800 talents. Pliny mentions the lighthouses of Ostia and Ra- venna. The name of Pharos was given in allusion to that of Alex- andria, which was the model for their construction. Phidias, the great Greek sculptor and director of the works under Pericles Phonics, the doctrine of sounds, otherwise named acoustics Phosphate of iron is a native ochre, which classes in colour with the deeper hues of ultramarine ashes, and is eligible for all their uses. (See Blue ochre.} Slate-clays and several native earths class with grays; but the colours of some of the latter, which have been tried, are not durable, being subject to become brown by the oxidation of the iron they contain. Physics, the doctrine of natural bodies, their phenomena, causes, and effects, with their various mo- tions, operations, affections, &c. Taken in its most enlarged sense, it comprehends the whole study of Nature, and includes physiology and natural history. Piazza, an open area or square; a covered walk or portico Pick, an instrument in common use as well in agricultural as in mining operations Pictura (Latin), a painting. The art of imitating the appearances of bodies upon an even surface, by means of light and shade, or co- lour, was most extensively cul- tivated by the ancients, but es- pecially by the Greeks, amongst whom it was carried to the high- est degree of technical develop- ment. Pier, in architecture, the strong columns on which the arch of a bridge is raised Pier, the solid mass between doors, windows, and other openings in buildings : the term is often ap- plied to pillars in Norman and Gothic architecture 334 Piers, walls built to support arches, and from which, as bases, they spring PilcB, square blocks placed upon the epistylia, and immediately over the columns in a basilica, for supporting the timbers of the roof. Pilre were also buttresses built against the walls of a mole, to resist the force of the waters. Pilaster, in architecture, a square column, sometimes insulated, but more frequently set within a wall, and only showing a fourth or fifth part of the thickness. Pilasters were unknown in Greek archi- tecture, in which only antse (see Antai} were admitted : they are employed by the moderns as sub- stitutes for an order in engaged columns, and are, perhaps, even preferable to the latter, inasmuch as they combine better and more naturally with the wall to which they are attached. Piles, as applied in engineering ope- rations, are used both in temporary and in permanent constructions. In the former cases, they are com- monly squared logs or baulks of timber, which are driven close to- gether in single or double rows, so as to enclose a space of water, and form a coffer-dam, from which the water is subsequently pumped out. and thus a dry space obtained for laying the foundations of piers, abutments, &c. in bridges and other similar works. The most substan- tial kind of coffer-dam, adapted for works which will be long in con- struction, is formed of a double row of concentric piling, a space of 3 or more feet being left between the two rows of piles, which is filled with clay, well puddled or rammed in. For permanent works, piles are driven in loose or uncertain strata in rows, leaving a space a few feet in width between them, and upon the heads of the piles the foundations of the superstructure are erected. In some of the iron bridges lately erected for railways, PIL PILING. PIL piles have been used as substitutes for solid piers in the water. "Wharf- walls have also been built with facings formed with piles. In most of these works the piles used are of cast iron, while those used for coffer-dams and foundations are of timber, the lower end being fitted with a wrought-iron pointed shoe, to facilitate the penetration of the strata, and the head of the pile guarded with a ring of the same metal, to prevent its splitting while being driven. Iron piles are cast in various forms ; sometimes so as to preserve similar external dimen- sions to timber piles, and hollow or tubular within ; and if for wharf- walls, they are formed with grooves in the sides, into which metal plates are fitted, the piles being placed from 4 to 7 feet apart, and the in- termediate spaces filled up with these plates. For piling in loose and moveable materials, and more especially for forming moorings, Mr. Mitchell has introduced a form of pile which is properly called a screw -pile, the lower end being formed as a screw, and fitted (for moorings) with a broad plate or disc of metal in a spiral or helical form. The most important purpose to which the screw-pile has been applied is for forming the foundations of light- houses, beacons, jetties, &c., in places where the sand or soil is too unstable to bear the weight of any massive structure, or where the force of the waves would endanger masses of masonry by undermining the materials below them. The lighthouse erected in the year 1840 upon the Maplin Sands may be in- stanced as a work which owes the very possibility of its existence to these screw-pile foundations. The piles used in this structure are nine in number, and made of malleable iron, 5 inches in diameter and 26 feet long, with a cast-iron screw 4 feet in diameter, screwed to the foot of each. Eight of the piles 335 were placed at the angles of an octagon, and the ninth in the cen- tre, and were put down in nine consecutive days, being screwed to a depth of 22 feet in the bank. Several similar works have been since constructed with complete success; and in 1847, the screw- piles were applied in the construc- tion of a jetty 260 feet in length beyond the old one, at Courtow 7 !!, on the coast of Wexford. Mallea- ble-iron piles, 5 inches in diameter, and laid in the ground 11 to 15 feet, were fitted with screws 2 feet in diameter. The facility and ra- pidity with which these piles are inserted are not the least among their qualifications. Before the introduction of screw- piles, the process of fixing which consists in giving them a rotatory motion by means of capstans, the fixing of piles was accomplished by driving them downwards by the force of an adequate weight, which was permitted to fall vertically on them from a considerable height. The machinery employed was there- fore properly called a pile-driver, and consisted simply of a vertical framing, provided with winches and chains, by which the weight or ' monkey' was alternately raised by manual power, and released so as to fall upon the head of the pile ; or a gin was applied, and horses used for the same purpose. Within the last few years a great improvement has been effected in the machinery for pile-driving, by the application of steam power. The earliest invention for this pur- pose is recorded in a patent granted in 1806, but no practical applica- tion appears to have resulted for many years. The patent referred to was dated June 6, 1806, and granted to William Deverell, for "improvements in the mode of giving motion to hammers, stamp- ers, knives, shears, and other things, without the application of wheels, pinions, or any rotative motion, by PIL PILES, MR. POTTS'. PIL means of various powers now in common use." The apparatus was designed to consist of a steam - cylinder with piston and rod, and a hammer, raised by admitting the steam below the piston. By the condensation or the escape of the steam, the hammer and the piston were allowed to descend, urged both by their own weight and by the elasticity of the compressed air in the top of the cylinder above the piston. This, therefore, established the principle of the steam-hammer; but the most successful application of it to the purposes of driving piles, as well as to those of the smithery, is due to Mr. James Nasmyth, whose steam - hammer consists of a steam -cylinder, which is closed at the bottom, but has openings in the top, to admit the passage of air. The rod of the piston passes through a steam-tight aperture in the bottom of the cy- linder, and has the ' monkey,' or driver, weighing 2| tons, suspended from it. The machine is worked with high-pressure steam, which, entering the bottom of the cylinder, raises the piston and 'monkey.' When the piston reaches the height intended, it shuts the induction and opens the eduction pipe (also at the bottom of the cylinder), by which the steam escapes, and the monkey falls. A heavy iron cap slides between standards and round the head of the pile, and thus guides it in its descent. This machine, as used at Devonport, in driving piles for the steam-dock, made seventy strokes per minute, and drove piles 14 inches square and 18 feet in length. In the year 1843 (December 5), a patent was obtained by Dr. L. H. Potts, for "improvements in the construction of piers, embankments, breakwaters, and other similar structures." The several objects comprised in this invention were sought with considerable ingenuity, and have been realized with suc- 33G cess. The invention includes the application of hollow piles of iron, of a cylindrical or other convenient form, and sinking them by with- drawing the sand, &c. within them by the action of an air-pump. For this purpose the pile is fitted with an air-tight lid, through which a pipe passes to connect the interior of the pile with a receiver. The receiver is connected by a pipe with a three-barrelled air-pump, by working which the air is exhausted from the hollow pile, and the sand and water raised into the receiver, which is emptied as often as neces- sary. A second purpose proposed in this patent is the use of skeleton frames or cases of cast iron in con- nection with the piles, for securing them together, and preserving their relative positions. A third object is the injection, by hydraulic press- ure, of such chemical solutions about the feet of the piles as will consolidate the sand upon which they stand, and thus secure the work. And the inventor also pro- posed to use hydraulic cements in a dry state, delivered at the base of the piles, by the admixture of which cements with the water they would become solidified, and thus materi- ally aid in strengthening the super- structure. Recently these piles have been successfully used on the Goodwin Sands, by the Trinity Board. Pre- viously, engineers had been baffled in finding a bottom. The piles have now been fairly affixed to the hard bottom, seventy-five feet through the sand. In connection with Mitchell's, Nasmyth's, and Potts' modes of piling, it is proper to notice also Cram's patent pile-dr,iving locomo- tive machine, which was successful in its operation in the United States. The volume (' Ensamples of Rail- way-Making') from which the fol- lowing extract has been made was edited by the publisher of this Dictionary, with a view to induce a PIL PILE-ROAD. PIL cheaper mode of construction of railways in countries less wealthy than those already intersected hy iron roads : Pile-road. As a considerable length of the Utica and Syracuse railroad passes through a deep swamp, a foundation of great per- manency was required: this gave rise to a modification of the super- structure, and formed that which is known as pile-road. The swamp varied in depth from 10 feet to 60 feet, and was nearly on a dead level throughout : the grade-line closely corresponded with its surface; so that it was necessary to reach the hard bottom before any foundation could be effected. Piles were adopted as the cheapest and most efficacious means to secure a dura- ble and substantial basis : they were driven to their places by a steam pile-driver. This was a ma- chine formed of a platform about 25 feet long and 8 feet broad: at one end were erected two pairs of leaders or guides, in which the hammers moved. Immediately be- hind the leaders were fixed the rollers, with the 'necessary brakes and gearing for working the ham- mers, raising the piles, &c. The rollers were revolved by a small high-pressure steam engine, occu- pying the rear of the machine. The arrangement of the leaders was the same as in ordinary piling machines: a curved piece of wood forced open the sheers when the hammers reached their elevation. The ham- mers were confined to the leaders by a groove : they weighed about 1000 fts. each, were made of cast iron, and at their last blow fell through a space of 27 feet. A pair of piles were driven at one opera- tion by this machine ; when driven, cast-iron rollers were placed upon their heads, and the machine, by means of an inverted rail, moved on to the next place. The heads of the piles, sawed off to reduce them to the proper level, were 337 found sufficient to supply the fur- nace with fuel. The men employed in operating the machine were, a foreman, a steam engineer, two brake-men, and two men in front at the saws ; also a horse and cart, to furnish water for the boiler. Properly geared in front of the machine, and between the leaders, was a saw that played on a sway-bar and could be pressed against either pile as it was driven home. The machine was manu- factured complete for the cost of 400. Each pile was prepared for being driven by simply sharpening one end to a point, and squarely butt- ing the other ; it was drawn up by ropes worked by the engine, se- cured in position between the leaders, and driven to the hard bottom. Generally the piles mani- fested no disposition to split : when they did, their heads were encom- passed with an iron hoop. When the pile was not of sufficient length to reach the hard bottom, another was dowelled upon its head, and this was repeated as often as ne- cessary. The piles w r ere charred, to increase their durability ; and an auger-hole, bored in their heads for the purpose, was filled with salt, and securely plugged up. Pillar, a kind of irregular column, round and insulate, but deviating from the proportion of a just column. The term pillar is more usually applied to Gothic architecture than to the Classical, the latter being governed by the rules of proportion: not so with the Gothic pillar, it being subject to no fixed rules. Pillars (monumental), columns raised for the commemoration of events, a practice from remote antiquity. " Jacob set a pillar upon her grave : that is the pillar of Rachel's grave unto this day." (ew.xxxv. 20.) Pillars, in ship-building, pieces fixed under the middle of the beams, to support the decks PIL PISE. PIS Pillion, the tin that remains in the slags after it is first melted. Pinacotheca, a picture gallery. The public gallery at Munich is called the PinaJcothek. Pindrill, a drill used for cutting a recess for a bolt-head, or for en- larging a hole Pines and Firs are cone - bearing timber-trees which thrive best in cold climates : they are of great variety, and the general uses of the wood are innumerable, besides those for ships and house car- pentry. Its use in England is most extensive : it is principally imported from America, Norway, the Baltic, Memel, Riga, Dantzic, &c. Pinion, in mechanics, an arbour or spindle, in the body of which are several notches, into which the teeth of a wheel catch, that serves to turn it round ; it is also the name of a lesser wheel that plays in the teeth of a larger one Pinite, a micaceous mineral Pink, in navigation, a name given to a ship with a very narrow stern Pinnacle, an ornament placed on the top of a buttress as a termination to an angle or gable of a house, church, or tower; also a summit or lofty apex Pins, in ships, are fixed in the drum- heads of capstans, through the ends of the bars, to prevent their unshipping; sometimes put through the bolts to belay a rope, and called belaying pins ; and some- times the main bolts are called bolt-pins Pipe, a tube for the conveyance of water, gas, or steam, of various dimensions and uses Pipe, in mining, a running vein, having a rock root and sole Piscina. Pliny says the Romans adorned the walls, ceilings, and floors of their baths. It was on the piscina they bestowed the most art. In the baptisterium they dipped their whole body, and this was large enough to swim in ; but 338 when they were disposed to swim at large in warmer water, they en- tered the piscina, a basin so called, as its size bore some resemblance to a pond. When the thermae were built, they were made to contain lakes of warm water : the water ac- quired its heat by passing through the fire in a brass pipe, and must have been more or less hot according to the length of its pro- gress. Piscina, a shallow stone basin, or trough, with a hole in the bottom, formerly placed near to the altar in Roman Catholic churches, and fixed at a convenient height above the floor, to hold the water in which the priest washed his hands; also for rinsing the chalice at the time of the celebration of the mass. It was usually on the right-hand side, on the approach to the altar. Pise, a peculiar mode of forming buildings, particularly those for cottages and farming purposes, with some sort of stiff earthy materials of a loamy quality. The earth so collected, framed, is well rammed until the moisture is driven out, and used to make the walls or sides of the building, instead of bricks. It has been used with much economy and success on the Continent, and in some parts of England. Pistici, or Pastici, a term by which Italians distinguish pictures which cannot be called either original or copies, being the works of some artists who have had the skill to imitate the manner of design and colouring of other eminent masters ; sometimes borrowing part of their pictures, sometimes imitating their touch, their style of invention, their colouring, and expression. Several painters, of considerable reputation for their own original performance, have made themselves remarkable in this way ; but none of them more than David Teniers, who so successfully counterfeited Giacopo Bassan, as to deceive the most judicious, in many instances, PIT PLAIN SAILING. PLA at the first sight ; though, upon a closer inspection, his light and easy pencil, and a predominant gray tint, which is observable in the colouring of that master, show a perceptible difference between his pencil and colouring, when they are carefully examined and com- pared with Bassan's. (See Pas- tici.) Piston, a moveable air-tight division within the steam-cylinder, acted upon by the steam. Pistons are either metallic or packed. Metallic pistons usually have segments of brass or cast iron, called junk- rings, pressed outward by springs. Packed pistons are surrounded by well-greased hemp. Piston-rod, the rod fixed to the piston, to communicate its motion to the crank Pitch, in building, the vertical angle of a roof, or the proportion between the heights and spans, as when the height is one-fourth, one-third, or one-half, of the breadth of the building. If the height is one-half of the breadth, the inclination of the planes, forming the vertical angle, is a right angle. Pitching -piece, in staircasing, a ho- rizontal piece of timber having one of its ends wedged into the wall, at the top of a flight of steps, to support the upper ends of the rough strings Pitch-wheel. When two toothed- wheels work together, the circles of contact are called the propor- tional circles, or pitch circles. Pit-man, one employed to look after the lift of pumps and the drainage Pit-work, the pumps and other ap- paratus of the engine shaft Pivot, a stud or small pin on which any thing turns Pix, in church rituals, a little chest or box, in which the consecrated host is kept Plain chart, in navigation, is a sea- chart, wherein the meridian and parallels are straight parallel lines, as in Mercator's projection ; con- 339 sequently the degrees of longitude are the same in all latitudes Plain sailing, in navigation, the art of working a ship's motion on a plain chart, which supposes the earth to be an extended plane, or flat, and not globular Plan. The plan of a building may be familiarly described as an ar- chitectural map ; therefore only those who cannot comprehend a geographical or topographical map can be at any loss to under- stand an architectural one, the latter being precisely of the same nature as the others, with this dif- ference in its favour, that it is much less conventional. To define it more exactly, a plan is a hori- zontal section supposed to be taken on the level of the floor through the solid parts of the fabric walls, columns, &c., so as to show their various thicknesses and situations, the dimensions of the several spaces or rooms, the position of the doors by which they communicate with each other, and various particulars that cannot otherwise be explained. Studying buildings without plans, is like studying geography without maps. A plan frequently costs the architect more study than all the rest of his design, and much mistaken are those who suppose that convenience alone has chiefly to be considered. Convenience is, of course, or ought to be, made a sine qua non ; yet it is not so much a positive merit in itself, as the want of it is a positive defect. Mere convenience is not an artistic quality: from that to beauty of plan, to striking combinations, and studied effects, and varied play of arrangement, the distance is very great. A common-place plan is but a very dull, uninteresting affair: it is no more than what any builder can accomplish ; but a plan replete with imagination, pi- quant play, and well-imagined con- trasts, is no every-day matter. Planceer, the soffit or under side of PLA PLANING MACHINE. PLA the corona of a cornice, in Classical architecture Plane, in surveying, a level surface, parallel to the horizon. In car- pentry, an instrument by which the surfaces of bodies are smoothed. Plane, inclined: in mechanics, this resembles one half of a wedge that has been cut in two parts lengthwise Plane, in geometry, a plain level figure, or a surface lying evenly within its boundary lines Planing Machine, an invention for di- minishing the great labour of plan- ing the surfaces of planks and boards of wood, and for reducing the surface to a true and smooth face, by means of planes, or instru- ments of a similar nature, which are actuated by the power of the machinery instead of the strength of a man's arm Planing Machine. The invention of the ' slide - rest,' which has effected such an important im- provement in cylindrical and conical turning, has been of far superior advantage in its application to the planing of surfaces, as the planing machine is but the slide-rest ap- plied to a traversing table. In planing machines of the ordinary construction, the bed or basement frame has two angular ridges from end to end, one on each side, which fit into corresponding angu- lar grooves in a traversing table. This table rests upon the ridges, and is moved backwards and for- wards by a screw-rack and pinion, or chain : its surface is accurately planed, and the work being fast- ened upon it partakes of its mo- tion, and is constrained to move in a perfectly straight line. Over the traversing table, at the centre of the machine, is fixed a slide-rest, which is held fast by being bolted to two upright standards fixed to the bed, one on each side. The horizontal slide has another at right angles to it, which serves to hold the cutting tool and adjust it to the work, so as to take a cut 340 more or less deep, as required. To the long screw of the horizontal slide mechanism is connected, which causes it to advance the vertical slide and tool a very small distance across the machine, just before the commencement of each forward movement of the table ; so that by a repeated series of move- ments to and fro of the table, the tool is made to traverse the whole surface of the work ; and thus, by the perfectly level movement of the table in the one direction, and that of the slide in the other, a per- fectly plane surface is obtained. In some machines the table is made to travel backward at a much faster rate than in the forward motion, so as to save time ; and in others, the cutting tool acts in both movements, by being turned at the end of each. Planish,m carpentry, &c., to smoothe, to polish Planifiher, a thin flat-ended tool, used by turners for smoothing brass- work Planisphere, in geometry, &c., a sphere projected on a plane ; such are maps of the heavens or of the earth Plank, a term applied to all super- ficial timber which is 4 inches thick and under, except 1 -inch, and some- times 1 -1-inch, which come under the denomination of board Plank-sheers, in ship-building, pieces of plank laid over the timber heads on the quarter-deck, forecastle, and round-house Plane-tree, a native of Europe; it is also abundant on the banks of the Mississippi and Ohio. This, per- haps one of the largest of the American trees, is sometimes 12 feet in diameter, and is much used in that country for quays. It is used here for musical instruments, and other works requiring a clean light-coloured wood. Plasm, in the arts, a mould ; a matrix in which any thing is cast or formed PLA PLATINUM. PLE Plaster of Paris, in mineralogy and the arts, gypsum deprived of its water by burning, and reduced to a white powder, which is afterwards mixed with water. It serves many purposes in building, and is used likewise in sculpture, to mould and make statues, basso-relievos, and other decorations in architecture. It is dug out of quarries in several parts of the neighbourhood of Paris, whence its name. The finest is that of Montmartre. It is known also as gypsum. Plastering, the art of covering the walls and ceilings of a house or other edifice with a composition, of which the groundwork is lime and hair mortar, finished with a coating of finer materials Plat, in mining, ground appropriated to ore or deads Plat-band, a flat fascia, band, or string, whose proportion is less than its breadth ; the lintel of a door or window is also sometimes so named Plate, and other services for the table. In the time of Henry VIII. and Elizabeth, amongst the nu- merous costly and magnificent ar- ticles for the table, wrought in silver, gold, and other precious materials, were chargers, dishes, plates, porringers, saucers, vases or cups, pots or tankards, flagons, pitchers, pottels, ewers, creuses, bowls, goblets, basins, washing- basins and ewers, horns, cups for caudle cruets, spice-plates, spiceries, salt-cellars, pepper-boxes, spoons, and candlesticks. Plate, a term applied to horizontal timbers, placed on walls, &c., to receive other timber- work : that at the top of a building immediately under the roof is a wall-plate; those also which receive the ends of the joists of the floors above the ground floor are called the same Plate-bending Machine. Thisinvention was contrived for bending plates of metal into any required curve, and is particularly useful in the con- struction of boilers and the buckets 341 of water-wheels : it consists of two side-frames, which carry three iron rollers and the spur-wheels and pinions necessary to communicate motion to two of them, one of which is placed immediately over the other, and can be raised or lowered by screws to the thickness of the plate to be bent. The third roller is placed behind the first two, and it is the height of this roller, with respect to that of the other two, that determines the de- gree of curvature of the plate : it is therefore made capable of ad- justment by set-screws, and being placed to the proper height, and the machine set in motion, the plate is passed between the first two rollers, till, coming in contact with the third, it rises upward and takes the form of a curve. Platina, yellow, is, as its name im- plies, a preparation from platina, which affords a series of yellow pigments, the deep colours of which resemble the Terra di Sienna, but are warmer in tone and richer in colour and transparency, much resembling fine gall-stones, for which they are valuable sub- stitutes. They work well, and are permanent both in water and oil, when carefully prepared; but any portion of palladium in the metal from which they are prepared neutralizes their colour and renders them useless. Platinum is found in the metallic state alloyed with other metals, but not in large quantities. It is not so white a metal as silver, but is very malleable and ductile, either when hot or cold. No fur- nace can melt it ; but by the oxyhy- drogen blow-pipe, or by a voltaic current, it is capable of being fused, and may be dissipated in the air. Alone it is insoluble in nitric acid, but when alloyed with other metals it is soluble. Plenum, in physics, a term used to signify that state in which every part or space or extension is sup- PLI PLUTEUS. PLU posed to be full of matter. It is used in opposition to vacuum. Plinth, a square member forming the lower division of the base of a column, &c. ; also the plain pro- jecting face at the bottom of a wall, immediately above the ground. In Gothic architecture the plinth is occasionallydivided into two stages, the tops of which are either splayed or finished with a hollow moulding, or are covered by the base mould- ings. Plinth, the square footing below the bases of Ionic and Corinthian columns. In Grecian architecture plinths do not appear to have been employed, the bases of the columns resting upon the upper step of the building. The Latin wordplinthus is derivedfrom the Greek, signifying a tile. Plinthus, any rectangular parallele- piped ; a brick or tile Pliny, whose villas were by the Ro- mans objects of much attraction, for their design and ornament, was a person of excellent judgment in all the useful arts, and, living under Trajan, had an opportunity of see- ing the performances of and ad- vising with Apollodorus, one of the greatest architects that any age produced : whether artists or mas- ters employed by Pliny, or Pliny himself, designed these villas, is not to be determined; but Pliny was perfectly acquainted with the whole that was necessary to be understood in their situation and disposition Plotting, among surveyors, the art of describing or laying down on paper, &c., the several angles and lines of a tract of ground surveyed by a theodolite or like instrument, or a chain Plotting -scale, a mathematical instru- ment used in plotting ground, usually of box-wood, sometimes of brass, ivory, or silver, either a foot or a foot and a half long, and about an inch and a half broad j Plug-rod, the air-pump rod of a Cornish engine. The tappets which 342 give motion to the valve are fixed upon these rods. Plumb, in ship-building, signifies to be perpendicular Plumbago forms gray tints of greater permanence arid purity than most blacks in general use, and it is now employed for this purpose with approved satisfaction by ex- perienced artists Plumb-line, in architecture, &c., a line perpendicular to the horizon, made by dropping a plummet Plummer-block, a short carriage or support for a shaft to turn in, with a flat base to bolt on a frame Plummet, in carpentry, navigation, &c., a weight of lead hung on a string, by which depths are ascer- tained and perpendicularity dis- i cerned Plum-tree, a handsome wood, a native of Europe, used principally in turning, and in Tunbridge works ; in the endway of the grain it resembles cherry-tree Plus, in algebra, a term commonly used for more, and denoted by the character +, as 6 + 10 = 16, in contradistinction to , or minus, less, as 16-10 = 6 Pluteus, the wall which was some- times made use of to close the in- tervals between the columns of a building, and was either of stone or some material less durable. The latter method was adopted only in places under cover, whence that kind of building was called opus intestinum. The pluteus was also a kind of podium, intervening be- tween any two orders of columns placed one above the other. The word is used in this sense in the description of the basilica and the scene of the theatre. The pluteus has been adopted between every two orders of columns in the ex- terior of all the theatres and am- phitheatres of the Romans which are known. Pluviometer, in the arts, a rain- gauge, an instrument to measure the quantity of rain that falls PLY POINTED ARCHITECTURE. POL Flyers, in mechanics, a kind of ba- lance used in raising or letting down a drawbridge Plying to windward, in navigation, the endeavouring to make a pro- gress against the wind Pneumatics, the properties of air or fluids ; a branch of hydrostatics Pnyx, a name given to a place near Athens, at which assemblies were held for oratory, and for the discussion of political affairs of the state; the ancient place of the Athe- nian parliament. It was, accord- ing to Plutarch, describing the change effected by the Thirty Tyrants, in the aspect of the ora- tory, and was turned from the sea in order to divert the assembled people from being reminded by their orators of maritime affairs, the basis of Athenian dominion. No traveller, it is said, has hitherto re- marked the circumstance of the position of the ancient city wall, by which the Pnyx was doubtless enclosed during and after the Pelo- ponnesian war. Plutarch further remarks : " Themistocles did not bring the Piraeus into the city, as Aristophanes would have had it ; but he joined the city by a line of com- munication to the Piraeus, and the land to the sea." This measure strengthened the people against the nobility, and made them bolder and more intractable, as the power came with wealth into the hands of masters of ships, mariners, and pilots. Hence it was that the oratory in the Pnyx, which was built to front the sea, was after- wards turned by the Thirty Tyrants towards the land, as they believed a maritime power to be inclinable to a democracy, whereas persons employed in agriculture would be less uneasy under an oligarchy. Podium, in Greek architecture, a continued pedestal, for supporting a row of columns, or serving for a parapet, or forminga sort of terrace, as the podium of a theatre or am- phitheatre. It consists of a plinth, 343 base, die, and corona, all which were continued without interrup- tion around three sides of the building. The podium was also adopted in the scenes of theatres ; and here, instead of being unin- terrupted, it was frequently broken round the basis of the columns, and formed what are commonly called pedestals. Vitruvius seems to consider the podium as a pede- stal continued the whole length of. a building, and to have been so called both when there were pil- lars placed on it, or only supported by a wall. When pillars were placed on the sides of buildings, sometimes, instead of having the podium continued the whole length in one line, it was made to break forward under every pillar, which part so advancing was called the stylobate, and that which was be- twixt the pillars under the wall, was the podium. Pointed or Christian Architecture had its rise about the 12th century. Very many beautiful examples exist in England. It was also employed in Germany. Mr. W. Pugin says, that Pointed architecture does not conceal her construction, but beau- tifies it. A buttress in pointed ar- chitecture at once shows its pur- pose, and diminishes naturally as it rises, and has less to resist. Here are the true principles of Christian architecture, by the conversion of an essential support of the building into a light and elegant decoration. Point, in navigation, one of the thirty-two divisions into which the circumference of the horizon and the mariner's compass are distinguished, each comprehending 11 15' Point of horse, in mining, the spot where the vein is divided into one or more branches Polacre, in navigation, a merchant vessel of the Mediterranean, having three pole -masts, without tops, caps, or cross-trees, with a bow- sprit of one piece POL POLYCHROMY. POL Polarization. If a round hailstone drop upon the sloping roof of a house, it will act, as regards its rebound, just in the same manner whether the slope be towards the north, south, east, or west. But this will not be the case with an arrow under the same circum- stances, because it has a distinction of sides, and its behaviour will vary according as the plane of its barbs is parallel with the eaves or with the rafters of the roof, or in- clined to both. A bullet in its flight from a gun has also sides to its motion (though not to its form), because it revolves on an axis, which may be vertical, horizontal, or inclined; but if shot from a rifle, it has no such sides, because, though spinning on an axis, that axis has, by a particular contri- vance, been made to coincide with its line of motion, so that it pre- sents the same aspect above, below, or on either side. Now if these projectiles were too small or too rapid for us to discover the reason of these differences, we might still observe the differences themselves, and should express them by saying that the motion of the arrow or the gun-bullet possessed polarity, or polarization, which was not the case with that of the hailstone or the rifle-bullet. Polarity, then, means simply a difference of sides. That a ray of light should (in some cases) possess this property, is not perhaps so wonderful or un- expected as that man should have been able to detect a fact so refined and remote from common observa- tion, and even to distinguish dif- ferent varieties of it, and investi- gate its laws. Indeed, these must be regarded as the very penetralia of physics, the very inmost secrets of Nature that man has been en- abled to wrest from her. If the measurable spaces occupied by the waves of light be minute, how far less, in all probability, must be those immeasurable spaces to which 344 its vibrations are confined (which even in sound are mostly inappre- ciable, though the waves occupy many feet) ; yet it is to the posi- tions of these inconceivably mi- nute vibrations that the differences of polarization are due. Poldway, coarse sacking for coal- sacks, &c. Pole-masts, in navigation, are those made of single trees or spars, in contradistinction to those made of several pieces Pole-plate, a small wall- plate used in roofs to receive the pitch of the rafters Polroz, in mining, the pit underneath a water-wheel Polychromy is the art and practice of painting in positive colours, either on flat surfaces or sculp- tured forms, and has been referred for its origin to other than sesthe- tic motives. The object of poly- chromy is to heighten the effect of architectural decoration, either by causing a more just subordination of the various parts than can be obtained by mere chiaio-scuro, or in supplying deficiencies that could not be so well filled up by any other means. Professor Cockerell, who travelled and learned much in Greece, was the first who brought it to light in this coun- try. This very interesting deco- rative art had its origin doubtless in Egypt ; but the Greeks excelled, as in all art, by the existing evi- dence of the temples of their per- fection of architectural art. The interior decorations of Pompeii are also evidences of a refinement of taste, and in Gothic polychromy the designers and operatives have shown some talent. A free and bold style in arabesque prevailed from the time of Henry III. until the close of the reign of Edward III. Bright and lively colours were applied to masses, and the grounds covered with compositions of foliage and birds, animals and human figures ; sometimes in one POL PORCH. POR tint, sometimes in varied colours. Many beautiful examples still exist in our cathedrals and some parish churches. Polyfoil, an ornament formed by a moulding disposed in a number of segments of circles Polystyle, having a number of co- lumns. Where columns occur be- hind columns, as where a portico has inner columns, like that of the Royal Exchange, such portico may be termed polystyle. Pomel, a boss or knob used as an or- namental top of a conical or dome- shaped roof of a turret, &c. A large copper ball or pomel is on the summit of a timber spire of Lincoln cathedral. Pons (Latin), a bridge. The most ancient bridge upon record is the one erected by Nitocris over the Euphrates at Babylon. Poon wood, of Singapore, is of a light porous texture, and light greyish cedar colour; it is used in ship- building for planks, and makes ex- cellent spars. The Calcutta poon is preferred. Poplar wood. There are five species common to England, of which the abele, or great white poplar, and the Lombardy poplar, are most used. The woods are soft, light, easy to work, suited for carving, common turnery, &c. Poppets, perpendicular pieces that are fixed on the fore and aftermost parts of the bulgeways, to support the ship while being launched Poppet-head, that part of a lathe which holds the back centre, and can be fixed on any part of the bed Poppy, an ornament representing the poppy-head, used on the tops of the upright ends or elbows which terminate seats, &c. in churches Poppy-head, in architecture, a carved ornament at the apex of a standard or open seats in Gothic churches, also carved into an ornamental finial, pomel or crest, &c. Porcelain clay, in mineralogy, a sub- 345 stance of great infusibility, derived from disintegrated felspar Porch, in architecture, a roof sup- ported on pillars before a door ; a kind of vestibule supported by pil- lars. Any small portico consider- ably lower than the main structure to which it is attached may be so termed, in contradistinction from one carried up the height of the building, or as high as the principal cornice. Porches were used in Nor- man architecture, in Early English, and commonly in subsequent dates. When the fashion of building houses on quadrangular plans was discon- tinued, a porch of at least two stories, and sometimes the whole height of the building, succeeded the gate-house. Low porches had been used as entrances from inner courts from an early date; and of the time of Henry VIII. one may be mentioned at Cowdry, attached to the door leading from the court to the hall. Pores, small interstices between the solid particles of bodies Porisms, in geometry, a name applied by the ancients to certain compre- hensive and indefinite problems Port, in navigation, the larboard or left side of a ship ; as ' a-keel to port' is an inclination to the lar- board side Ports, the holes in the ship to run the guns out Port-lids, shutters to the ports Ports and buildings constructed in water, Vitruvius writes :" The op- portunity which presents itself of giving some account of ports, and by what means protection may be afforded to ships from the elements, ought not to be neglected. The positions best adapted by nature to such a purpose are bays with capes and promontories at their extremi- ties, from which the shore recedes inwardly in a curved line. Upon shores of this description, docks may be built or porticoes erected, or a channel cut from the port to the emporium, defended by towers FOR PORTICUS. FOR on each side, in which machines may be constructed for throwing booms across the passage. If, how- ever, no situation can be found capable by its formation of protect- ing vessels against the violence of the sea, we must search for a spot where a promontory presents itself on one side, and where no river discharges itself so as to oppose its application to the purposes of a harbour, and supply the want of a corresponding projection on the other by building walls and but- tresses. The walls, which it be- comes necessary in this case to construct in the water, may be thus formed : sand should first be procured from that part of the coast lying between Carnac and the promontory of Minerva, and mixed with lime in the proportion of two parts to one ; then rows of grooved beams must be driven in the water, connected by oaken planks, and bound together by chains. The surface of the ground below the water, on which the wall is to be raised, must then be made evenbymeans of transtilli,and the space comprehended between the beams filled with a composi- tion consisting of rough stone and cement, made in the manner just described. Such is the quality of the sand produced in these spots, that the composition becomes a solid wall." Port the helm. In navigation this phrase directs a ship's course fur- ther to the right, or starboard, by putting the helm to larboard. Porta (Latin), the gate of a city, cita- del, or other open space, enclosed by a wall, in contradistinction to janua, which was the door or entrance to any covered building Portal, the arch over a door or gate- way ; an entrance under cover Portcullis, a strong defensive frame- work of timber, hung in grooves within the chief gateway of a fort- ress, or a castle, or an edifice of safety : it resembles the harrow, but 346 is placed vertically, having a row of iron spikes at the bottom, and is let down to stop the passage in case of assault Portico, in architecture, a covered walk supported by columns, arid usually vaulted ; a piazza or arched pathway. (For the different plans and denominations of porticoes, see ' Rudimentary Architecture,' Part I.) Portions (Latin), a walk covered with a roof which is supported by columns. A portico was either attached to temples and public buildings, or it was built indepen- dent of any other edifice. Porticus(deinde). Inthehouses of the Roman citizans, bet ween the atrium (hall, or servants' room) and the inner court, there was usually a room called the taUinum (corri- dor ), mentioned by Vitruvius. This porticus lay betwixt the atrium and the cavadium. The reason for his giving it this round form may be upon two accounts : first, to give a greater grace to its pro- jection, and to make the fore part of it serve for a more beautiful vestibulum to the house; and in the next place, as being designed for a shelter in tempestuous weather, it the better broke the force of those winds that blew on that side than if it had been more square. Porticus. By the Romans this was a common name given to all build- ings that had walks under the cover of a roof or ceiling, sup- ported by pillars or pilasters, though differently called, according to the disposition of the pillars : when placed on the outside of a building, as round some of their temples, it was called peripterium ; when these ranges of pillars were within a room, as they were some- times in their triclinia, basilica, atria, and temples, the void space betwixt the pillars and the side walls was called alee; but when pillars surrounded courts, and had walks betwixt them and the walls, FOR PRESSURE OF FLUIDS. PRI these ranges of pillars were called peristylia, and the walk betwixt was called a portions I Portland-stone, an alkaline sandstone, of a dull whitish colour, heavy and moderately hard, and somewhat flat texture, and composed of large rounded grit, cemented together by an earthy spar, and intermixed with numerous glittering spangles of pure spar : the grit splits in the cutting of the stone, so that it is capable of being brought to a sur- face very smooth and equal : it will not strike fire with a steel, and burns to a slight ashen hue. It has been and is much used for all kinds of buildings, particularly in the large structures in London : it is brought from the island of Portland, in Dorsetshire Post, an upright timber in a building; those used in modern roofs are called king-posts or queen-posts, according to their number and position Post Meridiem (P.M.}, after mid-day Postern, a small doorway or gateway at the back of a building ; a small doorway for private communica- tion with the exterior of a castle or fortress Postigue, in architecture, an orna- ment of sculpture superadded when the original plan has been com- pleted Pot-metal, a species of stained glass, the colours of which are incorpo- rated within the glass while in a state of fusion Poudrette, a French word, signify- ing powdered dung ; but the word is applied, when treating of human excrement, in its meaning to the solid of that soil after the liquid manure has discharged itself. In a vine-growing district near Paris, (See article Fosses d'aisances,')po\i- drette was used for manure, and, although the application of it pro- duced a great abundance of fruit, yet the wine proved very inferior to that which had been previously made on the same ground. 347 Power, in mechanics: this denotes a force which, being applied to a machine, tends to produce motion or pressure Power, horse, in mechanics, an ex- pression used to denote the power of a steam engine, that is to say, how many horses' work it will save. If a horse standing still can by his strength keep a weight of 169 fts. from falling, when suspended over a pulley, he will exert 121 fts. at two miles per hour; 100 fts. at three; Sifts, at four; 64fts.atfive; 49 fts. at six ; 36 fts. at seven ; 25 fts. at eight; 16 fts. at nine; 9 fts. at ten; 4 fts. at eleven; and 1ft. at twelve miles per hour. Power-loom, in mechanics, a loom moved by the mechanical force of steam, wind, water, &c., as contra- distinguished from hand-weaving Poyntell, paving formed into small lozenges or squares laid diagonally Pracinctiones, the passages or corri- dors which separated the several ranges of seats in an ancient Ro- man theatre Pressure of fluids consists of two kinds, elastic and non-elastic. The first is comprehended in the science of pneumatics, the second in that of hydrostatics. Both classes of fluids deviate from solid substances in their greater distribution of any pressure to which they may be subjected. Thus solid bodies press downwards only by the force of gravity ; all fluids, on the contrary, press not only in this direction, but upwards, sideways, and every way equally. The incompressi- bility of water renders it service- able, by this principle, in the hy- drostatic press. Preventer bolts, those which are driven at the lower end of the pre- venter plates, to assist the strain of the chain bolts Preventer plates, in ships, plates of iron below the links of the chains Pricker, a thin piece of iron, used to make a hole for the fusee or match to fire a blast PRI PRIORY. PRI Prill, a solid piece of ore, a specimen under the principal rafters or pa- Priming, the effect engendered by rallel to them, in a state of com- having too little steam room in the pression, assisting with the princi- boiler of a steam engine. Minute pals to support the timbers of a particles of water being carried into roof : they are employed in the pre- the cylinder, collect in a body, sent roof of St. Paul's church, which obstructs the passage of the Covent Garden piston, and causes a considerable Priory, a monastic establishment for loss of power. the devotional requirements and Prince's metal, in metallurgy, an alloy maintenance of a religious frater- of copper, in imitation of silver, in nity, under the government of a which the proportion of zinc is prior. Many priories were for- greater than in brass merly scattered over Britain, as Principal brace, a brace immediately the subjoined list will show : NAME. ORDER. DATE. COUNTY. Abergavenny . . . Benedictine Wm. Conq. Monmouthshire Abernethy .... Augustine 1273 Perthshire Acornbury .... Do. King John Herefordshire Alberbury .... Black Monks Henry I. Shropshire Aldeby 1355 Norfolk Allensborne .... Augustine 1466 Suffolk All Saints .... Do. 1166 Dublin Alvingham .... King Stephen Lincolnshire Andover Hampshire Anglesey Augustine Cambridgeshire Appledercomb . . . Benedictine Henry III. Hampshire Ardchattan .... Vallis Caulium 1230 Argyleshire Astley Benedictine Wm. Conq. Wortestershire Aucot .... 1151 Warwickshire Austin of Braden-1 stoke . . . . / Augustine 1142 Wiltshire Austin Friars . . . 1253 Middlesex Austin Priory of "1 Do. 1230 Leicestershire Bradley . . . J Austin Priory of "1 Mickleham . . J Do. Henry III. Sussex Austin Priory . . . Do. 1358 Middlesex Badlesmere .... Do. Edward II. Kent Bamborough . . . Do. Henry I. Northumberland Banester .... Do. 1182 Oxfordshire Bareham ..... Crut ch ed Friars Edward I. Cambridgeshire Barlinch Augustine Henry II. Somersetshire Barnstaple .... Cluniac Wm. Conq. Devonshire Barnwell Augustine 1092 Cambridgeshire Bartholomew (St.) . Do. 1133 Middlesex Basedale Cistercian 1162 Yorkshire Beaston Augustine King John Norfolk Beaulieu Vallis Caulium 1230 Ross-shire Beauvale .... Carthusian Edward III. Nottinghamshire Bees (St.) .... Benedictine Wm. Rufus Cumberland Belton-Grace-Dieu Augustine 1277 Leicestershire Belvoir Benedictine 1076 Lincolnshire Bexdon ..... Augustine 1343 Essex 348 PHI PRIORIES. PRI NAME. Bicknacre .... Bilsington .... ORDER. Augustine Do. Benedictine Do. Augustine Do. Do. Black Monks Augustine Do. Benedictine Augustine Do. Benedictine Augustine Do. Do. Do. Benedictine Do. Augustine Do. Do. Benedictine Augustine Do. Do. Do. Benedictine Ciuniac Augustine Do. Do. Gilbertine Augustine Do. Do. Do. Do. Do. Do. Do. Do. Benedictine Do. Cistercian Cluniac Augustine Do. Cluniac Augustine Gilbertine DATE. Henry II. 1253 Henry I. Henry II. Henrv II. 1283 King John 1296 Henry I. 1088 1120 1120 Henry I. Henry I. 1138 980 King John King Stephen Henry I. 1144 1375 Henry I. Henry I. 1110 Henry III. Henry I. 1155 1113 Richard I. 1005 King Stephen King Stephen Richard I. 1338 1171 1199 1148 1152 1244 1296 King John 1142 1291 Edward I. 1071 1188 1085 King John King Stephen COUNTY. Essex Kent Norfolk Cheshire Bedfordshire Caernarvonshire Northumberland Essex Lanarkshire Suffolk Nottinghamshire Cornwall Yorkshire Sussex Essex Lincolnshire Wiltshire Leicestershire Buckinghamshire Brecknockshire Leicestershire Cork Yorkshire Dorsetshire Gloucestershire Northumberland Suffolk Norfolk Hampshire Shropshire Norfolk Rutlandshire Somersetshire Norfolk Lincolnshire Lancashire Berkshire Suffolk Somersetshire Caermarthenshire Bedfordshire Suffolk Roxburghshire Northamptonshire Staffordshire Glamorganshire Cardiganshire Devonshire Hampshire Lancashire Norfolk Northamptonshire Lincolnshire Birkenhead .... Bissemede .... Bithkalest .... Blackburn .... Blackmore . . . . Blantyre .... Blighburgh .... Blythe . . . v, .' Bodmin Boltori Borgrove .... Botolph (St.) . . . Bourn '* Bradenstoke . ... Bradlev . Bradwell Brecknock .... Bredon . . . j '. Bridgetown .... Bridlington .... Bridport Brimsfield .... Brinkburge .... Brisite .... Bromehill .... Bromere Bromfield . . . . Bromholm . . ... . Brooke . . . < ', Bruton . . . ' Buckenham, Old . . Bullington . . ..,- :> Burscough .... Bustlesham . . * . Butley . . ... Byrklev . . . *; . Caermarthen . . . Calderell Camper Canonby .... Canons Ashby . ,.s r ? 4 Canwell Cardiff Cardigan Careswell .... Carisbrooke .... Cartmele . . Castleacre . ... Castle Hvmel ... . Catteley' 349 PRI PRIORIES. PRI NAME. Charletan .... Chaucomb .... Chepstow .... Chetwood .... Chicksand .... Chipley Chirburg ..... ORDER. Premonstrant Augustine Benedictine Augustine Gilbertine Augustine Do. Do. Do. Do. Gilbertine Cluniac Augustine Do. Do. Do. Do. Benedictine Do. Do. Augustine Do. Do. Cluniac Benedictine Do. Augustine Do. Do. Benedictine Augustine Cluniac Augustine Do. Benedictine Nunnery Augustine Benedictine Gilbertine Augustine Do. Carthusian Augustine Cistercian Trinity Benedictine Do. Do. Cluniac DATE. 1187 King John King Stephen 1244 1150 1468 Henry III. 1150 1108 | 1248 King John Henry I. Henry III. Henry II. 673 Henry II. 1082 1043 980 1226 King John St. Columba Henry II. Wm. Rufus Win. Conq. 980 1124 1139 Edward I. Henry I. 1140 Henry I. 1161 1104 Henry I. Henry I. Henry III. 1358 Henry I. 1212 1166 1166 Richard II. Henry II. 1172 Henry III. 1217 1141 1100 Wm. Conq. 1125 COUNTY. Wiltshire Northamptonshire Monmouthshire Buckinghamshire Bedfordshire Suffolk Shropshire Hampshire Middlesex, within Aldgate Suffolk Oxfordshire Herefordshire Oxfordshire Norfolk Oxfordshire Scotland Lancashire Lincolnshire Warwickshire Dorsetshire Norfolk Herefordshire Argyleshire Kent Northamptonshire Somersetshire Gloucestershire Hampshire Lincolnshire Suffolk Devonshire Kent Yorkshire Staffordshire Essex Bedfordshire Essex Do. Wiltshire Rutlandshire Yorkshire Lincolnshire Do. Do. Warwickshire Yorkshire Wiltshire Northamptonshire Glamorganshire Herefordshire Suffolk Wiltshire Christchurcb . . . Christchurch . . . Clare Clattercote .... Clifford Cogges Cokesford .... Cold Norton . . . Coldingham .... Coningshead . . . Covenbam .... Coventry . . Cranbourne .... Creak Cresswell .... Crusay .... Cumbwell .... Daventry .... Denestro Denhurst .... Dennis (St.) . . . Depyng Dodnash . . Dorley .... Dover Drax Dudley Dunmow .... Dunstable .... Earles Colne . . . Easebourn .... Edington .... Editbweston . . . Ellerton Ellesham .... Eltham Ep worth Erdbury Essehold Eston . . . Everdon Ewenny Ewyas Eve . Farley 350 PRI PRIORIES. PRI NAME. Feale ...'.. Filley ORDER. Cluniac Augustine Benedictine Augustine Do. Benedictine Gilbertine Black Monks Augustine Augustine Gilbertine Sempring. Augustine Cistercian Augustine Do. Augustine Do. Do. Cistercian Augustine Do. Do. Benedictine Do. Black Monks Augustine Sempring. Augustine Cluniac Augustine Do. Benedictine Augustine Do. Benedictine Carthusian Gilbertine Benedictine Sempring. Cluniac Benedictine Do. Premonstrant Cluniac Premonstrant DATE. 1156 1196 1347 Richard I. 630 Henry IIL Wm. Conq. 1114 1220 1179 Henry I. 1291 1212 1113 1153 Henry I. 1141 1129 William II. 1164 1324 Henry I. 1170 1150 1150 Richard I. Henry I. Henry I. 1135 1200 1137 1125 1203 1155 1472 Henry III. 1223 1000 1185 1173 1222 Edward III. 1319 King John 1291 Saxon period 1089 1296 Henry II. Henry II. COUNTY. Ayrshire Nottinghamshire Durham Herefordshire Norfolk Kent Cambridgeshire Dorsetshire Lincolnshire Devonshire Aberdeenshire Cornwall Cambridge Yorkshire Monmouthshire Yorkshire Derbyshire Yorkshire Glamorganshire Yorkshire Do. Lincolnshire Yorkshire Norfolk Yorkshire Bedfordshire Somersetshire Sussex Essex Do. Do. Pembrokeshire Lincolnshire Yorkshire Do. Hampshire Sussex Suffolk Hertfordshire Devonshire Norfolk Leicestershire Somersetshire Hertfordshire Lancashire Lincolnshire Dorsetshire Norfolk York Kirkcudbrightshire Essex Lancashire Essex Finehale Flanesford .... Flitcham .... Folkestone .... Frampton .... Freston . . . V V Frothelstoke . . . Fyvie . German (St.) . . . Gilbertine . . Gilbertine .... Goldcliff. . . " * Greenfield . . . ' . Grosmont . . '. . Gwenny . . . ~ Gysburgh . . -|i ( Hackness . . . . Hagh . . . * : '. Haltempraie . . . Hampton .... Hanepole . . . . Harwolde . . '''.. Hasilberge . . V . Hastings .... Hatfield Broadodk . . Hatfield Peverell . . Hatfield Regis . . . Haverfordwest . . . Haverholm .... Hedley Helagh Helen's (St.) . . . Heringham .... Herringfleet . . . Hertford . . 'tf- . Hertland Hickling .... Hinkley . . .' > Hinton . . . . * . Hitchen . . . / V Holland . . . . '> > Holland Brigge v' . Holme . . . . \. Holycourt . . ; { * Holy Trinity . ,-^ / Holywocd . . Horkesley Parva . . Hornby . Hornchurch . . . 351 PRI PRIORIES. PRI NAME. Horsham .... Horsley ... OKDER. Benedictine Trinity Benedictine Augustine Benedictine Augustine Do. Do. Benedictine Augustine Do. Do. Benedictine Do. Do. Carthusian Augustine Do. Trinity Augustine Benedictine Augustine Do. Do. Black Monks Augustine Do. Do. Do. Do. Cluniac Augustine Cluniac Augustine Do. Cistercian Augustine Benedictine Do. Do. Augustine Carmelite Benedictine Do. Augustine Do. Gilbertine Do. Augustine DATE. 1105 Win. Conq. Edward I. King Steph. William I. Henry I. 1177 David I. 1001 Henry II. 1100 Edward III. 1130 1184 Edward III. 1359 1121 King John Henry II. 1004 1169 1108 1136 Edw. Conf. 1270 1126 1125 1119 Henry III. Henry I. 660 1078 Henry III. Alex. I. 1122 Henry I. 1175 1291 1100 1291 1124 1206 1292 1083 1171 King Stephen Henry II. King John Richard I. 1336 COUNTY. Norfolk Gloucestershire Middlesex Suffolk Huntingdonshire Berkshire Lincolnshire Suffolk Fifeshire Huntingdonshire Wiltshire Suffolk Do. Caermarthenshire Tipperary Herefordshire Yorkshire Leicestershire Yorkshire Do. Lincolnshire Lancashire Cumberland Monmouthshire Gloucestershire Staffordshire Essex Cornwall Leicestershire Kent Essex Nottinghamshire Herefordshire Suffolk Sussex Cambridgeshire Kinross-shire Perthshire Dorsetshire Lincolnshire Wiltshire Norfolk Lancashire Northamptonshire Cheshire Essex Worcestershire Do. Wiltshire Lincolnshire Wiltshire Cambridgeshire Warwickshire Hounslow .... Hoxne Huntingdon .... Hurley . Hyrst . . . Ipswich .... Isle of May . . . Ives (St.) .... Ivychurch .... I x worth . . Kersey Kidwelly .... Kilcomin .... Kilpeck Kingston .... Kirby Beler . . . Kirkham .... Knaresborough . . Kyme Lancaster .... Lanercost .... Lantony .... Lantony .... Lapley . Latten Launceston . . . Leeds Lees, or Lighes . . Lenton . . Leominster .... Letheringham . . . Lewes Lochleven .... Loch Tay .... Lodres . . Long Bennington . . Longlent .... Lynn Lvthom . Luffield Mabberly .... Maldon Malvern Major Malvern Minor . . Mardin Bradley . . Markbv .... Marlborough . . . Marmond .... Marstoke .... 352 PRI PRIORIES. PRI NAME. Martin (St.) . . . Massingham Magna . Mattersey .... Maxtoke .... Mav . . ORDER. Augustine Gilbertine Augustine Cluniac Do. Augustine Cistercian Benedictine Augustine Benedictine Do. Augustine Benedictine Do. Augustine Cluniac Benedictine Cluniac Benedictine Do. Cluniac Benedictine Augustine Trinity Carthusian Benedictine Augustine Benedictine Do. Augustine Do. Benedictine Cluniac Augustine Gilbertine Augustine Gilbertine Do. Cluniac Do. Augustine Gilbertine Augustine Do. Do. Benedictine Do. Gilbertine Do. Augustine DATE. 1260 1192 1336 David I. iing Stephen 1196 ing Stephen Edw. Conf. 1121 Edw. Conf. King John Henry III. iing Stephen Wm. Conq. f William \ the Lion Henry II. Henry II. Henry II. Henry I. Henry I. King John 1124 1264 1200 1113 King John 1121 1145 Wm. Conq. Henry I. Henry II. 1173 1170 Henry III. King Stephen 1160 1076 King Stephen 1330 Henry I. 1162 1202 1149 1150 King John COUNTY. Kent Norfolk Nottinghamshire Warwickshire Fifeshire Leicestershire Suffolk Yorkshire Warwickshire Essex Surrey Cornwall Oxfordshire Sussex Devonshire Norfolk Aberdeenshire Yorkshire Herefordshire Kent Warwickshire Monmouthshire Somersetshire Shropshire Hampshire Kent Yorkshire Norfolk Tipperary Huntingdonshire Durham Surrey Yorkshire Gloucestershire B uckingham shire Bedfordshire Lincolnshire Nottinghamshire Lincolnshire Do. Norfolk Northamptonshire Yorkshire Lincolnshire Cheshire Yorkshire Buckinghamshire Ireland Wiltshire Yorkshire Do. Northumberland Melton Mowbray . . Mendham .... Menton Mereval . . . ^'- . Merton Michael (St.), Mount . Minster Lovel . . ; <\ . Mixhalham . . -.. . Modbury . . , . Molycourt . . . Monimusk . . ; . Monk Breton . . . Monkland . . . Monks Horton , . Monks Kirby . *'('? ' Mottenden . . .. . Mountgrave . * Mountjoy .... Nanah . . . Neot's(St.) . . . Nesseham .... Newark Newburgh .... Newington Longaville Newnhani .... Newsham . . >/ . Newsted Newstede .... Normannesbirch . . Northampton . . . North Fernby . . . North Ormesby ii ! Norton . . . -:" Nostell . . Nutley Oegmild Old Malton .... Ovingham .... 353 PRI PRIORIES. PHI NAME. Panfeld ORDER. Benedictine Do. Do. Augustine Benedictine Benedictine Augustine Do. Vallis Caulium Augustine Cluniac Augustine Do. Do. Carthusian Cluniac Gilbertine Augustine Benedictine Augustine Do. Cistercian Augustine Black Friars Augustine Do. Do. Do. Do. Do. Benedictine Augustine Do. Do. Benedictine Augustine Do. Do. Benedictine Gilbertine Augustine Do. Benedictine Carthusian Gilbertine Do. Benedictine Do. Premonstrant Augustine DATE. Wm. Coriq. 1098 1221 1200 1200 1200 Wm. Conq. Do. 1230 1121 Wm. Rufus 1133 11GO Richard II. Edward III. 1151 Henry II. Henry III. Henry I. 1296 1268 1124 1172 Henry II. 1146 Henry II. 1064 1200 1205 1114 Henrv II. Ill4 1233 1075 1139 Henry II. Henrv I. 1444 Richard I. 1155 Henry III. 1296 1133 Henry I. COUNTY. Essex Pembrokeshire Anglesea Norfolk Pembrokeshire Devonshire Lancashire Norfolk Fifeshire Moray Devonshire Yorkshire Hampshire Kinross-shire Berkshire Lincolnshire Essex Wiltshire Sussex Do. Shropshire Buckinghamshire Yorkshire Forfarshire Flintshire Perthshire Derbyshire Staffordshire Dumbartonshire Staffordshire Ross-shire Herefordshire Suffolk Surrey Berkshire Do. Staffordshire Yorkshire Ross-shire Hampshire Sussex Lincolnshire Sussex Nottinghamshire Hampshire Surrey Norfolk Lincolnshire Suffolk Buckinghamshire Kirkcudbrightshire Hampshire Dorsetshire Pembroke .... Penmon Peterson .... Pille Pilton Pinnortham .... Pintney . . . . ' . Pittenweem .... Pluscardine .... Plympton .... Pontefract .... Porchester .... Port Moack . . . Poughley .... Priory in the Wood . Prittlewell .... Pulton Pyneham .... Ramestede .... Ratlingcope .... Ravenston .... Redholm .... Restennote .... Rhudland .... Rindelgros .... Ripton Ronton . Rosneth .... Roucester .... Rowadill .... Royston Rumburgh .... Ryegate Sandford .... Sandleford .... Sandwell .... Scokirke .... Scurinoke .... Selburne .... Sele Sempringhain . . . Shelbred .... Shelford .... Shenburn (West) . . Shene Shouldham .... Sixhill Snape Snelleshall . . .. . Soul's Seat .... Southwyke .... Speatesbury . . . 354 PRI PRIORIES. PRI NAME. ORDER. DATE. COUNTY. Spinney . Augustine Henry III. Cambridgeshire Spinney ..... Do. Edward I. Do. Stanesgate .... Cluniac 1176 Essex Stanley 1146 Gloucestershire Stanley St. Leonard . Benedictine 1146 Do. Staverdale .... Augustine 1263 Somersetshire St. Andrew .... Benedictine Ulster St. Andrew .... Cluniac 1076 Northamptonshire St. Andrew at York . Sempring. 1200 Yorkshire St. Catherine ... Do. 1148 Lincoln St. Clare Cluniac 1291 Caermarthenshire St. Denys .... Augustine 1124 Hampshire St. Dogmel's . . . Tyrone Wm. Conq. Pembrokeshire St. Faith, at Horsham 1105 Norfolk St. Guthlac . . . ; . Benedictine about 1000 Herefordshire St. James , .< Cluniac 1140 Derby St. James . . ;> Do. 1157 Exeter St. James . .... Benedictine 1147 Bristol St. John the Evan- 1 gelist / Augustine 1211 Kilkenny St. Julian .... Do. 1107 Essex St. Leonard .... 1394 Norwich St. Leonard, Stamford 658 Lincolnshire St. Martin . . *;;, Benedictine 1146 Yorkshire St. Martin .... Do. 640 Dover St. Mary's Isle . . . David I. Kirkcudbrightshire St. Mary Magdalen . Do. 1291 Lincolnshire St. Mary Overy . . Augustine 1106 Surrey St. Neot's . . . :, Benedictine 850 Huntingdonshire St.Osith v * ...='* Augustine 635 Essex St.Oswalde . . . Do. 909 Gloucester Sts. Peter and Paul, "1 Ipswich J Do. Henry II. Suffolk St. Thomas .-.. Do. 1172 Dublin St. Thomas .... Do. 1180 Stafford Stevesholm . .+*<' Cluniac King Stephen Norfolk Steyning. .- f : . Benedictine Wm. Conq. Sussex Stoke Curry .'. Do. Henry II. Somersetshire Stone . . . ,: . Augustine Henry I. Staffordshire Do. 1180 H untin gdonshire Strathfillan .... Do. R6b'. Bruce Perthshire Studley Do. Henry II. Warwickshire Sudbury . .^. .7* Benedictino 1139 Suffolk Swavesay . . * , * Do. William I. Cambridgeshire Tandridge . . >: ri Augustine 1308 Surrey Do. Henry I. Somersetshire Thetford .... Cluniac 1103 Norfolk Thetford . . ..-/; Do. 1114 Norfolk Thoby . . Augustine 1141 Essex Thornham .... Do. King Stephen Lincolnshire Thorsling . . . . Do. Cambridgeshire Thremhale .... Do. Wm. Conq. Essex Thurgarton .... Do. 1130 Nottinghamshire 355 PRI PRIORIES. PRI NAME. Tickford ORDER. Cluniac Benedictine Augustine Do. Black Monks Augustine Do. Do. Benedictine Augustine Do. Do. Do. Gilbertine Benedictine Cluniac Benedictine Augustine Do. Benedictine Do. Cistercian Benedictine Augustine Cluniac Benedictine Augustine Do. Gilbertine Augustine Benedictine Gilbertine Benedictine Cluniac Augustine Benedictine Augustine Premonstrant Benedictine Benedictine Carthusian Augustine Do. Do. Do. Do. Benedictine DATE. William II. 633 Edward I. Wm. Conq. King John 1376 ante John Wm. Conq. 783 1217 Henry I. Henry I. Richard I. King Stephen 1080 1291 1169 1150 Edward II. David 1. 1225 1236 1147 William I. 1061 1105 1160 1081 Henry I. Henry I. 1132 Henry I. 1150 Henry II. Henry I. Richard I. Wm. Conq. Wm. Conq. Wm. Rufus about 1000 Edward I. David I. Wm. Rufus tCing Stephen 1181 Henry III. Henry I. 1200 1250 Henry I. Henry I. COUNTY. Buckinghamshire Northumberland Essex Down Surrey Lincolnshire Sussex Do. Devonshire Staffordshire Westmeath Essex Kent Surrey Lincolnshire Staffordshire Buckinghamshire Cornwall Hampshire Leicestershire Moray Monmouthshire Lincolnshire Berkshire Norfolk Suffolk Do. Hertfordshire Dorsetshire Warwickshire Yorkshire Warwickshire Yorkshire Norfolk Northamptonshire Cambridgeshire Norfolk Shropshire Norfolk Cumberland Norfolk Kirkcudbrightshire Sussex Lincolnshire Buckinghamshire Somersetshire Sussex Shropshire Suffolk Shropshire Yorkshire Warwickshire Tinmouth .... Tiptree Toberglorie .... Tooting . Torkesay .... Tortington .... Tortington .... Totness Trentham .... Tristernagh .... Tukeley .... Tunbridge .... Tunbridge .... Tunstal Tutbury Tykeford .... Tywardreth . . . Twinhain .... Ulverscroft .... Urquhart .... Usk Vaudey Wallingford . . . Walsingham . . . Walton St. Felix, &c. . Wanford .... Ware Wareham .... Warmington . . . Wartre Warwick (St. Sepul-1 chre) . . . . J Watton Wayburn .... Weedon Pinkney . . Welles Wells . Wenlock .... Westacre .... Wetherall .... Weybridge .... Whitshorn .... Wilmington . . . Wingall Winge Withain Wolenchmere ... Worabridge . . . Woodbridge . . . Woodhouse .... Woodkirk' .... Wooton Waven . . 1 356 PRI NAME. Worksop Wormegay . Wormeleye . Worspring . Wrangford . Wroxton Wyraondsley Yarmouth , PROPORTION IN ARCHITECTURE. PRO ORDER. Augustine Do. Do. St. Victor Cluniac Augustine Do. Benedictine Prism, in geometry, a body or solid whose two -thirds are any plane figures which are parallel, equal, and similar, and its sides paral- lograms Prism, in optics, a triangular bar of glass, well known from the effect it produces on a ray of light trans- mitted through it : this effect is a decomposition of the light into its component emanations, consisting of the three primary colours and the secondary tints arising from their intermixture, which together form what is termed the solar spectrum. The lensic prism is a new optical glass, in which the powers of the lens and prism are combined. i Prison, an edifice, unfortunately mostly of large dimensions, for the con- finement of persons warring against society Profile, the outline of a series of mouldings, or of any other parts, as shown by a section through them Profile of an Order, in architecture, an assemblage and arrangement of essential and subservient parts. That profile is preferable wherein the parts are few, varied, and fitly applied. Some member should pre- dominate in each division, which it should appear the office of the other parts to fortify, support, or shelter. In a cornice the corona is supported by modillions, dentils, ovolos, &c., and sheltered and co- vered from the effects of the wea- ther by its cyma or cavetto. Projectile, in mechanics, a body put in motion by an external force Projectiles, in mechanics, that branch DATE. Henry I. 1468 King John 1210 1160 Henry III. Henry III. 1101 Nottinghamshire Norfolk Herefordshire Somersetshire Sussex Oxfordshire Hertfordshire Norfolk which considers the mass, velocity, range, &c. of a heavy body pro- jected into void space by an exter- nal force, and then left to the free action of gravity Projection, in geometry, drawing, &c., a plan or delineation ; in chemistry, the crisis of an operation Projecture, in architecture, the out- jutting or prominence which the moulding and members have beyond the plane of a wall or column Prolate, in geometry, an epithet ap- plied to a spheroid produced by the revolution of a semi-ellipsis about its long diameter Pronaos, the area immediately before a temple. The term is often used for the portico in front of a build- ing. The posticus in one front corresponds to the pronaos in the other : in some temples, the cella was entered through both. The generality of Grecian temples had two approaches. Proportion, in architecture, the mag- nitude of one part as compared with some other. The term ' pro- portion' is used absolutely in the sense of 'good proportion,' although every thing that has shape has proportions of some kind or other. The subject of proportion has been greatly mystified by writers, who have laid down certain fixed pro- portions as the best of all on every occasion, and as the ne plus ultra of artistic taste. But fixed propor- tions can be followed mechanically by every one alike ; whereas it re- quires ability to deviate successfully from routine measurement, and apply the poco pia or the poco meno as the particular occasion or the 357 a 5 PRO PROPYL^EA. PRO particular effect aimed at may re- . quire at least, justify. It is the eye that takes cognizance of pro- portions ; and the architect's own eye ought to be quite as correct as that of other people. Proportion, that branch of mathema- tical science which defines the ra- tio of numbers or quantities to each other Proportions of rooms should be suited to the purposes for which they are used : all figures, from the square to one and a half the breadth of the room, may be employed for the plan. Some have extended the plan to a double square. Galleries may be from five to eight times their breadth. The height, if with flat ceilings, is not required to be so great as in those that are coved. The height of square apartments should not exceed five-sixths the side of the square, nor be less than four-fifths ; but in rooms that are oblong, the height ought to be equal to the breadth. The height, of square rooms that are coved should be equal to one of the sides of the square ; but coved oblong rooms require a height equal to the breadth, added to one-fifth, one- quarter, or, at most, one-third of the difference between their length and breadth. The height of gal- leries should be from one and three- fifths, at most, to one and one-third, at least, of their breadth. Cornices and dressings in the interior of houses are always to be kept more delicate than those on the out- side. Propylceum, in Greek architecture, the porch of a temple or great hall Propylcea : the entrance to a Greek temple, a sacred enclosure, con- sisted of a gateway flanked by buildings, w y hence the plural of the word. The Egyptian temples gene- rally had magnificent propylsea, con- sisting of a pair of oblong truncated pyramids of solid masonry, the faces of which were sculptured with hiero- glyphics. The word, however, is 358 generally used to signify the en- trance to the acropolis of Athens, which was the last completed of the great works of architecture executed under the administration of Pericles. Pausanias relates that " there is only one entrance to the acropolis, it being in every re- maining part of its circuit a preci- pice, and fortified with strong walls. This entrance was fronted by a magnificent building, called the propylsea, covered with roofs of white marble, which surpassed for beauty, and the dimensions of the marble, all that he had before seen." Thebuildingwas commenced during the administration of Pericles, and finished in five years, Mnesicles being the architect, at the expense of 2012 talents, or nearly 464,000 sterling. There were five gates to the propylaea, and before it stood two lofty piers, on each of which was placed an equestrian statue, supposed to be the sons of Xeno- phon. On the right of the pro- pylsea was the temple of Victory without wings, whence is a pro- spect of the sea; and from this place it was said that ^Egeus threw him- self down headlong, and died. On the left of the propylaea was an edifice adorned with paintings, the work of Polygnotus, of which, says Pausanias, though some were ef- faced by time, there still remained those of Diomedes and Ulysses, the one bearing off the bow and arrows of Philoctetes from Lemnos, the other, the Palladium from Troy. There were those also of Orestes slaying ^Egisthus, and Py- lades encountering the sons of Nau- plius, who had come to succour Jigisthus ; Polyxena, at the se- pulchre of Achilles, about to be sa- crificed, and Ulysses addressinghim- self toNausicaa and her maidens, as described by Homer. Several other pictures in the same place are described by Pausanias. These three contiguous buildings origi- nally formed one front, occupying PRO PULLEY. PUL the whole breadth of the rock from side to side, at its western end, so that the only admission into the acropolis was through the middle building, the five gates of which are still remaining, and prove it to have been the propylaea. It may be supposed that the Hermes Propy- Iteus was here placed, and perhaps the Graces, a piece of sculpture by the hand of Socrates, in which that celebrated philosopher, deviating from the practice of the sculptors who preceded him, had represented them not naked but clothed. Other sculptors are also mentioned by Pausanias who seem to have deco- rated this stately entrance. Proscenium, the area in front of the scene of a theatre, which was per- ceived when the pulpitum was re- moved, and when it is probable the temporary scenes were taken away in order to exhibit the front of the permanent scene Prostyle, a temple which has a por- tico in one front, consisting of in- sulated columns with their entabla- tures and fastigium. When the temple had a portico in both fronts, it was termed amphi-prostyle, or prostyle in all parts. Protractor, in surveying and trigo- nometry, an instrument by which angles taken in the field with a theodilite-circumferentor are repre- sented on paper Prow, in navigation, the head or fore- part of a ship, in opposition to the poop or stern Prussian Blue, otherwise called Ber- lin blue, Parisian blue, Prussiate of iron, cyanide of iron, or, in lan- guage more pedantically chemical, per-ferro-cyanate of iron, with alumine, &c., is rather a modern pigment, produced by the com- bination of the prussic or hydro- cyanic acid, iron, and alumina. It is of a deep and powerful blue colour, of vast body and consider- able transparency, and forms tints of much beauty with w r hite-lead, though they are by no means equal 359 in purity and brilliancy to those of cobalt or ultramarine, nor have they the perfect durability of the latter. Prussian Brown is a preparation of Prussian blue from which the blue colouring principle has been ex- pelled by fire, or extracted by an alkaline ley : it is an orange brown, of the nature and properties of Sienna earth, and dries well in oil Prussian Green. The pigment cele- brated under this name is an im- perfect prussiate of iron, or Prus- sian blue, in which the yellow oxide of iron superabounds, or to which yellow tincture of French berries has been added, but is not in any respect superior as a pig- ment to the compounds of Prussian blue and yellow ochre. A better sort of Prussian green is formed by precipitating the prussiate of potash with nitrate of cobalt. Prussiate of Copper differs chemically from Prussian blue only in having copper instead of iron for its basis. It varies in colour from russet to brown, is transparent and deep, but being very liable to change in colour by the action of light or by other pigments, it has been very little employed by artists Pryan, in mining, that which is pro- ductive of ore, but does not break in.large stones, but only in pebbles with a mixture of clay Pseudo-dipteral, a temple which has a single range of columns in the flanks, at the same distance from the walls of the cella as though the temple had been dipteral Pteroma, the spaces between the walls of the cella of a temple and the columns of a peristyle ; called also ambulatio Puddling, in metallurgy, a process in the refining of iron which consists in stirring it actively about Pulley, one of the six mechanical powers. The pulley is a small wheel turning on an axis, with a rope or chain passing over it. The PUL PUMP. PUM circumference is generally grooved to receive the rope, which is at- tached on the one end to the mov- ing power, and on the other to the resisting force. Pulleys are of two kinds fixed and moveable. The fixed pulley gives no mechanical advantage, but is of great utility in altering the direction in which it may he applied. The moveable, on the contrary, doubles the power, which may be increased in any ratio by adding to the number of pulleys. In a combination of pulleys, the advantage, however, is greatly diminished by the fric- tion of the axles and of the ropes. Too complex a combination there- fore would not be of service, as the friction would be increased without a proportional advantage, and from the complexity of the machine would be more liable to be put out of order. Pulpit, an elevated stage or desk from which sermons are delivered. (For beautiful examples, see Mr. Parker's ' Glossary of Architecture,' and the ' Papers on Architecture,' 4 vols. 4to.) Pulpitum, the wooden stage of the theatre upon which the mimic as well as dramatic exhibitions of the Romans were represented. In the Greek theatre, the pulpitum was used only by the histriones, or performers in the drama, and was probably removed before the amusements of the orchestra were exhibited. Pulvinated. A frieze whose face is convex instead of plain is said to be pulvinated, from its supposed resemblance to the side of a cushion, which swells out when pressed upon. Pump, an engine for raising liquids, made in various forms, of more or less complexity of parts and effec- tiveness of action, depending in its s'mplest form upon the external pressure of the air on the surface of the water, and in other forms deriv- ing its power from the abstraction of 360 the air within the tube or barrel. The simplest form of pump is that of the common lift-pump, which consists of a straight tube with two valves, one of which is fitted to the lower end of the tube, and the other is made to slide air-tight in the cavity of the tube or barrel. Both of these valves are adapted to open upwards only, and thus the water is admitted and lifted from the lower part of the tube to the dis- charge aperture above. This pump acts by the pressure of the atmo- sphere upon the external body of water from which the supply is raised, but by the forcing-pump water may be raised above the level to which it is driven by the pressure of the atmosphere. The forcing- pump consists of a barrel fitted with a solid piston or forcer, the barrel being also provided with a branch forcing -pipe. The lower J part of the barrel and the branch pipe are each fitted with a valve opening upwards, and by repeated strokes of the piston, the pressure of the air from abovebeing removed, the fluid is brought up to fill the space between the two valves, and being prevented from returning by the lower valve, it passes through the upper valve of the branch pipe into a capacious upper vessel, and there accumulating, may be ejected in a constant instead of intermittent stream. The lift-pump, being simple and economical in construction, is well fitted for extensive works in which the quantity of water to be raised is considerable, and is there- fore usually employed in works for supplying water for towns. The pumps used at the Metropolitan and other water -works are of great size, and deliver immense volumes of water at each stroke. Those used at Haarlem are 63 inches in diameter, and the pistons have a stroke of 10 feet in length. Each pump delivers 6 tons of water at each stroke. Pumps of this mag- nitude ai-e worked by water or steam PUM PUMP. PUM power. Those at Haarlem, eleven in number, are worked simultane- ously by a steam engine, having two steam cylinders, one within the other, the larger being 12 and the smaller 7 feet in diameter, with a stroke of 10ft. (See Forcing-Pump.} Pump. Mr. Appold's centrifugal pump for draining marshes, and for other purposes, will discharge 10 gallons of water per minute, and is only 1 inch diameter : one of the same shape, 12 inches dia- meter, will discharge at the same speed of the outside circumference, or -Jg- the number of i-evolutions, 1440 gallons per minute, being ac- cording to the square of the dia- meter, and not according to the cubic contents. From various ex- periments, it has been found that the larger model with the curved vanes does the most duty, on ac- count of its receiving and delivering the water more obliquely : it will discharge 1800 gallons per minute, with 607 revolutions, but does the most duty at 535 revolutions, dis- charging 1400 gallons ; therefore, if a pump 1 inch diameter raise 10 gallons, and another 1 foot dia- meter 1440 gallons, it follows that one gals, per min. 10 feet diameter, of the best shape, will pump 1-10,000 20 ditto, ditto . . . 560,000 40 ditto, ditto . . . 2,240,000 To do the above duty, the cir- cumference of the 20-feet pump would be required to travel 560 yards per minute, which would be only 53-| revolutions, and the 40- feet 26. From the results of various ex- periments, it has been found that the loss of power would not be more than 25 per cent. It will be observed, the centrifugal force is not so much in the large diameter, on account of the water moving more in a straight line ; but that is compensated for by the force being 361 applied to a greater depth of water, being 10 feet in the 40 -feet, and only 3 inches in the 1-foot. ft. high. 159 revolutions, with the 1- foot, will raise the water, without discharging any, 1 318 revolutions 4 636 ditto 16 1272 ditto 64 The highest elevation to which the water has been raised with the 1-foot pump, is 67 feet 8 inches, with 1322 revolutions per minute, being less than the calculated height, which may be accounted for by leakage with the extra strain. While the 1-foot pump is raising 8 tons of water 5 feet 6 inches high per minute, there is no greater strain on any part of the pump than 160 fts. on the 6-inch drum, which is equal to a leverage of 3 inches. (See the results of various experiments in the Table on the the next page.) It will pass almost any thing that is small enough to go through, there being no valves. A quantity of nut-galls (about ^ a gallon) were thrown into the 1-foot pump all at once, when it was at full speed, and they passed through without breaking one. Dimensions of the Pump. Diameter 1 foot. Width 3 inches Contents 1 gallon. PUM PUNCHING MACHINE. PUN Table of Mean Results of various Experiments with Mr. Appolffs Centrifugal Pump. Strain in fibs. on a drum of No. of 4 ft. diameter Equivalent revolutions per minute Number of gallons raised driving one of 6 in. diameter, strain on the steam engine, Per centage of work done of 6-inch 5 feet 6 inches Equivalent in as measured rated in tbs., compared drum and high per tfcs. raised 1 foot by a raised 1 foot high with power pump. minute. high per minute. dynamometer. per minute. expended. 400 500 27,500 74 44,400 61-7 412 600 33,000 80 49,440 66-7 427 700 38,500 87 55,723 69- 440 800 44,000 94 62,010 70-9 453 900 49,500 100 67,950 72-8 474 1000 55,000 106 75,366 72-9 481 1100 60,500 113 81,479 74-2 495 1200 66,000 118 87,615 75-3 518 1300 71,500 121 94,017 76- 535 1400 77,000 126 101,115 76-1 563 1500 82,500 134 113,163 72-9 580 1600 88,000 138 120,060 73-3 595 1700 93,500 142 126,733 73-6 607 1800 99,000 150 136,575 72-5 Pump, marine, a machine to draw together with them, to sustain some water out of a ship's hold large weight Pump-chain. This consists of a long Punching and Plate-cutting Machine. chain with valves at proper dis- The operation of punching holes tances, working on two wheels, one through thick metal plates requires above and one below, and passing machinery of a very massive de- down through one wooden tube and scription, on account of the violent returning upwards by another. strains to which it is subjected ; Pump-cistern, to receive the water and the power of these machines from the pumps being exerted only at intervals, it Pump-dales, pipes to convey water is necessary to apply some means of from the pump-cisterns through the rendering the motion tolerably uni- ship's sides form, and thereby diminishing as Pumping engine, a steam engine for much as possible the violence of raising water the strain. This is effected by Punch, in mining, a piece of timber setting in motion a heavy fly-wheel, used as a support for a roof so that the power expended in Punch, a tool for making an im- giving a certain velocity to the pression, or for forcing a hole wheel shall be stored up till the through a plate operation of punching commences, Puncheon, a measure of liquids con- which tends to retard the motion : taining eighty-four gallons the accumulated power in the Puncheons, small upright timbers in wheel will then tend to maintain wooden partitions, now usually the speed, and thus an approxima- called studs or quarters; they are tion to uniform motion is obtained. placed upright between two posts The machine consists of a strong whose bearing is too great, serving, frame, at the front of which is a 362 PUN PURPLE LAKE. PUR broad slide, moved vertically up and down by an eccentric fixed oil the end of a shaft passing length- wise through the frame : on this shaft there is a large wheel, which receives motion from a pinion on another shaft carrying the fly- wheel and driving-pulieys. The punches, the number of which varies according to the size of the holes, are fixed in the lower end of the vertical sliding piece, and 'im- mediately under them is fixed a piece of steel, called the dies, which has holes in it to correspond with the punches. The plate in which holes are to be punched is fastened upon a travelling table in front of the machine; and the slide being up, and the surface of the tahle level with that of the dies, the part where the holes are to be punched is placed between the punches and the dies, so that when the machine is set in motion, the punches are forced through the plate by the action of the eccentric, and the pieces driven out fall through the holes in the dies : after the punches have risen above the surface of the plate, the tra- velling table is set forward to the required distance by self-acting apparatus, and the operation is re- peated by the machine till the re- quired number of holes has been punched. The plate-cutting apparatus con- sists of two steel plates, forming a pair of shears; the lower plate is fixed on the frame of the machine, and the upper one is attached to a slide, as in the case of the punches, acting in a similar manner. The shears are moved by the same shaft as the punches, and act while the punches are being raised : sometimes they are placed at the top of the punching slide. Punt, in navigation, a sort of oblong, flat-bottomed, small boat, with a square head and stern Pur beck -stone, an alkaline sandstone, harsh and rough, of a disagreeable ~~363 I ash colour, very heavy, and mo- derately hard ; of a texture not very compact, but somewhat porous, and composed of an angular grit, ce- mented together by an earthy spar. It cuts freely, and with a tolerably even or smooth surface, but will not take a polish : it is used principally in London. The quarries are in the island of Purbeck, Dorsetshire. Purlins, in carpentry, those pieces of timber that lie across the rafters on the inside, to keep them from sinking in the middle Purple, the third and last of the secondary colours, is composed of red and blue, in the proportions of five of the former to eight of the latter, which constitutes a perfect purple, or one of such a hue as will neutralize and best contrast a per- fect yellow in the proportion of thirteen to three of surface or in- tensity. It forms, when mixed with its co-secondary colour, green, the tertiary colour olive, and when mixed with the remaining secondary orange, it constitutes the tertiary colour russet. Purple Black is a preparation of madder, of a deep purple hue, ap- proaching to black ; its tints, with white-lead, are of a purple colour. It is very transparent and power- ful, glazes and dries well in oil, and is a durable and eligible pigment, belonging perhaps to the semi- neutral class of marrone. Purple Lake. The best purple lake, so called, is prepared from cochi- neal, and is of a rich and powerful colour, inclined to crimson. Its character as a pigment is that of a cochineal lake, already described. It is fugitive both in glazing and tint, but, used in considerable body, as in the shadows of draperies, &c., it will last under favourable cir- cumstances a long time. Lac lake resembles it in colour, and may supply its place more durably, al- though not perfectly so. Purple Ochre, or Mineral Purple, is a dark ochre, a native of the forest of PUR PYRAMID. PYR Dean, in Gloucestershire. It is of a murrey or chocolate colour, and forms cool tints of a purple hue, with white. It is of a similar body and opacity, with darker colour than Indian red, which has also been classed among purples, but in all other respects it re- sembles that pigment. It may be prepared artificially, and some na- tural red ochres burn to this colour, which has been employed under the denomination of violet de mar. Purple wood is from the Brazils, im- ported in logs from 8 to 12 inches square, and 8 to 10 feet long, prin- cipally used for ramrods, buhl- work, marquetry, and turnery Purser, the cashier or paymaster of mines; also the paymaster of a ship Pursuivant, in heraldry, a messenger who formerly attended the king in his wars, or at the council table, and ultimately became herald Puteal, the enclosure surrounding the opening of a well, to protect persons from falling into it. It was either round or square, from 3 to 4 feet high. There is a round one in the British Museum, made of marble. Putlogs or PutlocJcs, in building, are short pieces of timber about 7 feet long, used in building scaffolds. They lie at right angles to the wall, with one of their ends resting upon it, and the other upon the poles which lie parallel to the side of the wall of the building. Putlog-holes, small holes left in walls for the use of the workmen in | erecting scaffolding Putty, in the arts, a kind of paste used by glaziers, composed of whiting and linseed oil (with or without white-lead), beaten toge- ther to the consistence of a tough dough Puzzolano, or Pouzzolano, in mine- ralogy, a volcanic sand of a violet red colour, (the pulvis Puieoli of Pliny,) brought from Italy, which forms a cement that hardens under 364 water. It appears to be a species of argillaceous earth that probably has been calcined and then ejected from a volcano. Its constituents are silex, alumina, oxide of iron, and a little lime. It was first dug out of the earth by the Romans near the town of Pouzzol, not far from Vesuvius. The environs of Rome furnish it equally. It has been found in France in the ex- tinct volcanoes of Vivares. There are a few regions exposed to ig- neous agency w r hich are destitute of it, but it presents itself under very different physical appear- ances, sometimes pulverulent, sometimes in coarse grains, often in slag, pumice, tufa, &c. Its colour, which is generally brown, passes to yellow, gray, and black. The only preparation this material undergoes previous to use is that of pounding, or grinding and sift- ing, whereby it is reduced to pow- der, in which state it is beaten to a proper consistency with a due proportion of lime. Artificial pouzzolano is also much used, and is produced by pulverizing the clay, the psammite, or the arene, which is soluted, and the strewing a layer of it, about four-tenths of an inch, on a plate of iron, heated to a point between a cherry-red and forging heat. It is left till it be raised to the same degree, for a space of time which varies, for each kind of material, from five to twenty minutes. It must be con- tinually stirred with a small rod, in order that the whole of the par- ticles may be uniformly calcined. Pycnostyle, that arrangement of j Greek or Roman columns, in which the intercolumniations are equal to one diameter and a half of the lower part of the shaft Pyramid, in geometry, is a solid figure whose base is a polygon, and whose sides are plain triangles, their several points meeting in one Pyrites, in mineralogy, a name given to certain metallic ores contain- PYR QUARTER-GALLERY. QUA ing a large portion of sulphur ; native compounds of sulphur with different metals, and more espe- cially with iron. The term is derived from the use to which the stone was formerly applied, that of obtaining sparks by percussion, an application of pyrites mentioned by Pliny. Pyrites, Copper, in mineralogy, a combination (sulphuret) of copper and sulphur, being the most com- mon ore of copper Pyrites, Iron, in mineralogy, a com- bination (sulphuret) of iron and sulphur, one of the most abundant minerals in nature Pyrometer, in chemistry, an instru- QUA QUADRA, in architecture, a name given by Vitruvius to the square piece, commonly called the socle, used to support the pedestals of statues, vases, and other orna- ments Quadras, the bands or fillets of the Ionic base, between which the scotia or hollow occurs ; also the plinth, or lower members of the podium Quadrangle, a figure having fourangles and four sides Quadrant, the fourth part of a circle, being bounded by two radii per- pendicular to each other, and a quarter of the circumference, or 90 degrees Quadrature, the finding a square equal in area to another figure Quadrifores, folding - doors whose height was divided into two. Folding-doors which opened in one height were termed fores val- vatce, or valvae. Vitruvius directed the doorways to be made wider when these were used, and the height to be increased when the folding-doors were divided in height. The lifores of Vitruvius were two single doors. 365 ment for measuring very high tem- peratures, depending on the uni- form and permanent contraction of pure clay Pyrometer, a contrivance for ascer- taining the temperature of the flues of boilers, by fixing an iron wire at the back of the flue, and connecting it to a lever in front of the boiler, which indicates the de- gree of expansion and consequently the temperature Pyx, Pioc, a tabernacle or shrine, a depository for the Host, or con- secrated wafer, used in Roman ceremonies. (See Theoreca.) Pyx, in navigation, the box in which the nautical compass is suspended QUA Quarry, a place underground from whence are taken marble, freestone, slate, limestone, and other stones proper for building and paving Quarry, a pane or piece of glass cut in a lozenge or diamond form Quarter, in heraldry : this word is sometimes used for an escutcheon or coat of arms : there are sixteen quarters required to prove nobility Quarter (ship's), the after-part of the top-side Quarters, in building, those slight up- right pieces of timber placed be- tween the puncheons and posts, used to lath upon. These are of two sorts, single and double : the single quarters are sawn to 4 inches thick and 4 inches broad ; the double quarters are sawn to 4 inches square. It is a rule in car- pentry that no quarters be placed at a greater distance than 14 inches. Quarter-deck, in ship -building, the short upper deck from the after- most end of the main chains to the stern Quarter-gallery, the projecting con- venience and ornament of the top- side which is connected with the stern QUA RAFTERS. RAF Quarter-pieces, the carved figures at the aft-part of the quarter-gallery which joins to the taffrail, and forms the boundary of the stern Quartering, in heraldry, the act of dividing a coat of arms into four or more quarters, by parting, couping, &c., by perpendicular and hori- zontal lines. The sovereign of Great Britain in the first quarter bears gules, the lions passant, or, &c.; in the second, formerly, azure, three fleurs-de-lis, &c. Quatrefoil, an ornament of frequent occurrence in Gothic architecture, formed by a moulding disposed in four segments of circles Quears, in mining, crevices in lodes Queen-post, a vertical timber sup- porting the rafters of a trussed roof Quercitron Lake, or Quercitron Yel- low, is what its name implies. It is dark in substance, in grains of a glossy fracture, perfectly transpa- rent, and when ground is of a beau- tiful yellow colour, more durable than the common yellow lakes, al- though not perfectly permanent. Quick lime, such lime as is in the RA13 RABBET, that part of the keel, stern, and stern-post of a ship which is cut for the plank of the bottom to fit into ; the edges of plank or deal for bulk-heads that are lapped one over the other, and wrought square, making each side of the bulk-head a smooth surface to the distance of two rooms and spaces Rack, in mining, an inclined plane on which the ore and slime are w r ashed and separated Rack, a flat bar with teeth on one side, to work into those of a pinion Racking, in mining, a process of se- parating small ores from the earthy particles by means of an inclined wooden frame: the impurities being washed off, the ore remaining near the head of the rock is taken 366 caustic or most active state, and wilich possesses the greatest power of operating upon different sub- stances with which it may come in contact. It is quite the opposite in its qualities and properties to that which has fallen down into a powdery state, in consequence of being saturated with water and carbonic acid gas or fixed air, or which is slaked and become effete. Quick-work, the short pieces between the ports withinside a ship Quink, in building, a piece of ground taken out of any regular ground- plot or floor : thus, if the ground- plot be oblong or square, a piece taken out of a corner to make a court or yard, &c. is called a quink Quirk, a small acute channel or recess, much used between mouldings in Gothic architecture : in Grecian ar- chitecture ovolos and ogees are usually quirked at the top, and sometimes in Roman Quoins of stone, the corners of brick or stone walls : when they stand out beyond the brick-work, they are called 'rustic quoins' RAD from thence, and undergoes toss- ing Radiant point, any point from which rays proceed Radius, in geometry, the semi-diame- ter of a circle, or a right line drawn from the centre to the line of cir- cumference ; in anatomy, a bone of the fore-arm, which accompanies the ulna from the elbow to the wrist Radius-rods, the guiding rods in a parallel motion, jointed to the con- necting-links, to counteract the vi- bratory motion communicated by j the beam, by guiding the links so that there is a point Rafters, in carpentry, the secondary timbers of a house; the timbers let into the great beam RAG RAILWAYS. RAI Rag-stone,in mineralogy. The Kentish rag-stone is a kind of lime-stone, much preferred to other stones of a similar nature : it is found in beds varying from 6 inches to 3 feet in thickness, and is composed of the following substances : carbo- nate of lime, with a little magnesia, 92-6 ; earthy matter, 6 5 ; oxide of iron, 0*5 ; carbonaceous matter, 0-4 = 100. This stone is now much used. Rail or life guards, in locomotive en- gines, strong iron rods reaching down within about 2 inches of the rails, to catch and throw to one side any obstruction which may be on the rails Rails, the moulding ornaments in the top-side, likewise in the head and stern of a ship Railways, or roads in which tracks of iron or other smooth material are laid for the easy passage of wheel- carriages, appear to have been in- troduced between the years 1600 and 1650, in the neighbourhood of Newcastle, to facilitate the carriage of the coals from the pits, in ' waynes' or waggons, to the 'staythes' or discharging places on the Tyne. In 1676 they were de- scribed to be thus formed : " The manner of the carriage is by laying rails of timber from the colliery to the river, exactly straight and pa- rallel; and bulky carts are made, with four rollers fitting those rails, whereby the carriage is so easy, that one horse will draw down four or five chaldrons of coals." These " rails of timber" were laid upon transverse timbers or sleepers, and secured with pegs of wood, the sleepers being embedded in the material of the roadway. Before the year 1716, it became the practice to preserve the edges of the rails by nailing thin plates of malleable iron upon their upper surfaces in places where the draught was harder than usual. About the year 1767, cast-iron bars were sub- stituted for the wooden rails, and 367 this change is said to have been suggested by the wish of the iron- masters to keep their furnaces at work during a season of unusual depression in the market value of their manufactures. These iron bars were found too valuable to admit of a return to the wooden rails, and improvements of various kinds were introduced. Thus the rails were cast in the form of long narrow plates, with a vertical rim along one side (the transverse sec- tion resembling the form of the letter L), and thus the wheels of the waggons were retained in their places without the projecting rims or flanges which were required for wheels running on the plain rails or bars. These rails were called 'tram' or 'plate rails,' and thus dis- tinguished from subsequent forms of iron rails which were introduced to dispense with the longitudinal timbers heretofore required beneath them, by casting the rails of suffi- cient depth to carry their load, and of reduced width, the fianged- wheels being returned to. Malle- able-iron rails were introduced about the year 18 15, at coal-works in Cumberland, with a view to re- medy the defect of frequent break- age, to which those of cast iron were liable : these malleable-iron rails were simply bars of iron from 2 to 3 feet in length, and 1 to 2 inches square ; but the narrowness of their surface was found to injure the wheels so severely, that the restoration of cast-iron rails ap- peared likely, when an ingenious invention was made by Mr. Birkin- shaw, who obtained a patent in October, 1820, for his improve- ments, which consisted in passing bars of iron, red-hot, between rollers having indentations in their peri- pheries, corresponding with the in- tended shape of the rails. By this mode malleable - iron rails were rolled in lengths of 12 or 15 feet each, and could be formed in any required shape, the section varying RAI RAILWAYS. RAI throughout the length, so as to give increased depth and width at the points intermediate between the intended bearing places. The rails now generally used are pro- duced in a similar manner, and the permanent way consists of a levelled surface of roadway formed with metalling or suitable ballasting, transverse sleepers, commonly of larch, about 9 feet in length, 8 to 10 inches in width, and about 6 inches deep. These sleepers are laid from 2 feet 6 inches to 3 feet apart, and saddles or chairs of cast iron are fastened upon them with spikes. Two of these chairs are fixed upon each sleeper, at such distance apart that the rails, when placed in them, shall have the in- tended distance or gauge between them, commonly 4 feet 8 inches. The rails are parallel throughout, and of a form resembling that of the letter K laid on one side, the depth of the rail being about 5 inches, the width over the top and bottom tibout 2| inches, and the thickness of the middle vertical rib about inch ; all the angles of the section being carefully removed by rounding the meetings of the seve- ral surfaces. For the ' broad-gauge,' in which the rails are laid 7 feet apart, continuous longitudinal tim- bers, about 12 inches square, are employed, and connected by cross- timbers framed to them. The rails are of a bridged or arched section, and rolled with a projecting plate along each side, bolts passing through which secure the rails to the longitudinal timbers. The theory of a perfect railway requires that it should be level in its vertical position and uniform in direction. Practically, these con- ditions are sacrificed within certain limits ; but the attainment of great speed and safety, upon the present locomotive system, forbids any very wide extension of them. The con- sequence is, that great and expen- sive works are required in earth- 368 works, bridges, viaducts, &c., to obtain the required inclination of surface and direction. The cost per mile at which the principal j British railways have been con- j structed may be thus stated : Arbroath and Forfar . . 9,213 Chester and Birkenhead . 34,198 Dublin and Drogheda . . 15,652 Dublin and Kingstown . 59,122 ' Dundee and Arbroath . . 8,570 Durham and Sunderland . 14,281 Eastern Counties & North- "1 ern and Eastern J Edinburgh and Glasgow . 35,024 Glasgow, Paisley, and Ayr 20,607 Glasgow, Paisley, &Greenock 35,015 Grand Junction .... 22,293 Great North of England . 26,855 Great Western . . . . 56,372 Hull and Selby .... 22,290 Liverpool and Manchester 50,923 London and Birmingham . 52,882 London and Blackwall . .288,177 London and Brighton . . 56,981 London and Croydon . . 80,400 London and Greenwich . 266,322 London and Southwestern 27,874 Manchester and Birmingham 67,000 Manchester and Bolton . 61,624 Manchester and Leeds . . 47,824 Midland and Bristol and"! or , you find that the quantity a r will have for its definitive value r=4146. III. If we have the formula av 6-6075 + -002415 10000 it will amount to the following arithmetical explanation : To the number 1 add the num- ber 8, and multiply the sum by the number r. IGO" To this product add the number /, and multiply the resulting sum by the number -002415. To the latter product add the number 6-6075, and keep apart this partial result, which expresses, in one number, what proceeds from all the operations comprised in the great parenthesis. Then multiply the number a by the number v, and divide the pro- duct by the number 10000, which will give you another partial result, expressing the portion of the for- mula situated beyond the paren- thesis. Finally, multiply the former par- tial result by the latter, and the definitive product will be the re- quired value of S. For the values above attributed to the different letters contained in the formula, the result of the cal- culation will give S = -67. IV. If we have the formula S 10000 v' = - a 1-492 + -002415 P it will be paraphrased as follows : Multiply the number -002415 by the number P, and add to the pro- duct the number 1-492 ; divide the number 10000 by the sum thus obtained, and write the quotient apart. Then divide the number S by the number a, which will give a second quotient. Finally, multiply the former quo- tient by the latter, and the result- ing product will be the required value of v'. With the values already indi- cated for the letters, and, more- over, for P = 9380, the result of the preceding formula will give /=176. V. In fine, as a last example, we will suppose the formula ar' = (P-/-2118). It plainly will signify as follows : From the number P deduct first THE TIDE. TID the number/, and again from the remainder deduct the number 2118. Then to the number 1 add the number 8, and divide the number a by the sum thus obtained. Finally, multiply this quotient by the difference before obtained, and the definitive product thus formed will be the required value of a r'. The operations thus indicated would, for the case wherein the letters should have the values al- ready given above, produce for the required value of a r' the quantity 9777. Thus we see how easy it is to replace all the formulae by their expressions in words ; and, conse- quently, the sight of algebraic for- mulae ought in nowise to intimi- date persons unfamiliar with al- gebra. Theotheca, Monstrance, or Remon- strance, sacrament-house in the Ro- man Catholic Church (thepix), the receptacle of the consecrated host, made generally of the most costly materials, and, in some cases, of expensive and beautiful design. Two magnificent examples are given in the 'Divers Works of Early Masters.' The sacrament- house in the church of St. Law- rence at Nuremburg, date 1510, is 64 feet in height ; and another, in the church of St. George at Lim- bourg, is upwards of 30 feet high. Thermometer, an instrument used for measuring the degrees of heat. (See Temperature of different Thermo- meters.) Thesaurus (Greek), a treasure-house. That buildings of this description were required, especially by kings and states, in the earliest period of civilization, is self-evident; and tradition points to subterranean buildings in Greece, of unknown antiquity and of peculiar formation, as having been erected during the heroic period, for the purpose of preserving precious metals, arms, and other property. 461 Thole, a term used in building : the scutcheon or knot in the midst of a timber vault ; also a place in temples where donaries (gifts) were hung up Tholobate, a cupola, and a base : that part of a building on which a cupola is placed Tholus, an appellation given to ail buildings of a circular form. Vi- truvius uses it to signify the roof of a circular building. Thowl, a piece of timber by which oars are kept in their places in rowing Throat, in ship-building, the hollow part of knee-timbers. Throttle-valve, a valve in the steam- pipe of an engine, for regulating the supply of steam to the cylinder. In land engines it is generally con- nected to a governor. Thurible, a censer used in some of the services of the Roman Catholic Church, made usually of metal in the form of a vase Thurl, a long adit in a coal-pit Thymele, in antiquity, a sort of altar, surrounded with steps, placed in front of the Greek stage or orchestra Thyrorea, the doors of a Greek tem- ple or house Thyroreum, a passage in the houses of the Greeks, at one end of which was the entrance from abroad, and at the other the doorway leading to the peristyle Tiara, an ornament for the head, an- ciently used by the Persians Ticketings, the weekly sales of ores. The adventurers or their agents meet together at noon, and whilst sitting round a table, each buyer gives in his ticket, offering a cer- tain sum per ton for so many tons of ore. The tickets are then read aloud by the chairman, and the persons present note the prices offered, the lots or different samples being sold to the highest bidder. Tide, the natural fluctuation of the w r ater of the sea and some rivers, whereby it increases and diminishes its quantity at particular times and places, the first being called the TID TIDE-GAUGE. TID tide of flood, the last the tide of ebb : when the tide or flow of water runs against the wind, it is called a windward tide, in which case the sea breaks most, and runs highest Tide-gauge. The merit of this in- vention is due to Mr. Meik, the engineer of Sunderland Harbour, whose attention had been for some time directed to the necessity of having conspicuous tide - gauges erected at all harbours and docks. Intrusted with the management of a tidal harbour with an intricate and narrow channel, and where frequently from 150 to 200 sail of vessels entered or quitted during a single tide, he perceived that the number of vessels that could safely depart on their outward voyage depended not only on the extent of each tide, but also on the know- ledge of those in charge as to the rate of its flow, by which alone they would be enabled to form a correct judgment as to the suffi- ciency of water to enable the ves- sels to proceed to sea. It was evidently essential that any tide-gauge for this purpose should be rendered intelligible to seamen of all grades, and so situ- ated as to be seen from all vessels in time to allow the course of those outward bound to be checked, should there not be sufficient depth of water to enable them to pass over the bar ; or should the vessel be inward bound, and the depth indi- cated by the gauge proved insuf- ficient, she might be brought up, or put off again to sea ; also if the vessel was at anchor in the road- stead, the captain on board should be able to know, from prominent characters,the earliesttime at which he could take the harbour. The first port provided with a regular set of signals for this pur- pose was that of Leith. The signals used there are very com- plete, and, with the assistance of a careful man to work the system according to the rise of the tide, 462 are of essential benefit to the ship- ping. But few seamen pay suf- ficient attention to matters of this kind to carry in their memory the exact depth of water corresponding to the signals shown; and before the book is consulted, the vessel may be driven on the shore, or stranded on the bar. The signals at Leith, although perfect of their kind, are used only during the day ; while it is evident that night is the time when they are most required by sea- men, to inform them of the state of the tide. By day they generally have some imperfect mode of ar- riving at the depth of water, by observing when the tide reaches certain points on shore, or covers some known rocks at sea; but at night they cannot guess at the tidal flow even by such inaccurate means, and consequently the gauge- marks or figures should have the property of being clearly distin- guished at night as well as by day, otherwise little advantage will be gained, nor will the loss of life be materially lessened. From these considerations, and for the purpose of exhibiting the advantages to be derived from their adoption at the different ports, a self-acting tidal gauge, combining the above - mentioned properties, as far as relates to out- ward-bound ships, has been erected at Sunderland Harbour, by Mr. Meik, in conjunction with Mr. Wat- ; son. of Newcastle. The construction of the gauge is as follows : A well, carefully boxed l in, and of similar depth to the water \ on the bar, is sunk below the j building which contains the appa- ratus. Within this well, in an in- terior pipe or trunk, and rising and falling with the tide, works a float suspended by a copper wire cord, which is carried over a spiral cone j fixed in an upper story of the build- ing. By the simple arrangement of a wheel and pinion at the oppo- i TID TIE-BEAM. TIE site end of the axle to which the cone is fixed, a web of wire gauze works on two rollers fixed at the upper and lower ends of the web. The lower roller is regulated by the movement of this wheel and pinion ; the upper one by a balance-weight attached to a copper wire cord, which also passes over another spiral cone, having at the extremity of its axle a second wheel and pinion similar to the first. As the float rises and falls with the tide, the wheels and pinions connected with the cones, over which the cords of the float and balance- weight respectively pass, move the rollers on which the gauze web travels. On this web are painted in large figures the various depths from high to low water, and as the web works, two fixed pointers in- dicate the number of feet and half- feet on the bar at any hour of the tide. The web and the figures on it can be made of any size, and to travel 4, 6, 8, 10, or any other pro- portion to 1 of the float, by regu- lating the size of the wheels and pinions. By day the figures on the web are shown white on a black ground ; by night they appear dis- tinctly lighted up, the ground still remaining dark. A white trans- parent varnish is used for the figures, and an opaque black for the ground. The illumination by night is so steady and powerful, that the figures, if made large enough, and the apparatus fixed at a sufficient elevation, are visible at a con- siderable distance at sea, and thus afford vessels the means of knowing the exact depth of water at the mouth of any harbour before enter- ing it. This simple piece of me- dhanism is applicable to all places where the want of a correct and conspicuous gauge has been felt, not only in harbours and docks, but at railway stations, for signals and such like purposes. The ap- paratus used occupies so little space, 463 that it can all be contained and worked in a column or pillar, with- out any other building. In the same building is erected, for the Commissioners of the River Weir, a self-registering tide-gauge, to which it is also intended to fix a barometer. The working of this self-registering gauge, which has for some time been in use at a few other ports, is as follows : A pencil is fixed in a rack, which registers the variations of the tide, the time of each change being also marked ; and immediately under which is a cylinder. On this is fastened a sheet of paper, properly ruled for the purpose, and of suf- ficient size to receive the variations of the tide, traced by the pencil, for fourteen days. The rack con- taining the pencil is connected with a wheel, over which a copper wire cord passes, having attached to it a float, which works in a well of similar construction to that already described as used for the new tide- gauge. This float and cord move, by the action of the tide, the rack and the pencil in it, and trace the diagram on the paper below. A dial on one side of the rack is worked by the same machinery, and points out as a clock the hours and minutes of the day, and the number of feet from high to low water. A time-piece, furnished with a strong minute-hand, gives the re- volving movement to the cylinder on which the paper is rolled, and serves to mark the time of the variations of the tide. The float and wheel, in fact, are the means of showing the depths of water ; the time-piece, the exact hour and mi- nute of each change of tide. Tie-beam, a beam which acts as a string or tie, to hold together two things which have a tendency to spread apart Tie-rod, a wrought-iron bar or rod for bracing together the frames of steam engines, roofs, &c. TIE TIN. TIN Tierce, a vessel containing forty- two gallons, or the third part of a pipe : in the Romish Liturgy it is one of the canonical hours for prayers, viz. eight in the winter, and ten in the summer, at night: at cards it is a sequence, or three following cards of one sort : in heraldry it is the division of a shield into three equal parts Ties, in navigation, the ropes by which the yards hang; in mechanics, tension-rods Tigna, the principal timbers of a roof extending across ancient temples, in contradistinction to the trabes, which were timbers placed upon the columns or walls in the same direction with them. The tigna correspond to our tie-beams. Tiles, baked clay in thin plates of different shapes, used to cover roofs. Tiles curiously and richly orna- mented were formerly used in the early Christian churches for pave- ments. Titter, a piece of timber fitted into the head of a rudder, to which it forms a handle Tilt-hammer. The most simple ma- chine by which iron is forged is the German forge-hammer, often called the tilt-hammer. This ma- chine, often of a fanciful form, is very extensively employed. The leading principle sought in its con- struction is solidity; and various forms have been invented to give permanency to the structure, which is mainly endangered by the action and re-action of the strokes. The cast - iron tilt - hammer varies in weight, according to the purposes for which it is designed, from 50 to 400 pounds. For drawing small iron and nail rods, a hammer of the former size is sufficiently heavy; but for forging blooms of from 60 to> 100 pounds in weight, a ham- mer weighing 300 or 400 pounds is employed. Such a hammer should be cast from the strongest gray iron, and secured by wooden wedges to the helve. 464 Timber-man, in mining, the man em- ployed in placing supports of tim- ber in the mine Timbers, in ship-building, the ribs which branch outwards from the keel in a vertical direction Timbers in the head, in ship-building, pieces with one end bearing on the upper cheeks, and the other ex- tended to the main rail of the head Timbers of ermine, a term in armoury or blazon; the rows or ranks of ermine in noblemen's capes Tin. This very useful metal is found in small round lumps, in the beds of some rivers near the mines, the principal of which are in Cornwall, but it is generally in nature as an oxide, though occasionally as a sulphate, and associated with many other metals. Tin is a silvery white metal, with a very slight shade of yellow: the purest is the grain-tin, which is prepared from what is found in the river beds, and known as stream-tin, and is judged by its splitting when a mass is heated till it is brittle and allowed to fall from a height. It is very malleable and soft : it dissolves in hydrochloric acid, evolving hydrogen gas : nitric acid converts it into a hydrated binoxide. Tin, oxide of. When tin is digested in strong nitric acid, a whitish powder is deposited, which, after being washed, and subsequently fused and pulverized, is known in the arts under the term putty- powder, and is used for polishing glass, stones, &c. Tin white resembles zinc white in many respects, but dries badly, and has even less body and colour in oil, though superior to it in water. It is the basis of the best white in enamel painting. There are various other metallic whites of great body and beauty, such as are those of bismuth, antimony, quicksilver, and arsenic ; but none of them are of any value or reputation in painting, on account of their great dispo- Till TOOLS. TOO sition to change of colour, both by light and toul air, in water and oil. Tincture, a staining or dyeing; also a term in heraldry, signifying a variable hue of arms Tinsel, a kind of cloth composed of silk and silver, glistening like stars or sparks of fire Tire, in mechanics, the strong iron hoop that binds the circumference of a wheel Tires, of locomotive engines, the out- side hoops round the wheels, gene- rally with a flange to keep and guide them on the rails. Stephen- son's patent engine and eight- wheeled engines are usually made without flanges on the tires of the driving wheels. Some tires are steeled on the part subjected to most wear, which renders them more durable. Titanate of iron (Titaniferous iron, Iron sand,) is an oxide of iron and titanic acid, and belongs to the class of the magnetic oxides. It is at- tracted by the magnet, is of a deep black colour, metallic lustre, very hard, and perfectly opaque ; melts into a black slag by a high tem- perature. It is generally found j near volcanoes or volcanic rocks, ' but seldom in quantities sufficient to justify the erection of iron-works; nevertheless the quality is mostly good, and the volcanic regions around the lakes of America may present, in the course of time, encouraging prospects. Titanium. This metal is found oc- casionally in the slag of smelting- furnaces, in small cubical crystals of a copper colour: it exists in anatase, and several varieties of titanate of iron, but combined with oxygen. Ton, a weight which varies in dif- ferent districts : the common ton is 20 cwts.of 112fts., or 2240 Ibs.; in Cornwall the miner's ton is 21 cwts. of 112tbs., or 2352 fts. Tontine, a term derived from the name of the inventor, Lorenzo Tonti, a na- tive of Naples, who originated the 465 scheme so called, first adopted in 1653, in France. The subscribers were divided into ten classes, ac- cording to their ages, or were al- lowed to appoint nominees, who were so divided; and a proportion- ate annuity being assigned to each class, those who lived the longest had the benefit of their survivor- ship, by the whole annuity being divided amongst the diminished number. Some remarkable cases have occurred in England : a ton- tine of a recent date consisted of a less number than ten members, all of whom, with the exception of one, died within a very few years from the commencement, leaving this survivor in the receipt of an enormous sum of money annually, derivable from the pro- fits of the undertaking, which are unvarying Tools, instruments employed in the manual arts for facilitating mecha- nical operations, namely, hammers, punches, chisels, axes, adzes, planes, saws, drills, files, &c., by means of percussion, penetration, separation, and abrasion of the substances ope- rated upon ; for all of which ope- rations various motions are required to be given either to the tool or to the work. In handicraft work the tool receives motion, but in self- acting or automatic tools, motion may be given to either. In the case of the turning lathe, the tool remains fixed, and the object moves. In that of the planing machine, the tool may remain fixed, or be made to move according to the duty re- quired to be performed. In almost all other machines, such as the slotting, the key -grooving, the punching, the drilling, the nut- cutting, the teeth of wheels cutting, the boring, the screw-cutting ma- chines, the tools receive motion. In the screw, bolt, and nut machines the tool is either moveable or fixed. The use of handicraft tools is coeval with the earliest periods of anti- quity, and the recent researches of TOO TOOLS. TOO modern travellers have proved the ancients to have been acquainted with almost all the tools now in use. ' The potter's wheel, the axe, the chisel, the saw, c., attest the perfection to which the mechanical arts were carried by the Greeks and Romans ; and subsequently in the arts of turning exhibited by the Dondi family, in the construction of their clocks and of machines for spinning silk, in the middle of the 13th century, in Italy, and after- wards by Bessoni, De la Hire, De la Condamine, Grand Jean,Plumier, and Morin. The three plates of Bessoni show the different modes of turning and cutting screws of all sorts of fancy-work. De la Hire shows how all sorts of polygons may be made by the lathe, and Condamine shows how a lathe may be made to turn all sorts of irre- gular figures by means of tracers moved over the surface of models and sculptures, medals, &c.; and this is perhaps the first idea of the machine called the Tour a Por- trait. The work of Plumier enters most extensively into the art of turning, for he shows the construction of the lathe and its different parts, the art of making, hardening, tem- pering, and sharpening tools, the different kinds of motions which may be given to the lathe by means of Avhecls, eccentrics, and models, and the different inventions relative to works of art which have been performed by the lathe, among which may be mentioned the move- able or slide rest. In the common rest which supports the tool, the idea of iixing the tool and pushing it in the direction of the parallel bed of the lathe, so as to cause the tool to traverse the work parallel to it, must have been obvious; and as this could have been easily ef- fected by means of the screw and handle, it required little ingenuity to carry out the idea to its fullest extent, by constructing a rest to allow of the slide traversing the horizontal or vertical plane in any direction. The machine described by Plumier is neither more nor less than the slide-rest and planing machine combined: it consists of two parallel bars of wood or iron connected together at both extre- mities by bolts or keys of sufficient width to admit of the article re- quired to be planed : a moveable frame being placed between the two bars, and motion being given to it by a long cylindrical thread, is capable of giving motion to any tool which may be put into the sliding frame, and consequently either causing the screw, by means of a handle at each end of it, to push or draw the point or cutting edge of the tool either way. If also motion be given to the tool by means of guides upwards or down- wards, it is evident that any kind of reticulated form can be given to the work, as in the machine de- scribed by Plumier, which was in- tended for ornamenting the handles of knives, and which is called by Plumier, Machine a Manche de Couteau d' Angleterre, from its having been an English invention. The Machine a Canneler, described by Bergeron, a mode of grooving columns, is probably derived from the same source, from its resem- blance to the English machine. The origin of the planing machine, in more recent times, is said to have arisen from the grooving or ! fluting of the drawing rollers used in cotton machines, shortly after the introduction of Arkwright's in- ventions. The patent of Sir Samuel Bentham in 1793, for various new methods for working wood, metal, and other materials, certainly con- templates the working of tools similarly to the tools employed in the planing machine, as it comprehends giving all sorts of motion to tools : and the patent of Joseph Bramah, taken out in 1802, was " for machinery for producing | 466 TOO TORSION. TOR straight, parallel, and smooth sur- faces and other materials requiring truth, in a manner more expe- ditious and perfect than can be performed by the use of axes, screws, planes, and other cutting instruments used by hand in the usual way." Billingsby, of Birkenshaw, took out a patent in 1802, for boring cylinders in a vertical position, al- though horizontal machines had their advantages. The boring of large cylinders by horizontal ma- chines had long been practised by Smeaton,Wilkinson,Walker,Darby, and Boulton and Watt, and at But- terley and other great iron- works ; but it was many years subsequently that the vertical boring machines came into use. As respects the introduction of the first planing machines which have been used during the present century, opinions are at variance. Messrs. Fox, of Derby, the eminent tool - makers, state that the first machine employed for this pur- pose was constructed by Mr. Fox, senior, in the year 1821, for the purpose of planing the wrought and cast iron bars used in the lace machines : the machine was capable of planing an article 1 feet G inches in length, 22 inches in width, and 12 inches in depth: others give the credit of tbe invention to Man- chester, and G. Rennie, Esq., puts in a claim for constructing a planing machine with a moveable bed, urged by an endless screw and rack, and furnished with a revolving tool, so early as 1820, having several years previously employed the prin- ciple for grooving and planing pa- rallel bars. Mr. Bramah, in 1811, employed the revolving cutter to plate iron. Mr. Clement states that he made a planing machine, for planing the sides of weaving looms and the triangular bars of lathes, previously to 1820. He afterwards constructed a beautiful machine for planing 467 large and small work with the greatest accuracy. The bed moved on rollers, and the tools cut both ways. The beautiful wdrk exe- cuted by this tool, for Mr. Babbage's calculating machine, evinces the perfection of its performance. It is thus by the aid of automatic tools that the greatest precision and identity of parts in machinery is produced ; and it is probable that, ere long, the chisel, the file, and the grindstone will be banished from the factory, and that nicety of parts and uniformity and silence of action, blended with the science of con- struction, will eventually supersede the expensive and imperfect con- struction of the handicraft system. Toon ivood is of a reddish brown colour, rather coarse-grained, much used all over India for furniture and cabinet-work Top and But, in ship-building, the general method of working the English plank (except in the top- side) to make good work and con- version, which is by disposing of the top end of every plank within 6 feet of the but-end of the plank above or below it, leaving all the planks to work as broad as possible, so that every other seam is fair Top-timbers, in ship-building, the up- permost timbers : the first general tier of timbers that reaches the top of the side are, or should be, called top-timbers ; those which scarf on the heads of the upper futtock are called short timbers Torricellian tube, in pneumatics, a glass tube named after the inventor, open at one end and hermetically sealed at the other Torricellian vacuum. This is pro- duced by filling a tube with mer- cury, and allowing it to descend to such a height as to be counter- balanced by the pressure of the atmosphere, as in the barometer. Torsion is that force with which a thread or wire returns to a state of rest after it has been twisted by- being turned round on its axis TOR TRACERY. TRA Torsion - electrometer, an apparatus for measuring the intensity of elec- tricity Torus, the convex member of the Tuscan and Ionic bases. In the attic base there is both an upper and lower torus. Tossing, Tozing, or Terloobing, a pro- cess consisting in suspending ores by violent agitation in water: their subsidence being accelerated by packing, the lighter and worth- less matter remains uppermost Tower, an ancient elongated vertical building, variously formed and con- structed in different countries 7W'n//0//,MansionIIouse; in France, Hotel de Ville; in Italy, Palazzo Publico ; in Holland, Stadhaus ; an edifice in which all the municipal laws and regulations and the inte- rests of a city are conducted Tracery, that species of pattern- work formed or traced in the head of a Gothic window by the mul- lions being continued, but diverg- ing into arches, curves, and flowing lines enriched with foliations. " Each country (says Mr.Garbett in his ' Rudimentary Treatise on the Principles of Design in Archi- tecture') has had its successive styles of tracery, and each has begun with the simple subdivision of one arch into two, and these sometimes into two again, filling up the space between the heads with a circle, as at Marburg; a foiled circle, as at Salisbury chap- ter-house, and the aisles of Co- logne ; or finally a foil-circle, as at Westminster, and the clerestory of Cologne, where it is subfoiled: thence proceeding to pack together such forms over an odd number of lights, to which the method of continual bisection would not apply, as at the aisles of York ; and thus the first kind, which may be called packed tracery, became complete. Deviations from the principle of packing led to the general tracery, absurdly called 'geometrical;' for all Gothic tracery is geometrical, none is hand-drawn. This beau- ! tiful purely unmeaning tracery was succeeded in all countries by the flowing loop or leaf, and then by the peculiar national After-Gothic. Germany, however, as it had been the first to perfect, was also the last to abandon the ' geometrical ' tracery, which continued there, even into the fifteenth century, our Per- pendicular Period. England and France, however, in the fourteenth century, abandoned the unmeaning for the flowing leaf - tracery ; and this, notwithstanding its beauty, had hardly time to show itself before it was superseded, here by the perpendicular, and in France by the flamboyant. Hence it hap- pens that of the three great classes of tracery, geometrical, flowing, and perpendicular, while the last is, as every one knows, by far the ! commonest in England, the most i abundant kind in France is flowing j (flamboyant), and in Germany geo- j metrical, i. e. unmeaning. " The unmeaning tracery of Ger- many is very beautiful, and gene- rally partakes of the packed cha- racter; the following forms, which are the elements of German tra- cery, occurring very abundantly. Elements of German tracery. TRA TRACERY. TRA " The convex-sided triangle and square are placed in all posi- tions indifferently, and the frame- less trefoils and quatrefoils are frequently formed on the basis of these figures instead of the cir- cle. The foilings and subfoilings, formed by a very narrow but deep chamfered member, leave their little spandrils (called eyes by our workmen) entirely open, thus pro- ducing almost the lightness of metal-work. " The Germans seized on the idea at growth, and the budding and sprouting expression ; but perhaps the French were most successful in increasing the aspiring expression : by a slight change in the prevail- ing forms of the flowing tracery, they converted the loops or leaves into flame-like forms, till the flamboyant buildings appeared not vegetating, as in Germany, but blazing from the foundation to the bristling finials. The difference be- tween this style of tracery and our own flowing style (exemplified in the west window at York), is, that English leaf-tracery. while the upper ends of our loops or leaves are round or simply pointed, i. e. with finite angles, the upper ends in France terminate, like the lower, in angles of contact (those formed by two curves that have a common tangent). It was necessary to the leafy effect that the lower angles should be tan- gential; but to the flame-like ef- 469 feet, that the upper ones should be so, even if the lower were French flamboyant tracery. finite; and hence some examples of flamboyant tracery, turned up- side down, form a kind of leaf- tracery. '* Our countrymen, however, adopted a method which was less conducive to the aspiring expres- sion, and which conducted them to a style less rich and certainly less varied thin any of the other After- Gothics. Erroneously supposing that an abundance of vertical lines would increase this character, they were led to convert all the flowing lines of the window tracery into vertical ones, to omit the capitals of nearly all the smaller shafts or shaftlets, thus converting what had been blank arcades into mere panels, and then to multiply, di- minish, and extend these panels and endless repetition of vertical lines over every part of the inte- rior, and, in florid buildings, even of the exterior." TRA TRACTION. TRA Traction, in mechanics, is the act of drawing a body along a plane, usually by the power of men, ani- mals, or steam; as when a vessel is towed on the surface of water, or a carriage moved upon a road. The power exerted in order to pro- duce this effect is called the force of traction. Numerous experiments have been made for the purpose of ascertain- ing the value of a force so exerted ; and when men are employed to draw laden boats on canals, it is found that if the work be continued for several days successively, of eight hours each, the force of trac- tion is equivalent to a weight of 31 tbs. moved at the rate of 2 feet per second, or 1-i mile per hour, (it being understood that such weight is imagined to be raised vertically by means of a rope passing over a pulley, and drawn in a horizontal direction.) The force of traction exerted when, without moving from his place, a man pulls horizontally against a weight so suspended, is estimated at 70 fts. The action of a horse in drawing a vessel on a canal is said to be equivalent to a weight of 180 fts. raised vertically, as above supposed, with a velocity of 3 feet per second, or 2 miles per hour; but this estimate has been considered too high; and from experiments which have been made on the power of horses in waggons, carts, and coaches, on level ground, it is found that the force of traction exerted by a stout horse is equiva- lent to 80 ibs. raised at the rate of 4 feet per second, or 3 miles per hour. Tredgold considers that a horse exerts a force of traction expressed by 125 fts. raised at the rate of 3 feet per second, or 2 miles per hour. A man or a horse can, however, double his power of traction for a few minutes without being injured by the exertion ; and when the carriage is in motion, so that the friction on the ground is alone to be overcome, a horse can 470 draw, during a short time, on a level road, a w r eight exceeding 1500 fts. The force of traction is found to vary nearly with the term (w v)~ 2 , where w is the greatest walking velocity of a man or horse when unresisted (6 feet per second, or 4 miles per hour, for a man, and 10 feet per second, or 6^ miles per hour, for a horse), and v is the velocity with which the vessel or carriage is moved. From theoreti- cal considerations it has been de- termined that the greatest effect is produced when the velocity of the object moved is one-third of that with which the man or animal can walk when unresisted. If a wheel-carriage were situated on a level plane which opposed no resistance, it is evident that, what- ever were the diameter of the wheels, the smallest conceivable power of traction applied to the axle would suffice to put the car- riage in motion. But when a wheel in moving meets with an obstacle on the ground, that obstacle is pressed at the point of contact by a force acting in the direction of a line drawn to it from the centre of the wheel, and arising from that part of the weight which is sup- ported by the wheel, together with the force of traction ; therefore, by the ' resolution of forces,' the ratio between the resistance which is to be overcome by the moving power and the weight on the wheel will become less as the diameter of the wheel is increased : also the most advantageous direction in which the force of traction can be exerted is perpendicular to the line of press- ure drawn from the centre of the wheel to the obstacle. But the height of the wheels cannot exceed certain limits, depending on the use to which the carriage is applied ; and when the latter has four wheels, the height of those which are in front must be such only as will allow it to be turned round within TRA TRANSEPT. TRA a given space : also, when a horse is employed to move a carriage, attention must be paid to the con- ditions under which his power may he advantageously exerted. It was first observed by M. De- parcieux, and published in the ' Memoires de 1' Academic des Sci- ences,' 1 760, that horses draw heavy loads rather by their weight than by their muscular force. Sir David Brewster has also remarked, that when the resistance is great, a horse lifts both its fore-feet from the ground ; then, using his hinder- feet as a fulcrum, he allows his body to descend by its weight, and thus overcomes the obstacle : and it may be added, that when this action takes place with a two- wheeled carriage, if the loading is disposed so that some portion of it may press on the horse's back, the effect of the animal's weight will thereby be increased. Now, if the traces, or the shafts of the carriage, were attached to the horse's collar, near his centre of gravity, a line imagined to be drawn from the latter point to his hinder-feet may represent his weight, and a line drawn perpendicularly from his feet upon a plane passing through the traces or shafts may represent the lever of resistance : but while the former line remains the same, this lever becomes less as the plane of traction (that of the traces or shafts) inclines more upwards from the wheel ; and therefore, in order that the power of the horse may be advantageously applied, the dia- meter of the wheel should be as small as is consistent with other circumstances. Experiments have shown that when the angle of traction, as it is called, that is, the angle which the plane of the traces makes with the road on which the carriage is mov- ing, is 15 or 16 degrees, a horse pulls with good effect; and the height of the points at which the traces are attached to a horse's 471 collar being about 4 feet 6 inches from the ground, it follows that, in order to obtain this inclination, the lower extremities of the traces or shafts should be 2 feet 3 inches from the ground. In general, how- ever, in two-wheeled carriages the height of these extremities is about 3 feet. As an example of the force of traction exerted by steam, it may be stated, that on a level line of railway, an engine with an 11 -inch cylinder, and having an effective pressure of 50 ft>s. per square inch in the boiler, drew 50 tons at the rate of 30 miles per hour, working 10 hours daily ; and that the same engine, with an equal pressure in the boiler, drew 160 tons at the rate of 15^ miles per hour. Trail, a running enrichment of leaves, flowers, tendrils, &c., in the hollow mouldings of Gothic architecture Trail- boards, in ship -building, the carved work between the cheeks ; that which is fastened to the knee of the head Trailing springs, the springs fixed on the axle-boxes of the trailing wheels of a locomotive engine, which bear slightly against the side frames, so as to leave as much weight as pos- sible upon the driving springs, and to assist in deadening any shock which may take place Trailing wheels, the wheels placed behind the driving wheels of a locomotive engine Trammel, a rod of iron or wood, with sliding pieces having points, which can be fixed at any distance apart ; used for drawing large cir- cles, or setting off distances Transept, the transverse portion of a cruciform church; that part which is placed between and extends be- yond those divisions of the building containing the nave and the choir Transit, a term expressing the pas- sage of a railway train, &c. In astronomy, the passage of any hea- venly body over a larger one, as Mercury or Venus over the sun. TRA TRENCH. TRE Transition, as applied to the architec- ture of the middle and later ages, the progress of changing from one style to another. There were several periods of transition : Romanesque to Saxon, Norman to Early English, Early English to Decorated, from the Decorated to the Perpendicular to that of the Tudor and to that of the Elizabethan age. Transom, a horizontal mullion or cross-bar in a window. The most ancient examples are found in the Early English style. Transom, in carpentry, a thwart-beam or lintel over a door. In ship- building, certain timbers extending across the stern-post of a ship, to fortify and strengthen it. In mathematics, the vane of an in- strument called a cross-staff, being a piece of wood fixed across, with a square socket upon which this slides. Transparency, that quality of certain bodies by which they transmit the rays of light, in contradistinction to opacity Transposition, in music, the changing a tune or lesson, and putting it into a higher or lower key or clef Transtra, horizontal timbers in the roof of a building. The term is applied to the transverse beams of a gallery which extend from side to side and connect the ribs, in the same manner as these horizontal pieces connect the axis or princi- pals of a roof. Transverse, in geometry, something that goes across another, from cor- ner to corner, like the diagonals of a square or parallelogram Transyte, a narrow or triforial pas- sage Trapezium, in geometry, a plane figure contained under four right lines, of which neither of the oppo- site sides are parallel Trapezoid, an irregular figure whose four sides are not parallel, resem- bling a trapezium Traveller, in navigation, a sort of thimble, whose diameter is much 472 larger, in proportion to the breadth of its surface, than the common ones: it is intended to facilitate the hoisting and lowering the top- gallant yards at sea Travelling crane, a crab fixed on a carriage which may be moved upon rails across a building, and the cross-rails, together with the car- riage, moved lengthwise upon other rails fixed at or near the top of the building Traverse sailing, in navigation, is the variation or alteration of a ship's course occasioned by various causes; or it is a compound course in which several different courses and dis- tances are known Traverse-table, in navigation, is the same as a table of difference and departure, ready calculated for any distance under 100 miles Treadle, a lever or frame connected by a rod to the crank of a foot- lathe, to give motion to the crank- shaft : it is pressed down by the left foot of the turner, and raised by the centrifugal force of the fly- wheel or large pulley which is fixed on the shaft Treasury, a building or an apartment where money or valuables are de- posited Tree -nails, or TrenneU, in ship- building, long cylindrical wooden pins Trefoil, an ornament formed by mouldings so arranged as to re- semble the trefoil or three-leaved clover Trellis, a gate or screen of open work; lattice -work either of metal or wood Trench, a ditch ; a defence for soldiers. Trenches, approaches, or attacks, are works carried on by besiegers, with parapets for the men to gain ground and draw near a citadel or fortification : if the ground be hard or rocky, trenches are raised above it with fascines, bags of earth, &c. ; but if the earth can be easily dug, then a ditch or way is sunk, and edged with a parapet next to the TRE TRIGLYPIIS. TRI besieged, the depth being com- monly about six or seven feet, and the breadth seven or eight feet. Trend, in navigation, to bend, to lie in a particular direction Trestle-trees, in ship-building, two strong bars of timber fixed hori- zontally on the opposite sides of the lower mast-head, to support the frame of the top and the weight of the topmast Tret, an allowance in weight for waste or impurities Triangle, a figure bounded by three sides, and consequently containing three angles. Triangles are of the several kinds, plane or rectilinear, spherical, and curvilinear. Tribometer, in mechanics, a term applied to an instrument for esti- mating the friction of metals Tribunes, magistrates among the old Romans, chosen to preserve the privileges and secure the liberties of the people against the power and encroachments of the nobles: at first their number was but two, and these afterwards associated three more to them, whose number was in process of time increased to ten. Their authority was so great that they could assemble the people for what purposes they pleased, hinder the deliberations of the senate, ap- prove or annul its decrees, summon the other magistrates before the people, and also their own col- leagues and associates : they went so far as sometimes to imprison consuls and fine dictators. At first their jurisdiction reached but a mile out of the city of Rome, but some time afterwards it was ex- tended into the provinces. These officers kept then* doors open day and night, to receive such of the common people as sought for shel- ter with them. The office grew into so much authority and honour, that the greatest men in the state chose it, and by clashing with the consuls and senate occasioned great tumults. There were also military 473 tribunes, but their powers were more limited. Tribute, in mining, a proportion of the ore which the workman has for his labour. Tributers gene- rally work in gangs, and have a limited portion of a lode set them, called a ' tribute pitch,' beyond which they are not permitted to work, and for which they receive a certain portion of the ore, or so much in the pound as agreed upon in value of what they raise. Triclinium, the eating-room of a Ro- man house; so called because in general it contained couches upon which the ancients or their guests reclined at their meals. The term was also applied to the couches themselves. Triforium, the gallery or open space between the vaulting and the roof of the aisles of a church, generally lighted by windows in the external wall of the building and opening to the nave, choir, or transept over the main arches. In the Temple church it is built around the nave, and has a curious and singular effect. Triglyphs, in architecture, ornaments repeated at equal intervals in the Doric frieze. Each triglyph con- sists of two entire gutters or chan- nels cut to a right angle, called glyphs, and separated by their in- terstices, called. fermona, from each other as well as from two other half -channels that are formed at the sides. Trigonometry, the art of measuring triangles, or of calculating the sides of any triangle sought, either plain or spherical. (See Ordnance Sur- vey.) Trim, in navigation, the best posture of a ship's proportion of ballast, arrangement of sails, and position of masts, with a view to her sailing well Trimmer, a piece ef timber inserted in a roof, floor, wooden partition, &c., to support the ends of any of the joists, rafters, &c. TRI TUBES. TUB Tringle, in architecture, a name com- mon to several little square mem- bers or ornaments, as regulets, lestets, and platbands Tripod, any utensil or article of fur- niture supported upon three feet Triptic, a tablet in three divisions, to open and shut, the two outer folding over the centre one when closed Trisection, the division of a line, an angle, &c. into three equal parts Trochilus, a hollow moulding ; also called scotia; constantly occurring in the bases of the classical orders of architecture Trochoid, in geometry, a particular description of curve generated by the motion of a wheel Tropics, two lesser circles on the globe or sphere ; one on each side, distant 23^ from the equator, which are the bounds or limits of the sun's deviation from the equa- tor : at his approach to these cir- cles the sun seems to stand still for a few days, and then returns towards the equator again : that on the north side is called the tropic of Cancer, and, when the sun is there, makes our longest day; and that on the south side is called the tropic of Capricorn, and causes the longest night. Troubles, in mining, faults or inter- ruptions in the stratum Trucks, in navigation, circular flat pieces of elm, with a small sheave on each side, fixed upon the upper end of flag-staffs, and used to reeve the halliards Truncated, in geometry, a pyramid or cone, the top or vertex of which is cut off by a plane parallel to its base Trunk engine, a marine steam engine used for driving a propeller: the cylinder is fixed horizontally TrunJcing, the process of extracting ores from the slimes : the ores sub- sequently undirgo the process of racking and tossing Trunnions, knobs of metal in pieces of ordnance which project from 474 the sides and bear the guns on the cheeks of the carriage Truss, the collection of timbers form- ing one of the principal supports to a roof, framed together to give mu- tual support and to prevent strain- ing or distortion from the super- incumbent weight Truss, to strain, support or keep tight : a trussed roof is one which by means of the tie-beams, rafters, king-posts, &c., is strained, or held together in its proper position Trussing, in carpentry and ship-build- ing, a series of diagonal braces dis- posed in triangles, the sides of which give to each other a mutual support and counteraction Trussing-beds, in Tudor times, were beds which packed into chests for travelling : in cases of frequent re- moval, they must have been found very convenient. John of Ghent seems to have always slept in such beds. Tub, a cast-iron cylinder put in the shaft instead of bricking, for the purpose of beating out the water and making it rise to a level Tubes, in locomotive engines, are of brass or iron, about two inches outside diameter. They are of the same length as the boiler, and fixed in it by a ferrule driven in at each end, which makes them steam- tight. They are surrounded with water externally, and internally open to the atmosphere by the chimney. The heated gases and smoke from the fire pass through them, and they are thus the means of rapidly generating steam. The number of tubes in boilers varies from 60 to 70 up to above 200, according to the power of the engine. Tube ferrules, in locomotive engines, slightlytapered hoops, one of which is driven in at each end of each tube, to fix it securely in the boiler: formerly they were made of steel and iron ; now, cast-iron ferrules are found to answer very well Tube plugs, in locomotive engines, TUB TUBULAR BOILERS. TUB are formed of tapered iron or wood, and used for driving into the end of a tube when burst by the steam Tube plug-ram, in locomotive engines, a long rod with a socket end, into which the plug fits, and is thus driven into the burst tube, and the plug-ram withdrawn Tubular Boilers. Boilers of an an- gular, prismatic, or indeed any but a cylindrical form, or even then if not made of wrought metal, be- come the peculiar seat of danger in high-pressure engines; and all sorts of safety apparatus, as well for preventing too great a pressure as for avoiding other sources of danger, are but uncertain in their operation, and not to be depended upon. The great object to be sought is so to construct boilers that their explosion may not be dangerous in its result. This condition has been approxi- mated to by the invention and ap- plication of tubular boilers ; but it would seem that these have been suggested rather by the necessity of providing, for many technical purposes, and particularly for steam carriages, boilers of less content and weight, than by the desire of removing or lessening danger from explosion. Tubes should have that form which is best adapted to resist pressure, viz. the cy- lindrical. If they are of small dia- meter, of not too great thickness, and of suitable material, they may be made to carry out the before- named principle ; i. e. they them- selves, in case of bursting, will not cause any dangerous consequences to the neighbouring persons or pro- perty. This has been amply proved by experience. Unfortunately, however, there are no tubular boilers which satisfy all conditions required. The sub- ject is often mentioned as one of little difficulty, easy of decision, and unencumbered with practical obstacles ; but such is the language only of the prejudiced and the in- 475 experienced. To arrive at the truth, it must be sought with long-con- tinued perseverance, and with no small share of physical knowledge, as the subject is beset with diffi- culties on every side. It becomes a most complex pro- blem to construct a tubular boiler for a large supply of steam, by rea- son of the difficulty of arranging and connecting the great number of tubes it must contain into one convenient whole. The modern English locomotive boilers cannot be legitimately called tubular boil- ers, because they fail altogether in the grand distinguishing quality of all such, namely, the small dia- meter of the generating apparatus: the tubtes of these boilers are no- thing more than a splitting-up or subdivision of the fire-tube of the Trevithick steam-carriage boiler. From their great outer diameter, locomotive boilers do not avoid the evil of the old capacious form, and therefore do not diminish the objection to it: they have also a defect in the close proximity of the tubes to each other, whereby the water space between them is ren- dered too confined, and the heated tubes become liable to be laid bare of water. This circumstance gives the key to the well-known fact, that the tubes become so soon de- stroyed, or, at least, require con- stant repair, and add to the mischief occasioned by their expansion, through their connection with the end plates of the cylindrical part of the boiler. It is evident that from the passage upwards of the steam formed among the lower tubes, the upper ones must be most liable to be uncovered with water; while these, being exposed to the hottest part of the fire current, are most likely to receive damage there- from. A tubular boijer ought to pre- serve, as much as possible, the tu- bular form in all its parts ; or, at least, the larger portions ought to TUB TUBULAR BOILERS. TUB be cylindrical, and not of too great diameter, or should be so strongly made that the tubes should form the weakest part of the whole boiler. The tubes themselves should be of such diameter, and be con- structed of such metal, that in case of their actual bursting, no dan- gerous explosion may ensue. This, however, is only possible when their thickness is so small, and the metal of such a kind, that bursting takes place by a compara- tively small internal pressure, and is followed by only a ripping open of the tube, and not a scattering about of massive fragments. Under all circumstances, however, the tubes must be the sole generating vessels : they alone must receive the action of the fire, and be ex- posed to its destructive influence. All other and larger vessels, or parts connected with the tubes, should be most carefully protected from not only this but all other dangerous influences, in order that they may remain in their original proved condition of strength. Only such a tubular boiler as fulfils all these conditions can be called a safe one. In its use there is no further danger from high- pressure steam, and near it its owner may repose undisturbed by a care for the safety of life or pro- perty. The requisites in the use of the tubes are the following : They must be placed in such a position, with regard to the furnace, that the flame may act upon them in the most favourable manner, and that the heat may be absorbed as com- pletely as possible. They must have such a proportion between their length and diameter, that neither the ebullition in them may become too violent, and the water be thereby ejected from them, nor that they become warped or made crooked by the heat. They must properly convey away all the gene- rated steam, and be regularly sup- 476 plied with water. They must be connected with the main part of the boiler in such a manner, that in case of a rupture of one of them, the whole content of water and steam cannot suddenly and dan- gerously discharge itself. They must lie so deep under the general water-level of the boiler (in the receivers or separators), that some considerable sinking of the water may be allowed to take place with- out leaving any of them empty; and in case the latter effect should occur, such tubes must first be emptied as are least exposed to the heat of the furnace. Lastly, they must be connected with each other in such manner that no destructive expansion may be allowed to take place, and that all may be easily and conveniently cleansed of the earthy matters deposited in them. The larger portions of the boiler, or receivingvessels, may themselves consist of tubes of a larger diame- ter, or may form flat chambers, constructed of a strength to with- stand a very high pressure (say 400 to 500 ibs. per square inch) : this involves no difficulty. The diameter of the receivers should not, where it can be avoided, ex- ceed 16 inches, and they should be constructed of plate iron of at least f of an inch thick, securely and exactly riveted together into a cy- lindrical form. When it is neces- sary that they should be capacious, their length should be increased, and not their diameter beyond that specified, or their number should be greater. Their covering lids may be flat and of cast iron, but of considerable thickness (1 to 2 inches), and these must be con- nected to the cylinders securely, and in such a way that they may be easily taken off when cleaning is required. They must, under all circumstances, be entirely removed from all strong action of the fire, and must at most be exposed only to such currents as have discharged TUB TUBULAR BRIDGES. TUB the greatest portion of their heat against the generating tubes. In order to preserve them from rust, their internal and external surfaces may be covered with several coats of oil-varnish, and the coating re- newed, at least on the inside, every year. Since these receivers or larger parts of the boiler usually serve as separators, and as means of con- nection between the generating tubes, they must be perfectly adapted to fulfil these purposes. As separators, they must efficiently separate the steam from the water, so that none of the latter may pe- netrate into the working parts of the engine; and to this end the water surface in them must be of sufficient extent. In order that the water may not rise to a dangerous height in them by violent ebulli- tion in their tubes, their water space must bear a certain propor- tion to that of the tubes and the other parts of the boiler. The steam room in them must also be proportioned to the content of the engine cylinder ; so that the press- ure may not be too much lessened by the discharge into the engine, and a foaming of the water thereby be caused. Tubular Bridges are those in which the requisite strength and rigidity are obtained by disposing the mate- rials in the form of a horizontal tube, through which the passage is formed for the traffic. They are to be distinguished from trussed bridges, which, when constructed of timber and covered over, as in several of the American bridges, resemble a tube, or two or more parallel tubes, being formed en- tirely without trussing, and there- fore admitting of construction with iron only. Tubular bridges are to be regarded as an original and highly important invention, admi- rably adapted for spanning wide spaces, and affording all required strength with a positive minimum of depth. In all arched bridges some portion of the space below, or head room for navigation, is sa- crificed by the depending haunches; or, on the other hand, if the road- way is made to correspond with the chord of the arch, the crown is necessarily elevated to a consider- able height, and additional weight involved in sustaining and preserv- ing the position of the higher parts of the structure. Hence flatness, or the reduction of the total depth, has always been a desideratum in the designing of bridges, and scien- tific skill andboldness have achieved several examples in which this pro- perty is attained in a much greater degree than it was once thought safe and prudent to attempt. The wrought-iron tubular bridge, how- ever, is safely constructed with a total depth of -J^th of its span, and with sufficient strength and rigidity to sustain great loads, such as rail- way trains, without sensible vibra- tion or deflection. For bridges of small span, the tubular principle may be adopted in the construction of malleable-iron girders, each of which is itself a rectangular tube of small section, the roadway being thus supported upon two or more of these tubular'" girders arranged in parallel positions, and at some distance apart. In these bridges a level roadway is formed with a small depth, but the roadway and traffic occupy an additional depth ; whereas in the tubular bridge, as constructed for large spans, the depth of the tube itself comprises the entire depth of the structure, and it may therefore be considered as a vast hollow girder, through w r hich the roadway is formed. Mr. Robert Stephenson appears to have first suggested the idea of form- ing tubular bridges ; and that over the Conway, erected on the line of the Chester and Holyhead Railway, was completed and opened in 1849. This bridge consists of two tubes, placed parallel to each other over 477 x5 TUB TUBULAR BRIDGES. TUB a clear span of 400 feet. Each tube, with its castings, &c., weighs about 1300 tons, and is constructed of plate iron riveted upon malle- able-iron ribs, the section of the tube being a rectangle about 30 feet in height and 15 feet wide. The sides, top, and bottom of the tubes consist of long narrow plates of malleable iron, varying in length up to 12 feet, and in width from 1 foot 9 inches to 2 feet 4 inches : they vary in thickness from f to f inch. The internal ribs are of T-iron, 3| inches deep, and placed .at intervals of 2 feet. A depth of about 1 foot 9 inches across the tube is occupied at top and bottom with narrow cells formed with plate iron and L-iron corner pieces, all firmly riveted together. These cells are for the purpose of giving the requisite stiffness to these parts of the tube, and are closer together at the top than at the bottom of the tube, as the tendency of a load is to compress the upper part and distend the lower part of the struc- ture, and wrought iron is, it ap- pears, much better able to resist extension than compression. In his report to the Directors of the Chester and Holyhead Railway, their Engineer, Mr. Stephenson, thus referred to some of the re- sults of the experiments which were made in order to determine the form and proportions for his proposed tubular bridge over the Menai Straits. "The first series of experiments was made with plain circular tubes ; the second with elliptical ; and the third with rect- angular. In the whole of these this remarkable and unexpected fact was brought to light, viz. that in such tubes the power of wrought iron to resist compression was much less than its power to resist ten- sion, being exactly the reverse of that which holds with cast iron : for example, in cast-iron beams for sustaining weights, the proper form is to dispose of the greater portion 478 of the material at the bottom side of the beam ; whereas with wrought iron, these experiments demon- strate beyond any doubt that the greater portion of the material should be distributed on the upper side of the beam. We have arrived, therefore, at a fact having a most important bearing upon the con- struction of the tube; viz. that rigidity and strength are best ob- tained by throwing the greatest thickness of material into the upper side. Another instructive lesson which the experiments have dis- closed is, that the rectangular tube is by far the strongest, and that the circular and elliptical should be discarded altogether." Another tubular bridge, similar to that at Conway, is now (1850) in course of construction over the Me- nai Straits, near Bangor, intended to exceed the Conway bridge in ex- tent, consisting of two water bays of 460 feet span each, and two land bays, one at each end, of 230 feet span each. These grand bridges differ little less in the mode of constructing and erecting them than in their design from ordinary bridges of stone, timber, or iron. Thus the larger tubes over the water-way are put together adjacent to their final resting-place, and when com- plete as tubes, they are launched upon pontoons, floated to the piers, and raised to their places complete and entire by hydraulic presses operating at each end. For this purpose of raising, strong tempo- rary frames of cast iron are fitted to the ends of the tube, and made fast to solid bar-link chains, the upper ends of which are forced up- wards by successive lifts of the hydraulic press, each lift being 6 feet, and the ends of the tube being packed up as the raising proceeds. One end of each tube is perma nently laid upon cast-iron rollers, to admit of the changes of length produced by variations of tempera- TUD TUDOR STYLE. TUD ture. For the purposes of the rail- way, transverse plates of iron are fixed edgewise on the bottom of the tube, and support longitudinal balks of timber, upon which the rails are laid. The height of the Conway Bridge is 18 feet at the bottom of the tubes above high water; that over the Menai Straits, called the ' Britannia' Bridge, 102 feet above the same level. Tudor Badges. The badges of the house of Tudor were either assumed or derived from descent or alliance : the red rose was the peculiar dis- tinction of the house of Lancaster, and was borne by Henry VII. as Earl of Richmond. The portcullis was the badge of the Beaufort branch of the same family, assumed by the descendants of John of Ghent, born in the castle of Beau- fort; and agreeably to heraldic simplicity, a part of the castle, its most prominent feature, was depict- ed for the whole. The fleur-de-lis was also a badge of the house of Lancaster, and was introduced, to- gether with the rose, in the border of Henry's arms, as Earl of Rich- mond. Descended from Cadwalla- der, the last of the British kings, and deriving from him the name of Tudor, he assumed the badge of the red dragon, Cadwallader's en- sign. After the battle of Bosworth Field, Henry took as a badge the hawthorn bush, crowned, in allu- sion to the circumstance of the crown being found in a hedge, whence it was taken and placed on his head. The red rose, or rose of Lancaster, he placed on the sun- beams, as the white rose had been by the head of the house of York. This monarch assumed the Tudor rose, or the red rose charged with the white, as emblematical of his united claims to the throne by his marriage with Elizabeth, the daughter and sole heir of Edward IV. Upon the marriage of Prince Arthur with Catherine of Arragon, he adopted, in compliment to her, 479 the badges of her house. The castle was an ancient badge of the house of Granada. The sheaf of arrows was assumed by the house of Ar- ragon on the conquest of Gra- nada, which had been achieved by the superiority of the Arragonese archers. The rose dimidiated with the pomegranate was adopted as being symbolical of the junction of England and Spain. The phoenix in flames was assumed by Edward VI., in allusion to the particular nature of his birth, and was grant- ed by him to the family of Sey- mour. A white falcon, crowned, and holding a sceptre, was assumed by Queen Anne Boleyn as her pe- culiar badge, and was continued by her daughter, Queen Elizabeth. The harp, an ancient badge of Ire- land, was used by Queen Elizabeth. The rose environed by the garter, with its motto, was- a badge of several branches of the Tudor family. All these badges were re- presented crowned, when borne by the monarch, and were occasionally placed between the royal sup- porters. Tudor Style of Architecture, a con- tinuation of the Perpendicular Style, merging into a peculiarity in the time of Henry VIII., when it was much applied to domestic pur- poses and to edifices for collegiate halls, and several foundations for educationaland charitable uses,thus appropriating the proceeds of mo- nastic revenues. The mansions of the Tudor period usually consisted of an inner and base court, between which stood the gate-house. The principal apartments were the great chamber, or room of assembly, the hall, the chapel, the gallery for amusements, on an upper story, running the whole length of the principal side of the quadrangle, and the summer and winter par- lours. Of quadrangular houses, the seats of the Bishops of Car- lisle, Cowdry, Halnaker, &c., may be taken as fair examples. In TUG TUNNEL. TUN Lamb's ' Studies of Ancient Houses' (a book of a convenient size and price) are some fine examples in this style, but of a smaller kind. Very many splendid examples of larger dimensions of halls, man- sions, &c., still exist scattered over the country. Lincoln's Inn Hall, newly built in this style, is the most successful practice probably that has yet been accomplished, done with all the spirit and grace and the picturesque without sacri- fice of any principle of this ad- mired style. Tufa, a calcareous earth, composed of broken and concreted shells, or the deposit from water impregnated with lime Tugs, in mining, hoops of iron fasten- ed to the covers to which the tackles are affixed Tugs, steam, small steam vessels em- ployed in towing other craft Tulip wood, the growth of the Bra- zils, is frequently unsound in the centre, very handsome, but soon fades : it is used in turnery and Tunbridge ware Tumbling -home, in nautical language, the falling into midships of the top-side above the main breadth, to bring the upper deck guns nearer the centre of the ship Tummals, in mining, a great quantity or heap Tumulua, a heap, or mound of earth, sometimes called a burrow, used for the burial of the dead pre- vious to the Roman invasion of Britain Tunnel, a large and subterraneous arch, driven through an elevation or hill, or under a river, for the passage of boats, carriages, &c. Among the costly and laborious works of a railway, its tunnels oc- cupy the first place. Like mining, and all other subterranean ope- rations, the construction of a tunnel can be but little aided by me- chanical appliances; it chiefly re- quires hard manual labour, exer- cised under circumstances which 480 do not admit of that thorough superintendence which promotes economy, and, moreover, liable to unforeseen interruptions, of sur- mounting which neither the manner nor the expense can be prede- termined. Thus the Kilsby tunnel, on the London and Birmingham Railway, was estimated to cost about 40 per yard lineal; whereas its actual cost was 130 for the same length, owing to its inter- secting a quicksand, which the trial borings had escaped. Thus a vast expense was necessarily in- curred in setting up and working pumping machinery in order to dry the sand. The pumps brought up nearly 2000 gallons per minute, and were working during a period of nine months. The quicksand extended over a length of about 450 yards of the tunnel. The Box tunnel, on the Great Western Rail- way, excavated through oolite rock, and being lined with masonry only through a portion of its length, cost upwards of 100 per lineal yard. The Bletchingley tunnel, on the South Eastern Railway, cost 72 per lineal yard; and the Salt- wood tunnel, on the same line of railway, cost 118 per lineal yard. This greater cost in the latter work was occasioned by the great body of water in the lower green-sand which the tunnel intersects. The method of proceeding with tunnelling depends mainly upon the kind of material to be ex- cavated. This having been gene- rally ascertained by borings and trial shafts, the work is commenced by sinking the working shafts, which must be sufficiently capa- cious to admit readily of lowering men and materials, raising the ma- terial excavated, fixing pumps, and also for starting the heading of the intended tunnel when the required depth is reached. Besides the trial and working shafts, air-shafts are sunk for the purpose of effecting ventilation in the works below. TUN TUNNEL. TUN The working shafts are made cylindrical, and from 8 to 10 feet internal diameter: 9 feet is a fa- vourite dimension. They are of brick-work, usually 9 inches thick, and carried up 8 or 10 feet above the surface of the ground, finished with stone coping. These, and all other shafts, rest upon curbs of cast iron, fitted into the crown of the tunnel, and forming a level base for the shaft. The air-shafts are of similar thickness and form, but usually about 3 feet internal diameter. They should not be allowed to be sunk near to the working shaft, or at a less distance than 50 yards from it. All the shafts are, of course, sunk on the centre line of the intended tunnel. In the Bletchingley tunnel, the trial shafts, 6 feet diameter in the clear, 9 inches thick, and 35^ yards deep, cost 6 per yard down through the Weald clay. A similar shaft in the Saltwood tunnel, 25 yards deep, cost 4. 15s. per yard down, in the lower green -sand. Horse-gins are usually employed in raising and lowering the ma- terials, &c., and also in drawing the water up the shafts, unless large pumps are used and worked by steam-power. The engineer cal- culated the expense of horse labour thus exercised at 2frf. per ton lifted 100 feet high, and including the boy to drive the horse. The number of working shafts will depend chiefly upon the rate of speed with which the work is required to be accomplished. With plenty of men, horses, materials, and plant, the work is much facili- tated by sinking extra shafts, which will usually well repay their cost. The Watford tunnel, 75 chains in length, on the London and Bir- mingham Railway, was specified to be worked with six shafts, not less than 8 feet diameter within the brick-work, and 9 inches thick ; the brick-work moulded to fit the circumference of the shaft, and 481 laid in two half-brick rings; an air-shaft at a distance of 50 yards on each side of each working shaft, and not less than 3 feet 6 inches diameter inside ; the arch and side- walls of the tunnel, usually two bricks thick, and the invert, one and a half brick, except in places where the stratum passed through seemed to require an increased, or admit a diminished thickness. The form of the top of the tunnel is nearly semicircular, supported by curved side walls standing on stone footings or skew-backs, which rest on the invert forming the base of the tunnel. The ends of the tunnel are formed with wing-walls. The brick-work at the enda of the tunnel is bound by wrought-iron rods 1 00 feet long, secured at each end in a cast-iron rim or plate built into the brick-work. The Northchurch tunnel, which is 16 chains in length, on the same line of railway, was worked with two shafts, each 9 feet diameter. In the construction of this tunnel, a heading was driven, 4 feet wide and 5 feet high, throughout the entire length of the tunnel, and between two shafts sunk for this purpose, one near each end of it. It was specified that this heading should be driven through before any part of the tunnel was com- menced, and supported and kept open during the execution of the entire work by sufficient timbering. In commencing the works of the Saltwood tunnel, already referred to, great difficulty was encoun- tered from the great quantity of water in the lower green - sand which the tunnel intersects. The course adopted was to make a heading or adit quite through the hill on a level with the bottom of the tunnel, in which the water was collected and drained off. The size of this, and of the Bletch- ingley tunnel, is 24 feet wide at the broadest part, 30 feet including the side walls ; 25 feet high in the TUN TUNNEL. TUN clear, 30 feet including the invert and top arch, or 21 feet clear above the level of rails. The brick-work in the top arch and walls is from two and a half to four bricks in thick- ness ; the invert three bricks thick. When water occurs in the sink- ing of the shafts or the building of a tunnel, the back of the brick- work should be well lined with puddle, and Roman or metallic cement substituted for mortar. The whole of the Kilsby tunnel, on the London and Birmingham Rail- way, was built in either Roman or metallic cement, and the thickness of the brick-work is chiefly 27 inches. This tunnel is about 2423 yards long, and its length is divi- ded by two ventilating shafts, cy- lindrical, and 60 feet in diameter. These shafts are 3 feet thick in brick-work, laid in Roman cement throughout. They intersect the line of the tunnel, and thus form curved recesses by that portion of their circumference which extends beyond the width of the tunnel on either side. These shafts were built from the top downwards, by excavating for small portions at a time, from 6 to 12 feet in length and 10 feet deep. The Box tunnel, on the Great Western Railway, intersects oolite rock, forest marble, and lias marl, with fullers' earth. Eleven prin- cipal shafts, generally 25 feet in diameter, and four immediate shafts 12 feet 6 inches, were sunk for the purpose of carrying on the works of this tunnel, the entire length of which is 3123 yards, or a little more than If mile. The section of the tunnel was designed to be 27 feet 6 in. wide at the springing of invert, and 30 feet at a height of 7 feet 3 inches above this ; clear height above the rails 25 feet. As a great portion of the tunnel was con- structed by mere excavation, and without masonry, these dimensions were in some cases departed from, in order to clear away loose por- 482 tions of the stone and secure solid surfaces. Where brick-work is used, the sides are seven half -brick rings in thickness, the arch six, and the invert four. During the con- struction, the constant flow of wa- ter into the works, from the nume- rous fissures in the rock, compelled pumping on a most expensive scale to be adopted. From November, 1837, to July, 1838, the works were suspended, the water having gained so completely over the steam pump then employed, that the por- tion of the tunnel then completed was filled with water, as also a height of 56 feet in the shafts. A second pump, worked by a steam engine of 50 horse-power, was ap- plied, and enabled the works to be resumed. When the working shafts are sunk sufficiently deep, a narrow heading is excavated, from 6 to 12 feet in length, 3 or 4 feet wide, and high enough for a man to work in. The top of this heading should be so much above the intended soffit of the tunnel-arch as to admit the thickness of the brick-work, besides the bars of timber and boarding by which the roof of the heading is sup- ported, and several inches should be allowed for the settlement of the timber, which always occurs as the excavation is proceeded with, and before the brick-work can be got in. This allowance is of the utmost importance, as without it the brick- work will, when the settlement occurs, be forced down, and can only be raised to its proper level by removing the superincumbent earth piecemeal, and at great cost. The bars, and poling and packing boards, are introduced in the most convenient manner, according to the nature of soil excavated, and the degree in which it requires support, or may be safely left un- supported. The heading is extended on either side by first cutting narrow gaps TUN TUNNEL. TUN horizontally, or rather dipping downwards in directions following the intended form of the tunnel- arch. Into these gaps, crown bars are laid lengthwise, and supported upon props ; and poling boards are put in between them, to retain the earth at the sides of the excavation, when extended. When the head- ing has thus been widened by ex- cavating right and left, and a suffi- cient length cleared, the centerings are fixed, and the brick-work is commenced. As this proceeds, the earth is carefully rammed behind it, and all vacancies filled up, to prevent any subsequent settlement of the surrounding earth upon it. The crown bars which are in- serted in the heading, and always during the excavations, are not invariably removed. If they can be drawn forward as the heading ad- vances, without disturbing the adja- cent ground, and the spaces filled up with broken stone, or other suitable material, no objection can arise ; but otherwise they should be allowed to remain, and be built in. The whole of the operations require carefully regulating, so that none of them shall advance too rapidly for those which follow. Contractors are therefore usually restricted to carry the excavation not more than 6 or 8 feet in ad- vance of the brick-work, or less, if so directed by the engineer, should any change occur in the strata which he thinks may require such precaution. When the faces of two contiguous excavations ap- proach within about 50 yards of each other, a heading should be driven quite through the inter- vening ground, and the workings joined before the whole excavation and brick- work are proceeded with. Experience has proved that the quality of the bricks used in tun- nel-work is of the utmost import- ance. If these contain lime, on which the weather operates in- juriously, the face of the work soon 483 decays, and requires extensive re- pair or restoration. This was the case with the Beechwood tunnel on the London and Birmingham Railway, which in less than three years was considered to be in an unsafe condition, owing to this cause. The remedy adopted was of the most complete character; it consisted in an entirely new lining of brick-work, 9 inches thick. This tunnel is about 302 yards long, and passes through strata consisting of alternate layers of rock and marl, abounding with springs of water. By judicious ar- rangement, the lining was com- pleted in forty days. The traffic being diverted to one of the two lines of rails which are laid in the tunnel, and a hoarding erected along the centre, the casing was carried up on one side to the height of 4 feet 6 inches above the springing. At this point a course of York paving, 4 inches thick, was bonded into the original work, and the new work was securely attached beneath it with wedges of iron ; half-brick toothings were also inserted in chases cut 2 feet 3 inches apart in the original work. The traffic was then turned into the line on the side thus cased, and the other wall was similarly treated. Bearers were then fixed 6 feet apart over head, and a close floor- ing laid upon them. Upon each bearer a pair of ribs was raised, and keyed stays and laggings were fixed, and the brick-work, in En- glish bond, brought up on each side simultaneously, leaving a cen- tral space 2 feet 3 inches wide at the crown. A moveable centre of this length was used to close in this space with two half-brick rings. Vertical chases, 4^ inches square, besides those cut for the toothings, were made in the face of the old walls previous to lining. These formed permanent drains, termi- nating in the culvert beneath the centre of the tunnel. TUR TURBINE WHEEL. TUR Turbine Water-wheel The hori- zontal water-wheel so called, as used in France and Germany, was invented by M. Fourneyron : the water enters at the centre, and, diverging from it in every di- rection, it then enters all the buckets simultaneously, and passes off at the external circumference of the wheel. The pressure with which the water acts on the buckets of the revolving wheel is in proportion to the vertical column of water, or heights of the fall, and it is conducted into these buckets by fixed curved girders se- cured upon a platform within the circle of the revolving part of the machine. The efflux of the water is regulated by a hollow cylindrical sluice, to which stops are fixed, which act together between the guides, and are raised or lowered by screws that communicate with a governor, so that the opening of the sluice and stops may be en- larged or reduced in proportion as the velocity of the wheel requires to be accelerated or retarded. Tur- bines may be divided into high- pressure and low-pressure engines. High-pressure turbines are par- ticularly available in situations such as often occur in hilly districts where high falls of water may be commanded, and the character of the site affords facilities for con- structing reservoirs, so that a con- stant supply may be insured. In these cases the height of the co- lumn of water will compensate for the smallness of its volume, and the high-pressure turbine will be found applicable with great ad- vantage' to the grinding of corn, crushing ores, working threshing machines, or actuating other ma- chinery. The low-pressure tur- bines produce great effect with a head of only nine inches, and are suitable for situations in which a large bulk of water flows with little fall. The results of an in- vestigation by MM. Arago, Prony, 484 Gambey, and Savary, who were appointed by the French Academic des Sciences to report upon tur- bines, are given in a treatise by M. Moriri on the subject, and are as follows : 1. That these wheels are appli- cable equally to great and to small falls of water. 2. That they trans- mit an useful effect, equal to from 70 to 78 per cent, of the absolute total moving force. 3. That they may work at very different velo- cities, above or below that cor- responding to the maximum effect, without the useful effect varying materially from that maximum. 4. That they may work from one to two yards deep under water, without the proportion which the useful effect bears to the total force being sensibly diminished. 5. In consequence of the last pre- ceding property, they utilize at all times the greatest possible propor- tion of power, as they may be placed below the lowest levels to which the water surface sinks. 6. That they may receive very va- riable quantities of water without the relation of the useful effect to the force expended being mate- rially lessened. The practical value of these ma- chines is most obvious when they are applied to small falls of water. Smeaton's experiments proved that with a high fall in which an over- shot water-wheel can be intro- duced, 80 per cent, of the original moving power may be realized. And there is little doubt, accord- ing to Ruhlman, whose treatise on turbines has been so well trans- lated and edited by Sir Robert Kane, that where an overshot wheel, or a wheel with tolerably high breasts and overfall sluices, can be erected, they are to be pre- ferred to the turbine, except there is much back-water to contend against, when the turbine may be sunk to a considerable depth in the back-water without any mate- TUR TURBINE WHEEL. TUR rial loss of its power. Even in cases which admit the working of overshot wheels, the peculiar ap- plicability of the turbine, which affords a direct horizontal motion to the working of corn-mills, should command full consideration before it is relinquished in favour of the overshot wheel. In every case of fall, either higher than that suit- able for an overshot wheel, or lower than that required for such a breast-wheel as just described, the turbine decidedly deserves the pre- ference. Smeaton proved that un- dershot wheels realized only 30 per cent, of the original force. In falls of great height, the ve- locity of the machine is so rapid that it may be applied to spinning machinery without mill-work, or with very little, to produce the required speed. The turbine in its present form is of compara- tively modern date ; the experi- ments of M. Fourneyron, which resulted in its invention, having been commenced in 1823, and the first machine was erected in 1827. In tracing this form of water-moter to its elements, however, the con- trivance which is known as Dr. Barker's mill, must necessarily be noticed. This machine, which is of very old date, consists of an up- right pipe or tube, which revolves on a vertical axis, and is formed with an open funnel-shaped top, and closed at the bottom, from which project two horizontal hol- low arms or pipes. These arms are closed at their outer ends, but have each a round hole near the extremity, and so placed that the two holes are opposite to each other. The upright pipe is kept filled with water, which flows into the funnel-shaped top. The issu- ing of the water from ttye holes on opposite sides of the horizontal arms causes the machine to re- volve rapidly on its axis, with a velocity nearly equal to that of the effluent water, the force being in 485 proportion to the hydrostatic press- ure which is exerted by the ver- tical column, and to the area of the apertures; there being no solid surface at the hole on which the lateral pressure can exert itself while it is acting with its full force on the opposite side of the arm. This unbalanced pressure is, according to Dr. Robison, equal to the weights of a column having the orifice for its base, and twice the depth under the surface of the water in the trunk for its height. If the orifice were closed, the pressure upon it would equal the weights of a column reaching to the surface ; but when open, the water issues with a velocity nearly equal to that acquired by falling from the surface, and the quantity of motion which is produced is that of a column of twice this, length moving with this velocity. The revolution of the machine causes the water, which having de- scended the vertical pipe moves along the arms, to partake of the circular motion, thus producing a centrifugal force that is exerted against the ends of the arms of the machine. According to the laws of motion, this force increases in proportion to the square of the distance from the centre at which it is developed. Thus the velocity of the efflux is increased, and also the velocity of revolution. But as the circular motion has to be im- parted to every particle of water as it enters the horizontal arm, which is done at the expense of the motion already acquired by the arm, there is a limit to the velocity even of an unloaded ma- chine. Barker's mill has been treated of by Desaguliers, Euler, John Bernouilli, and M. Mathon de la Cour, the latter of whom pro- posed, in 17 75, to bring down a large pipe from an elevated reservoir, to bend the lower part of it up- wards and attach to it a short pipe with two arms, like Barker's TUR TURBINE WHEEL. TUR mill reversed, and revolving in like manner upon a vertical spindle ; the joint of the two pipes being contrived so as to admit of a free circular motion without much loss of water. By this arrangement a fall of any extended depth may be made available. An improved form of Barker's mill was patented sub- sequently by Mr. Whitelaw, in which the modifications suggested by M. M. de la Cour were partly included, and a peculiar form given to the horizontal arms, adapted to preserve the centrifugal force from loss or counteraction. In this mill the two arms form the letter S, the water being emitted from their extremities in the direction of the circle traced by their revolution, the sectional capacity of the arms increasing as they approach the centre of rota- tion, so as to contain a quantity of water, at each section of the arm, inversely proportional to its velocity at that section. With a well-made model of this mill, the patentee obtained an effect equal to 73' 6 per cent, of the power employed, and nearly equal results are said to have been realized in actual practice. The following particulars of the height of fall and useful effect produced with turbines, already erected on the Continent, will tend to show their increasing value in proportion to the heights of the acting co- lumn of water. Heights of fall in feet. 7- 63 79 126 144 Useful effect per cent, of power employed. 71- 75 87 81 80 In 1837 a turbine water-wheel was erected by M. Fourneyron, an account of which is here quoted from Mr. Joseph Glynn's 486~ Report to the British Association for the Advancement of Science in 1847. This turbine is "erected at St. Blasier, or Blaise, in the Black Forest of Baden, for a fall or column of water of 72 feet (22 metres). The wheel is made of cast-iron with wrought -iron buckets ; it is about 20 inches in diameter, and weighs about lOofts.; it is said to be equal to 56 horses' power, and to give an useful effect equal to 70 or 75 per cent, of the water-power employed. It drives a spinning- mill belonging to M. d'Eichtal. A second turbine, at the same establishment, is worked by a column of water of 108 metres, or 354 feet high, which is brought into the machine by cast- iron pipes of 18 inches diameter of the local measure, or about 16| inches English. The diameter of the water-wheel is 14, or about 13 inches English, and it is said to expend a cubic foot of water per second : probably the expen- diture may be somewhat more than this. The width of the water- wheel across the face is '225, or less than a quarter of an inch. It makes from 2200 to 2300 revolu- tions per minute ; and on the end of the spindle, or upright shaft of the turbine, is a bevelled pinion of nineteen teeth, working into two wheels on the right and left, each of which has 300 teeth : these give motion to the machinery of the fac- tory, and drive 8000 water-spindles, roving - frames, carding - engines, cleansers, andotheraccessories. The useful effect is reported to be from 80 to 85 per cent, of the theo- retical water-power. The water is filtered at the reservoir before it enters the conduit-pipes ; and it is important to notice this, since the apertures of discharge in the water- wheel are so small as to be easily obstructed or choked." Turbith or Turpith mineral, ( Queen's yellow,} is subsulphate of mercury, of a beautiful lemon yellow colour, TUR TURF. TUR but so liable to change by the action of light or impure air, that, not- withstanding it has been some- times employed, it cannot be used safely, and hardly deserves atten- tion as a pigment Turf is generally found in bogs, in horizontal layers from 10 to 30 feet in thickness ; sometimes in the form of a blackish-brown mud ; sometimes it is a dark peaty mass, and often a combination of roots and stalks of plants : frequently the turf layers interchange with layers of sand or clay. Sea-water is better adapted to the formation of turf than rain or spring water. Turf is simply dug with spades, and then dried. If too moist, the semi-fluid mass is piled upon a dry spot, and there left until the water leaks off, and until the mass appears dry enough to be formed into square lumps in the form of bricks. In many instances, however, the freshly dug turf is triturated under revolving edge- wheels, faced with iron plates per- forated all over their surface : through the apertures in these plates the turf is pressed till it becomes a kind of pap, which is put into a hydraulic press, and squeezed until it loses the greater - part of its moisture : it is then dried and charred in suitable ovens. The charcoal made in this way de- serves the notice of the artisan. The component parts of turf dif- fer from those of wood. This dif- ference is owing to the fact of its being decomposed woody fibre. The following is an analysis of several specimens : One hundred parts of good turf contained, besides ashes, Carbon. Hydrogen. Oxygen. I. 57-03 5-63 3176 II. 58-09 6-93 31-37 III. 57-79 6-11 30-77 The charring of turf is far more easily effected than the charring of wood, partly on account of its 487 square form, partly on account of its chemical composition. In pits, the charring of turf is not difficult, if the same method is pursued as that adopted in the charring of wood ; but channels or draft-holes must be left in the kiln, because the square pieces pack so closely, 1 that, without this precaution, suffi- cient draught would not be left to conduct the fire. Turf is generally found in considerable masses in one spot ; therefore the erection of char-ovens is no object of mere speculation, but affords all the ad- vantages of a permanent establish- ment. TurnbulVs blue (ferricyanide of iron.} Professor Graham's account of this variety of Prussian blue is nearly as follows : It is formed by adding ferricyanide of potassium (red prus- siate of potash) to a protosalt of iron : it results from the substi- tution of three equivalents of iron for three equivalents of potas- sium. The same blue precipitate may be obtained by adding to a protosalt of iron a mixture of yel- low prussiate of potash, chloride of soda, and hydrochloric acid. The tint of this blue is lighter and more delicate than that of Prus- sian blue. It is occasionally used by the calico-printer, who mixes it with perchloride of tin, and prints the mixture, which is in a great measure soluble, upon Turkey red cloth, raising the blue colour after- wards by passing the cloth through a solution of chloride of lime, con- taining an excess of lime. The chief object of this operation is to discharge the red and produce white patterns, where tartaric acid is printed upon the cloth ; but it has also the effect incidentally of precipitating the blue pigment and peroxide of tin together on the cloth, by neutralizing the chlorine of the perchloride of tin. This blue is believed to resist the action of alkalis longer than ordinary Prussian blue. TUR TURNING TOOLS. TUR Turner's yellow, Casselyelloiv, Patent yellow. This is an oxychloride of lead, which may be prepared by different processes : when litharge or the protoxide of lead is acted upon by a solution of common salt, there are formed, soda, which remains dissolved, and a white com- pound, which is hydrated oxychlo- ride of lead ; and this, when heated, loses water, becomes of a yellow colour, and is the compound re- quired. It is composed nearly of one part of chloride and nine parts of oxide of lead: it may also be obtained by heating chloride and oxide of lead together in the requi- site proportions, or by heating a mixture of one part of hydrochlo- rate of ammonia with ten parts of protoxide of lead. In fusing these compounds it is requisite to be ex- tremely careful to avoid any ad- mixture of carbonaceous or com- bustible matter, as that would reduce a portion of the oxide of lead to its metallic state, which would injure the colour of the product. Turning tools. These are of two classes, viz. hand-tools and tools fixed in the slide -rest. Of the former, the principal are the heel- tool, graver, planisher, gouge, and chisel: there are many others which, however, are but modifications of these, and are required only in particular cases. The slide-rest tools are distin- guished by the same names as the hand-tools, but vary from them slightly in the forms of their cut- ting parts, which in the hand-tools are in general rather broader, in order that the part to be cut away may be acted on as long as possible before shifting the tool ; for forward motion is in their case continuous only for the short period while the cutting edge can be brought to bear on the material without shift- ing forward the resting point of the tool. The face or front edge of the tool should in every case be 488 nearly perpendicular to the hori- zontal diameter of the work, but a small difference is required for clearance. The angle of the cutting edge should be more or less acute, ac- cording to the nature of the mate- rial to be turned ; in general, the softer and more uniform the mate- rial, the more acute should be the angle : for w r ood, it should be very acute, and for iron and steel less acute. The velocity with which the work is made to revolve must also be adapted to the material, and must be such that the tool may take the greatest effect consistent with the preservation of its cutting edge. The hardening and tempering of turning tools require much expe- rience on the part of the workman ; for although they may be of the best possible shape, they are worse than useless unless properly hard- ened. The general process of hardening and tempering tools is as follows : The cutting end of the tool is slowly heated in a clear fire, and when of a light red heat is cooled quickly in water ; it is then very hard and brittle, and requires tempering or reducing to the pro- per degree of hardness : to effect this, it is necessary to brighten the part, so that a change of colour may be readily observed, and then place it upon a red-hot bar ; when it has become heated to a certain degree by contact, the bright part will have a pale straw colour ; this gradually deepens, and when it has arrived at the requisite depth of tint, the tool is removed and again cooled, after which it is fit for use. (See also the article Tools.) Turnsole, a kind of colour used in painting Turn-table, a circular table, with cross-rails fixed on its surface, sup- ported by rollers, and capable of being turned on a central pivot ; used for moving a railway carriage from one line of rails to another TUR TUYERES. TUY Turret, a small tower attached to and forming part of another tower, or placed at the angles of a church or public building, especially in the style of Tudor architecture Tuscan Style of Architecture. This originated in the north of Italy, on the first revival of the arts in the free cities, and beyond which it has never yet travelled, except in some examples which were introduced by Inigo Jones in the first church of St. Paul, Covent Garden, and by Sir Christopher Wren in porticoes at St. Paul's cathedral, London. This style is characteristic of the people who practise it. The Tus- can, it has been said, should pe- culiarly be adopted in England. Tuyeres. Before puddling became so generally introduced, the shape and position of the tuyere at a blast- furnace received considerable atten- tion, but since the quality of pig iron has been sought for with but little anxiety, these have ceasedto be con- sidered of much importance. The chief purpose of the metallic tuyere is the preservation of the fire-proof hearthstones ; the direction and form of the blast are of minor im- portance. This protection is ac- complished, in some measure, by making a coating of fire-clay in the tuyere -hole which is cut in the hearthstones. By this means, con- stant attendance, and repeated re- newal with clay, the tuyere may be maintained narrow : whether formed of clay or metal, it should never be wider than the nozzle. Where one of the former kind ex- ceeds the width of the nozzle, it burns away, and the earth is ex- posed to destruction. The preser- vation of the original dimensions of the hearth is the main object which the manager of a furnace seeks to secure; and as the clay tuyere does not effect this object, those made of copper or cast iron have been substituted in its place. These reach further into the fur- nace than those of clay, and there- 489 fore, as it is decidedly of advantage that the blast should be driven as far as possible into the centre of the hearth, the former are much pre- ferable to the latter. If formed of wrought iron, they are liable to burn, as the iron, in consequence of its purity, oxidizes, and forms with the clay around it a very fusible silicate, which is precipitated into the fur- nace. Gray is preferable to white cast iron, and also to wrought iron ; the carbon and impurities it con- tains protect it against oxidation and destruction. Copper is the best metal for tuyeres ; it is a good conductor of heat, and is kept cool by the blast more easily than iron. Its silicates also are infusible. If copper oxidizes, and forms a silicate, the latter will protect it. The ad- vantages derived from the copper tuyere have, in Europe, been ac- knowledged for more than a cen- tury ; still the charcoal furnaces in America, at which cold blast is employed, are generally blown by clay tuyeres, the result of which is the waste of much coal, and the production of inferior iron. This is mentioned as one of those rare cases in which Americans do not make the best use of the means at their disposal. The copper tuyere is protected against the heat of the furnace by the cold blast, which touches it, and for this rea- son should not be wider than the nozzle. In this point of view, it may be regarded merely as a pro- longation of the nozzle, and is, of course, governed by the rules appli- cable to the latter. So long as pig iron is to be made by the charcoal forge, the desire to make white plate iron in the blast-furnace will exist. It is very difficult, almost impossible, to keep a blast-furnace constantly running upon a certain kind of iron ; and therefore the dif- ference which the quality of that in the furnace exhibits is modified to a more or less general standardly means of the position of the tuyere, TUY TUYERES. TUY such as its direction and inclina- tion. Very skilful management is required, in many instances, to pro- duce the desired effect. In some parts of Europe, where cold -blast iron for the forge is manufactured, the copper tuyere is yet in use ; but where pig iron for puddling is made, or hot blast employed, such close attention is not ne- cessary. In America, the niceties involved in adjusting the tuyere can scarcely be appreciated, not even at the forge fires ; but this adjustment is unaccompanied with any practical convenience, as the trouble it requires is never com- pensated. The advantages which arise from a scrupulous attention are, at best, very small ; and such attention would, under the condi- tions which exist in America, es- pecially the high price of labour, result in loss instead of gain. At cold-blastfurnaces, in America, clay or cast iron tuyeres, principally the former, are consequently gene- rally employed. Water tuyeres are in use at forges, fineries, hot-blast, and at some cold-blast furnaces. A common one for the Catalan forge, the charcoal forge, finery, and charcoal blast-furnaces, is made of boiler plate. The top part is hollow, while the bottom part, which is generally flat, is solid. A water-pipe, of ^-inch bore, con- ducts a current of cold water through the hollow top : this pre- serves the tuyere, and protects it against burning. The bottom is made flat, so as to serve as a sup- port to the nozzle; and thus the latter may be readily moved to those places where it is most needed. At blast-furnaces and fineries, this precaution is not of much use, as the nozzle remains at the place where it is fixed ; but at forges it must be moveable. Both of the water-pipes are, in most cases, at the top ; but this arrangement can scarcely be considered so advan- tageous as though one pipe, or the 490 entrance of the water, were nearer the bottom, and the other pipe, or the outflow, at the top. Tuyeres for anthracite, coke, and most of the charcoal furnaces, are perfectly round, and made of boiler plate; seldom of copper or cast iron. The tapering of them does not affect the furnace ; and for all the evil this tapering occasions, it j may be a perfect cylinder. In using hot blast, it makes no differ- ence how the air is conducted into the furnace, provided the tuyere is kept open, and bright; which is all that is necessary. The nozzle is laid into the tuyere, how far it reaches into it, is a matter of no consequence, and the space be- tween them filled up with clay. At a cold- blast furnace, it requires some attention not to push the nozzle too far in, or to draw it too far back. The water-pipes are of lead, f-inch, seldom 1-inch bore; one on the lower, and the other on the top part of the brim. The lower pipe conducts the water to the tuyere, and the upper one from it. The former is, in many cases, pushed as far as possible into its interior, to bring the cold water into the furnace ; and the water is thus applied where the heat is greatest. A constant, uninterrupted supply is necessary to prevent the melting of the tuyere. The water must be pure ; else it will leave a sediment in it which is sure to cause its destruction. There must, also, be a sufficient supply of cold water : if the formation of steam is going on in the interior of the tuyere, the latter is sure to be burned. Copper and brass last longer than iron ; but if iron tuyeres are well made, and sol- dered with copper, and if there is no lack of water, they may last a long time. "Where there is a de- ficiency of water, or where there are sediments in the interior of a tuyere, a few hours' heat will de- stroy it. If it be found that they TUY TUYERES. TUY do not wear well, attention must be directed to the water; and if nothing appears wrong, the appli- cation of larger pipes, or higher hydrostatic pressure, will then re- medy the evil. Water tuyeres are generally from 10 to 20 inches long ; those that are too short are liahle to be burnt, by the fire working around them, because there is not sufficient room to keep it closed up. Another disadvantage is, that their want of length prevents them from being pushed into the hearth; but length is necessary when the earth is burned out, and when the blast should be carried further into the interior. The external size is also a matter which requires atten- tion in the construction. The total surface determines the amount of water which is necessary. The larger the surface, particularly the diameter, the greater the amount of water necessary, and of course the greater the danger of burning. A tuyere is seldom more than four inches in diameter inside ; but the diameter outside is sometimes twelve, and even more inches. With such an increase of the diameter, however, the danger is augmented. Tuyeres may be considered a pro- longation of the nozzle or the blast- pipe, and disconnected from it merely for the sake of preservation, and of more convenient access to the interior of the furnace. Those for cold blast should taper more than those for hot blast, because the former clinker in a greater de- gree, and require cleaning more frequently than the latter. The more acute the angle of the tuyere, the colder it works ; and the more tapered it is, the hotter it works. These observations are of practical importance. In most cases the blast is required as far in the in- terior of the furnace as possible, because fuel is thus saved, better iron produced, and the hearth pro- tected. There is some difficulty in giving cold-blast tuyeres a slight 491 taper, because they should be very wide outside ; but this difficulty can be overcome by making their in- teriors more curved. If the extreme end, as far back as the diameter of the mouth, is cylindrical, the same purpose is accomplished as though the whole were cylindrical. If too much tapered, which is shown by its working too hot, the evil is diminished, in some measure, by pushing the nozzle further into the furnace. This is but a temporary, not a radical remedy; and a tuyere of a proper form must be substi- tuted. If it works too cold, that is, sets on too much cold cinder, the only resource is scrupulously to keep it clean, and to replace it as soon as possible by one more tapered, or with a more obtuse cone. From these considerations, it is evident that different kinds of ore require a tuyere of different taper ; but for the exact degree of this taper no general rule can be given. Experience must, in this instance, be the only guide. This will appear more evident on taking into consideration the kind of fuel and the pressure of the blast re- quired. Calcareous ore, as well as the pig iron made from it, works naturally hot at the tuyere ; conse- quently, those more acute are em- ployed, and serve to drive the blast far into the furnace, by which means they are kept cool. This result can be effected by a water tuyere. Clay ores, which work naturally cold, work better with one that is tapered. These consi- derations, which have a special bear- ing upon the working of furnaces and forges, are entirely of a practi- cal nature ; and for this reason the management of the furnace or forge is accompanied with such different results. It is evident that the mo- dification of a tuyere cannot, at times, be so quickly accomplished as may be desired : months, and even years, are often consumed, before the required form can be TUY TUYERES. TYT accurately determined; in many cases, this form is never arrived at. The shape is therefore a matter which, at blast-furnaces, generally depends on the decision of the keeper or founder; and as those formed of clay may be altered very conveniently, this may be assigned as one of the reasons why so many of that kind are in use. The whole matter, however, is divested of its mystery when it is found that an obtuse tuyere tends to work warm, while one more acute produces an opposite effect, and is more advan- tageous as respects both the quality and quantity of work ; but it is more difficult to manage. The form of the nozzle, as well as that of a metal tuyere, is permanent; and as the advantage of either shape can be arrived at, in a more or less perfect manner, by pushing in or drawing back the nozzle, no solid objection exists against those formed of metal. Some difference should be made between the form of the nozzle and that of the tuyere. An obtuse nozzle should work with the latter more acute; a slightly tapered nozzle, with one greatly tapered. The latter form is generally pre- ferred, on account of the facility of cleaning. In applying hot blast, the form of the tuyere and the nozzle is a matter of indifference ; but in their construction it is found desirable to adopt the rules here suggested. The advantages of hot blast are sometimes doubtful; and it is therefore better to unite, by means of perfect forms of apparatus, all the advantages derivable from the cold blast, and thus to regain what is lost in quantity by its employ- ment. In forge fires there are generally but one tuyere and two nozzles. At refinery fires the tuyeres are often all on one side ; at other places on opposite sides. All these differences are the result of local causes, originating in the form of 492 the apparatus, the quality of the iron and fuel, the pressure of the blast, and the qualification of the workmen. Their number and their position in the blast-furnace de- serve attention. In using cold blast, few should be employed, and in using hot blast as many as pos- sible. Cold-blast tuyeres are natu- rally troublesome ; they are apt to become black, and require constant attention, as well in moving the nozzle as in patching them with clay; they also tend to produce white iron, and they cool the lower parts of the hearth. For these reasons their number should be reduced as much as possible, as the hot-blast tuyere works very hot, occasions but little trouble, is much inclined to produce gray iron, and tends to reduce silex, and conse- quently to produce a poor quality of iron. Therefore, the use of as many hot-blast tuyeres as can be conveniently employed is recom- mended. The position of tuyeres is most favourable when placed on both sides of the hearth. The timp is that part of the hearth which is first burnt out; and if the tuyere is in the back part of the hearth, the distance from it to the op- posite timp is unnecessarily in- creased. Tying, in mining, the term for wash- ing ores Tympan of an arch, a triangular space or table in the corners or sides of an arch, usually hollowed, and en- riched with branches of laurel, olive, oak, &c., and sometimes with emblematical figures Tympanum, the triangular panel of the fastigium of any building, com- prehended between its corona and that of the entablature : the panels of a framed door were called tym- pana by the Romans Typhoon is a name frequently applied to a tropical storm: it is also given to the hot winds which occasion- ally blow with great violence in Africa, Syria, Arabia, and Persia; ULT UNDERSHOT WHEELS. UNI and which are felt, though rarely and with much-diminished force, in the southern parts of Italy and Spain. The sirocco of Egypt and the coasts of the Mediterranean, the simoom of Arabia, and the har- mattan of the coast of Guinea, are understood to be so many desig- ULT ULTRAMARINE, LazuRne, or Azure, is prepared from the lapis lazuli, a precious stone found principally in Persia and Siberia. It is the most celebrated of all modern pigments, and, from its name and attributes, is probably the same as the no less celebrated Armenian blue, or cy- anus of the ancients. Of the lat- ter, Theophrastus informs us that the honour of inventing its factiti- ous preparation (by perhaps a very singular chemico-mechanical pro- cess still used for ultramarine) was ascribed in the Egyptian annals to one of their kings ; and it was so highly prized, that the Phoenicians paid their tribute in it, and it was given in presents to princes : hence it was a common practice, in those times, to counterfeit it. Ultramarine ashes (mineral gray) are the residue of lapis lazuli from which ultramarine has been ex- tracted, and vary in colour from dull gray to blue. Although not equal in beauty, and inferior in strength of colour, to ultramarine, they are extremely useful pigments, affording grays much more pure and tender than such as are com- posed of black and white, or other blues, and better suited to the pearly tints of flesh, foliage, the grays of skies, the shadows of dra- peries, &c., in which the old masters were wont to employ them. Ul- tramarine broken with black and white, &c., produces the same ef- fect, and is thus sometimes car- ried throughout the colouring of a picture. The brighter sorts of ul- 493 nations of the typhoon ; all of them being supposed to originate in the same cause, with modifi- cations depending merely on the nature of the particles exhaled from the ground in the different countries. They are also said to cause water-spouts at sea. UNI tramarine ashes are more properly pale ultramarines, and of the class of blue; the inferior are called mineral gray. Umber, commonly called Raw Umler, is a natural ochre, abounding with oxide of manganese, said to have been first obtained from ancient Umbria, now Spoleto, in Italy. It is found also in England, and in most parts of the world ; but that which is brought from Cyprus, un- der the name of Turkish umber, is the best. It is of a brown citrine colour, semi-opaque, has all the properties of good ochre, is per- fectly durable both in water and oil, and one of the best drying co- lours we possess : it injures no other good pigment with which it may be mixed. Undecagon, a polygon of eleven sides Undercroft, a subterraneous apart- ment or crypt Underlay. When a vein in a mine hides or inclines from a perpendi- cular line, it is said to underlay Underlay shaft, a shaft sunk on the course of a lode Underlayer, in mining, a perpendi- cular shaft sunk to cut the lode at any required depth Undershot wheel, in hydraulics, a wheel with a number of flat boards, which receive the impulse of the water conveyed to the lowest part of the wheel by an inclined canal Uniform motion. The velocity of a moving body is said to be uniform when the body passes over equal spaces in equal times Union screws or joints, in locomotive UNI VACUUM. URN engines, the brass unions for con- necting the elastic bore-pipe of the tender to the feed-pipe of the en- gine; smaller ones also connect the tender steam. pipe with the feed-pipe and with the boiler. The feed-pipe is likewise attached to the lower end of the pump by a large union screw. Unit of work. The measure of any amount of work is the work done where a pressure of 1 ft. is exerted through 1 foot, the pressure acting in the direction in which the space is described. If, instead of 1 ft. being moved through 1 foot, it be moved through 2 feet, it is clear that the work is doubled, or that two units of work have been done. The difference between the aggre- gate work done upon a machine during any time by those forces which tend to accelerate the mo- tion, and the aggregate work, dur- ing the same time, of those which tend to retard the motion, is equal to the aggregate number of units of work accumulated in the moving parts of the machine during that time, if the former aggregate ex- ceed the latter, and lost by them during that time, if the former ag- gregate fall short of the latter. In reference to the unit of time, the unit of mechanical power has been assumed to be 1 ft. raised 1 ft. high, and 1 minute as the unit of time ; the unit of work will there- fore be represented by 1 ft. raised VAC VACUUM, a vacuity or space unoccu- pied by matter; in pneumatics, the vacuum caused by an air-pump, which is a degree of rarefaction sufficient to suspend the ordinary effects of the atmosphere. Vacuum-pump, a pump connected to the boiler of a marine engine, for charging the boiler with water from the sea by discharging the air, 494 1 foot high in 1 minute. Now, it is assumed that a horse is capable of doing 33,000 such units of work, i. e. that he is capable of raising 33,000 fts. 1 foot high in a minute, or 1 ft. 33,000 feet high ; and this is called a horse's power, and is the unit of work in reference to the unit of time commonly used in this country. Universal chuck, a circular plate to screw on the mandril of a lathe, and hold a nut or any small piece of metal to be bored : in the plate are two or more radial slots, fitted by the jaws or pieces which pro- ject from the face of the chuck, moved by screws towards the cen- tre, and tightened upon the nut Unmoor, in navigation, to reduce a ship to the state of riding by a single anchor and cable Unship, to remove any thing out of a ship Urn, an ancient utensil, used for a variety of purposes ; sometimes as the receptacle of lots or for votes at the public election of magis- trates ; but its greatest and most frequent use was as a receptacle for the ashes of the dead after their bodies were burnt. These urns were sometimes kept in houses, and also put under tombstones, or within vaults or graves. Urns and similar vessels have been found in the bu- rial-places of the ancient Britons. In modern times, the urn is an utensil of domestic use. VAL causing the water to rise within the boiler, from the pressure of the atmosphere without : by this means much labour and time are saved, which would otherwise be ex- pended in lifting the vats Fair, a term in heraldry, being a fur composed of four distinct colours ; argent, gules, or, and sable Valve, in hydraulics, &c., a lid con- VAL VAPORIZATION. VAP trived to open one way, to admit a fluid into a tube, but which shuts when pressed from the other, to prevent its return. In anatomy, a kind of membrane which opens in certain vessels to admit the blood, and shuts to prevent its regress. Valves, in blast machines, are essen- tial in blast-conducting pipes ; first, for shutting up the blast entirely ; secondly, for diminishing and in- creasing it at pleasure. The first kind is needed where the blast is generated, for various purposes, by the same blast machine. The valves in use are, the sliding, the conical, and the trundle. The two first named are but little em- ployed. If well made, the latter kind of valve is very useful. At one end it has a handle, and, in many instances, a graded scale, which indicates the amount of air which passes through the valve, or, in other words, it shows the open- ing of the valve. At each tuyere or nozzle a valve is required, which serves either to shut off the blast entirely, or to regulate the passage of whatever amount is needed. At the nozzle-valve, a scale is very useful, partly for the purpose of adjusting the blast, and partly for that of fastening the handle of the valve, and keeping it in a certain position. The laws which govern the con- struction of blast-pipes, valves, and tuyeres, are summarily as follows: The interior of the blast conductors should be as smooth as possible, as an uneven surface causes great friction. The friction of the air is proportional to the length of the pipe, and to the density of the air which passes through it. It is proportional to the square of the speed of the air, and the reverse of the square of the diameter of the pipe. Obstructions caused by short bends in such pipes are inversely proportional to the angle of the bend, and are governed by the laws of hydrostatics. Sud- 495 den contractions and expansions of the pipe occasion a whirling disturbance in the current of the air a loss of power, or, what is the same, of blast. Valve, the safety, in pneumatics, a valve in a steam engine, to obviate the danger of explosion, by allow- ing the steam to escape when the pressure is raised beyond a certain weight Valve-seat, the flat or conical surface upon which a valve rests Vandyke Brown, a pigment hardly less celebrated than the great painter whose name it bears, is a species of peat or bog-earth, of a fine deep semi-transparent brown colour. The pigment so much es- teemed and used by Vandyke is said to have been brought from Cassel ; and this seems to be justi- fied by a comparison of Cassel earth with the browns of his pic- tures. The Vandyke browns in use at present, appear to be terrene pigments of a similar kind, purified by grin ding and washing over: they vary sometimes in hue, and in de- grees of drying in oil, which they in general do tardily, owing to their bituminous nature, but are good browns of powerful body, and are durable both in water and oil. Vane, or Wind-vane, in navigation, a thin slip of bunting; a string of feathers, &c., stuck up to wind- ward, to show the direction of the wind Vanes, In Europe, the custom of placing vanes on church steeples is very old ; and, as they were made in the figure of a cock, they have been thence denominated weather- cocks. Vanning, removing the impurities from tin ore Vaporization. The presence of mois- ture in the air is accounted for by a modification of the process of vaporization. Water evaporates, or is converted into steam (by steam we here mean the elastic vapour of water, which is always invisible; VAP VAPORIZATION. VAP what is commonly called steam, but properly cloud, is liquid water in a finely divided or powdered state, wafted like dust by currents of air or of steam, properly so called,) at all temperatures, until the whole space above it, whether containing air or not, is pervaded with watery vapour of a certain fix- ed density and elasticity, depend- ing on the temperature, and con- nected therewith by certain laws. The elasticity or expansive ten- dency of a fluid is estimated by the number of pounds or ounces with which it presses on each square inch of surface that it touches ; or by the number of inches of mer- cury that it will support, as on a barometer. Steam can exist at any given temperature, and of such density as to have a certain fixed pressure, and no more; and (if there be water enough present) steam will be accumulated till it has this den- sity ; but no more can then be ac- cumulated without raising the tem- perature: and if the temperature be lowered, a portion of the steam will immediately become water, so that (occupying in this state some thousands of times less space than before) it may leave room for the remaining vapour to expand, till its expansive force is reduced to that which the new temperature can support. The pressure of steam is, therefore, always the same at the same temperature. At 2 12 its elastic force is equal to that of the atmosphere, and it will support a column of mercury 30 inches high, which is the reason that boil- ing requires this temperature in the open air, when the barometer is at 30 inches ; but rather less or more, when the barometer stands lower or higher. Above this temperature it becomes high-pressure steam, which at 220 will support nearly 35 inches of mercury; at 230, nearly 42 inches, and so on. But the steam which is thrown off from the waters of the earth, from damp soil,from the foliage of plants, and even from ice and snow, has but a very small pressure. Steam at 32 will support only 0-200 of an inch of mercury : at 40, 0-263 of an inch; at 50, 0-375 of an inch; at 60, 0-524, or rather more than half an inch of mercury ; at 80, it will support one inch, and so on. When the air contains as much vapour as can exist at the existing temperature, it is said to be satu- rated. If in this state it experience the smallest reduction of tempera- ture, some of the vapour must im- mediately become liquid, assuming the form of cloud, fog, or rain. These effects depend on the cool- ing of the air below the tempera- ture necessary to retain all its vapour. But when a solid body is cooled below this temperature, (the air remaining above it,) a dif- ferent kind of deposition occurs, called dew, which does not fall in drops from the air, but grows, as it were, on the solid. Dr. Wells proved, by a most complete inves- tigation of this subject, that instead of dew cooling bodies, as commonly supposed, it is their cooling which causes dew ; and its formation even mitigates the cold, by the heat pre- viously latent, which the steam gives out on condensing into water. The degree of heat at which dew begins to be formed is called. the dew-point, and instruments called hygrometers have been invented to measure it. The difference between the temperature of the dew-point and the temperature of the atmo- sphere indicates the degree of dry- ness, which in this country seldom reaches 30; that is, the tempera- ture of the earth necessary to con- dense the vapour of the air is seldom 30 below the temperature of the air. In India it has been known to be 61 below it, and in Africa probably lower still. If, while dew is forming, the earth continues to cool down until 496 VAR VELOCIPEDE. VEL it reaches the freezing-point, hoar- frost is formed. The beautiful figures seen in winter on the inner surface of window panes, cooled by the external air, are produced by these cold surfaces condensing the moisture of the warmer air within. Varry, a term in heraldry, denoting the mixture of argent and azure together Varry cuppy, a term applied to a fur of cups Vat, & wooden tub, used to wash ores and mineral substances in ; a work- ing-tub of any kind Vault, in architecture, an arched roof, so contrived as that the several stones by their disposition shall support each other Veering, or Wearing, in navigation, the operation to which a ship, in changing her course from one board to the other, turns her stern to windward, in opposition to tack- ing, wherein the bow is turned to the wind and the stern to lee- ward Vein, a course of metal in a mine: a rake vein is perpendicular, or nearly so ; a pipe vein, nearly hori- zontal Vein, in mining, to wash or cleanse a small portion of ore in a shoal Velocimeter, an apparatus for measur- ing the rate of speed of machinery. When the velocity is uniform, the instrument is merely a measurer of distance ; but this is not the case with a variable velocity, which re- quires a much more elaborate con- trivance for its estimation. Such a velocity-measurer was constructed by Breguet, of Paris, under the di- rection of M. Morin, the principle of which may be briefly explained as follows : A circular disc, covered with card or paper, is made to re- volve with an uniform motion by means of clock-work, regulated by air-vanes: upon this disc, a re- volving pencil, whose motion is caused by and corresponds with that of the body whose variable 497 velocity is to be measured, describes a curved line ; and from this curve, which results from a combination of the variable with the uniform motion, the velocity may be easily ascertained by processes and for- mulae adapted to the purpose. One of these cards, with the curve traced on it by the piston of the Cornish steam engine at Old Ford, is engraved in the ' Transactions of the British Association for the Ad- vancement of Science.' This beau- tiful and ingenious contrivance, by which spaces described in the ten- thousandth part of a second may be easily discerned, is the invention of M. Poncelet, and was carried into execution by M. Morin. The instrument, when put in order, was first tried at King's Col- lege,London,avariablemotionbeing given by a fcrnall carriage made to de- scend an inclined plane. The cor- respondence of the velocity shown by the machine with that deduced by the known laws of dynamics, was such as to give great confidence in its accuracy. After a few minor alterations, suggested by frequent trials, it was removed to the East London Water- Works, and attached to the Cornish engine at work there, from which several diagrams were taken ; and the velocities cal- culated from these have been ex- pressed in the form of geometrical curves, whose abscissae represent the spaces passed over by the pis- ton of the engine, and whose ordi- nates indicate the corresponding velocities at the different points of the stroke. Velocipede, a carriage which is capa- ble of being propelled along a road by the muscular power of the rider acting upon treadles and levers which communicate with a cranked wheel axle Velocity, in dynamics, is the ratio of the quantity of linear extension that has been passed over in a certain portion of time; or it is the ratio of the time that has been VEL VELOCITY. VEL employed in moving along a deter- minate extension. When a man ascends verti- cally, his velocity is reduced to about one -half of his horizontal velocity, indicating that he acts against a double resistance ; there- fore, when a man ascending a ladder, carries a load, the maximum effect will take place when his ascending velocity is about one- fourth of the velocity he can walk horizontally without a load. A man of ordinary strength will not be able to walk, unloaded, at a quicker rate than 3 miles an hour, if this exertion is to be continued for 10 hours every day. Indeed, those who examine the subject with a view to a fair average, will find this to be about the extreme velocity that can be continued, without injury, for any considerable time ; therefore a man ought to move with half this velocity to produce a maximum effect ; that is, at the rate of If mile an hour, which is about 2 feet per se- cond. But this supposes the whole load to be the useful effect, whereas part of it must consist of the ap- paratus employed to carry it, or the friction of the intermediate ma- chine, or other circumstances of a like nature. About one-fifth of the velocity may be considered equivalent, at an average, to the force lost in friction, &c., in all cases ; in many it will exceed one- fifth. Hence the maximum of use- ful effect will take place when the velocity is 2 feet per second, or about 11 furlongs an hour, con- tinued for 10 hours each day. Smeaton is said to have made numerous comparisons, from which he concluded that the mechanical power of a man is equivalent to 3750 tbs. moving at the velocity of one foot per minute; and taking this average to be near the true one, as there is reason to conclude it is, we have 498 3750 2 x 60 31-25 ibs. Therefore, we make the average me- chanical power of a man 31 '25 tbs. moving at the velocity of 2 feet per second, when the useful effect is the greatest possible ; or half a cubic foot of water raised two feet per second ; a very convenient ex- pression for hydrodynamical in- quiries. If a man ascend a vertical ladder, according to a preceding remark, the velocity which corresponds to the maximum of useful effect will be 1 foot per second, and the load double that which he carries hori- zontally ; consequently the average of useful effect is 62-5 Ibs. raised one foot per second. Bricklayers' labourers in London ascend ladders with a load of about 80 ibs. besides the hod ; sometimes at the rate of one foot per second, but more frequently about 9 inches per second. Ascending stairs is more trying to the muscles of the legs than ascending a ladder ; and therefore the useful effect is less, till a per- son has become accustomed to this kind of labour: and it is also to be observed that the space moved over is increased, unnecessarily, except where the horizontal dis- tance is part of the path over which the load is to be moved. The force of a horse is, at an average, about equal to that of six men, according to various esti- mates ; and the rate of travelling about the same, perhaps rather less than that of a man, when his exertion is continued for 8 hours : consequently the velocity corre- sponding to the maximum effect will be about 2- feet per second. Whence, the average mechanical power of a horse may be estimated at 18 7-2- ibs. moving with a velocity of 2^ feet per second, or 3 cubic feet of water raised 2| feet per se- cond ; the day's work being 8 hours. VEL VENTILATION. YEN Velocity of motion. The following is a list of the velocities of moving bodies, extracted from Peschel's * Elements of Physics,' &c. Feet per second. Rivers .... 3-4 A very rapid stream . . 13 Wind (ordinary) . . 10 Storm .... 54 Hurricane . . . 80-120 Sound (through air) . .1100 (through metal) . 12,000 Air into a vacuum 1280 Ball from air-gun (air con- "I 697 densed 100 times) Musket-hall . . .1280 Rifle-ball (at most) . .1600 Cannon-ball (24-pounder) . 2450 Earth's rotation (at equator) 1525 centre (in its orbit) 101,061 Miles per hour. Race-horse ... 60 Pigeon .... 20-30 Peregrine falcon . . 120 Ocean steamers . . 12 River steamers ... 22 Railway train . . . 80 Sailing vessel ... 10 Malay proa ... 20 Miles per second. Light .... 200,000 Electricity . . . 576,000 Velvet painting is the art of colouring on velvet with transparent liquid and other ready diluted colours, compounded and made up with various acids, alkalies, &c., accord- ing to their nature and qualities Venetian Red or Scarlet Ochre. True Venetian red is said to be a native ochre, but the colours sold under this name are prepared artificially from sulphate of iron, or its resi- duum in the manufacturing of acids. They are all of redder and deeper hues than light red, are very per- manent, and have all the proper- ties of good ochres. Prussian red, English red, and rouge de Mars, are other names for the same pig- ment. Ventilation and warming of buildings is a twofold purpose that should 499 enter into the constructive design of all edifices intended for the resi- dence or occasional congregation of human beings. The necessity for this purpose arises from the fact that the breathing of air (as one of the functions of animal life) renders it unfit for re-inspiration, the lungs retaining the vital pro- perties and emitting the remainder, which consists of ingredients detri- mental to health, and even de- structive of life itself. In order to keep an apartment in a healthy and pleasant condition, fresh air should be constantly supplied at a temperature from 60 to 65, and the vitiated air should be as con- stantly removed ; and all the varied schemes which have been pro- pounded for ventilating buildings have this common purpose of con- stant supply and removal. The vitiated air, on being emitted from the mouth, has a temperature be- tween 80 and 90 ; and as the uni- versal effect of heat, manifested in the increase of temperature of the supply, 60 or 65 to 80 or 90, is to expand and lighten, the viti- ated air has a natural tendency to rise to the upper part of the room. To allow this action to proceed, it is evidently necessary that means for its escape at the top should be provided, and also that fresh air should be introduced at the lower portion of the apartment. The operation would, however, be nulli- fied if the heated air, on emerging from the top of the room into a shaft or chimney intended to con- duct it away, were met by a down- ward current of cold air ; and it has therefore been deemed advisable to provide not only such a shaft or chimney, but also some means, by stoves or other apparatus, of arti- ficially heating the air in the shaft, and thus assisting the escape of the foul air. And further, in order to secure the constant accession of fresh air and give sufficient impulse to it to overcome any tendency YEN VENTILATION. YEN that might be created to oppose its introduction by a retrograde movement of the atmosphere of the building, means have been adopted of forcing this fresh air in with fans or bellows. But these two sets of apparatus have been seldom combined. Those who have adopted the shaft have usually con- temned the fan, trusting to the sucking action of the former to draw off all the vitiated air, and concluding that fresh air must enter as rapidly to fill its place ; and, on the other hand, the adopters of the fan decry the addition of the heating apparatus in the shaft, and contend that its only effect is to draw down foul air for its own supply, and to impede the upward current created by this fan. This effect should be obviated in a well- acting apparatus, which would then doubtless assist the fan in pro- moting the continual passage of pure air throughout the building. The objection which has been en- tertained against the use of the shaft without the fan, or some other adequate forcing apparatus, is well-founded on the well-known elasticity of the atmosphere, by which it is susceptible of rarefac- tion to a considerable extent. The heated shaft consequently acts as a pump in sucking the warmed air upwards, and if no force is in ac- tion from below to drive this air upward by the pressure of fresh air entering the apartments, the atmosphere becomes rarefied to a degree which is both unpleasant and prejudicial to sentient exist- ence. It is therefore essential that the two processes of exhaustion and supply shall proceed simul- taneously, and be so regulated that no rarefaction shall be suffered in the air to be breathed. The pur- pose of warming the air in winter, and of cooling it in summer, that is, more properly, of attemperating it, should be sought, and may be attained conjointly with that of 500 ventilation; and one of the best arrangements yet carried out for these combined objects is pre- sented in the system adopted at the Reform Club House in London. The supplying apparatus there em- ployed consists of a large fan which revolves rapidly in a cylindrical case,andis adapted to throw 11,000 cubic feet of air per minute into a spacious subterranean tunnel under the basement story of the building. This fan is driven by a steam engine of 5-horse power, working expansively. It is placed in a vault in front of the building, and as it burns anthracite coal and cinders from the house fires, is not pro- ductive of any nuisance or offensive smoke. The steam of condensa- tion supplies three chests, con- structed of cast iron, with the heat requisite for warming the building. Each of these chests is a cube in form, and measures 3 feet ex- ternally, and is internally divided into seven parallel cases, each 3 inches wide, and separated by al- ternate parallel spaces of similar width, for the passage of the air as it is impelled by the fan. By this economical arrangement, which thus makes good use of tlie steam of condensation, 2 cwt. of fuel is sufficient for working the engine during twelve hours, the engine being besides available for pumping water for the purposes of the establishment, and raising coals to the several apartments on the upper stories. The air in passing through the cells between the steam cases is heated to a genial temperature of from 75 to 85, and thence enters a chamber of brick- work in the basement, from which it is ad- mitted into several distinct flues, regulated by dialled valves or re- gisters, and thus conducted in any required quantities to the several apartments of the building. A stove is placed in the top story, and is formed as a rectangular chest of cast iron, contracted above YEN VIADUCT. VIA into a round pipe, which discharges the burnt air and smoke into a series of horizontal cast-iron pipes, about 4 inches in diameter, which traverse the room beneath the ceiling and terminate in a brick chimney. One advantage of such an apparatus as is here described would be that of introducing cool air during sultry weather, for which purpose it might be readily adapted. Ventilator, a machine made to turn with the wind, and placed in a wall or roof, in order to throw a due quantity of fresh air into a close apartment Verdoy, a term in heraldry, applied when a border is charged with leaves, fruits, and flowers, and like vegetables Verge, a rod, wand, or sergeant's mace ; also the compass about the king's court that bounds the ju- risdiction of the lord steward of the king's household, and of the coroner of the king's house, and is accounted 12 miles' compass; also a rod whereby one is admitted tenant, holding it in his hand and swearing fealty to the lord, of the manor, and for that cause called tenant by the verge Verge, a small ornamental shaft in Gothic architecture Vermiculated, chequered; continuous; embroidered with several colours Vermile, a cloth or napkin on which the face of Christ is depicted, de- rived from the incident related of of St. Veronica Vcrmillion, a sulphuret of mercury, which, previous to its being le- vigated, is called cinnabar. It is an ancient pigment, and is found in a native state, and produced artificially. Vermillion probably obtained its name from resem- blance to or admixture with the beautiful though fugitive colours obtained from the vermes or in- sects which yield carmine Vernier, a graduated moveable index, used for measuring minutely the 501 Y 5 parts of the space between the equidistant divisions of a graduated scale Versed sine of an arc, in geometry, the position of the diameter in- tercepted between the sine and the commencement of the arc Vert, in heraldry, a green colour; in the ancient forest laws, every thing that grows and bears a green leaf within the forest that may cover and hide a deer Vestiary, a wardrobe, or place to lay clothes or apparel in Vestibule, in architecture, the porch or the first entrance of a house Vestibulum, part of the andronitis of a Greek house, similar, probably, to the prostas of the first peristyle or court Vestment, a set of hangings for the service of an altar ; and also a suit of robes for a priest Via (Latin), by way of; in the time of the Romans, a road or a right of road. Two shallow trenches were commonly dug parallel to each other, marking the breadth of the proposed road : this in the great lines, such as the via Appia, the via Flaminia, the via Valeria, &c., is found to have been from 13 to 15 feet, on the via Tusculana 11 ; while those of less importance, from not being great thorough- fares, such as the via which leads up to the temple of Jupiter La- tialis, on the summit of the Albau Mount, and which is to the pre- sent time singularly perfect, seems to have been 8 feet wide. Viaduct, a term applied to extended constructions of arches or other artificial works to support a road- way, and thus distinguished from aqueducts, which are similar con- structions to support water-ways. This term has become much more familiar within the present cen- tury, in consequence of the great number of vast structures so de- signated which have been erected in various parts of Great Britain for the purpose of carrying rail- VIA VIADUCT. VIA ways over valleys and districts of low level : but the general name of viaduct is now recognized as applicable to all elevated roadways for which artificial constructions of timber, iron, bricks, or stone-work are established; and accordingly among the principal railway-works are to be enumerated viaducts of all these materials. The vast di- mensions of some of these struc- tures are not more striking to the casual observer, than their great strength, as particularly adapted to railway traffic, is apparent upon a careful study of their construction. The several members of a viaduct are the same as those of a bridge ; indeed, the former structure may be considered as an extendedbridge, frequently resorted to in situations where no water is to be crossed. The necessity which is imperative in the construction of railways for preserving a horizontal level for the roadway, or at least departing from this level within very restricted limits, imposes the raising of the railway surface in many places, and to a considerable extent above the natural level. Various considera- tions arise as to the preferable mode of effecting this raising, whether by solid embankments of earth- work or by an open or arched structure of other materials. Em- bankments of earth-work are often liable to subsidence from want of cohesion in the materials, or the effect of long-continued rains ; and if free from actual danger arising from these liabilities, they are al- ways sources of much constant ex- pense in making up the surface to the required level, to compensate for the continual depression caused by the passage of heavy loads over them. As a question of economy, therefore, viaducts are often to be preferred, since their repairs in- volve less expense than those of embankments. It must also be considered that the latter, owing to their necessary extension of base, 502 cover a much wider portion of ground than viaducts, and at the same time cover it in a more ab- solute and objectionable manner. A solid embankment, like a black line across a picture, spoils a beau- tiful landscape, and often precludes all view beyond it from sites which otherwise would command an ex- tended range. If the sub-forma- tion of the valley be of a very loose and boggy nature, embankments are scarcely admissible, nor, if the height to be raised exceeds 30 or 40 feet, can they be entertained. Indeed, in the majority of cases, valleys, whether having rivers of magnitude or not, are more eco- nomically crossed upon viaducts than embankments. Whatever the materials of the structure or its finished design, the same points are to be observed in the construction ; and the first of these is the strength and durability of the foundations. A substantial and permanent character should j always be secured for these, even j if the superstructure is intended to j aim at cheapness rather than so- J lidity. It is often requisite that the | piers and abutments be constructed j upon piling, a form of foundation j adapted, if thoroughly executed, to afford the most secure basis; but if done carelessly and insufficiently, liable to involve the most destruc- tive failures. The citation of a few T of the most extended works of this class, of modern date, will best show the details of the present approved kinds of construction. Of timber viaducts, two fine ex- amples of similar construction are presented on the line of the New- castle, North Shields, and Tyne- mouth Railway, and erected accord- ing to designs by Messrs J. and B. Green, of Newcastle. One of these works, which crosses the Ouse bourn, besides a public roadway, a mill-race, and the adjacent valley, consists of five spans or arches of timber-work, and four end arches VIA VIADUCT. VIA of masonry. Of the former arches, three are 116 feet wide in the clear, and two 114 feet. Two of the end arches are 43 feet span, and the other two 36 feet. The height of the rails above the bed of the bourn is 108 feet. The width of the structure allows 26 feet for a double line of rails, and 5 feet for a footway. The total length of the viaduct is 918 feet, and the two middle piers are erected upon piles, from 21 to 27 feet in length. All the piers are of masonry, and tapered up- wards, the principal being 21 feet wide above the footings, and 15 feet at the springing of the arches. The piers are continued upwards, of reduced dimensions, to the level of the roadway, the whole of the five main arches, spandrilling, and superstructure, being formed of timber. The radius of these arches is 68 feet, and their rise or versed sine about 33 feet. The ribs form- ing the arches are composed of planks of Kyanized Dantzic deal, the lengths of which vary from 20 to 46 feet, by 11 inches wide, and 3 inches thick. These planks are so arranged, that the first course of the rib is two whole deals in width, the next is one whole and two half -deals, the joints being crossed longitudinally, as well as in the depth. The thickness of each rib is made up of fourteen deals, which are bent over a centre to the required form, and fixed together with oak tre- nails, H inch in diameter, placed 4 feet apart, and each trenail per- forating three of the deals. Be- tween the joints a layer of strong brown paper is placed, previously dipped in boiling tar. The span- drils are formed of trussed fram- ing ; and the platform of the road- way, which is composed of 3-inch planking, is supported upon trans- verse beams laid 4 feet apart. The platform is covered with a com- position of boiling tar and lime, 503 mixed with gravel in applying it, thus forming a coating impervious to water. There are several other modes of constructing timber viaducts, without introducing the arches, composed of planks curved into proper form, and which, being laid together like leaves, as just de- scribed, have obtained for this kind of construction the name of the ' laminated bridge.' In other forms of timber viaducts, the requisite strength is obtained by trussing, the peculiar description and com- plication of which depends, of course, mainly on the extent of the span or width of each lay of which the entire structure consists. Where a great width of clear open- ing is required, a system of diagonal bracing offers peculiar advantages, being susceptible of any desired strength and rigidity. A viaduct of great extent, built upon this principle, is on the line of the Richmond and Petersburgh Rail- way, North America. The length of this structure is 2900 feet, and the trusses are supported upon eighteen granite piers, the dis- tances between which vary from 130 to 153 feet. They are founded on the granite rock, and are 40 feet high above the water. The depth of the truss-frames (which are ho- rizontal on top and bottom) is 20 feet. Another work of the same kind crosses the Susquehannah, and is 2200 feet in length, divided into spans of 220 feet each. Of viaducts formed of brick-work and masonry, that named the ' Avon Viaduct,' on the line of the North -Western Railway, may be mentioned^ This consists of nine semi-elh'ptical arches, 24 feet in span, and 7 feet 6 inches rise, and three semicircular arches at each end of 10 feet span. This viaduct is entirely faced with stone, the interior of the work being of brick. The end arches have brick inverts between the piers above the found- VIB VILLAS OF THE ANCIENTS. VIL ations, which are laid uniformly in a solid bed beneath these arches, with steps according to the nature of the substratum. An invert of brick-work is built to the three middle arches, forming an artificial channel for the river, and faced at each end with a row of sheet- piling, driven through the loam into a bed of strong gravel beneath. All the foundations which do not reach the gravel are laid upon beds of concrete, and a layer of the same material covers the extrados of the arches, and forms a level bed for the gravel in which the sleepers of the railway are bedded. Many similar works of much more extended dimensions have been erected for railway communication. One of these, of peculiarly light appearance, is known as the ' Vic- toria Bridge,' and built over the valley of the river Wear, on the line of the Durham Junction Rail- way. This work consists of two main arches, one 160 feet span, the other 144 feet, two others, each 100 feet span, and six end arches of 20 feet span. The height of the parapet above the high- water level at spring-tides is 125 feet, and all the arches are semi- circular. The central pier is 23 feet 9 inches in width, and 69 feet high from bottom of footings to springing of arches. The two con- tiguous piers are 21 feet wide, one 50 feet, the other 52 feet high. The height of the parapet above the springing line of the two main arches is 78 feet. A viaduct, re- cently constructed over the Moine, at Clisson, near Nantes, in Brit- tany, is worth notice, for a pe- culiarity in its construction, which, although not strictly new, is to be found in very few examples. This peculiarity is, that the piers are pierced with a pointed arch, which intersects the cylindrical soffit of the main arches in the direction of the length of the viaduct, so that the roadway is supported upon a 504 groined vault, which, seen from the abutments, has the appearance of the aisle of a Gothic cathedral. This viaduct consists of fifteen arches, and is 348 feet in length. The abutments rest upon a granite foundation, the structure itself being constructed of a fine white granite, and the stones of large size. The foundations are 6 feet below the bed of the river, the height from which to the spring- ing line of the arches being 33 feet, and the total height from the foundation to the top of the parapet 61 feet. Vibration, the regular reciprocating motion of a body, as a pendulum, musical chord, &c. Vice, a tool for holding a piece of metal, while operating upon it, by placing it between two jaws or nip- pers, and screwing them towards each other Vice-bench, the bench to which a vice is fixed Villa, among the Romans, a farm or country house Villa rustica, a tasteful country re- sidence. (See Parker's Villa Rus- tica'). Villa urbana, a residence so called by the Romans, because its interior arrangements corresponded prin- cipally with those of a town -house Villas of the ancients. Varro Colu- mella says, "An estate should be in a wholesome climate and fruitful country ; one part champaign, and the other hilly, with easy descents either to the east or south ; some of the lands cultivated, others wild and woody ; not far from the sea or a navigable river, for the easier ex- portation of the produce of the farm, and the importation of ne- cessaries. The champaign lying below the house should be dis- posed into grounds for pasture and tillage, osiers and reeds ; some of the hills should be naked and without trees, that they may serve best only for corn, which grows in a soil moderately dry and rich, VIL VILLAS OF THE ANCIENTS. VIL betterthan in steep grounds ; where- fore the upper corn-fields should have as little declivity as possible, and ought to resemble those in the plain : from thence, the other hills should be laid out into olive-grounds and vineyards, and produce trees necessary to make props for those fruits, and, if occasion should re- quire building, to afford timber and stone, and also pasture for cattle. Moreover, constant rivu- lets of water should descend from thence upon the meadows, gardens, and osier-grounds, and also serve for the convenience of the cattle that graze in the fields and thickets : but such a situation is not easily to be met with; that which enjoys most of these advantages is cer- tainly most valuable ; that which has them in a moderate degree, is not despicable. The natural good qualities of a situation mentioned by Palladio are, a salutary air, plenty of wholesome water, a fruitful soil, and a commodious place : we may hence conclude that those places are healthy that are not located in deep valleys, or subject to thick clouds, where the inhabitants are of a fresh com- plexion, have clear heads, good sight, quick hearing, and a free dis- tinct speech ; for by these things is the goodness of the air distinguish- ed; and the contrary appearance proclaimsthat climateto be noxious. The unwholesomeness of water may be thus discovered : in the first place, it must not be conveyed from the ditches or fens, or rise from minerals, but be very trans- parent, not tainted either in taste or smell, without settlement, in winter warm, in summer cold; but because nature often conceals a more lurking mischief, in these outward appearances, we may judge whether water is good by the health of the inhabitants : if their cheeks are clear, their heads sound, and little or no decay in their lungs and breasts ; for gene- 505 rally where the distempers in the upper part of the body are trans- mitted down to the lower, as from the head to the lungs or stomach, there the air is infectious : besides, if the belly, bowels, sides, or veins, are not afflicted with aches or tu- mours, and there is no ulcer in the bladder; if these or the like are apparently in the major part of the inhabitants, there is no cause to suspect the unwholesomeness of the air and water. The fatal con- sequences proceeding from bad air, Varro tells us, are in some measure to be alleviated, if not prevented, by the skill of the architect. His words are: That land which is most wholesome is most profitable, because there is a certain crop; wliereas, on the contrary, in an un- healthy country, notwithstanding the ground is fertile, yet sickness will not allow the husbandman to reap the fruits of his labour ; for where one exposes his life to cer- tain dangers, for uncertain advan- tages, not only the crop, but the life of the inhabitant, is precarious ; wherefore, if it is not wholesome, the tillage is nothing else but the hazard of the owner's life and his family : but this inconvenience is remedied by knowledge, for health, which proceeds from the air and soil, is not in our disposal, but under the guidance of nature ; yet, nevertheless, it is much in our power to make that burthen easy by our own care ; for, if upon account of the land or water, or some unsavoury smell, which makes an irruption in some, part of it, the farm is made unwholesome, or upon account of the climate, or a bad wind that blows, the ground is heated, these inconveniences may be remedied by the skill and ex- pense of the owner, which makes it of the last concernment where the villas are placed, how large they are, and to what quarters their porticoes, gates, and windows are turned. Did not Hippocrates the VIL VILLAS, ROMAN. VIL physician, in the time of a great plague, preserve not only his own farm, but many towns, by his skill? When Varro and his army and his fleet lay at Corcyra, and every house was filled with sick persons and dead bodies, by his care in making new windows to the north- east, and obstructing the infection by altering the position of the doors, he preserved his companions and family in good health. As a house should be built in a wholesome country, so it should be in the most wholesome part of a country ; for an open air, and at the same time infected, causes many distempers." Villas (Roman). The term villa was applied to a cluster of buildings in the country for the accommodation of the family of a wealthy Roman citizen. Very extensive villas were divided into three parts ; the Ur- bana, the Rustica, and the Fruc- tuaria. The first contained the eating-room, bed-chambers, baths, covered porticoes, walks, and ter- races. The villa rustica was the division for the servants, stables, &c. ; and the fructuaria for wine, oil, and the produce of the farm. Although the Roman villas were the boast and delight of poets and philosophers whose works have for- tunately reached us, yet no de- scription has been conveyed of their external architecture. From the magnificent style of public build- ings at Rome, moderns were led to suppose that the villa architecture bore some analogy in splendour of outward appearance ; but from in- spection of their remains, and from the late disinterment of one on the outside of the walls of Pompeii, little doubt now remains on the subject. It is true that the exten- sive remains of Adrian's villa, and that of Mecaenas, covered ground equal almost to a small town, but no regular plan of architectural elevation can be traced with all the ingenuity of even a Roman anti- quary. The Pompeian is certainly 506 the most complete example of an ordinary sized Roman villa: situ- ated on a sloping bank, the front entrance opened, as it were, into the first floor, below which, on the garden side, into which the house looks, (for the door is the only aperture on the road side,) was a ground floor, with extensive ar- cades and open rooms, all facing the garden; and above were the principal rooms. It was spacious, and near the entrance was a bath with all the necessary appendages ; in the rear the best rooms opened upon a terrace, running the whole width of the house, and overlook- ing a garden about 30 yards square, surrounded by a covered walk or portico continued under the terrace. The lower apartments under the arcade were paved with mosaic, coved and beautifully painted. One of the rooms had large glazed bow- windows; the glass was thick, of a green colour, and set in lead like a modern casement. The walls and ceilings of the villa were orna- mented with paintings of elegant j design, all of which had relation to the uses of the respective apart- ments. In the middle of the gar- den was a reservoir of water, sur- rounded by columns. The cellars extended under the whole of the house and the arcades. Pliny tells us that the size of the villa urbana, and its number of parts, were determined by the pleasure or quality of the master, but those parts belonging to agri- culture, by the bulk of the farm and the number of cattle. The ser- vants that in most great men's houses were more immediately for the master's use, and may be said to have belonged to the villa urbana, were the atrienses, which included all those we call livery servants, and those belonging to the bed-cham- ber ; and the topiarii, which were gardeners belonging to thepleasure- garden ; with comedians, musicians, and the notaries or secretaries. The VIL VILLAS, ITALIAN. VIS principal person over the other parts of the villa was the procurator or bailiff; then the villicus or hus- bandman, who had under his care the tillage of the land, and the disposal of the produce of the earth about the villa; next was the villica or house-keeper, to whose care every thing within doors belonged, and who had immediately under her command the women servants that were employed in those affairs, but particularly those belonging to the feeding and clothing of the house- hold. The master of the cattle may take the next place, and under his command were all the herds- men, shepherds, goatherds, swine- herds, and grooms. The care of all those fowl that were within the bounds of the villa was committed to the poulterer. In great villas it was thought necessary to keep within the family useful mechanics, as smiths, carpenters, &c. The cattle within the villa were horses and mules, &c. ; and to make pro- vision for the several persons and animals, and also for corn and the necessary offices of the house, was the architect's care ; and the disposition of each part was go- verned by rules that may be col- lected from Cato, Vitruvius, Varro Columella, and Palladius. Of the Greek villas, no descrip- tion has been transmitted to us ; in villa gardening, however, con- siderable progress at that time was made, borrowed probably from Asia Minor : myrtles and roses adorned them ; the box and lime tree were planted for topary works ; and Theophrastus tells us, that flowers and fruits were cultivated in the winter ; and the violet more particularly was in profusion in the market of Athens while snow was on the ground. Villas (Italian}. The description of an Italian villa built in the time of Michael Angelo, Raphael, Julio Romano, Dominichino, Paul Ve- ronese, and Pietro da Cortona, de- 507 servesthenotice of architects. "The palace of Caprarola is situated on the summit of Mount Camino, near Viterbo: below is the village of the same name, of which the prin- cipal street runs in a direct line down the descent from the front of the building, but with a sufficient space between them. A double stair, partly direct, partly curved, with terraced landing-places deco- rated with balustrades, leads to the palace. Entrances under the ter- races of the stairs conduct to the underground parts of the building. The form of the palace is a pen- tagon flanked by five bastions, sur- rounded by a sunk area. Hence there is a mixture of civil and military architecture that has a good effect. The palace is built in two orders of architecture ; the one, Ionic, with semicircular-headed windows ; the upper, Corinthian, comprehending both the first floor and the mezzanine above. Within the pentagonal figure is included a circle, comprehending the court, the porticoes, the offices, and stairs. The decorations of the whole and the parts are executed with much skill. Although the entire edifice is not great, yet the parts are on a great scale, apparently." Virtuoso, a man skilled in antique or natural curiosities, studious of painting, statuary, or architecture Vis absoluta, absolute force Vise, a spiral staircase, the steps of which wind round a perpendicular shaft or pillar, called the newel Vis inertia, the propensity of nature to remain in its actual condition, whether of motion or rest, and to resist change Vis insita, the power or innate force essentially residing in any body, and by which it endeavours to preserve its present state, whatever that be Viscount, in law, signifies as much as sheriff: in heraldry, it signifies a degree of nobility next to an earl Vis viva (work). The vis viva of a body is its mass multiplied by VIT WAINSCOT. WAL the square of its velocity : work, or dynamical effect, supposes a body moved, and a resistance overcome; and either of these, without the other, is insufficient to constitute work. The work produced by a pressure moving* body through a certain space is defined to be the product arising from multiplying the pressure by the space through which this pressure acts. Vitreous, glassy ; consisting of or resembling glass Vitrification, the act of changing into glass Vitriol, oil of, sulphuric acid Vitruvian Scroll, a peculiar pattern of scroll-work, consisting of con- volved undulations, used in clas- sical architecture Viz. (To wit], that is; a contraction of videlicet Voider, in heraldry, a gentlewoman's armory, consisting of an arch line, moderately bowing from the corner of the chief toward the nombril or centre of an escutcheon Voiding, a term in heraldry, signifying WAG WAGGONS, vehicles for the convey- ance of persons, merchandise, &c., varying in form according to their use, and dating in their origin from the remotest antiquity : " Jo- seph gave them waggons, according to the commandment of Pharaoh, and gave them provision for the way." Gen. xlv. 21. Waggon-boiler, a low-pressure boiler, having the form of a waggon, with arched top and incurvated sides Wainscot, a name given to boards em- ployed to line the internal walls of an apartment, so called from foreign species of oak named wains- cot being first used for such a purpose. Wainscoting, as it is called, both of Flemish and Eng- lish oak, was commonly used for interior linings in Tudor, Eliza- bethan, and Stuart times. 508 exemption of some part of the in- ward substance of things voidable, by reason whereof the field is trans- parent through the charge Volant, in heraldry. When a bird is drawn flying, or having the wings spread out, it is said to be volant. Volute. The characteristic ornaments and indicial marks of the Ionic capital formed by circumvolving spiral mouldings are termed vo- lutes. The small circle in which the spiral or springs terminate is called the eye of the volute. The introduction of volutes is said by Vitruvius to have arisen from an imitation of the mode in which women were formerly accustomed to ornament their hair; but they are thought, with greater proba- bility, to have represented the horns of the Ammonian Jupiter. Voussoirsjn architecture, vault-stones, or those that immediately form the arch of a bridge, vault, &c., and are cut somewhat in the shape of a truncated pyramid Vugh, in mining, a cavity WAL Waist, in a ship, the uppermost part of the top-side Wake, in navigation, denotes the print or track of a ship on the surface of the waters. Two dis- tinct objects seen at sea are said to be in the wake of each other when the view of the furthest is inter- rupted by the nearest. Wales, in ship-building, are an as- semblage of strong planks extend- ing along a ship's side, serving to reinforce the decks and form the curves of the vessel Wall-plate, a piece of timber placed along the top of a wall, to receive the ends of the roof timbers, or so placed on a wall as to receive the joists of a floor Walnut wood. The royal or com- mon walnut is a native of Persia and the north of China : it was WAR WATER. WAT formerly much used in England before the introduction of ma- hogany. The heart wood is of a grayish brown, with black-brown pores, and often much veined with darker shades of the same colour. Some of the handsome veneers are now used for furniture, frames of machines, gun-stocks, &c. Wardrobe, a place where the gar- ments of kings or great persons used to be kept ; and he that keeps the inventory of all things belonging to the king's wardrobe is called Clerk of the King's Wardrobe Wards and Liveries, a certain court erected in the time of Henry VIII. Warp, in navigation, to change the situation of a ship in harbour, &c., by means of ropes or warps attached to buoys, posts, rings, trees, &c. Washing, in painting, to lay a colour, such as Indian ink or bistre, over a pencil or crayon drawing, to render it more natural, and add to the shadow of prominences, aper- tures, &c. Wassail, a term which is said to have had its origin at the meeting of Vor- tigern and Rowena, the daughter of Hengist. Geoffrey of Monmouth states, that the lady knelt before the king, and presenting him with a cup of wine said, ' Waes-hael,' which in Saxon means ' Health be to you/ Vortigern, as he was in- structed, replied, ' Drinc-hael,' i. e. ' drink the health :' Rowena drank, upon which Vortigern took the cup and pledged her. Hence the term and custom. Waste steam-pipe, in steam engines, the pipe leading from the safety- valve to the atmosphere Waste water-pipe, in steam engines, the pipe for carrying off the surplus water from the hot well Water is the most abundant and im- portant fluid in nature : it is proved to be composed, by weight, of 8 parts of oxygen and 1 part of hydrogen, and is resolvable into 509 both these gases by voltaic action, and by intensely ignited platinum : other heated metals combine with its oxygen, and liberate the other gas. When hydrogen and oxygen are mixed in trie proportion given, and ignited, they unite with explo- sion, and water alone is produced. The purest water in nature is that which descends from the atmo- sphere; that of springs, rivers, and the ocean being more or less charged with mineral matter. When the foreign substance is not volatile, the water is easily separable by distillation in the form of a pure vapour or steam, while the fixed substance remains. In nature, the solar heat produces this effect on a vast scale, evaporating enormous quantities of water into the atmo- sphere, whence, by cooling to va- rious degrees, it falls again in the form of rain, hail, or snow : this, in its passage through different strata towards its lowest level, dis- solves any soluble matters which it may encounter, of which salt is the most conspicuous, conveying them ultimately into the ocean. This process, operating for ages, is fully sufficient to account for the prevalence of so soluble a mineral as common salt in sea-water, and the comparative purity of that of rivers. When water runs through beds of chalk or selenite, it acquires both an acid and alkaline quality in a small degree. The acid is discovered by a few drops of solution of oil of tartar: this alkali will seize the acid, and descend with it in a cloud to the bottom of the glass, where, if permitted to stand a sufficient period, it will concrete into a neu- tral salt. The alkaline part is discoverable by a few drops of the solution of oxalic acid. This acid has so strong an affinity to calcareous earth, that the smallest quantity in water is detected by it. There are numerous tests which discover acid and alkali in water ; WAT WATER. WAT as, the syrup of violets, tincture of turnsole, ash-bark, logwood, &c. Strictly, philosophically speaking, sea-water is not salt, because if a given quantity is put into a glass retort, by sand heat from material fire it will pass over perfectly fresh, and the marine salt it contained will be left behind. Snow and rain waters, when collected at a distance from smoky towns or cities, if collected and kept in a stagnated state, go repeatedly into a state of fermentation, and some- times become putrid, by the ex- traneous matters they receive in passing through the lower atmo- sphere, previous to their reaching the earth. If the specific gravity of water is considered at 1000 ounces the cubic foot, common air will be If, fine gold will be ^o TO^ and pure platina ^ w ; or if a datum is taken of 1 for water, gold will be 20, and refined platinum 22. Water is incompressible, as expe- riment proves. It has been put into a gold globe, and great power applied in vain to press it into a smaller compass; it passed off by oozing or sweating through the pores of gold. It will rise in some cases above its own level, in a small degree, by capillary attrac- tion. If a piece of dry loaf sugar or sponge is put into a shallow vessel of water, and have part of it unimmerged, the fluid will be seen to ascend above its level. Water will also ascend to the height of 32 or 33 feet above its level in a vacuum, as in pumps, by the pressure of the atmosphere, which varies more or less according to its density, that is, calculating on the pressure of the atmosphere, at the height of 15 miles. The pressure of water on the base of the vessel in which it is contained is as the base and perpendicular altitude, whatever be the figure of the vessel that con- tains it. A body immersed in water loses as much weight as an equal bulk of the water weighs, 510 and the water gains the same weight. Thus, if the body be of equal density with the water, it loses all its weight, and so requires no force but the water to sustain it : if it be heavier, its weight in the water will be only the differ- ence between its own weight and the weight of the same bulk of water, and it requires a force to sustain it just equal to that differ- ence ; but if it be lighter, it re- quires a force equal to the same difference of weight to keep it from rising up in the fluid. Water of great rivers may cer- tainly be deemed the most pure and wholesome for all culinary j and domestic concerns, independ- ent of its superior fertilizing powers when used for the purpose of agri- culture or the growth of plants ; and when thrown into reservoirs, and cleared of its sediment, it be- comes clear and equally transparent with the brightest water proceeding from the hardest rock ; for, pre- vious to its being thus deposited, while swiftly gliding within its banks, it deposits large portions of its bituminous, calcareous, argil- laceous, and chalybeate qualities. Water is a conductor of atmo- spheric air, as well as sound. In Ralph Dodd's ' Civil Engineer ' an accident is mentioned, by which one of his workmen was buried, by the falling of 40 feet of a shaft, the bottom of which approached to a sand highly charged with water. He remained from Friday evening till Tuesday morning. The workmen were this considerable time before they came to him, conversing together and excavating over his head, which considerably increased his hope of being re- leased from his horrid captivity; for he became aware of their endeavours for his release as soon as the workmen had entered the sandy stratum, through which the water filtered downward, a strong evidence of its conveying sound, j WAT WATER-COLOUR PAINTING. WAT as well as atmospheric air, or, doubtless, he could not have ex- isted. Day-springs, either lying near the surface of the earth, or finding fresh passages thither, break forth into open air on their own account ; while those of a deeper nature are sunk down so low as to require hydraulic machinery to bring them up again. Next, they are called top-springs, inasmuch as they ap- pear either above the rock which severs the soil from the mine, or underneath it. Top-springs differ from deep or other springs, in that they stagnate between the super- ficies of the earth and the surface of the parts confining them, till they are opened by the miner; and those springs that can be let off by drifts, headings, soughs, and trenches, are distinguished from those of the deep, the draining of which by such means is alto- gether impracticable or absolutely impossible. In the search after the original source of those cur- rents of water, which, issuing out of the earth, and are commonly called day-springs, the first con- sideration that arises is, that their natural course, as consisting in motion, is merely local, and caused by the propension of their own weight, still drawing them down- ward, towards the centre of the earth : their course must always be upon a constant descent from a higher situation to a lower, and so must proceed originally from rain, distilled from the clouds. And if it happen, that at their emersion out of the earth, their spring rises upwards, it is caused by the curvity of their passage, that (syphon-like) points the way ; while the preponderance of the water contained in its other arm, descending from a greater height, forces it to rise contrary to its natural inclination. The specific gravity of rain -water is 1000; weight of a cubic foot 511 62 \ its. ; weight of a column, one inch square and a foot in height, 0-434 fts.; of an ale gallon 1 0-2 tbs.: expands -^ of its bulk in freezing, and ^^5-3- for every degree of heat : boils at 212 under the ordinary pressure of the atmosphere : max- imum density 39 0> 38 of Fahr. The specific gravity of sea-water is 11-0271. Water-colour painting is the art of making a picture with colours ground up with various kinds of aqueous gums or sizes, then called transparent colours. These draw- ings are executed on various kinds of paper, and are generally termed tinted drawings. The following are the most permanent colours, and therefore most valuable to the water-colour painter : blues ul- tramarine, French ultramarine, co- balt, indigo, and smalt : reds In- dian red, light red, Venetian red, scarlet vermillion, carmine, pink madder, rose madder, purple lake, and red orpiment: yellows cad- mium yellow, gamboge, yellow ochre, Indian yellow, mars yellow, lemon yellow, Roman ochre, brown ochre, mars orange, raw sienna, Italian pink, gallstone, and king's yellow : purples purple madder, Indian purple, and burnt carmine : Aroww burnt sienna, brown pink, burnt umber, Vandyke brown, se- pia, mars brown, Cologne earth, bistre, and madder brown : greens emerald green, olive green, and green oxide of chromium : blacks ivory black, blue black, neutral tint, and British ink : whites ox- ide of zinc or Chinese white, and sulphate of barytes or constant white. Water-crane, an apparatus for sup- plying water from an elevated tank to the tender of a locomotive engine Watering the streets of Paris (the contract for}. The contractor for this service receives 105,000 francs per annum, or 4200 sterling. It lasts from March 15th to Octo- ber 15th. WAT WATER SUPPLY. WAT He is bound to hold at the dis- posal of the engineers who are charged with the direction of the roads, twenty-five carts during the first month of the season ; during the second, the number is fixed at fifty-five ; during the remainder at ninety, with fifteen others in re- serve. These carts can only be used for the service of the town ; and they are repainted every year. They contain 1 metre cube, or 1 ton each, and are drawn by one horse. They have a double dis- charge hose ; at the front and at the back. At half-play they water 1000 metres superficial. At full play they water 700 metres super- ficial. In the first case, they are emptied in 10 minutes; in the second, in 6 minutes. Each cart costs 800 francs, or 32; of which 200 francs, or 8, are for the ma- chinery necessary for the distribu- tion of the water. The Avenue de Neuilly in the Champs Elysees forms a special service, on account of the immense number of carriages which traverse it. The total surface is 32,000 metres superficial, or nearly 8 acres English (7-976 a.) The cost per day in the summer months is as follows : 2 water carts, horse and driver included, each at 11-10 f. = . . . 22-20 84-OO m cube water (a metre cube = 1 ton) at 0-137 f. = . . . 11-50 Turncock (portion of his time) 2-00 Total 35-70 or 0-001116 f. per metre super- ficial. It has been found that the streets of Paris require to be watered 135 days on the average ; the numbers are between 107 in the wettest season, and 147 in the driest. On the above average of 135, 100 days require a double watering. The quantity consumed is about 1 litre 512 (1-760773 pints English) per metre superficial ; 1 litre, when the roads are so very dry as to require a more abundant watering; and 1-60 litre (or 2-82 pints English) in the Avenue de Neuilly. The water columns are spaced so as to avoid any useless movements of the carts ; in fact, in such a manner as to allow of their being emptied be- tween one column and the other. The usual distance is 500 metres (about 550 yards.) Water-sail, in navigation, a small sail spread occasionally under the lower studding-sail or driving - boom, during a fair wind and smooth sea Water-spout, a strongly agitated mass of air, which moves over the sur- face of the earth, and revolves on an axis, of which one extremity is on the earth and the other in a cloud. From this cloud a conti- nuation proceeds down wards, which forms the upper portion of the wa- ter-spout ; while the lower portion, besides air, consists sometimes of water, sometimes of solid portions, according as the waterspout passes over land or over water. Some have separated water-spouts over the land and over the water from each other ; but this creates confu- sion, for water-spouts have been ob- served which were formed over wa- ter, and advance over land ; and vice versa we have accounts of wa- ter-spouts which were formed over land, and afterwards suspended over the surface of water. Water supply for towns. A plentiful supply of water fitted for drinking, culinary, and detergent purposes, is so essentially an article of every- day use, that in all ages, where- ever a quantity of human beings have been congregated together, contrivances have necessarily been resorted to, to procure a supply: in some situations wells are sunk to a considerable depth, from which water is lifted by means of buckets, pumps, or like contrivances ; in WAT WATER SUPPLY FOR TOWNS. WAT others, the rain-water falling on the roofs of houses is caught and hus- banded in suitable receptacles, or, as was much practised in ancient times, where large populations ex- isted, rivers are diverted for their use from their natural channels, and conducted over valleys and through mountains in artificial courses having a small but con- tinuous decline. Much has been written and said of the plentiful supply of water brought into ancient Rome and towns in Italy, Spain, and other places, by means of aqueducts ; but the streams supplying these aqueducts would yield but little water in the dry summer and autumn weather, as is proved from the number of sources from which water was frequently brought to a town. Ancient Rome, according to some writers, was supplied from no less than twenty aqueducts, all deriving their water from different sources. These aqueducts were built at separate times, and they were doubtless made to supply a pressing want ; for although in wet and moderate seasons, probably one-third this number would have yielded a supply adequate to the demand, it is much to be doubted if this was the case in seasons of drought ; especially as the ancients made no provisions by means of impounding reservoirs to store a supply from wet to dry seasons. In ancient times, water was brought to a town from rivers or springs more elevatedthan the town itself, and was distributed through fountains to the inhabitants, who fetched it in vessels to their houses. In modern times, excessive floods are frequently stored in large re- servoirs, to yield a supply to our towns in seasons of drought; or water from a neighbouring river, or from deep wells sunk in a sub- terranean reservoir, or water-bear- ing stratum situated below the level of a town, is frequently lifted ~ 513 by means of pumps, worked by steam or water power, through a line of cast-iron pipes into a reser- voir of sufficient altitude to admit of its being conducted from thence through other pipes to the highest house in a town ; and it is no un- common thing at the present time to lift water from 200 to 300 feet in elevation for this purpose. But the greatest improvement lately made for supplying towns with water consists in the arrange- ments for conveying it, when raised to a sufficient altitude, in cast iron or lead pipes, into the house of every inhabitant, even to the upper story, so that this necessary article can always be secured by the turning of a cock : it is also dis- tributed in the same manner for watering roads, and for use in case of fire ; and it is principally in the excellent system of distribution, which perfection in the art of making the pipes has induced, that renders modern water-works supe- rior to those of ancient times. It is of the utmost importance to every house to be supplied plen- tifully with wholesome soft-water, and there are now few places in which this cannot be accomplished at a cheap rate. The modern cost of supplying water to a large town may now be taken at a low estimate per head of the population supplied, according to the facilities or diffi- culties that exist for procuring and distributing the supply : as a gene- ral rule, river-water, when unpol- luted with the drainage of a town, or the rain-water flowing down the sides of steep hills of a retentive character, when properly filtered, is superior in quality, and better adapted for most domestic uses than the brightest spring-water, owing to its freedom from saline matter, which is usually denomi- nated softness. All rain and surface water should, however, be carefully filtered be- WAT WATER-WHEEL. WAT fore it is supplied for domestic uses, not only to free it from earthy me- chanical impurities, but to rid it of organic matter, which in summer time and warm weather is always mixed with such water in a greater or less degree, and the presence of which renders it unwholesome for drinking or culinary uses. It Is principally owing to its freedom from organic matter that spring- water, though usually hard, is pre- ferred to river-water as a beverage. Water-ways, in ship-building, the planks of the deck which are close to the timbers Water-wheel, a wheel turned on its axis by the weight of water falling upon its circumference, and thus adapted as a machine for deriving power wherever a fall of water can be commanded. For this purpose the wheel is erected in a vertical position upon a horizontal shaft or axis, and the periphery of the wheel is so formed that the great- est possible effect shall be received from the weight or gravity of the falling water. To obtain this ef- fect, the rim of the wheel is pro- vided with small troughs or buckets in which the water is received, and its weight made active in carrying down that part of the periphery on which the loaded buckets are situ- ated. As they approach the lowest position, they become emptied, and are thus prepared to be carried up- ward during the revolution of the wheel, while the descendingbuckets are successively receiving their supply from the fall of water. Water-wheels are commonly dis- tinguished according to the height of the fall in comparison with the diameter of the wheel, and the po- sition at which the water acts upon the buckets. Thus if the depth of fall equals the diameter of the wheel, (besides allowing a little de- clivity below the wheel, for the ready escape of the back-water,) so that the water falls on the highest point of its periphery, the wheel is 514 said to be an 'overshot' water- wheel. If the depth of fall is less, so that the water falls upon the wheel, only a little above the level of its centre, the wheel is called a 'breast' wheel. And if the depth of fall is so little that the water acts by impulse only against the lower parts of the wheel, it is called an 'undershot' water- wheel. Water- wheels are now made in the most improved manner of iron, the arms being of wrought iron, the centres of cast iron, and the buckets of plate iron. A water-wheel thus constructed consists of a centre boss, and shaft, arms, buckets, and shrouding, the latter being the term applied to the rims of the wheel, between which the buckets are enclosed. In order to derive the greatest working effect from a given fall of water, the principal object is to shape the buckets so that they shall retain the water during the longest possible period. One great difficulty experienced in seeking this object has been the opposition exerted by the air to the admission of the water into the buckets ; and, to counteract this evil, several methods have been devised. The only efficient remedy yet introduced is that invented by Mr. Fairbairn, and which he de- nominates the ' Ventilating Water- wheel,' the general object of which is to prevent the condensation of the air, and to permit its escape during the filling of the bucket with water, as also its re-admission during the discharge of the water into the lower mill-race. Several wheels erected and fitted upon this principle have proved entirely suc- cessful in realizing a maximum use- ful effect from a given fall of water. All these wheels are formed with wrought-iron arms radiating from cast-iron centres to the periphery, and so disposed that the entire structure is in a state of tension, and the motion of the wheel being communicated from internal WAT WATER-WHEELS. WAT toothed wheels fixed to the shroud- ing. As applied to common breast- wheels adapted for falls not ex- ceeding 18 or 20 feet, these venti- lating buckets effect so great an improvement, that if the wheel is plunged in back-water to a depth of 5 or 6 feet, its uniform speed is not impeded. In these wheels the sole of the buckets is close, and the tail end of them being turned up at a distance of 2 inches from the back of the sole-plate, and running parallel with it, terminate within about 2 inches of the bend of the bucket, immediately above it. The water in entering the bucket drives the air out through the aperture into the space behind, and thence into the bucket above, and so on in succession. The converse oc- curs when the buckets are emptied, as the air is enabled to enter as fast as the wheel arrives at such a position as to permit the water to escape. (For a more copious de- scription see Water-wheels with ventilating buckets.} There are many cases in which it is of importance to know the proportion of power necessary to give different degrees of velocity to a mill ; but as the construction of mills and the purposes they serve are various, it is perhaps im- possible to find any law of univer- sal application. Mr. Banks, in his ' Treatise on Mills,' has drawn a conclusion which he appears to consider invariable, namely, that " when a wheel acts by gravity, its velocity will be as the cube root of the quantity of water it re- ceives." But supposing a wheel to raise water by means of cranks and pumps on Mr. Banks's principle, Buchanan thought it might easily be demonstrated, that by reducing the velocity of the wheel to a cer- tain degree, the wheel would raise more water than would be neces- sary to move it at that velocity, a thing evidently impossible. 515 In this view it would seem tnat there is no actual case in which Mr. Banks's conclusions will hold true. But, however they may ap- ply to other mills, the experiments of Buchanan seem to prove at least that they do not apply to cotton-mills. On the ground of some experiments made at differ- ent times, and with all the atten- tion possible, did he presume to call in question an authority for which the highest respect is enter- tained. In January, 1796, he measured the quantity of water the Rothesay old cotton-mill required; first, when going at its common velocity, and secondly, when going at half that velocity. The result was, that the last required just half the quantity of water which the first did. It is to be observed, that in these ex- periments the quantities of water were calculated from the heads of water and apertures of the sluices. From these experiments he in- ferred, " that the quantity of water necessary to be employed in giving different degrees of velocity to a cotton-mill must be nearly as that velocity." He was satisfied with this expe- riment, and the inference drawn from it, till some gentlemen well acquainted with the theory and practice of mechanics expressed their doubts on the subject. He had then recourse to another ex- periment, which he considered less liable to error than the former. The water which drives the old cotton-mill falls a little below it into a perpendicular-sided pond, which serves as a dam for a corn- mill at some distance below it. To ascertain, therefore, the propor- tional quantities of water used by the old mill, nothing more was necessary than to measure the time the water took to rise to a certain height in that pond; and accord- ingly, on the 1st of May, 1798, he WAT WATER-WHEELS. WAT made the experiments noted in the following Table : Number of experi- ments 1 2 3 4 Revolutions of one of the upright shafts per minute ... 46 46 24 23 Rise of water in the pond in inches ..55 5 5 Time in minutes and seconds .... 6'58 6'57 14-45 15'0 The first and second experiments were made with the mill at its common velocity; the third and fourth at nearly half that velocity. The time which the mill re- quired to use the same quantity of water in these experiments may be taken, in round numbers, as follows: the proper velocity at 7 minutes, and half that velocity at 15 minutes. The result of these experiments approaches very nearly to that of 1796. The difference may be ac- counted for by the small degree of leakage which must have taken place at the sluices on the lower end of the pond ; and the time being greater in the third and fourth experiments, the leakage would of course be greater. Smeaton and others have proved in a very satisfactory manner, that " the mechanical power that must of necessity be employed in giving different degrees of velocity to the same body, must be as the square of that velocity." But it appeared to Buchanan, that the result of the above experiments may be easily reconciled to this proposition, by considering what Smeaton says immediately afterwards : " If the converse of this proposition did not hold true, viz. that if a body in motion, in being stopped, would not produce a mechanical effect equal or proportional to the square of its velocity, or to the mechanical power employed in producing it, the effect would not correspond with its producing cause." It is to be observed, that Smeaton's experiments were 516 made on the velocity of heavy bodies, free from friction and other causes of resistance; but in mills there is not only friction, but ob- stacles, to be removed : and ex- periments made on friction have proved that the friction of many kinds of bodies increases in direct proportion to their velocity. But the velocity of a cotton-mill at work may be considered as a me- chanical effect; and, if so, must correspond with its producing cause. The preceding experiments on the Rothesay mill are undoubtedly correct and consistent with the principles of motion and power, and also with the experiments of Smeaton on mills and mechanical power. The mechanical power is as the quantity of water on the wheel, multiplied into its velo- city when the wheel, fall, and other circumstances remain the same ; and since the mechanical effect is measured by the resistance multiplied into the velocity of the working point when the friction is constant, if the quantity of water be diminished by its half, either half the resistance, or half the velocity with which it is overcome, must be taken away, otherwise there will not be an equilibrium between the power and effect. But at the same time it is to be observed, than an increased velocity lessens the fric- tion of the intermediate machinery, and consequently a greater effect would be produced by the greater velocity, as appears to be the case by the experiments. There is not, however, in the detail of these ex- periments, sufficient data by which it becomes easy to arrive at any useful conclusion. Roberton, an engineer of some eminence, made observations on these experiments, alleging that the conclusions of Banks give most satisfactory evidence that particular care and judgment are necessary in WAT WATER-WHEELS. WAT making such trials. It appeared to Roberton, that the wrong con- clusions which have been drawn by many writers on this subject, have wholly arisen from misappre- hending some of Sir Isaac Newton's fundamental principles of mecha- nics, and from a love of establish- ing theoretical expressions rather than strict observations of the in- variable laws of nature, expres- sions such as these, viz. quantity of motion, instantaneous impulse. Taking a constant portion of time (viz. a second) to be the measure of a body, and an instant to be measure of the effect it pro- duces; or by taking time as the measure of the cause, and space as the measure of the effect, as to an instantaneous effect, Roberton argues that it is an absurdity in itself, as well as in mechanics, we can form no idea of a body put into motion, without the acting power or body act upon the body put into motion for some time, and also over some space ; and to sup- pose otherwise, leads us entirely out of the sound principles of mechanics. In mechanics every effect is equal to its producing cause. In the case of a power actingon abody producing motion, and also this body acting against another power which re- tards its motion, if the causes of action and resistance are each measured by the time the motions are produced and retarded, the result will be equal. If they be measured by the space over which they act, the re- sults will be equal ; and this is an universal principle, whether ap- plied to accelerating power and motion, as gravity, &c., or to ma- chines which act constantly and uniformly. Yet, in the case of uniform motion, space or time may be used at pleasure ; as from the uniformity of space and time they become a common measure. To illustrate this, suppose the 517 body A acted upon by the power of gravity through the space A B, in a portion of time whicli we will call one. When it arrives at B, it meets with another medium of re- sistance, which is ten times greater than the former : the body A will be resisted in pro- i portion to the cause of ac- tion and resistance; that is to say, if the time of action were one second, the time of resistance will be one-tenth of a second, and the distance A B will be to the distance B c as ten to one ; sothat whether space or time be taken as the measure of action, the same must be taken for the measure of the effect, to have the results propor- tionate and equal. But if the cause be measured by time, and the effect by space, the results will be as the squares of the time, < or, which is the same thing, as the squares of the ve- locity. Thus, suppose a body in motion, with a velocity of one, has a power to penetrate into a bank of earth 1 foot : if the same body, with a velocity of two, strike the bank, it will penetrate to the depth of 4 feet ; for the velocity is double, and the time of action is double, and therefore the results will be compounded of both, that is, as the square of the velocity. From the above it may be in- ferred that if equal bodies be acted upon by unequal powers, the time requisite to produce an equal mo- tion will be reciprocally propor- tionate to the powers ; that is to say, if a power of ten act upon a body for one second of time, and the power of one act upon an equal body for ten seconds, they will pro- duce equal velocities. But the spaces through which the bodies are carried are very unequal, being as WAT WATER-WHEELS. WAT ten to one ; and if the square roots of the powers producing the effects be taken, that will give the times they take in carrying the body acted upon through equal spaces. But it is obvious this doctrine has no more to do with the ope- ration of machines than to supply their first starting from rest to the motion necessary for working. When this is acquired, the power applied and the power of resistance balance each other, and whatever be the motion the machine moves at, the same power will carry it on, (if it be upheld,) provided the machine act in such a manner as not to accumulate resistance by the accumulation of motion, which is the case in forcing fluids through pipes, &c. In cases of this kind, the nature of the machine must be particularly kept in view, and no law whatever adopted to explain the resistance the acting body meets with, but what is simply deduced from the very machine which is under consideration ; but, in most cases, any machine may be con- sidered as acting purely on a sta- tical principle. The raising of weights, or overcoming friction, Roberton considers purely as act- ing on that principle; and when the power of action is equal to the resisting power, the machine is in- different to motion or rest. If the machine be at rest, the power will not move it, being a balance to the resistance. If the machine be set in motion, the power will keep it in the same motion, (provided the power be upheld,) the same as equal weights hung over a pulley, or in the opposite scales of a beam. If they be at rest, they will remain so ; and if they be put in motion, they will endeavour to persevere in the same. The above doctrine of a statical principle is proved in the most satisfactory manner by the experi- ments made at the old mill of Rothesay, the motion of the water- 518 wheel being exactly proportional to the quantity of water expended, and therefore an exact and equal load upon the wheel; that is to say, the buckets were equally full when the mill moved at its ordi- nary motion, or at half that mo- tion. The effect, therefore, of letting more water on a wheel is not to lodge a greater quantity in the buckets, but to supply the same quantity when the wheel is in a greater motion. Banks, however, made his ex- periments agree with his theory, yet Roberton took no trouble in inquiring into them, alleging it would be to little purpose to have done so. "Suffiqe it to say," he adds, " that the very small quantities of water which Banks made use of, and the slowness of the motion of his wheel in his experiments, give no ground for placing the smallest dependence on them ; and when compared with the more judicious and accurate experiments of Smea- ton, they dwindle into contempt." Roberton further says, that " Smeaton, in running his wheel at nearly 3 feet in the second, brought it nearly to a maximum, and lost but about one-fourth or one-fifth of the original effect (al- luding to his overshot wheels). Banks, at his highest motion, run his wheel about 1 foot in the se- cond, and reducing it to one-half of that motion, the same quantity of water then expended was ca- pable of performing four times the work; and by deduction from thence, it appears plain that his wheel (from his own theory) would perform about twenty times the quantity of work which Smeaton's could perform with the same quan- tity of water, and about sixteen times more than nature; so that the observation (alluding to the theory of Banks) is very just in saying that, by reducing the mo- WAT WATER-WHEELS, OVERSHOT. WAT tion of the wheel, it is demon- strable it would raise more water than supply itself." Waterrwheels (Overshot}. The best water-wheel is that which is cal- culated to produce the greatest effect when it is supplied by a stream furnishing a given quantity of water with a given fall. The mechanical effect depends on the proportion of the wheel's diameter to the height of the fall, and on the velocity of the circum- ference of the wheel. These are the two principal parts to be con- sidered in the theory of wheels, but there are also some other points w r hich ought to be attended to, be- cause the effect is much decreased when they are neglected. Of the proportion of the radhts of the water-wheel to the height of the fall. Let A B c D be the wheel, and E A the depth of the buckets ; then, according to experiments on water-wheels, it appears that the rotatory form of the water in the buckets is nothing at c and d, and that it increases nearly, if not ac- curately, in the direct ratio of the distance from c or d, and is greatest at A. That is, the force at any point a in a direction ea, or per- pendicularly to the radius, is as a c. A slight consideration of the figure is sufficient to demonstrate that the wheel will not produce the greatest effect when it receives 519 the water at the upper point c, and that there must be considerable advantage in making the wheel of a greater diameter, so that it may receive the water at the same point between A and c, the point which will insure the greatest ef- fect thus calculated. Let c = that portion of the cir- cumference which is to be loaded with water ; and x = the arc com- WAT WATER-WHEELS, OVERSHOT. WAT prehended between the point where the water flows upon the wheel and the horizontal line E A ; also make I = the area of the stream supplying the buckets. Then the solid which represents the effective force will be which is to be the greatest possible ; or C X = a maximum. By the principles of maxima and minima this takes place when x = c (1 - V?) o r x = '2929 c. Accordingly the arc c x must be the quadrant dg or 90, and the arc x = 37-27. Hence we have this important practical maxim. A water-wheel will produce the greatest effect when the diameter of the wheel is proportioned to the height of the fall, so that the water flows upon the wheel at a point about 52f distant from the summit of the wheel. If r be the radius of the wheel to the extreme part of the bucket, and h the effective height of the fall, then h = r (1 + sin. 37), or h = 1*605 r; for the sin. 37 = '605. Also -623 h = r. Therefore, when the effective height of the fall is determined, the radius of the wheel is easily calculated. When the ef- fective fall is f. of the whole fall, if we make h the whole fall, r = 554 h, or 1'108 h = the diameter of the wheel. The effective height of the fall is less than the true height by as much as is necessary for giving the water the same velocity as the wheel before it flows upon it. In low falls a wheel would work with advantage in a considerable depth of tail-water,, provided the 520 buckets were of a suitable form for moving through the water, and the effective fall made through a very accurate sweep, so that the sweep", and not the form of the bucket, should confine the water upon the wheel. Of the velocity of the circum- ference of the wheel to produce a maximum effect. It is necessary to premise, that the velocity with which the water flows upon the floating boards or buckets is con- sidered to be equal to the velocity of the wheel, and to strike against the floats as nearly as possible in the direction of the motion of the wheel. Let x be that part of the fall which gives the necessary velocity v to the water, when the effect is a maximum ; v will then be the velocity of the circumference of the wheel. Also, make a = that part of the fall which would correspond to the velocity of the circumference of the wheel when the power would be equal to the friction of the loaded machine only; or when the useful effect would be nothing. Now if h be the whole fall, the effective force of the water on the wheel will always be proportional to h sc, when the effect is a maximum ; and to h a, when the useful effect, or work done, is nothing. Hence v (h x h a) must be a maximum ; or v (a x} = a max.; but v = x^, therefore x^ {a x) = a max., which, according to the rules of maxima and minima, takes place when a = 3 x. It is evident that the value of a must entirely depend on the nature of the machine ; for if there be many moving parts between the power and the resistance, the friction will be greater, and consequently a will be less. The machine must be very simple indeed, if the friction be less than one-half the moving power, and it will often amount to WAT WATER WHEELS, OVERSHOT. WAT two-thirds of it. If we suppose it to be two-thirds, then and consequently and Hence, when the friction amounts to two-thirds of the moving power, the velocity of the circumference of an overshot wheel in feet per se- cond, should be 2-67 times the square root of the whole height of the fall, in feet. Again, that part of the fall is to be determined, which will give the water the same velocity as the wheel; and since a = , and 3# = a, o we have Hence, when the friction is two- thirds of the power, that part of the fall which will give the water the proper velocity is one-ninth of the whole height. These results may, then, be use- fully compared with the experi- ments of Smeaton; at the same time it is obvious that his experi- ments were not adapted for arriv- ing at general conclusions, because the water was always delivered upon the same wheel : for it is clear, from the preceding investi- gation, that every particular wheel must have its particular maximum. In Smeaton's experiments on overshot wheels, the wheel was 2 feet in diameter; therefore the height of the fall should be by substituting these quantities, we have 122-176 b h* fts. = the me- chanical power; or -0164 bh* = the number of horses, where h the whole height of the fall, in feet WAT WATER-WHEELS, VENTILATED. WAT and b = the area of the aperture through which the water flows upon the wheel, in feet. The effective force is 31-25 b c fts. when the water flows on either at the summit or at the level of the axis. When the water flows on at 52f degrees distant from the summit of the wheel, the effective force is 37-192 b c fts. or 45746 b h fts. Of the power of breast -wheels. When the water flows on below the level of the axis of the wheel, it may he termed a breast"- wheel. Let y be the distance below the axis measured on the circumference, then e 3 b v equal the mechanical power in cubic feet of water, or 31-25 fts. When y = c, the power will be re- duced one-half, and when y = 2 c, it will be reduced two-thirds, and so on. If we assume that the mechani- cal power of an undershot wheel is half that of an overshot one " under the same circumstances of quantity and fall ;" then it will be an ad- vantage to employ an undershot wheel whenever the fall is less than three-tenths of the radius of the wheel. But since the radius of the wheel may in many cases be diminished, it does not appear to be desirable to employ an under- shot wheel in any case, except where the quantity of water is great and the fall inconsiderable. Water-wheels with ventilated Buckets. Since the time of Smeaton's expe- riments in 1759, little or no im- provement has been made in the principle on which water-wheels have been constructed. The sub- stitution, however, of iron for wood, as a material for their construction, has afforded opportunities for ex- 523 tensive changes in their forms, par- ticularly in the shape and arrange- ment of the buckets, and has given, altogether, a more permanent and lighter character to the machine than had previously been attained with other materials. A curvili- near form of bucket has been gene- rally adopted, the sheet iron of which it is composed affording facility for being moulded or bent into the required shape. From a work entitled ' Meca- niques et Inventions approuvees par 1' Academic Royale des Sciences/ published at Paris in 1735, it ap- pears, that previous to the com- mencement of the last century, neither the breast nor the overshot water-wheels were much in use, if at all known ; and at what period, and by whom they were introduced, is probably equally uncertain. The overshot wheel was a great im- provement, and its introduction was an important step in the perfecting of hydraulic machines ; but the breast-wheel, as now generally made, is a still further improve- ment, and is probably better calcu- lated for effective duty under the circumstances of a variable supply of water, to which almost every description of water-wheel is sub- jected. Improvements have taken place during the last and the pre- sent centuries. The breast-wheel has taken precedence of the over- shot wheel, not so much from any advantage gained by an increase of power, on a given fall, as from the increased facilities which a wheel of this description, having a larger diameter than the height of the fall, affords for the reception of the water into the chamber of the bucket, and also for its final exit at the bottom. Another advantage of the in- creased diameter is the comparative ease with which the wheel over- comes the obstruction of back- water. The breast-wheel is not only less injured from the effects WAT WATER-WHEELS, VENTILATED. WAT of floods, but the retarding force is overcome with greater ease, and the wheel works for a longer time and to a much greater depth in back-water. The late Dr. Robison, Professor of Natural Philosophy in the Uni- versity of Edinburgh, in treating of water-wheels, says, " There fre- quently occurs a difficulty in the making of bucket-wheels, when the half-taught millwright attempts to retain the water a long time in the buckets. The water gets into them with a difficulty which he cannot account for, and spills all about, even when the buckets are not moving away from the spout. This arises from the air, which must find its way out to admit the water, but is obstructed by the entering water, and occasions a great sput- tering at the entry. This may be entirely prevented by making the spout considerably narrower than the wheel : it will leave room at the two ends of the buckets for the escape of the air. This obstruction is vastly greater than one would imagine ; for the water drags along with it a great quantity of air, as is evident in the water-blast, as de- scribed by many authors." In the construction of wheels for high falls, the best proportion of the opening of the bucket is found to be nearly as five to twenty-four ; that is, the contents of the bucket being 24 cubic feet, the area of the opening, or entrance for the water, would be five square feet. In breast -wheels which receive the water at the height of 10 to 12 above the horizontal centre, the ratio should be nearly as eight to twenty-four, or as one to three. With these proportions, the depth of the shrouding is assumed to be about three times the width of the opening, or three times the dis- tance from the lip to the back of the bucket, as from A to B, fig. 1, the opening being 5 inches, and the depth of the shroud 15 inches. 524 Fig. 1, For lower falls, or in those wheels which receive the water below the horizontal centre, a larger opening becomes necessary for the recep- tion of a large body of water, and its final discharge. In the construction of water- wheels, it is requisite, in order to at- tain the maximum effect,tohave the opening of the bucket sufficiently large to allow an easy entrance and an equally free escape for the water, as its retention in the bucket must evidently be injurious, when carried beyond the vertical centre. Dr. Robison further observes, "There is another and very seri- ous obstruction to the motion of an overshot or bucketed wheel. When it moves in back-water, it is not only resisted by the water when it moves more slowly than the wheel, which is very frequently the case, but it lifts a great deal in the raising buckets. In some par- ticular states of back-water, the descending bucket fills itself com- WAT WATER-WHEELS, VENTILATED. WAT pletely with water, and in other cases it contains a very considerable quantity, and air of common den- sity; while in some rarer cases it contains less water, with air in a condensed state. In the first case, the rising bucket must come up filled with water, which it cannot drop till its mouth gets out of the water. In the second case, part of the water goes out before this ; but the air rarefies, and therefore there is still some water dragged or lifted up by the wheel, by suc- tion, as it is usually called. In the last case, there is no such back- load on the rising side of the wheel, but (which is as detrimental to its performance) the descending side is employed in condensing air ; and although this air aids the ascent of the rising side, it does not aid it so much as it impedes the descending side, being (by the form of the bucket) nearer to the vertical line drawn through the axis." These were the difficulties under which the millwrights of Dr. Ro- bison's time laboured; and the remedy which they applied (and which has since been more or less continued) was to bore holes in what is technically called the ' start' of the bucket. This was the only means adopted for removing the air from the buckets of overshot wheels, in order to facilitate the admission and emission of the water. In lower falls, where wheels with open buckets were used, or straight float-boards radiating from the centre, large openings were made in the sole-planking, exclu- sive of perforations in each bucket, in order to relieve them from the condensed air. The improved con- struction of the present time is widely different, the buckets being of such a shape as to admit the water at the same time that the air is making its escape. During the early part of 1825, and the two succeeding years, two iron water-wheels, each of one 525 z 5 hundred and twenty horse-power, were constructed in Manchester for Messrs. James Finlay and Co., of the Catrine Works, under the auspices of the late Mr. Buchanan, and also for the same Company at Deanston, in Perthshire, of which firm Mr. James Smith (Deanston) was then the resident partner. These wheels are still (1850) in operation, and taking them in the aggregate, they may probably be considered as some of the most powerful and the most complete hydraulic machines in the United Kingdom. The construction of these wheels, and others for lower falls, first directed attention to the ingress and egress of the water, and led to the improvements which have since been introduced. The object of these modifications may be generally stated to have been, for the purpose of preventing the condensation of the air, and for permitting its escape, during the filling of the bucket with wa- ter, as also its re-admission during the discharge of the water into the lower mill-race. Shortly after the construction of the water-wheels for the Catrine and Deanston Works, a breast- wheel was made and erected for Mr. Andrew Brown, of Linwood, near Paisley. In this it was ob- served, when the wheel was loaded, and in flood-waters, that each of the buckets acted as a water-blast, and forced the water and spray to a height of six or eight feet above the orifice at which it entered. This was complained of as a great defect, and, in order to remedy it, openings were cut in the sole- plates, and small interior buckets were attached to the inner sole, as shown at b, 6, 6, fig. 2. The air in this case made its escape through the openings a, a, a, into the inner bucket, and passed upwards, as is shown by the arrows, through b,b,b, into the interior of the wheel. By these means it will be observed WAT WATER-WHEELS, VENTILATED. WAT Fig. 2. that the huckets were effectually cleared of air whilst they were filling, and that during the ob- structions of back-water, the same facilities Were afforded for its re- admission, and the discharge of the water contained in the rising buckets. The effect produced by this alteration could scarcely be credited, as the wheel not only received and parted with the water freely, but an increase of nearly one-fourth of the power was ob- tained, and the wheel, which still remains as then altered, continues, in alt states of the river, to per- form its duty satisfactorily. The amount of power gained, and the beneficial effects produced upon Mr. Brown's wheel, induced a new and still greater improve- ment in the principle of construc- tion: the first wheel erected on this, which has been called the ' ventilated ' principle, was one de- signed for Mr. Duckworth, at the Handforth Print -Works, in the neighbourhood of Wilmslow, in Cheshire. Close -bucketed wheels labour under great difficulties when re- ceiving the water through the same orifice at which the air es- capes, and in some wheels the 526 forms and construction of the buckets are such as almost entirely to prevent the entrance of the wa- ter, and to deprive the wheel of half its power. These defects may be easily accounted for where the water is discharged upon the wheel in a larger section than the opening between the buckets: under such circumstances the air is suddenly condensed, and, re-acting by its elastic force, throws back the wa- ter upon the orifice of the cistern, and thus allows the buckets to pass without their being more than half-filled. Several methods have been adopted for relieving them of the air : the most common plan is, by cutting holes in the sole-plates, close to the back of the buckets, or else making the openings be- tween them much wider, in order to admit the water, and at the same time to allow the air to es- cape. All these remedies have been more or less effective ; but they labour under the objections of a great waste of water and much inconvenience, by the water falling from the openings down upon the lower part of the wheel, exclusive of the puffing and blowing when the bucket is filling. Other remedies have been ap- plied, such as circular tubes and boxes attached to the sole-plates, which, extending upwards, furnish openings into the interior of the wheel for the air to escape; but these, like many other plans, have been, to a certain extent, unsuccess- ful, owing to the complexity of their structure, and the inadequate manner in which the objects con- templated were attained. In fact, in wheels of this description it has been found more satisfactory to sub- mit to acknowledged defects, than to incur the trouble and inconve- nience of partial and imperfect remedies. In the improvements made by Mr. Fairbairn, these objections are to a great extent removed, and a WAT WATER-WHEELS, VENTILATED. WAT thorough system of ventilation has been effectually introduced. Be- fore entering upon the description of this new principle of ventilation, it is necessary to remark, that in climates like Great Britain and Ire- land, where the atmosphere is charged with moisture for six or seven months in the year, it is no uncommon occurrence for the rivers to be considerably swollen, and the mills depending upon wa- ter are either impeded or entirely stopped by back-water; while at other times a deficiency of rain re- duces the water-power below what is absolutely required to drive the machinery. On occasions of this kind, much loss and inconvenience are sustained, particularly in mills exclusively dependent upon water as a motive power, and where a number of work-people are em- ployed. On the outskirts of the manu- facturing districts, where the mills are more or less dependent upon water, these inconveniences are se- verely felt ; and in some situations these interruptions arise as fre- quently from an excess of water as from a deficiency in the supply. To remedy these evils, reservoirs have been formed, and wheels have been constructed to work in floods ; but although much has been ac- complished for diminishing these injurious effects, and giving a more regular supply in dry seasons, yet the system is still imperfect, and much has yet to be done, before water can be considered equal, as a motive power, to the steam engine, which is always available where the necessary fuel is at hand. It is therefore obvious, that any im- provement in the construction of water-wheels, whereby their forms and requirements may be better adapted to meet the exigencies of high and low waters, will contri- bute much to the efficiency and value of mills situated upon rivers subjected to the changes alluded to. 527 ~ Water-wheels ( Ventilated} as adapted to low falls. The first wheel con- structed upon the ventilated prin- ciple was erected at Handforth, in Cheshire, in the summer of 1828 : it proved highly satisfactory to the proprietors, Messrs. Duckworth and Co., and gave such important re- sults as to induce its repetition, without variation, in cases where the fall did not exceed the semi- diameter of the wheel. In the earlier construction of iron suspension wheels by the late Mr. J. C. Hewes, the arms and braces were fixed to the centres by screws and nuts upon their ends, as shown in fig. 3. The arms c, c, passed through the rim b, b, and Fig, 3, the braces e, e, which traverse the angle of the rim/,/, are, as nearly as possible, in the position and WAT WATER-WHEELS, BREAST. WAT form adopted by Mr. Hewes. This arrangement, although convenient for tightening up the arms and braces, was liable to many objec- tions, arising from the nuts be- coming loose, and the consequent difficulty of keeping the wheels true to the circle, and the arms and braces in an uniform state of tension : gibs and cotters were therefore substituted for the nuts and screws, and since their intro- duction into the large wheels of the Catririe Works, Ayrshire, the objections have been removed, and the arms and braces are not only perfectly secured, but the peri- phery of the wheel is retained in its true and correct form. Having noticed the obstructions offered to the entrance of the wa- ter into buckets of the usual form, and the consequent loss which en- sues from its retention upon the wheel, after its powers of gravita- tion have ceased, it is now neces- sary to show the means whereby those defects were removed, and also to exhibit the relation existing between the breast and the under- shot wheels. These terms have, however, become nearly obsolete, as every description of water-wheel may now be properly called a breast- wheel ; and in 'every fall, however low, it is generally found advantageous for the water to act by gravitation, and not by impulse, as during the early periods of the industrial arts. Water-wheels (Breast), with close Soles and ventilated Buckets. The preceding statements have been principally confined to the form of bucket, and description of water- wheel, adapted for low falls. It is therefore necessary to describe the best form of breast- wheels for high falls, or those best calculated for attaining a maximum effect on falls varying from one-half to three- fourths of the diameter of the wheel. This is a description of water-wheel in common use, and 528 is generally adopted for falls which do not exceed 18 feet in height, and, in most cases, is pre- ferable to the overshot wheel. It possesses many advantages over the undershot wheel, and its near ap- proximation to the duty, or labour- ing force, of wheels of the former description, renders it applicable in many situations, especially where the fall does not exceed 18 or 20 feet, and where the wheel is ex- posed to the obstructions of back- water. In the latter case, wheels of larger diameter are best adapted; and provided sufficient capacity is left in the buckets, such wheels may be forced through the back- water without diminution of speed. Every wheel of this kind should have capacity in the buckets to re- ceive a sufficient quantity of water to force the wheel, at full speed, through a depth of 5 or 8 feet of back-water ; and if these provisions are made, a steady uniform speed, under every circumstance of freshes and flood-waters, may be attained. Irrespective of the advantages of clearing the buckets of air, ad- ditional benefit is obtained by the facility with which the water is discharged, and the air again ad- mitted, at the bottom of the fall, during the period of the emptying of the bucket into the tail-race. This is strikingly illustrated where the wheels labour in back-water, as the ventilated buckets rise freely above the surface, and the commu- nication being open from one to the other, the action is rendered perfectly free, at almost any depth to which the wheel may be im- mersed. In breast-wheels constructed for falls of 25 feet or upwards, the stone-breast is not required, as the buckets are formed with narrow openings, and the lip being ex- tended nearer to the back of the following bucket, the water is re- tained much longer upon the wheel. Under these circumstances, a stone- WAT WATER-WHEELS. WAT breast is of little or no value, when attached to a wheel with close buckets, on a high fall. The construction of the breast- wheels, as above described, is al- most exactly similar to that for the lower falls ; malleable iron arms and braces being common to both, as also the axle, shroud, and seg- ments. These, when duly pro- portioned and properly fitted to each other, form one of the strong- est, and probably the most per- manent structures, that can be at- tained in works of this description. Water-wheel (common Breast, not ventilated}, as constructed by Messrs. Fairbairn and Lillie, be- tween the years 1825 and 1827. These wheels were executed upon the plan of the overshot or breast- wheel, taking the water at an ele- vation nearly equal to that of its height. Four wheels of this de- scription were constructed for Messrs. James Finlay and Co., for a fall of 32 feet, at Ueanston, in Perthshire, and two others, for the same firm, at the Catrine Works, in Ayrshire, on a fall of 48 feet. Takinginto consideration the height of the fall, the Catrine water- wheels, both as regards their power and the solidity of their construction, are, even at the present day, pro- bably among the best and most effective structures of their kind in existence. They have now (1850) been at work upwards of twenty years, during which time they have required no repairs, and they remain nearly as perfect as when they were erected. It was originally intended to have erected four of these wheels at the Catrine Works, but only two have been constructed; prepara- tions were, however, made for re- ceiving two others, in the event of an enlargement of the reservoirs in the hilly districts, and more power being required for the mills. This extension has not yet been wanted, as these two wheels are equal to 529 240 horse-power, and are suffi- ciently powerful, except in very dry seasons, to turn the whole of the mills. These water-wheels are 50 feet in diameter, 1 feet 6 inches wide inside the bucket, and 15 inches deep on the shroud ; the internal spur seg- ments are 48 feet 6 inches diameter, 3 inches pitch, and 15 inches broad on the cog ; the large spur- wheels are 18 feet 2 inches in diameter, 3 inches in the pitch, and 16 inches wide on the cog; and the pinions are the same width and pitch, but are 5 feet 6 inches in diameter ; the large bevel-wheels are 7 feet in diameter, 3 inches in the pitch, and 18 inches broad on the cog, their proportions being calculated to convey the united power of all the four water-wheels, should the original design ever be completed. The water for the supply of the wheels is conveyed from the river Ayr in a canal and tunnel, and from thence, along the side of a rising bank, to the wheel-house. From this point it is conveyed to the water-wheels by a large sheet- iron trough, supported on iron columns. When viewed from the entrance, the two wheels already erected have a very imposing effect, each of them being elevated upon stone piers ; and as the whole of the cisterns, sluices, winding apparatus, gal- leries, &c., are considerably ele- vated, they, are conveniently ap- proached in every part. Under the wheels is a capacious tunnel, terminating at a considerable dis- tance down the river. Water-wheels on a principle in- troduced by M. Poncelet, have at- tained some considerable reputa- tion on the Continent ; and as Mr. Fairbairn has constructed one of them for Mr. De Bergue, it is ne- cessary to allude briefly to the pe- culiarities it possesses. The buckets are of a curvilinear WAT WATER-WHEELS. WAT form, and are quite open at the back, without any sole-plate ; so that they are perfectly ventilated. The water impinges upon them at nearly the lowest point of the wheel, the shuttle being arranged to draw upwards ; and as the wa- ter enters, it follows the inside ca- vity of the bucket, rises and falls over into the next in succession, and so on. By this system the force of the water is expended on the wheel itself, instead of losing much of its power in rushing along through the wheel -race, as ge- nerally occurs in even well-made undershot wheels. M. Poncelet has treated this subject at much length in his able work on water-wheels ; but it may be observed, that a practical im- provement might be effected by ter- minating the lower stone platform of the race somewhat short of the vertical line of the centre of the wheel, as the escape of the water would be facilitated, and the as- cending buckets would be more easily relieved of their contents : this is a point of such impoi'tance for all wheels, that it must equally apply to this form. Mr. De Bergue obtained nearly seventy-eight per cent, of power from a breast-wheel, with a good fall, when the periphery was travel- ling at a velocity of 6 feet per second. He had erected several of Ponce- let's wheels, and thought well of them; indeed, for certain situa- tions it was thought they were pre- ferable to any other form, although M. Poncelet had never yet been able to obtain very superior results from wheels erected under his own superintendence. Mr. De Bergue has explained the construction of a wheel, on this principle, erected at the Loubre- gat, near Montserrat, in Catalonia ; one of the same kind having been already erected by him at Gerona, between Barcelona and Belgrade. The diameter was 16 feet 8 530 inches, and the width was 30 feet, which, with a fall of 6 feet 6 inches, passed 120,000 cubic feet of water per minute, when the periphery travelled at a velocity of It to 12 feet per second. An or- dinary breast-wheel would require to be 90 feet wide, to use advan- tageously that quantity of water. It was found that the velocity of the periphery should be about 55 per cent, of that of the water flow- ing through the sluice ; and upon these data the power of the wheel would be about 180 horse-power. The buckets were of a curved form, and made of wrought iron, |th of an inch thick ; and it should be observed that there was a larger number of buckets than usual, and that the water eame upon them at a tangent, through an orifice of such a form and dimensions as to allow the buckets to fill easily, at the rapid speed at which the peri- phery passed before the sluice. This great primary velocity was very important, as it caused a con- siderable saving in the gearing of the mill. The main shaft was formed by a hollow cylinder of cast iron, 4 feet 6 inches diameter, in short lengths, bolted together; and the arms were of wrought iron, made very light, and of the same form as those of a paddle-wheel of a steamer, and placed very close to- gether. The strain was brought entirely upon the main shaft, and the weight of the wheel was thus reduced to about thirty tons, which was very little for so powerful a machine. The sluice was formed of cast- iron plates, with planed joints, bolted through the flanches, to form one large shuttle of the en- tire breadth of the wheel, and its motion was regulated by radial tie- rods, between the stone apron and the back of the sluice, which could thus be raised with great facility by racks and pinions, and be regu- WAV WEIGHTS AND MEASURES. WEI lated by the ordinary governor, the weight of the sluice being in a great degree supported by the water flowing beneath it on to the wheel. It moved very accurately between the side walls of the pen- trough, and cup-leathers at each side prevented any waste of water. This kind of wheel was less af- fected by back-water than any other form, and the water acted upon it with its full power of ve- locity, without any impediment from the air in entering, as there was no sole-plate : the buckets filled and emptied with great fa- cility. It is therefore most satis- factory for all falls under 8 feet in height, though the principle dif- fers essentially from that generally taken as the basis of construction of water-wheels. Waved, in heraldry, an indented out- line, indicating honours originally acquired at sea Way-shaft, in steam engines, the rocking-shaft for working the slide- valve from the eccentric Wax, the substance of which the honey-combs of bees are composed, and which is of considerable use in branches of art Weathercock, a vane made in the shape of a cock Weather-gage, in navigation. When a ship is to windward of another, she is said to have the weather-gage of her. Weather-glass, an instrument to fore- show the change of weather and the temperature of the air Weather-moulding, a label, canopy, or drip-stone, over a door or window, intended to keep off water from the parts beneath Wedge. The wedge is a solid piece of wood or metal, generally made in form of a triangle prism, of which the two ends or bases are equal and similar plane triangles, and the three sides rectangular parallelograms ; and it is called rectangular, isosceles, or scalene, according as its equal and similar 532 bases are composed of right angles, isosceles, or scalene triangles. As a mechanical power, the wedge performs its office, sometimes in raising heavy bodies, but more fre- quently in dividing or cleaving them ; hence all those instruments which are used in separating the parts of bodies, such as axes, adzes, knives, swords, coulters, chisels, planes, saws, files, nails, spades, &c., are only different modifica- tions that fall under the general denomination of the wedge. Weighboard, in mining, clay inter- secting a vein Weight and power, when opposed to one another, signify the body to be moved and the body that moves it. That body which communi- cates the motion is called the power, and that which receives it the weight. Weights and Measures. The system of weights and measures used in France at present, in all legal trans- actions, is called the ' metrical system,' from the fact of its being based upon the unity of length, which is designated ' the metre.' Before the great revolution of 1793, the separate provinces of the French kingdom had their different systems of measures; just as in England the different counties had theirs, before the introduction of the imperial measures. There was, consequently, the same confusion attached to the meanings of the different terms employed, which led our own Government to sim- plify the question. An acre in Normandy did not mean the same as an acre in Picardy ; a pound in Paris differed from a pound else- where. But here the analogy be- tween the conduct of the two Governments ceases. That of France reformed the whole system of weights and measures, and based the new one upon natural and easily verifiable principles, whilst our own retained the arbitrary and illo- gical system of the middle ages, WEI WEIGHTS AND MEASURES. WEI contenting themselves with merely fixing a sort of uniformity in the definitions of the several terms. The merit of having originated the metrical system is due to the government of Louis XV., who named a commission to pursue the investigations necessary to decide the principles upon which it was to be carried out. After a very se- rious consideration of the case, and a numerous series of observations carried on during the reign of Louis XVI., and under the Con- vention, the Academy of Sciences decided that all the different weights, measures, and coinages should be established according to certain definite relations to the di- mensions of the globe itself. These are, to all human perception, inva- riable. If therefore the standard were lost, it is always possible to refind it, by a repetition of the same sort of observations which gave rise to the fixing it in the first instance. The beat of a pendulum, chosen by our own Astronomical Board, is a very uncertain base for such calcu- lations ; for the conditions of the vacuum, the temperature of the atmosphere, the specific gravity of the pendulum, nay, perhaps, even the magnetic currents, may affect the length of the space it goes through, in a manner able to affect calculations which require such ma- thematical exactitude as those con- nected with ascertaining the stand- ard of a perfect system of measures. The length of the earth's meri- dian was ascertained by Messrs. Delambre and Mechain, in the por- tion between Dunkerque and Bar- celona ; and by Messrs. Arago and Biot, in the portion between Bar- celona and Formentera. The length of the meridian from the pole to the equator, passing through Paris, was then divided into ten million parts ; and one of these parts, called the metre, became the basis of the new system of weights and measures. Maupertuis had previously, in the 533 year 1736, measured a portion of the arc of a meridian passing through the North Cape, and his observations were combined with those of the second commission. In spite of all this care, however, an error was made in fixing the length of the metre ; for the dis- tance from the equator to the pole is really 10,000,738 metres, instead of 10,000,000. For any practical purpose, however, this error is inapplicable ; but it is very unfor- tunate. The length of the metre once as- certained, the other measures were derived from it. All the multiples and sub-multiples were formed on the decimal system, and respec- tively designated by Greek and Latin prefixes to the name of the unities. Thus, the multiples of the metre are the rfeca-metre, ten me- tres; the hecto-metre, a hundred metres ; the Mo-metre, a thousand metres; the myrza-metre, ten thou- sand metres. In deference to old customs the term 'league' has been retained, and a legal value of four kilometres affixed to it. The sub-multiples of the metre are : the rfm-metre, the tenth part of a metre ; the centi-metre, the hundredth part of a metre ; and the rmVft-metre, the thousandth part of a metre. The same prefixes are, of course, applicable to all the other unities. The unities of length in use for ascertaining the distances of places, are, as said before, the metre (the kilometre and the myriametre) and the league. The unity of surface is the ' are,' which is a square of ten metres on a side, or one hundred superficial metres. The usual multiples and sub-multiples are, the Aec#-are, a square of one hundred metres on a side ; and the centi-are, the metre superficial. The terms usually em- ployed in the sale of land and in agricultural discussions are, simply, those named above. WEI WEIGHTS AND MEASURES. WEI The unity of weight is the * gramme,' which is the equivalent of a cube of distilled water (at a temperature of 4 above the ' ice- melting point' of the centigrade scale), measuring a centimetre every way. The multiples and sub-mul- tiples are, as before : the deca- gramme, ten grammes ; the hecto- gramme, a hundred grammes ; the kilogramme, a thousand grammes ; the decigramme, a tenth part of a gramme, &c. A thousand kilo- grammes, then, would form a cube equal to one measuring a metre on every side ; and it is made the legal ton for heavy weights. The unity of capacity is the ' litre,' which is the equivalent of a cube measuring one-tenth part of a metre, or a decimetre, every way. The multiples and sub-multiples are formed as before. They are, the decalitre, the hectolitre, the kilolitre, the decilitre, and the centilitre, &c. The litre is usually employed in expressing the quan- tities of liquids ; the hectolitre in expressing those of grain. A thousand litres of water thus are equal to a metre cube every way, and are one ton in weight. Another advantage in this system is, that the tables of specific gravity serve at once to ascertain the weights of the different substances. Thus, inasmuch as the specific gravity of cast iron is 7202, the weight of a metre cube is at once 7202 kilogrammes, or 7 tons 202 kilogrammes. The 'franc/ the unity of the French coinage, is 5 grammes in weight of an alloy containing nine parts of pure silver to one of alloy, being thus connected with the whole metrical and decimal system. As investigations connected with the supply of water are of great importance, it may be added, that thequantityreckoned as the unity in such calculations is the module or 20 cubic metres ; being nearly the equivalent of the old ' ponce fon- tanier,' or the quantity usually de- livered by a hole of one inch dia- meter in the 24 hours. The law promulgating the me- trical system was dated in the year 1795. The forced application of it in legal transactions did not take place till nearly 50 years after- wards. A Table is subjoined of the dif- ferent French weights and mea- sures, with the corresponding Eng- lish equivalents. Weights and Measures French, with their English equivalents. FRENCH. WEIGHT. ENGLISH, Gramme .... { a mire^na^'ide 110116 ' 1 * 11 f *} 15 ' 438 grains troy f a thousand grammes, or a cube T .* , Kilogramme , . La tonne .... ENGLISH TROY. RECIPROCALLY. FRENCH. Grain equal to 0'06477 gramme Pennyweight ... 1 -55456 ,, Ounce 31-0913 grammes Pound Troy (Imperial) 0'3730756 kilogramme AVOIRDUPOIS. Drachm .... equal to 1'7712 gramme Ounce 28-3384 grammes Pound ,, 0-4534148 kilogramme Hundred-weight ... ,, 50'7826 kilogrammes Ton 1015-649 ,, 534 WEI WEIGHTS, COMPARATIVE. WEI To convert pounds avoirdupois into kilogrammes, or English tons into French tons, or vice versa, multiply or divide as follows : For pounds by ...... 0'4534148 For tons by ...... 1-015649 FRENCH. LENGTH, ENGLISH. f about 40,000,000th part of cirO , . J cumference of the globe, or 13-2808992 feet * "I 10-milliorith part of a quarter f T093633 yard L of do. J Kilometre ... one thousand metres . . . 1093-633 yards Myriametre . > . . ten thousand metres . . . 10936-33 yards Centimetre .... one-hundredth of a metre . . 0-393708 inch Millimetre .... one-thousandth of a metre . . 0*0393708 inch ENGLISH. RECIPROCALLY. FRENCH. The inch .... one-twelfth of a foot English . 2*539954 centimetres foot ........... 3-0479449 decimetres yard .... 3 feet ...... 0*91438348 metre ,, furlong. . . . 320 yards ..... 201' 16437 metres ,, mile .... 1760 yards ..... l609'3149 metres To reduce English measures into French, multiply by ; and to reduce French measures into English, divide by : Inches to centimetres . . 2'5400 Feet to metres . . . 0-3047945 practically 0'3048 Miles to kilometres . . 1'6093 Feet square to metres square 0-OQ290 cube to m re, cube . rw.14 ..... { FRENCH. SURFACE. ENGLISH. Centiare .... a metre superficial . . . 1' 196033 yards superficial Are ..... a square of 10 metres every side 0*098845 rood Hectare .... ,,100 2-471143 acres RECIPROCALLY. A yard square . . . contains ..... 0' 83697 metre square The rod, or . . . . perch square .... 25-291939 metres square ,, rood .... 1210 yards square . . . 10-116775 ares acre .... 4840 do. do. ... 0-404671 hectare In round numbers, the hectare may be taken as equal to 2 acres. FRENCH. CAPACITY. ENGLISH. T .. fa cube of one-tenth of a metre \ 1- 760773 pint Mtre ..... I on a side . . . . J 0-2200967 gallon Decalitre .... ten litres ..... 2-2009668 gallons Hectolitre .... one hundred litres . . . 22'00g668 ENGLISH. RECIPROCALLY. FRENCH. Pint ..... equal to ..... 0'567932 litre Quart ..... ..... 1-135864 Gallon Imperial ... ..... 4-54345794 litres Chaldron .... ..... 13'085l6 hectolitres To turn pressure calculated in pounds per inch superficial into their equivalents calculated in kilogrammes per centimetre superficial, or vice versa, multiply, or divide, by 0-0702774. Weight in pounds of one cubic foot of the following substances : Cast iron .... 450- Water ..... 62-5 Wrought iron . . . 486- Air ...... 0-075 Steel ...... 489- Steam ..... 0-036 Pine wood .... 29'5 535 WEI WEIGHT OF IRON. WEI Weight of a Superficial Foot of Plate or Sheet Iron. No. of th e wire-gauge Thickness in inches. Weight in pounds. No. of the wire- gauge. Thickness in inches. Weight in pounds. 1 40- 12 4-38 f 35- 13 3-75 f 30- 14 3-12 H 27-5 15 2'82 I 25- 16 & 2-50 * 22-5 17 2-18 * 20- 18 86 17-5 19 70 1 15- 20 54 1 A 12-5 21 40 2 12- 22 _L_ 25 3 11- 23 12 4 1 10- 24 1- 5 8-74 25 0-9 6 8-12 26 0-8 7 t^ 7-5 27 0-72 8 6-86 28 i 0-64 9 6-24 29 0-56 10 5-62 30 0-50 11 t 5- Weight of Rod Iron I foot in length, of the following Dimensions. SQUARE IRON. ROUND IRON. FLAT IRON. Inch. Pounds. Inch. Pounds. Inch. Pounds. * 0-2 * 0-14 i x 0-8 I 0-5 f 0-4 f 1-3 A 0-8 0-7 1-7 t 1-3 I 1- | 2-1 f 1-9 f 1-5 f 2-5 1 2-6 1 2- i 2 1-7 1 3-4 1 2-7 f 2 2-5 It 4-3 If 3-4 i 2 3-4 if 5-3 If 4-2 1 2 4-2 H 6-4 If 5- f 2 5-1 H 7'6 H 6- i 3 2-5 H 8-9 H 7- f 3 3-8 If 10-4 if 8-1 i 3 5-1 If 11-9 if 9-3 f 3 6-3 2 13-5 2 10-6 f 3 7-6 2 f 17-1 2i 13-5 i 4 3-4 21-1 24 16-7 f 4 5-1 2} 25-6 2f 20-1 i 4 6-8 3 30-4 3 23-9 1 4 8-4 3 41-4 H 32-5 f 4 10-1 4~ 54-1 4 42-5 i 5 4-2 5 84-5 5 66-8 f 5 6-3 6 121-7 6 95-6 i 5 8-4 7 165-6 7 130- 1 5 10-6 8 216-3 8 169-9 I 5 12-7 536 WEL WELLS. WEL Welding, the operation of combining or joining two pieces of iron or steel, by bringing the surface to be joined to a heat nearly equal to that of fusion Well, in ship-building, a partition to enclose the pumps, from the bot- tom to the lower decks, to render them accessible, and prevent their taking damage Wells. The practice of boring for water, adopted in the province of Artoise, in France, has given the denomination to those wells which are termed Artesian. Wells on this principle are very applicable in low level districts covered with alluvial deposit or clay; in such situations springs are seldomfound, and water cannot be obtained by sinking an ordinary well, unless at a disproportionate cost. The eastern part of Lincolnshire, which lies between the chalk range called the Wolds, and the sea, is a case in point. It was discovered, perhaps accidentally, in sinking through the clay to the subjacent chalk, that water rose to the surface in a perpetual fountain, and an ample supply was obtained over the whole of that district by the sim- ple operation of boring. A number of wells of this de- scription have also been executed in the neighbourhood of London by perforating the London clay in- to the porous bed of the plastic clay formation, and into the chalk. The principle of operation is simply this. The hole is bored through impervious strata that do not contain water, into lower strata that are fully charged with it, and the water rises by hydrostatic pres- sure. The height to which it will rise obviously depends upon the in- clination of the strata, and other causes which affect the relative levels of the hole that is made, and the subterraneous body of water that has been tapped. Under most circumstances it is 537 necessary to protect the perforation that is made by sinking iron pipes. The boring is thus secured against the accident of the sides falling in, and another advantage, which is of some importance, is obtained: it may chance that the object is to obtain a supply of soft water which has been ascertained to exist at a certain level, and that the strata which have to be pierced to get to it contain hard or impure water; in such a case the boring would be continueddown to the proper depth, and the pipes being plunged into the soft water, it would rise through them, and any water or impurity which might be found in the strata through which they passed would be effectually excluded. If it so happened that at a certain depth below the soft water a mineral water could be obtained, instead of going to the expense of a fresh bore from the surface, it would only be necessary (supposing that both would flow to the same level) to bore through the pipes already fixed, to the mineral water, and insert smaller pipes within the larger ones, for bringing it up to the surface. The history of the great Artesian well which was completed at Cre- nelle is one of the most remark- able instances of confidence in the principle, and of perseverance in execution, that is on record. The facts are believed to be substantially as follows : A person suggested to the authorities that an Artesian well would supply water in a situa- tion where it was greatly required; and after some discussion it ended in his undertaking the work on the stipulation, " No water, no pay." He bored down far beyond the point at which he expected to have terminated his labours ; but no signs of water appeared: he persevered, however, till he found that the expenses had ruined him. Under these circumstances, he consulted the celebrated Arago, WEL WELL-SINKING. WEL who encouraged him -to proceed. Again he went to work, and after unparalleled difficulties, at the ex- piration of six years, and at the depth of 1800 feet, the superin- cumbent mass was bored through, and the water came boiling up in such quantities, and with such force, as to flood the whole district. The water, when first obtained, was extremely foul : the partial in- troduction of an Indian-rubber hose is said to have remedied this, and the water thus procured from the main spring was quite pure, and at a very high temperature. Well-sinking. The process of boring may be thus briefly described : The auger, the chisel, or any of the great variety of implements which are required to meet differ- ent circumstances and overcome the numerous difficulties which are experienced, are screwed to iron rods, which are usually from 2 to 2^ inches square. The first rod which is attached to the tool is generally about 6 feet long, and the others are of the uniform length of 20 feet. Each rod has a screw at one end, and a tapped socket to receive a screw at the other, and they fit universally ; there is also a ' middle knob ' in the centre of each rod, which is used for suspending the rods al- ready fixed, whilst others are being added or detached, as the imple- ment is lowered into the bore, or drawn out of it. In commencing operations, a stage about 8 or 10 feet square, and 20 feet high, is erected, when the boring takes place from the surface. The men who work the tool stand upon this stage, and a windlass or crab is fixed, chiefly for hoisting and lowering the rods, but mechanical power is also re- quired for assisting in the working when the depth is very great. A boring handle is attached to. the rod, which is used for turning the tool round in boring with an 538 auger, or in ' jumping,' as is re- quired when cutting through rock or indurated clay with the chisel. When the boring has proceeded till it is found difficult to turn the rods, or at such times as practical experience dictates, it is necessary to draw out the implements and to bring up the loose material that may be at the bottom of the bore. Under ordinary circumstances a common windlass, or a small crab, gives sufficient power to work, hoist, and lower the rods ; but when the bore is of great depth, or the instruments of unusual size, an increase of mechanical power is ne- cessary. This may be conveniently obtained by placing a second crab on another stage ; or, in extraordi- nary cases, horses may be applied on the surface. An economical mode of boring has been adopted with success on some parts of the Continent by using a heavy cast-iron bar, 2 cwt. or more, armed with a chisel at the lower end, and surrounded by a cylinder or hollow chamber, which receives through valves and brings up the detritus of the per- forated stratum. This implement is suspended over a wheel or pulley fixed above the spot in which the hole is made, and is raised up and let fall by manual labour. As the rope is raised up and down, its tortion gives the chisel a circular motion, which varies the place of cutting at each descent. When the chamber is full, the whole apparatus is raised quickly to the surface, and the material it contains discharged. In cutting through a hard stra- tum, or under circumstances w r here iron pipes could be dispensed with, this plan of boring a hole w^ould doubtless answer ; but it is con- ceived that the bore could scarcely be made sufficiently straight to ad- mit of pipes being inserted. It is, however, a much less costly me- thod of executing the work where WEL WHARF. WHA it can be made to apply, and is well worth attention. Well-staircase, a winding staircase of ascent, or descent, to different parts of a building, so called from the walls enclosing it resembling a well, called frequently a geometri- cal staircase Weold, or Weald (Saxon), a forest Wharf, a levelled surface, terrace, or embankment, formed on a river or canal bank, or sea- coast, to facili- tate the landing and embarkation of persons and goods, and protected by an artificial frontage or struc- ture of masonry or other materials. The natural form of banks and coasts, unless defined by masses of rock, is usually shelving or inclined, so that the depth of water is gra- dually reduced, and thus prevents the close approach of floating ves- sels. By the construction of wharf- walls, which are either extended into the deep water, or the founda- tions of which are sunk so as to permit the subsequent removal of the bank, and thus bring deep water into contact with them, vessels are enabled to come close alongside, and thus discharge or receive their cargoes directly from the wharf. Wharf-walls are constructed of va- rious materials, but are always formed with a slope or batter out- wards towards the base, in order to give greater stability to them, and to resist the action of the tide and the waves. Much theory has been expended in attempts to determine the precise forms which should be given to these structures, and, ac- cordingly, some engineers approve of plane-faced walls, while others prefer curved faces; and another theory has been started to explain that a perfectly vertical face is the best of all adapted to resist the in- fluence of waves. Whether this position be theoretically correct or not, however, the value of an ex- tended base, in giving stability, is too well known to need demonstra- tion, and derives support from that 539 intuitive kind of feeling which pro- ceeds directly from the evidence of our senses. Adopting the inclined plane face as a good practical one for wharf-walls, the rate of inclina- tion or batter may be determined from 1 in 8 to 1 in 12, that is, with a total divergence from the perpen- dicular of or ^ of the total height, being from 1 to 1^ inch in a foot. The front of the wall, if of masonry, may be protected by a row of sheet piling, either of timber or iron. In the former case, the piles are driven close together, and bound along the top with a horizontal tie or waling firmly bolted to the piles. If iron piling is used, the piles are driven at intervals of from three to five feet, and cast-iron plates fitted in between them, being se- cured within grooves formed in the sides of the piles. The Brunswick Wharf, at Blackwall, affords a good example of this description of piling. The masonry of the wall is founded upon the piling, the length and closeness of the piles being determined with reference to the nature of the subsoil, and the whole of them, are driven to a firm bot- tom and levelled on the heads, being strongly secured in their po- sition by means of longitudinal and transverse ties or beams, on which the first course of footings was built. The durability of these walls is known to depend greatly upon the kind of mortar or cement used in connecting the masonry or brick- work. Cements known as water- cements, formed with lime which has the property of hardening under water, should 'be preferred to all others. The thickness of the wall must depend upon its height and the nature of the materials behind it. If these are likely to press se- verely against the wall, such as clays liable to hold great quantities of water, &c., the thickness of the wall will be required to be greater than if gravel, or other non-reten- tive material, forms the backing. WHE WHEEL-CUTTING MACHINE. WHE Strong ties of iron should in all cases be secured to the front of the wall, passing through it, and being secured by plates and keys in the front, and extending backward to a considerable distance, and se- cured to a row of piling driven into the solid ground. These land-ties will also considerably assist the wall in resisting the forward pres- sure of the soil behind it. Imme- diately at the back of the wall a firm body of concrete, or, at least, well-puddled clay, should be in- troduced. Whichever of these is used as a backing, it should be consolidated as much as possible, and it will thus resist the admission of moisture behind the wall, which is indispensable to secure its per- manent durability. The concrete should be cast in from a height above its intended position, and allowed to set before it is filled in ; and if clay be substituted, it should be thoroughly well rammed in, and made as solid as possible. Wheal. The ancient Cornish called a mine huel, which has been cor- rupted into wheal. Wheel and Axle. This machine is so named by reason of its consisting of a wheel and cylinders, having a common axis with pivots fixed in its extremities, on which the whole may revolve. This very simple and useful contrivance, although usual- ly designated a second mechanical power, requires the consideration of no other principles than those adduced for the lever ; it is nothing but a lever, having the radius of the wheel for one arm, and that of the cylinder or axle for the other, the fulcrum being the common centre of both. This machine is also termed the ' Perpetual Lever ;' for since the power and the resist- ance operate respectively at the circumference of a circle revolving about an axis, it is obvious that the rotation must maintain the continuity. Wheels, in locomotive engines : the 540 well - known invention for ob- taining a rolling progressive mo- tion. They receive names corre- sponding to the part of the engine or tender they support ; as leading, trailing, &c. Driving wheels vary in size from 4 feet 6 inches up to 10 feet diameter. Leading and trailing wheels vary from 3 feet up to 4 feet 6 inches in diameter. Tender wheels are usually about the same size as the leading and trailing wheels of the engines they are attached to. Wheel-cutting machine, a machine for cutting out the teeth of wheels. The most perfect machines for shaping the teeth of wheels are those invented by Mr. Lewis, of Manchester, which are adapted for cutting the teeth of spur, bevel, and worm wheels, of either metal or wood. The principal working parts of these machines and the mode of action is as follows : Two side frames have angular ridges from end to end, to fit into corresponding grooves in the bot- tom of a travelling frame : this frame can be adjusted by a screw moved by a hand-wheel at the back of the machine : at the front of the machine is a strong spindle, placed vertically, to carry the work which is fixed on the top of it, and at the lower part is a large worm-wheel moved by a screw, to which is connected a train of three wheels : the sizes of the first and third wheels must be such that half a revolution of a handle, which falls into a notch after each half-revo- lution, shall turn the work so that any point in the pitch-line of it will move through a distance equal to the pitch. To the travelling frame a slide is attached by bolts and joints, in such manner that it may be fastened to act vertically, or at an angle in the direction either of the length or breadth of the machine. The cutter, and its wheels for diminishing the speed and pulley for communicating mo- WHI WINCH AND AXLE. WIN tion to it, are carried by the slide. The cutter is a circular piece of steel notched like a saw, and shaped to fit the spaces between the teeth of the wheel, and is raised or low- ered by a rack at the back of the slide, worked by a pinion and han- dle. The travelling frame and slide being adjusted to the work, and the suitable wheels arranged for turning it the given distance, the machine is set in motion and the revolving cutter pressed down upon the rim of the wheel by the handle and rack till the space has been cut; the cutter is then raised, and by giving half a revolution to the handle attached to the worm-wheel apparatus, the spindle and work are turned so that the latter is in pro- per position for the cutter to act again.- For a spur-wheel the slide acts vertically, for a bevel-wheel it acts at the requisite angle in the direction of the length, and for a worm-wheel at an angle in the direction of the breadth of the machine. Whim, a machine used for raising ores, &c., worked by horses, steam, or water Whim-shaft, in mining, the shaft by which the stuff is drawn out of the mine by the horse or steam whim Whispering gallery, a curvilinear cor- ridor or balcony within the cupola of St. Paul's cathedral, London, and in other ecclesiastical build- ings White Chalk is a well-known native carbonate of lime, used by the artist only as a crayon, or for tracing his designs ; for which pur- pose it is sawed into lengths suited to the port-crayon. White crayons and tracing chalks, to be good, must work and cut free from grit. From this material both whiting and lime are prepared, and are the bases of many common pigments and co- lours used in distempering, paper- staining, &c. Wicker-work, at an early date, was occasionally employed for the roof- ing, if not for the entire construc- tion, of churches Wicket, a small gate or door within, or a part of a massive or large door or gate for the passage of pedestrians Willow wood is of many varieties : it is perhaps the softest and lightest of English woods ; it is planed into chips, and used for many simple purposes Wimple, a plaited linen cloth which nuns wear about their necks ; also a flag or streamer Winch or Wince, in mining, the wheel and axle frequently used to draw water, &c. in a kibble by a rope Winch and Axle,. ( "a machine consti- tuting a small windlass, and con- sisting of a cylinder of wood which is capable of turning on its axis between two upright posts of the same material, or between the ends of a cast-iron frame : a lever at one or at each extremity of the cylinder is attached to an iron axle passing through the latter at right angles to its direction, and is fur- nished with a handle, which is parallel to that axle. The name winch is given to a lever or handle of this kind, and the word is sup- posed to be derived from the verb guincher, signifying, in old French, to turn, or bend in a curvilinear manner. The machine is used to raise a weight vertically, or to draw an object towards it ; for which purposes the object is con- nected with it by a rope or chain which continually passes over the curved surface of the cylinder as the latter is made to turn on its axis by a man acting at the handle. Since the cylinder revolves once while the handle, or the extremity of the lever to which it is attached, is made to describe the circumfer- ence of a circle, it is evident that the mechanical power of the ma- chine is precisely that of the wheel and axle. When of a simple form, it is employed to raise water from a well, and earth or some other 541 2 A WIN WINCH AND AXLE. WIN material from the shaft of a small mine ; and one of a complex nature is used, by means of a crane, to raise casks or heavy packages from the ground to the upper part of a building. When great weights are to be raised, the machine is usually fixed in a frame of cast iron, which is rectangular on the plan, but its extremities or faces have the form of a triangle, or of the letter A. The axle of the cylinder is sup- ported on a horizontal bar at the middle of each end of the frame, and to the cylinder is attached a toothed wheel which turns with it on the common axis : above this wheel, and parallel to the cylinder, is an iron axle which carries a pinion with teeth working in those of the wheel, and causing the latter to revolve, the pinion itself being turned by means of the lever and handle at one or at each extremity of the frame. A machine of this kind is called a crab; and when a weight is to be drawn horizontally or raised above the cylinder, the machine must of course be bolted to the floor or firmly fixed in the ground, in order to prevent it from being moved from its place. In such machines there is generally, at one extremity of the cylinder, a wheel having on its circumference teeth like those of a saw; and a click or catch, which turns freely on a pin, is attached by that pin to the side of the frame in such a manner that it may fall between the teeth. By this contrivance, if the handle should break, or the moving power be taken off while the weight is suspended in the air, the latter is prevented from de- scending. Machines of this kind are occa- sionally constructed, which have the power of holding the weight in any part of its ascent or descent without a ratchet-wheel and catch. The only disadvantage attending the machine, when compared with 542 an ordinary winch or capstan, is, that it requires a much greater quantity of rope to raise or move the object through any given distance. It was first proposed in Europe by Mr. George Eckhardt, but machines of a like kind have, it is said, long been in use in the East. The winch is employed in the common jack, which is used to lift great weights, or to move them through small distances. The handle turns a pinion with teeth, which act on others at the circum- ference of a small wheel ; and on the axle of this is a pinion with teeth, which work in those of a rack-rod. The axles of the wheel and pinions being let into the sides of a case of wood or iron, the re- volution of the wheel produces a rectilinear motion of the rack; and one end of thecasebeingfixedtothe ground, or against an immoveable object, the extremity of the rack at the opposite end forces forward the body which is to be displaced. Sometimes, instead of a rack, the machine is furnished with a wheel whose axle is hollow, and cut in the form of a concave screw : within this screw is one of the convex kind, which by the revolution of the wheel and its axle is made to move in the direction of the latter, and thus to press before it the ob- ject which is to be removed. This machine has, however, consider- able friction. The force exerted by a man in turning a winch vertically, varies according to the position of the lever with respect to the horizon. When the lever, or that part which is perpendicular to the axle, is per- pendicular to the ground, and the handle is at the highest or lowest part of the circle described by the end of the lever, the man either pushes the handle directly from him or pulls it directly towards him ; and in each case he exerts a power which is estimated at 27 o-> 30 pounds ; but when the lever i WIN WIND. WIN in a horizontal position, the man either throws a great portion of his weight on the handle to press it down, or he exerts his muscular force in a direct manner to pull it upwards ; and the force exerted in these positions is estimated at 140 or 160 pounds. The force exerted must very evidently have different values between these quantities in other positions of the winch ; and the practice is to cause two men to work at the same time to turn the machine, one heing at each extremity of the axle of the cylin- der. The levers of the two winches are placed at right angles to one another; consequently, when one man is pushing or pulling horizon- tally, the other is pressing or pull- ing vertically, and thus the opera- tion of turning goes on with nearly uniform intensity ; the first man working in the least favourable position when the other is working in that which is most so. Wind (instrument for measuring the force and velocity of} : a fly (re- sembling that of a revolving ventila- tor, or the sails of a wind-mill) is fixed to the small end of the vane of a weather-cock, so as to be turned with its circular disc to the wind ; and it consequently revolves by the action of the wind with a rapidity increasing as the force of the wind increases. The revolutions of the axis of this fly are converted by a train of toothed wheels and screws into a vertical motion, by which a pencil is carried downwards, touch- ing the surface of a vertical cylin- der, the cylinder having the axis of the weathercock for its axis. As the vertical rod on which the pencil slides is attache*} to the vane of the weathercock, the point of the compass from tvhich the wind blows is recorded on the side of the cylinder on which the mark is made ; while the quantity of the wind is represented by the extent of the descent of the pencil. Wind-beam, in ancient carpentry, a 543 cross-beam used in the principals of many ancient roofs, occupying the situation of the collar in mo- dern king-post roofs Winding, in ships, twisting on an uneven surface Winding engines. In winding engines for drawing coals from a pit, where a given number of strokes are re- quired in drawing a corf, the dia- meter of the roll at the first lift must be ascertained. In this case the engine is supposed to have flat ropes, such as are generally used, and which lie upon each other. To find the diameter of a rope-roll at the first lift, it is necessary to know the depth of the pit, the thickness of the rope, and the number of strokes which the en- gine is intended to make in draw- ing up a corf or curves ; then, the thickness of the rope being known and the number of strokes, the thickness of the ropes upon the roll can be determined, let the dia- meter of the roll be what it may. Suppose the thickness of the rope to be 1 inch, and the number of strokes 10 ; then the radius of the roll is increased 10 inches, or the diameter is increased 20 inches, whatever that diameter may be. Windlass, in mechanics, a machine by which a rope or lace is wrapped round a cylinder : in navigation, a horizontal machine of strong tim- ber, used in merchant ships for heaving up the anchor, instead of a capstan Wind-mill, a mill which derires its motive power from the impulse of the wind. The building contain- ing the mill-work is usually lofty, and placed on elevated ground. The machinery consists of a shaft, upon one extremity of which arms radiate at right angles, similarly to the spokes of a wheel : upon these, vanes or sails are set at a small angle, (about 22.) By this means the wind, blowing directly upon the area occupied by the vanes, acts obliquely upon the whole of WIN WINDOWS. 544 WIN WOOD. WOO them, causing them all to move in a direction transversely to that of the wind. Suitable means are provided for bringing the sails into a position to confront the current of the wind. The motion of the sails is transferred by gearing to any machinery required to be driven, which is most commonly mills for grinding corn. Wind- mills were formerly extensively employed, in Holland, to give mo- tion to pumps for the drainage of land. The power of the wind is uncertain and variable in its inten- sity, and its application as a prime mover for mechanical purposes is consequently limited. Windows were almost unknown in the religious and other monumental structures of the Egyptians, Greeks, and Romans, but they constitute an essential and distinguishing feature of the Gothic, to which style they stand in the same rela- tion as Orders do to the temple architecture of antiquity. Windows admit of very rich and varied decoration, and those in Beccles church, Suffolk, (repre- sented on the opposite page,) are beautiful examples. The varied exuberance of fancy displayed in the tracery may possibly be accounted for by supposing each to have been the gift of some pious individual, who, while he perpetuated his mu- 1 nificence, marked also his taste and ingenuity. The practice of window tracery every where had its origin in win- dow -grouping, placing two or three lancet windows beside each other, and one or more foil or rosette windows above and between their heads, in order to fill out the arched cell of the vaulting, which then necessarily gave the whole group an arched outline ; and this was indicated by a general drip- mould or label. It then became desirable to lighten the irregular shaped masses of stone left between the perforations, and this was done 545 by piercing these masses, or span- drils, and reducing the solid frame of each foil or rosette to an equal thickness all round, as if several such frames or rings were packed into one great arched opening, which henceforth was regarded as one window instead of several. (For further illustration, see art. Tracery.) Wind -sail, in navigation, a sort of ventilator, consisting of a wide tube of canvas shaped like a fun- nel, to convey a stream of fresh air downwards to the hold and lower deck of a ship Wing transom, in ships, the upper- most transom of the stern-frame Winze, in mining, a sinking in a lode communicating with one level, for proving the lode or ventilating the drivings Wipers, the cogs of a horizontal wheel Wood, in its raw state, contains a large amount of water. This water contains more or less soluble mine- rals, and is called sap. By drying wood, a great part, but not all, of this water is evaporated. If wood is dried in a closed vessel, and then exposed to the atmosphere, it quickly absorbs moisture ; but the moisture thus absorbed is much less than the wood originally con- tained. The amount of water varies in different kinds of wood, and also varies according to the season. Wood cut in the month of April contains from 10 to 20 per cent, more water than that cut in the month of January. The following Table shows the percentage of water in different kinds of wood dried as far as possible in the air: Beech 18-6 Poplar 26-0 Sugar and common Maple 2 7-0 Ash 28-0 Birch 30-0 Oak, red 34-7 Oak, white 35-5 woo WROUGHT IRON. WRO Pine, white ..... 37-0 Chestnut ...... 38-2 Pine, red ...... 39-0 Pine, white ..... 45-5 Linden ...... 47*1 Poplar, Italian . . . . 48-2 Poplar, black .... 51-8 Wood cut during the months of December and January is not only more solid, but it will dry faster than at any other period of the year, because the sap by that time has incorporated a great part of its soluble matter with the woody fibre ; what remains is merely wa- ter. When the sap, during the months of February, March, and April, rises, it partly dissolves the woody fibre ; and the drying of the wood is not only retarded, but the wood is weakened, in consequence of the solid matter thus held in solution. The difference in chemical com- position of the woody fibre, in most kinds of wood, is but slight, as the following analytical Table Hy _ Oxy . Carbon, drogen. gen. Sugar Maple 52-65 5-25 42-10 Oak . . . 49-43 6-07 44-50 Poplar, black 4970 6-31 43'99 Pine . . . 50-11 6-31 43'58 Wood is generally bought by admeasurement, and its specific gravity is directly in proportion to its amount of carbon, hydrogen, and oxygen. The following Table shows the specific gravity of wood. Water = 1000 : Oak, white . . Oak, red . . Poplar . . . Beech . . . Sugar Maple . Birch . . . Pine, red . . Pine, white Ebony . . . Guaiac (lignum vitse) . . . 546 Green. 1-0754 1-0494 0-9859 0-9822 0-9036 0-9012 0-9121 0-8699 Air-dried. 0-7075 0-6777 0-4873 0-5907 0-6440 0-6274 0-5502 0-4716 1-2260 1-3420 Woolf's engine, a steam engine so called from its inventor's name, with two combined cylinders of differ- ent diameter, the eduction passage of the smaller cylinder communicat- ing with the steam passages of the other; high-pressure steam being used in the small cylinder, and made to act expansively in the large one, the steam being after- wards condensed in the usual manner. By this arrangement steam is economized, and a con- siderable saving of fuel is effected. Work, in mining, ores before they are cleaned and dressed Working-big, in mining, signifies sufficiently large for a man to work in Working drawings consist of plans, elevations, sections, and details in full, of the whole, and of all the parts of an edifice, to as large a scale as may be found convenient ; generally made in outline, except- ing the sectional parts, which are mostly shadowed, in order to make them more obvious to the work- man, for whose use these drawings are made Worm-wheel, a wheel having teeth formed to fit into the spiral spaces of a screw, so that the wheel may be turned by the screw Wreath, in heraldry, that which is between the mantle and the crest, called also a torce ; also a boar's tail, so termed among hunters Wrought iron. The chemical differ- ence between cast iron and wrought iron consists principally in the de- gree in which foreign matter is pre- sent in each; which is in larger amount in the former than in the latter. This rule is applicable only to a given cast iron, and to the wrought or bar iron which is made from it. There are many cases in which wrought iron contains a larger amount of impurities than cast iron, and still continues mal- leable ; while cast iron of the same composition may be very hard and brittle. Berzelius detected 18 WRO WROUGHT IRON. WRO per cent, of silex in a certain kind of bar iron, which was still mallea- ble and useful. One-tenth of that amount of silex will make cast iron brittle. The foreign matters gene- rally combined with pig iron are, . carbon, silicon, silex, sulphur, phos- phorus, arsenic, zinc, manganese, titanium, chrome, aluminium, mag- nesium, and calcium. Each of these tends to make iron brittle ; there- fore, in converting cast into wrought iron, it is necessary, as far as pos- sible, to remove them. The main difference between pig and wrought iron consists in their mechanical structure, or aggregate form. Pig iron is a homogeneous mixture of impurities and metal. Wrought or bar iron is a mixture of iron more or less pure with a mass of homogeneous impurities, or cinder, the latter filling the cre- vices between the crystals of the iron. Iron being fusible in pro- portion to the carbon it contains, if pig metal is melted, and the cin- der surrounding it exposed to the atmosphere, the carbon will be volatilized in the form of carbonic acid, and iron of greater or less purity will remain. To keep this iron liquid, a higher temperature is required: unless the temperature is raised, it will crystallize. In this state of metamorphosis its infusi- bility will increase, and after the expulsion of the carbon, it will contract into a solid mass in oppo- sition to the highest possible heat. By stirring and mixing the pasty iron, small crystals are formed ; at first, on account of the partial fusing of the iron, in small parti- cles; but, as the fusibility dimi- nishes, these particles unite by the force of cohesion ; and the bodies thus formed may, by exposure to a higher heat, be welded together. The mixing of cinder and iron will prevent the latter from forming large crystals : this result,of course, will be more easily prevented by diligent than by tardy manipula- 547 tion. Where the pig iron is of such a nature as to keep liquid while the work goes on slowly^ still bet- ter results will be obtained. This process is analogous to that of salt boiling, in which, by stirring the brine, the formation of large crys- tals is prevented. If the crystals of iron thus formed cohere, they produce, under the influence of motion, a porous, spongy mass, whose crevices are, if not filled, at least coated, with cinder. If these masses, which are the loups or balls at the puddling furnaces, are shin- gled or squeezed, the crystals of iron will not unite, but form coated cells with a film of cinder, of greater or less thickness, according to the fusibility of the cinder. Iron in a connected form, and cinder in sepa- rate cells, are thus blended in one homogeneous mass. The more this iron is stretched, the more it forms fibres. Fibrous bar iron resembles hickory wood, in being a combina- tion of fibres and spaces. In bar iron, these spaces are filled with cinder. When other circumstances are equal, the strength of the iron will be proportional to the fineness of the fibres. That portion of the iron which is not melted, which crystallizes too fast, or whose pre- mature crystallization cannot be prevented, is in the condition of cast metal, and cannot be convert- ed into fibrous wrought iron. In the puddling furnace it is necessary to prevent crystallization by ma- nual labour. If the characteristic between wrought and pig iron consists only in a well-regulated mechanical mix- ture of cinder and iron, fibrous iron should be producible from any cast iron, whether purified or not : this is actually the case. Very fibrous bar iron, which is strong and mal- leable, is made from very inferior cast metal, from which no impurity has been removed. At Hyanges, in France, very inferior metal is con- verted by a cheap and skilful pud- WHO WROUGHT IRON. WRO dling process, into a very fibrous bar iron, of great strength and ductility. But this iron is puddled and re-heated at the lowest possi- ble heat ; it is then rolled, and is ready for the market. For hoops, rails, and nails, it is a very useful article, but is of no use to the blacksmith. Heated to any tem- perature above that of the puddling and re-heating furnaces, it returns to its primitive state, in which con- dition it becomes worse than the cast iron from which it was origi- nally made. None but a very skil- ful blacksmith can weld it; for, when slightly re-heated, it falls to coarse sandy pieces, or melts like pig iron. That which thus loses its fibrous texture in heating, the smith calls ' burnt iron.' The philosophy of the improve- ment of metal consists in the cir- cumstance that a part of its impu- rities which are originally in che- mical combination, are converted into mechanical admixtures. Iron containing a small amount of car- bon, silicon, or phosphorus, is al- ways more hard and strong than pure iron. Pure iron is quite soft. Impure iron has the property of crystallizing, on being suddenly cooled : the size of these crystals is proportional to the amount of carbon in chemical combination with the iron, in proportion to other matter. Between the crys- tals minute spaces are left, which serve for the absorption of oxygen. By this means, silicon and calcium may be oxidized, but not carbon, phosphorus, and sulphur. The metal improves in quality in pro- portion as oxygen finds access to its impurities. The absolute cohesion or strength of wrought iron is not dependent upon the degree of purity of the metal, but upon a given mixture of cinder and iron. Pure iron, which is always soft, may be required for various purposes, as in the manu- facture of cast steel ; but, in most 548 cases, an impure but fibrous iron is preferable. In making wrought iron, the main difficulty consists, not in producing fibres in the first stages of the operation, for this may be accomplished by almost every experienced manufacturer, but in retaining these fibres through every subsequent stage of the ope- ration. Wrought iron of good quality is silvery white and fibrous ; carbon imparts to it a bluish, and often a gray colour ; sulphur, a dark, dead colour, without a tinge of blue ; silicon, phosphorus, and carbon, a bright colour, which is the more beautiful the more the first two elements preponderate. The lustre of iron does not depend principally upon its colour ; for pure iron, al- though silvery white, reflects but little light. A small quantity of carbon in chemical combination, phosphorus, or silicon, increases its brilliancy. Its lustre is diminished by silex, carbon in mechanical ad- mixture, cinder, lime, sulphur, or magnesia. Good iron should ap- pear fresh, somewhat reflex in its fibres, and silky, A dead colour indicates a weak iron, even though it is perfectly white. Dark but very lustrous iron is always supe- rior to that which has a bright co- lour and feeble lustre. Coarse fibres indicate a strong, but, if the iron is dark, an inferior article. Where the iron is of a white, bright co- lour, they indicate an article of superior quality for sheet iron and boiler-plate, though too soft for railroad iron. For the latter pur- pose, a coarse, fibrous, slightly bluish iron is required. Iron of short fibre is too pure ; it is gene- rally hot-short, and, when cold, not strong. This kind of iron is apt to result from the application of an excess of lime : its weakness is the result of the absence of all impuri- ties. The best qualities of bar iron always contain a small amount of impurity. Steel ceases to be hard XEB YELLOW OCHRE. YEL and strong, when deprived of the small amount of silicon it contains, or if the silicon is oxidized by re- peated heating. This is the case with bar iron. If deprived of all foreign admixtures, it ceases to be a strong, tenacious, and beauti- ful iron, but becomes a pale, soft metal, of feeble strength and lustre. Good bar or wrought iron is always fibrous: it loses its fibres neither XEB XEBEC, in navigation, a small three- masted vessel, without a bowsprit, principally used iu the Mediter- ranean Xenodochium, a room in a monastery for the reception and entertain- ment of strangers, pilgrims, and the relief of paupers XP. /., the initials of the Greek YAC YACHT, in navigation, a small ship for carrying passengers Yard, a court enclosed by walls and other buildings; also a measure of 3 feet : a yard or yerd was an- ciently a spar or rafter in a timber roof. Yardland, a certain quantity of land, called, in Saxon, gyrdlander; in Latin, virgata terra : in some places it is 20 acres of land, in others 24 or 30 Yellow is the first of the primary or simple colours, nearest in relation to and partaking most of the nature of the neutral white ; it is accord- ingly a most advancing colour, of great power in reflecting light. Compounded with the primary red, it constitutes the secondary orange and its relatives, scarlet, &c., and other warm colours. Yellow Lake. There are several pig- ments of this denomination, vary- ing in colour and appearance, ac- by heat nor by cold. Time may change its aggregate form ; but its fibrous quality should always be considered the guarantee of its strength. Iron of good quality will bear cold hammering to any ex- tent. A bar an inch square, which cannot be hammered down to a quarter of an inch, on a cold anvil, without showing any traces oi splitting, is an inferior iron. XYS names of Christ ; a monogram, re- presented in paintings and mosaics by the Greek Christians Xylography, the art of engraving on wood Xystos, in ancient architecture, a large portico in the gymnasium, for the accommodation of the wTestlers ; a sheltered walk YEL cording to the colouring substances used and modes of preparation. They are usually in the form of drops, and their colours are, in general, bright yellow, very trans- parent, and not liable to change in an impure atmosphere, qualities which would render them very valuable pigments, were they not soon discoloured and even de- stroyed by the opposite influence of oxygen and light, both in water and oil, in which latter vehicle, like other lakes in general, they are bad dryers, and do not stand the action of white lead or other metallic colours. If used, there- fore, it should be as simple as possible. Yellow Ochre, called also Mineral Yellow, is a native pigment, found in most countries, and abundantly in our own. It varies considerably in constitution and colour, in which latter particular it is found from a 549 2A5 ZEB ZIGZAG MOULDING. ZIN bright but not very vivid yellow to abrown yellow, called spruce ochre, and is always of a warm cast. Its natural variety is much increased by artificial dressing and com- pounding. Yellow Orpiment, or Yellow Arsenic, is a sulphurate oxide of arsenic, of | a beautiful, bright, and pure yellow j colour, not extremely durable in , water, and less so in oil. In tint with white lead, it is soon de- stroyed. It is not subject to dis- coloration in impure air. ZEB ZEBRA WOOD is the produce of the Brazils and Rio Janeiro ; it is sent in logs and planks as large as 24 inches. The colour is orange brown and dark brown variously mixed. Its beautiful appearance fits it for cabinet-work and turnery. Zero, the commencement of a scale marked 0, or nothing. It usually denotes the point from which the scale of a thermometer is graduated. Zeta, presumed to be a room over the porch of a Christian church Zigzag, a moulding by lines arranged in the manner of the heraldic chevron. Zigzag is found fre- quently used in Norman and An- glo-Norman architecture. Very many beautiful specimens of this ornament exist in doors and win- dows of the Anglo-Norman Gothic in England. (See Doors, and the Frontispiece for an early specimen.) Zinc. This metal exists in abundance, and is employed for many pur- poses. It is commonly combined with sulphur in zinc blende, and with carbonic acid in the mineral calamine, which is the most valu- able of all its ores. Zinc may be obtained pure by re-distilling in a porcelain retort, which is sold in commerce. It is obtained from the ores as follows : they are first washed and mixed with powdered coke or charcoal, are distilled from 550 Yew. The yew-tree is common in Spain, Italy, and England, and is in- digenous to Nottinghamshire. The tree is not large, and the wood is of a pale yellowish-red colour, hand- somely striped, and often dotted like amboyna. It has been long famed for the construction of bows, and is still so employed. The English species is a hard, tough, and durable wood, and lives to a great age. It is also used for the making of chairs, the handles of articles of furniture, &c. ZIN an earthen close vessel, with an iron tube passing through its bottom , the upper end of which is open, and the lower end entering a vessel of water. At a bright red heat zinc volatilizes, and is condensed in the water, gases passing off along with it. It is a bluish -white metal, which slowly tarnishes in the air. It is brittle at ordinary tempera- tures, but at about 300 it is mal- leable, and may be rolled or ham- mered into sheets, and retains its ductility when cold. At 400 it may be reduced to powder: it melts at 773. Zinc white is an oxide of zinc which has been more celebrated as a pig- ment than used, being perfectly durable in water and oil, but want- ing the body and brightness of fine white leads in oil ; while, in water, constant or barytic white and pearl white are superior to it in colour, and equal in durability. Never- theless, zinc white is valuable as far as its powers extend in painting, on account of its durability both in oil and water, and its innocence with regard to health ; and, when duly and skilfully prepared, the co- lour and body of this pigment are sufficient to qualify it for a general use upon the palette, although the pure white of lead must merit a preference in oil. ELE ADDENDA (ELECTRIC TELEGRAPH). ELE Zocle, a name given to a low, plain, square member or plinth support- ing a column Zoophorus, in architecture, a part between the architraves and cor- nice, so called on account of the ornaments carved on it, among which are the figures of animals Zyghyr, or Sigger, in mining. When a slow stream of water issues through a cranny, it is said to sigger, or zyghyr. ADDENDA. ANGLE-STAFFS or Staff-heads, vertical heads, generally of wood, fixed to exterior angles of a building, flush with the surface of the plaster, on both sides, for the purpose of fortifying them against accident. They serve also for floating the plaster. Their section is about three-fourths of a circle, with a projecting part from the other quarters, by which they are fast- ened to the wood-bricks, plugging or bond timber. Angular modillions, those which are placed at the return of a cornice in the diagonal vertical plane, pass- ing through the angle or mitre of the cornice Electric Telegraph. The employment of electricity in the transmission of intelligence originated at an early period of the history of electrical science. Plans to this effect had been brought before the public ; but all wanted a simplicity of prin- ciple and of construction. In 1837, Messrs. Cooke and Wheat- stone obtained their first patent for an electric telegraph, applicable to general purposes. This patent has been subsequently followed at short intervals by others, in which the invention has been gradually brought to its present form ; the principles originally employed have been progressively rendered more varied and general in their ap- plication, and the apparatus more simple in its details. By these improvements the number of wires necessary for the conveyance of intelligence has been reduced, and the construction has been rendered cheaper and more perfect. The electric telegraph involves 551 in its construction two essential principles. First, that a magnetized needle, which is free to rotate about its centre, being brought near to a wire, through which an electric current is passing, has a tendency to place itself at right angles to that wire ; the direction of its motion following a certain invariable law. This fact was the discovery of Prof. (Ersted, of Co- penhagen, in 1819. Secondly, that a piece of soft iron, not being per- manently magnetic, is rendered temporarily so, during the trans- mission of an electric current along a wire coiled spirally around it. The figures to which reference is here made, in the brief descrip- tion of the apparatus, are, 1. A view of the interior of the single- needle instrument, showing the position of the coil and of the battery connections. 2. A vertical section of the same, through the coil and handle. 3. The handle or key, in the position for giving a signal, part being removed, to ren- der the battery connections more distinct. 4. Plan of the same. The double -needle instrument differs from the single-needle only in the duplication of all the parts. The coil A, figs. 1 and 2, consists of a light hollow frame of brass or wood, around which are wound, in two portions, about 200 yards of fine copper wire, covered with silk or cotton. This length of wire renders the indications of the nee- dle distinct and prompt, even with a low-battery power, or when form- ing part of a very extended circuit. The resistance which would be of- fered by the fine wire of the coil ELE ADDENDA (ELECTRIC TELEGRAPH). ELE *>j! f S 552 ELE ADDENDA (ELECTRIC TELEGRAPH). ELE (its diameter being about -j-^-th of an inch) to the passage of a current of electricity, derived from an or- dinary battery of a few cells only, is overcome by using a battery ar- rangement of considerable inten- sity, but which develops the elec- trical fluid only in small quantity. Or, speaking rather more correctly, we should say, that the electro- motive resistance, both of the bat- tery and also of the ordinary circuit, being very considerable, the intro- duction of the resistance of the coil into the latter produces but little influence upon the transmis- sion of the current. Within the brass frame, and therefore interior to the coils of wire, is suspended a magnetic needle, upon a horizontal axis b, which passes across the middle of the frame, and turns on fine pivots at the back and front of the coil. In front of the frame and of the dial of the instrument is fixed on the same axis b, a second needle having its poles oppositely placed to those of the first. This outer needle serves as the indicator or pointer, by which the signals are made, and at the same time is acted upon by the coil, though in a less degree than the inner needle. The combination of the two needles being thus rendered astatic, it is necessary to give a slight prepon- derance to their lower ends, in or- der that they may recover their vertical position, after having been deflected; and the action of gravity has been found more effectual, in bringing the needle to rest without oscillations, than either springs ap- plied at the sides, or the directive influence of permanent magnets. With the coil and needles thus ar- ranged, it is evident that signals may be given by the combination of successive deflections to one side or the other; the extent of such deflections being limited to any degree that may be found con- venient, either by pins fixed on the dial of the instrument, or by stops 553 placed at the sides of the brass frame of the coil. In fact, all that is necessary for rendering these movements of the needle available for the transmission of intelligence, is a contrivance for reversing with ease and rapidity the connection of the battery with the ends of the two conducting wires. This expe- dient is provided by the handle or key of the instrument. The conductor through which the electrical current is to circulate must be absolutely complete in all parts. It is not necessary that the material of the circuit be the same throughout, but only that its con- ductibility be maintained from the one pole of the battery to the other ; the slightest want of con- tinuity of the conducting matter, at any part of the circuit, being fatal to the passage of the fluid. So long as the wires for telegra- phic purposes were extended be- tween the two points of communi- cation, by being laid within tubes buried in the earth, a second wire was requisite to enable the current to return from the distant station to the point whence it set out. It was well known that the earth itself afforded such a means of return ; but the insulation of the wires in the tubes from the earth, could not be rendered sufficiently perfect, to make the use of the earth, as a portion of the circuit, either prudent or desirable. When, however, the wires were suspended in the air, according to Mr. Cooke's patent of 1842, the earth was ad- vantageously employed as half the circuit. All that was found neces- sary, was to connect the extreme ends of the conducting wire with plates of copper or other metal of two or three feet of surface, buried at some depth in the ground ; or with any system of gas or water- pipes, which might afford a con- tinuous metallic path for the fluid to the earth. In either case, the depth of the connection beneath ELE ADDENDA (ELECTRIC TELEGRAPH). ELE 554 ELE ADDENDA (ELECTRIC TELEGRAPH). ELE the surface must be sufficient to insure certain contact with moist earth or with water, provided that this latter be not confined within any cistern or reservoir. When all these precautions have been taken, the passage of electri- city is readily effected, the earth appearing to offer little or no re- sistance to its progress. Accord- ing to the law established by Ohm, the resistance of any conductor varies directly as its length, and in- versely as its sectional area. The earth may evidently be regarded as a conductor, of which the dia- meter is infinite, compared with its length, and we might therefore be led to expect the result mentioned above. To return, however, to the de- scription of the apparatus, the key or handle by means of which the connection of the battery is effected and varied, consists of a cylinder, in which is a middle zone, e, of hard wood or ivory, while the ends are of metal. One of these ends, _ ^_ 1 ~S Sawbridgeworth. Stortford. ( P" Stanstead. Elsenham. ^% _rfi^ X- -c _0 .0 Newport. Wendon. R Chesterford. Whittlesford. Shelford. ) CAMBRIDGE. ) c? i) /I0^ ^^ Jl^-l ' - _o_ a l K 1C 1 \ Waterbeach. Ely. 1 Mildenhall road. Lakenheath. BRANDON, jllk Jbk Junction with I)/ /_ ^Norfolk Railway. RjT ) c^ ) ^ %^y ^0 N^ K; ;===; "H II! Jc ^-^Ip 558 ELE ADDENDA (ELECTRIC TELEGRAPH). ELE lets, seen in fig. 11, a hammer, h, rapidly strikes a small bell g. Im- mediately, however, that the cur- rent ceases to flow through the coils, the iron within them loses its magnetism, a small re-acting spring, *, draws hack the armature, and interposes the detent so as to stop the clock-work. It is neces- sary that the iron of the magnet should be quite pure and soft, as otherwise the magnetization is to a greater or less degree permanent ; and this may be the case to such an extent as to keep the armature attracted, even after the cessation of the electric current. The bell would then continue to ring until the disengagement of the armature were caused by the hand of the attendant. The bell or alarum may form part of the telegraphic system in two modes. In the first, and most economical, its coil is made to form part of the circuit of one of the needle wires, in conjunction with a key or rheotome. In the second and more complete method of in- troducing the alarum, a distinct wire is employed for it, in the course of which the magnet coils at the several stations are inter- posed. A key of different con- struction (shown in section at fig. 14) is then employed. The body is of brass, but two stout wires, z and c, are conducted through ivory tubes, and terminated in studs, pp, at the top and bottom of the cylin- drical end of the key; the wires and studs being insulated from each other, and from the key, by the ivory in which they are fixed. The collar, if, and nut, t, serve to se- cure the key to the side of the case or box in which it is placed, the former, /', also containing the spring, by which, after use, the key is brought back to its quiescent position. Two springs, not shown in the figure, then rest against the metal of the end, one on each side, and while in this position, merely 559 complete, by the intervening metal, the circuit of the bell-wire which is connected to the foot of one spring directly, and to the foot of the other by the intervention of the bell coil. The wires, z and c, are joined to the two poles of the bat- tery by pieces of thin wire, which will offer no resistance to the revo- lution of the key on its axis. In the quiescent position, the course of a current entering from a distant station would be, from the line- wire on one side, along one spring, across the body of the key to the other spring, and thence through the alarum coil to the continuation of the line -wire, or to the earth connection. When, however, the bell is to be rung to call the atten- tion of the clerk at another station, the key is for a moment turned one- quarter round. This brings the battery studs, pp, into the circuit, instead of the body of the key ; and the current then proceeds from the battery of the ringing station by the spring and wire on one side, passes along the line, and returns by the earth through the other spring again to the battery. The relative advantages of these two methods may be briefly stated. The first has the recommendation of economy, inasmuch as no addi- tional wire is necessary for the bell. If, however, the clerk in charge of an instrument, after turning off his bell preparatory to sending or transmitting intelli- gence, should chance to leave his telegraph, and omit to turn the key so as to replace the bell in the circuit, no means are left to other stations of calling his attention, except by working the needles, with the chance of their movement meeting his eye. By the adoption of the second method, the expense of an additional wire is incurred, but the bells at all stations are constantly in a position to be rung if necessary. In addition to this, it may be remarked, that by keep- ELE ADDENDA (ELECTRIC TELEGRAPH). ELE ing the bell and needles distinct from each other, no derangement of the one is to he feared from injury to or derangement in the other. Mr. Cooke's first plan, in the extension of the conducting wires between distant points, was, as has been already stated, to cover each wire with cotton or silk, and then with pitch, caoutchouc, resin, or other non-conducting material, and to enclose them, thus protected, in tubes or pipes of wood, iron, or earthenware. Excepting in those localities where the suspension of wires is impracticable, as in streets, towns, or on public roads, the early plan has given place to more re- cent inventions. In 1842, a patent was obtained by Mr. Cooke, for a means of suspending and insulating the wires in the air, and the me- thod described in his specification has been since adhered to, with little variation. The wires are generally of iron, which is galva- nized, to protect it from the action of the atmosphere. They are of about one -sixth of an inch in dia- meter, corresponding to No. 8 of the wire-gauge. Being obtained in as great lengths as possible, in the first place, successive pieces are welded together, until a coil of about 440 yards is formed. These rings or bundles weigh about 120 pounds each. The wires are sus- pended on the line, from stout squared posts or standards, of Dantzic or Memel timber. At each quarter-mile, a stronger post is fixed, from which the succeeding lengths of wire on either side are strained or tightened up. Inter- mediate to these principal posts, are placed smaller standards at from 45 to 55 yards asunder, for the purpose of supporting the wires. The straining apparatus is very simple, consisting merely of a reel or pulley, turning between two cheeks of cast iron, and carrying upon its axis a ratchet-wheel, into 560 the teeth of which a click or catch falls. These winding heads, shown at rr, figs. 7 and 9, are connected through the post by a bolt of wrought iron 5, tapped into each head. This bolt not only bears the strain of the wires, but also forms the metallic communication between their ends wound on the two reels. In order to insulate the bolt from the wood of the post, the hole in this latter is bored very large, and collars of eathen\vare, 1 1, are inserted at each side, in which the bolt rests, and against their outer surfaces the winding heads are screwed up tight. Fig. 9 is a section through the post and collar, showing this arrangement. Fig. 7 is a front, and 8 a side view of the head of a straining orquarter- post. The wires are usually arranged in two vertical planes, at the back and front of the standards, or intermediate posts. They are not strained at each quarter-mile, but at intervals of half a mile al- ternately ; those in the front plane at one post, and those in the back plane at the next. The standards or supporting posts have merely to sustain the weight of the wires without relation to their tension. They have on each side two stout arms of oak or ash, secured by j bolts, passing from one to the | other, and resting in collars of j earthenware, sc x, where they pass through the standard. The wi/e pass through pieces of earthe ware, of a double cone shape, e t fastened to the outside of the arms by staples or clips, having a nut and screw at the end. These staples embrace the cones at a groove in the middle of their length. An j arm similar to those on the stand- \ ards is fixed to the back and front ! of each post alternately, to support j that plane of wires which passes without being strained. The in- sulating earthenwares between the arm and post, y y, are, however, different in shape from those used ELE ADDENDA (ELECTRIC TELEGRAPH). ELE with the standard arras, as greater length is requisite. The following are the principal dimensions of the posts and poles : AT BASE. AT TOP. LENGTH. Posts. Standards. Posts. Standards. ft. in. in. in. in. in. in. in. in. 18 9x8 6x6 7 x 6* 5* x 4* 22 10 X 8 7x6 do. do. 28 11 x 10 8x7 do. do. For intermediate lengths the dimensions are varied propor- tionally. In passing through tun- nels, or along the faces of walls or buildings, where posts cannot be conveniently fixed in the ground, the wires are supported on octago- nal standards of oak or ash, which are fixed at about six inches from the wall by holdfasts of galvanized iron. These standards are about two inches in diameter and three feet in length, being at the top and bottom turned down to a shoulder, so as to fit into a ring at the ends of the holdfasts. The same me- thod is adopted where the wires have to pass under bridges or archways. The batteries employed are of a somewhat peculiar construction ; they are made in the form of a Wollaston's trough, in which are arranged plates of copper and amalgamated zinc, each cell being Jhen filled with dry and perfectly clean sand. When about to be used, the sand is just moistened with dilute sulphuric acid. These batteries are singularly constant, having been known to remain in action during a period of from two to five months, with only the occa- sional addition of a little more acid solution, to supply the waste by evaporation and saturation. The effect of the sand appears to be, the prevention of too rapid an ac- tion, and, at the same time, the separation of the sulphates of cop- per and zinc. No copper is there- 561 fore deposited on the zinc plate, to the destruction of this latter by local action. The only points necessary to be observed, are the perfect amalgamation of the zinc plates, the absolute freedom of the sand from lime or other alkali, from carbonates or muriates, and the purity of the sulphuric acid. The zinc is formed in rolled plates of about % or ^ of an inch in thickness, and is cut into pieces of 4 inches by 3 inches. These plates will last with care for five or six months in almost constant action. A battery series of from 12 to 60 pairs is required, according to the length and nature of the line and the number of instru- ments in connection. Six wires are extended along the whole length of railway, of which the upper pair are used with a spe- cial double-needle instrument, for verbal communication, between the main stations, which are Nor- wich, Brundall, Reedham, and Yar- mouth. Each of the other four wires includes at every station a coil and single needle. On the dials connected with the first wire of these four, is engraved the name Norwich at all the stations ; with the second, that of Brundall, with the third Reedham, and with the fourth Yarmouth. The distinct telegraphic system belonging to each station has, therefore, its re- presentative at all the other sta- tions. Each needle or pointer re- presents the state of the portion of ELE ADDENDA (RENAISSANCE). REN line under the control of the sta- tion the name of which it bears. The alarum of each instrument is connected only with the wire of its own station, so that on moving either of the needles, the alarum will be rung at the place corre- sponding to the name of the needle, but at no other point, although the movement of the pointer will be visible throughout. The electric telegraph is now the chief mode of transmitting all the news of the Government, and the important correspondence of merchants and of the public gene- rally. Its influence has been al- ready felt by the press. The jour- nals of the large towns, which were taken in the country on account of their giving the most recent news, have lost a great number of their subscribers ; whilst there has been a very large increase in the cir- culation of the journals of the small towns near the extreme points of the electric telegraphs. Renaissance, that style which arose in all the arts of design, from the introduction of antique features, consequent on the revival of classi- cal learning, and the admiration of every thing classical after the fall of the Gothic system. In Italy, where the arts had never become thoroughly Gothic, the system so called having been an exotic never quite naturalized in that country, the renaissance of classical principles of taste com- menced as early as the 13th century ; but in the rest of Europe the Gothic had then hardly arrived at its complete development, or, if become a pure and consistent sys- tem, had hardly begun to display its luxuriance ; and two centuries at least were required to explore its vast capabilities, to work out its resources in all their wondrous variety, and to push on its sugges- tions beyond the limits of truth, and advance so far in complication andabsurdity, as to render a change 562 of style necessary; and accordingly the arts of Germany, the Nether- lands, France, and England, w^ere not ripe for this change, called the 'renaissance,' till the end of the 15th or beginning of the 16th cen- tury ; i. e. not till after the inven- tion of printing ; the great change of society resulting from which invention, rendered the introduc- tion of the (already renovated) classic taste into these countries a very easy and rapid transition, totally different from the slow process of renaissance and purifi- cation, by which this taste had. in Italy, gradually acquired con- sistency. In architecture (the only art here alluded to) the renaissance of classical forms and principles first distinctly shows itself in the works of Brunelleschi, the great Floren- tine architect, who lived from 1375 to 1444. His most famous work, the cupola of the cathedral, exhibits a bold emancipation from Gothic complexity, and return to classic simplicity, without the affectation of copying classic de- tails, which could only be abused and misapplied in a work so totally unlike in principles of construction to those of the ancients. His churches of S. Lorenzo and S. Spirito, though retaining Gothic plans and Byzanto-Gothic con- I struction, present a still more clas- sic treatment, not only in general design, but in that of details. The little octagonal chapel degli Angeli is as classic as any work of the ancient Romans, and the Pitti palace offers the first example of that eminently common-sense sys- tem of palatial architecture which continued to characterize the school of Florence throughout its career. Contemporary with this great man were Michelozzo, and L. B. Albert! the first modern writer on the art both of whom excelled the ancien Romans in purity of design, though the first could not give up the j REN ADDENDA (RENAISSANCE). REN Gothic window tracery, which he successively modified to his round- aiched style without losing its beauty. They were succeeded by Cronaca and Bramante, the latter of whom (born the same year that Brunelleschi died) carried the re- vival of classicism to its perfection by re-introdueing detached colon- nades and hanging architraves, never attempted since the fall of ancient art, and even now (by Bra- mante) only on a very small scale, in the round chapel in the cloister of S. Pietro in Monterio. He is considered the founder of the Ro- man school, as Brunelleschi was of the Florentine ; and his design for the modern St. Peter's, which he commenced, would have greatly excelled, in almost every kind of merit, the present jumble of twenty designs. His successor, M. Angelo, with his matchless genius for seizing whatever was grand rather than beautiful, returned (in the Capitoline Museum) to the classic simplicity of a single order, and an entablature unbroken from corner to corner: the renaissance was complete, and the modern Roman architecture having (like its sister arts) culminated in the hands of this wonderful man, or of Vignola, forthwith declined rapidly. San- micheli of Verona, who lived from 1484 to 1549, (a period comprised wholly in the life of M. Angelo,) originated that more fanciful and luxurious school which characte- rized the renaissant and modern architecture of Venice and its territory, and (being afterwards embellished by the beautiful pro- ductions of Sansovino, Palladio, and Scammozzi) became the favo- rite model for the schools of all transalpine countries, especially England. In this country, a way was pre- pared for the introduction of clas- sicism, by certain tendencies of our latest After-Gothic, the florid Per- pendicular, and Tudor; as (I.) the 563 tendency to subordinate the arch and archlet to the frame-work of vertical and horizontal lines ; the vertical constantly increasing in- deed in number, but the horizontal in strength and importance, pro- bably from a feeling that the number of the one should be ba- lanced by intensity in the other. (II.) By these horizontal masses of moulding beginning almost to approximate the effect of classic entablatures, in their division into two groups, the upper and greater answering to the cornice, the lower and smaller to the architrave, and the intermediate space being, like the frieze, either plain or sculp- tured, or with alternate squares of sculpture, like metopes, but never subdivided horizontally. (III.) By the roofs being reduced in pitch, (a change peculiar to the Anglo- Gothic decline,) and by towers being, on the same principle, finished without spires. (IV.) By the depression of the arch, the as- similation thereof to a semicircle or semi-ellipse, and the diminish- ing importance attached to its point, though that was never en- tirely omitted as in the French After-Gothic, called Burgundian. (V.) By the introduction of a large and bold scale of carved ornament, (as. in King's College chapel, where the architecture and carving are out of all proportion to each other, a leaf being often larger than an arch or canopy, and a rose larger than a pedestal and statue together,) and by the intro- duction, as strikingly seen in the same building, of attached orna- ment, quite contrary to a funda- mental Gothic principle, that of decorating by the removal of su- perfluous material, and not, as in classic architecture, by the addition of ornaments. These several predisposing ten- dencies of our debased After-Gothic rendered it easy to engraft there- on those Italian details which dis- REN ADDENDA (RENAISSANCE). REN tinguish the works of the reign of Henry VIII. The chantries of Bishops Fox and Gardiner, at Winchester, are instructive ex- amples of this process ; and so are the tomb of Henry VII., the wood- work of King's College chapel, and much of the architecture of Cam- bridge. At Ely is a chantry with purely Gothic vaulting, rather re- sembling that of the Mid-Gothic than any of the 15th century, still less of the 16th, but without bosses; and on a close inspection, rendered necessary by its dark situation, we find every rib com- posed of Italian cut mouldings, while the intermediate vault-sur- face, of plaster, is covered with the classic foliage commonly called arabesque. This shows capitally how the Gothic (or rather After- Gothic) principles of general de- sign were retained, but the details rendered more and more pedantic, both in our Elizabethan fashion, and in the corresponding manners of the Continent; a process just the reverse of every true advance that has taken place in architec- ture; for every real improvement (the arch for instance, or the pointed arch, or the buttress) has begun in main structural parts, and descended thence into details and ornaments ; but the pedantry of copying classic forms, instead of classic principles, begun, except in Italy, in the smallest and least es- sential details, and ascended into larger and larger features ; the con- stant aim being to hide a smaller falsehood by a greater, and thus ge- nerally rendering the whole system 564 of building, at least in this country, more and more false, till at length, in the Anglo-Greek buildings that followed the researches of Stuart and Revett, the process of renais- sance carried on for three cen- turies became complete, i. e. a building no longer a collection of many little or a few great dis- guises became in itself, as a whole, one immense sham. Nor does the popular disrepute into which the perfect and unap- proachable architecture of ancient Greece has now been brought by these attempts, nor yet the ro- mantic running after what has been (with singular ignorance) mistaken first for a ' national,' and then for a ' Christian' style, offer any pro- spect of escape from the effects of this ' renaissance,' or any approach towards a true renaissance of taste ; since the change is only from the mimicry of a more perfect to that of a less perfect, and (as now \ practised or perhaps practicable) a more limited and monotonous sys- tem : it is only from pseudo-Greek to pseudo-Gothic, from a sham > temple to a sham church. There : is no hope of real renaissance till f the real objects of the art be agreed upon and attended to, till it be ac- knowledged that nothing is beau- i tiful which is false, and till im- provements are introduced from ,' structural parts into ornaments, \ and not, as they have been in a r : English architecture since its cul- mination in the time of the first three Edwards, from mere orna- ments into the really structural parts. Hughes & llobinson, Printers, King's Head Court, Gough Square.