^,f(y ^.L-O'^02/ mn ^ II LIBRARY THE UNIVERSITY OF CALIFORNIA SANTA BARBARA PRESENTED BY Wi 1 bur R, Jacobs UCSB ^ I I''. >- G 1 >• K . L-Kf- ^ a THE USEFUL ARTS, CONSroERED IN CONNEXION APPLICATIONS OF SCIENCE WITH NUMEROUS ENGRAVINGS. BY JACOB BIGELOW, M.D. PROFESSOR OF MATERIA MEDICA IN HARVARD UNIVERSITY, AUTHOR OF ' THE ELEMENTS OF TECHNOLOGY,' ETC. ETC. IN TWO VOLUMES. VOL. n N E W Y O R K : HARPER & BROTHERS, PUBLISHERS, 329 & 331 PEARL STREET, FRANKLIN SQUARE. 1863. Entered according to Act of ('ongress, in the year 1840, by Marsh, Capkn, Lyon, and Webb, in the Clerk's Office of the District Court of Massachusetts. CONTENTS CUAPTER XIV. ARTS OF LOCOMOTION. Motion of Animals ; Inertia ; Aids to Locomotion Wheel Carriages : — Wheels ; Rollers ; Size of Wheels ; Line of Traction ; Broad Wheels ; Form of Wheels ; Axletrees ; Springs ; Attaching of Horses. Highways: — Roads; Pavements; Wood- en Pavements; McAdam Roads. Bridges: — Wooden Bridges ; Stone Bridges ; Cast-Iron Bridges ; Suspension Bridges ; Floating Bridges. Rail Roads : — Edge Rail-way ; Tram Road ; Single Rail ; Passings, or Sidings ; Turn Plate ; Curves ; Propelling Power ; Locomotive Engines ; Station- ary Engines. Canals : — Embankments ; Aque- ducts ; Tunnels ; Gates and Weirs ; Locks ; Boats ; Size of Canals. Sailing : — Form of a Ship; Keel and Rudder ; Effect of the Wind ; Stability of a Ship ; Steam Boats ; Steam Ships. Diving Bell : — Submarine Navigation. Aerostation : — Bal- oon ; Parachute, 9 CONTENTS. CHAPTER XV, ELEMENTS 01 MACHINERY. Machines ; Motion. Rotary, or Circular Motion :— - Band Wheels ; Rag Wheels ; Toothed Wheels ; Spiral Gear ; Bevel Gear ; Crown Wheels ; Uni- versal Joint ; Perpetual Screw ; Brush Wheels ; Ratchet Wheel ; Distant Rotary Motion ; Change of Velocity ; Fusee. Alternate, or Reciprocating Motion : — Cams ; Crank ; Parallel Motion ; Sun andPlanet Wheel ; Inclined Wheel ; Epicycloidal Wheel ; Rack and Segment ; Rack and Pinion ; Belt and Segment ; Scapements. Continued Rec- tilinear Motion : — Band ; Rack ; ^Universal Lever ; Screw ; Change of Direction ; Toggle Joint. Of Engaging and Disengaging Machinery. Of Equal- izing Motion : — Governor ; Fly Wheel. Friction. Remarks, . . 5^ CHAPTER XVI. OF THE MOVING FORCES USED IN THE AR1&. Sources of Power ; Vehicles of Power, Animal Pow- er : — Men ; Horses. Water Power : — Overshot Wheel ; Chain Wheel ; Undershot Wheel ; Back Water ; Besant's Wheel ; Lambert's Wheel ; Breast Wheel ; Horizontal Wheel ; Barker's Mill. Wind Power : — ^Vertical Windmill ; Adjustment of Sails ; Horizontal Windmill. Steam Power : — Steam; Applications of Steam ; By Condensation ; By Generation ; By Expansion ; The Steam En- gine ; Boiler ; Appendages ; Engine ; Noncon- densing Engine ; Condensing Engines ; Descrip- tion ; Expansion Engines ; Condenser; Valves ; Pistons ; Parallel Motion ; Locomotive Engine ; CONTENTS. 5 Power of the Steam Engine ; Projected Improve- ments ; Rotative Engines ; Use of Steam at High Temperatures ; Use of Vapors of Low Tempera- ture ; Gas Engines ; Steam Carriages ; Steam Gun. Gunpowder : — Manufacture ; Detonation ; Force ; Properties of a Gun : Blasting. Magnet- ic Engines, 81 CHAPTER XVII. ARTS OF CONVEYING WATER. Of Conducting Water : — Aqueducts ; Water Pipes 5 Friction of Pipes ; Obstruction of Pipes ; Syphon. Of Raising Water : — Scoop Wheel ; Persian Wheel ; Noria ; Ijj^e Pump ; Hydreole ; Archi medes' Screw ; Spiral Pump ; Centrifugal Pump ; ~ Common Pumps ; Forcing Pump ; Plunger Pump ; De La Hire's Pump ; Hydrostatic Press ; Lifting Pump ; Bag Pump ; Double-acting Pump ; Rol- ling Pump ; Eccentric Pump ; Arrangement of Pipes ; Chain Pump ; Schemnitz Vessels, or Hun- garian Machine ; Hero's Fountain ; Atmospheric Machines ; Hydraulic Ram. Of Projecting Water : —Fountains ; Fire Engines ; Throwing Wheel, . 135 CHAPTER XVIII. ARTS OF COMBINING FLEXIBLE FIBRES. Theory of Twisting ; Rope Making ; Hemp Spin- ning. Cotton Manufacture : — Elementary Inven- tions ; Batting ; Carding ; Drawing ; Roving ; Spinning ; Mule Spinning ; Vv^arping ; Dressing ; Weaving ; Twilling ; Double Weaving ; Cross Weaving ; Lace ; Carpeting ; Tapestry ; Velvets Linens. Woollens. Felting. Paper Making. Bookbinding, . . 164 1* CONTENTS, CHAPTER XIX. ARTS OF HOROLOGY. Sun Dial ; Clepsydra ; Water Clock ; Clock Work ; Maintaining Power ; Regulating Movement ; Pen- dulum ; Balance ; Scapement ; Description of a Clock ; Striking Part ; Description of a Watch, 187 CHAPTER XX. ARTS OF METALLURGY. Extraction of Metals ; Assaying ; Alloys. Gold : — Extraction ; Cupellation ; Partif% ; Cementation ; Alloy ; Working ; Gold Beating ; Gilding on Met- als ; Gold Wire. Silver : — Extraction ; Working • Coining ; Plating. Copper : — Extraction ; Work- ing. Brass : — Manufacture ; Buttons ; Pins ; Bronze. Lead : — Extraction ; Manufacture ; Sheet Lead ; Lead Pipes ; Leaden Shot. Tin : — Block Tin ; Tin Plates ; Silvering of Mirrors. Iron : — Smelting ; Crude Iron ; Casting ; Malleable Iron ; Forging ; Rolling and Slitting ; Wire Drawing ; Nail Making ; Gun Making. Steel : — Alloys of Steel ; Case Hardening ; Tempering ; Cutlery, 208 CHAPTER XXI. ARTS OF VITRIFICATION. Glass ; Materials ; Crown Glass ; Fritting ; Melt- ing ; Blowing ; Annealing ; Broad Glass ; Flint Glass ; Bottle Glass ; Cylinder Glass ; Plate Glass ; Moulding ; Pressing ; Cutting ; Stained Glass ; Enamelling ; Artificial Gems ; Devitrifica- CONTENTS. 7 tion ; Reaumur's Porcelain ; Crystallo-Ceramie ; Glass Thread ; Remarks, 247 CHAPTER XXII. ARTS OF INDURATION BY HEAT. Bricks ; Pressed Bricks ; Tiles ; Terra Cotta ; Cru- cibles ; Pottery ; Operations ; Stone Ware ; White Ware ; Throwing ; Pressing ; Casting ; Burning ; Printing ; Glazing ; China Ware ; Eu- ropean Porcelain ; Etruscan Vases, .... 262 APPENDIX. Artesian Wells. Mines. Depth of Mines. Canals in the United States. Rail-Ways in the United States. Manufacture of Maple Sugar. Manufac- ture of Beet Sugar. Voltaic Electrical Engraving. Photogenic Drawing, 275 Glossary, . . ... 369 Index, . , . 375 THE USEFUL ARTS CHAPTER XIV. ARTS OF LOCOAIOTIOX. Motioa of Animals, Inertia, Aids to Locomotion, Wheel Carnages^ Wheels, Rollers, Size of Wheels, Line of Traction, Broad W^heels, Form of Wheels, Axletrees, Springs, Attaching of Horses. High- ways, Roads, Pavements, Wooden Pavements,* McAdam Roads. Bridges, 1, ^V'ooden Bridges, 2, Stone Bridges, 3, Cast-Iron Bridges, 4, Suspension Bridges, 5, Floathig Bridges. Rail Roads, Edge Rail-way, Tram Road, Single Rail, Passings, or Sidings, Turn Plate, Curves, Propelling Power, Locomotive Engines, Stationary Engines- Canals, Embankments, Aqueducts, Tunnels, Gates and Weirs, Locks, Boats, Size of Canals. Sailing, Form of a Ship, Keel and Rudder, Effect of the Wind, Stability of a Ship, Steam Boats, Steam Ships. Diving Bell, Submarine Navigation. Aeros- tation, Balloon, Parachute. Animals, of the more perfect kinds, possess the power of shifting their place, at will, which power they exercise, both in transporting their own bodies, and in conv^eying other masses of matter. The chief obstacles, which op- pose locomotion or change of place, are, gravity and fric- tion, the last of which is, in most cases, a consequence of the first. Gravity confines all terrestrial bodies against the surface of the earth, with a force proportionate to the quantity of matter which composes them. Before they can be removed from one spot of this surface, to another, Df equal height, they must either be lifted from the ground, igainst the force of gravity, or carried, horizontally, along rhe surface, resisting with a degree of friction, which in- ireases with their weight. Most kinds of mechanism, both natural and artificial, which assist locomotion, are arrangements for obviating the effects of gravity and fric- lion. 10 ARTS OF LOCOMOTION. J\Iotio7i of Animals. — Animals, that walk, obviate fric- tion, by substituting points of their bodies, instead of large surfaces ; and upon these points they turn, as upon cen- tres, for the length of each step, raising themselves wholly, or partly, from the ground, in successive arcs, instead of drawing themselves along the surface. The hne of arcs, which the centre of gravity describes, is converted into an easy, or undulating hne, by the compound action of the different joints. As the feet move in separate hnes, the body has, also, a lateral, vibratory motion. A man, in walking, puts down one foot, before the other is raised, but not in running. Quadrupeds, in walking, have three feet upon the ground, for most of the time ; in trotting, only two. Animals, which w^alk against gravity, as the common fly, the tree toad, &c., support themselves by suction, using cavities on the under side of their feet, which they enlarge, at pleasure, till the pressure of the at- mosphere causes them to adhere. In other respects, their locomotion is effected like that of other walking animals. Birds perform the motion of flying, by striking the air, with the broad surface of their wings, in a downward, and backward, direction, thus propelling the body upward, and forward. After each stroke, the wings are contracted, or slightly turned, to lessen their resistance to the atmos- phere, then raised, and spread anew. The downward stroke, also, being more sudden than the upward, is more resisted by the atmosphere. The tail of birds serves as a rudder, to direct the course upward, or downward. When a bird sails in the air, w^ithout moving the wings, it is done, in some cases, by the velocity previously acquired, and an oblique direction of the wings, upward ; in others, by a gradual descent, with the wings slightly turned in an oblique direction, downward. Fishes, in swimming for- ward, are propelled chiefly by strokes of the tail, the ex- tremity of which, being bent into an oblique position, pro- pels the body forward, and laterally, at the same time. The lateral motion is corrected by the next stroke, in the op- posite direction, while the forward course continues. The fins serve, partly, to assist in swimming, but, chiefly, to balance the body, or keep it upright ; for the centre of INERTIA. 11 gravity being nearest the back, a fish turns over, when it is dead, or disabled.* Some other aquatic animals, as leeches, swim with a sinuous, or undulating, motion of the body, in which several parts, at once, are made to act obliquely, against the water. Serpents, in like manner, advance, by means of the winding, or serpentine, direction which they give to their bodies, and by which a succes- sion of oblique forces is brought to act against the ground. Sir Everard Home is of opinion, that serpents use their ribs, in the manner of legs, and propel the body forwards, by bringing the plates, on the under surface of the body, to act, successively, like feet, against the ground. f Some worms and larvas, of slow motion, extend a part of their body forwards, and draw up the rest to overtake it ; some performing this motion, in a direct line, others, in curves. When land animals swim in water, they are supported, because their whole weight, with the lungs expanded with air, is less than that of an equal bulk of water. The head, however, or a part of it, must be kept above water, to enable the animal to breathe ; and to effect this, and also to make progress in the water, the hmbs are exerted, in successive impulses, against the fluid. Quadrupeds and birds swim with less effort than man, because the weight of the head, which is carried above water, is, in them, a smaller proportional part of the whole, than it is in man. Inertia. — In consequence of the action of gravity upon bodies, their inertia becomes a greater obstacle to loco- motion than it would otherwise be. Every body tends, by its inertia, to preserve a state of rest, if it is still, and of uniform rectilinear motion, if it is not still. Changes, therefore, not only from rest to motion, but also changes * The swimming bladder, which exists in most fishes, though not in all, is supposed to have an agency in adapting the specific gravity of the fish to the particular depth, in which it resides. The power of the animal to rise or sink, by altering the dimensions of this organ, haa been, with some reason, disputed. t Lectures on Comparative Anatomy, vol. i. p. 116, &c. Sir E Home deduces this fact from the anatomy of the animal, and from the movements which he perceived, in suffering a large coluber to crawl over his hand. The ribs appeared to be raised, spread, carried for ward, depressed, and pushed backward, successively. 12 ARTS OF LOCOMOTION. of direction, and changes of speed, are resisted by the force of inertia. Bodies moving upon the earth's surface are obhged, by their gravity, to accommodate their mo- tions to the irregularities of this surface, and, consequent- ly, to change, often, both their direction and velocity The inertia thus becomes a continual source of expenditure of power, although it would not be so, if bodies moved at a uniform rate, and in a straight course. Aids to Locomotion. — All animals are provided, by Nature, with organs of locomotion best adapted to their structure and situation ; and it is probable that no animal, man not being excepted, can exert his strength more ad- vantageously, by any other than the natural mode, in moving himself over the common surface of the ground.* Thus walking-cars, velocipedes, &c., although they m.ay enable a man to increase his velocity in favorable situations, for a short time, yet they actually require an increased expen- diture of power, for the purpose of transporting the ma- chine made use of, in addition to the weight of the body. When, however, a great additional load is to be transport- ed with the body, a man, or animal, may derive much assistance from mechanical arrangements. Wheel Carriages. — For moving weights over the com mon ground, with its ordinary asperities and inequalities of substance and structure, no piece of inert mechanism is so favorably adapted, as the wheel-carriage. It was in- troduced into use, in very early ages, as affording a facil- ity for the carrying of heavy loads, and, finally, for trans porting man himself; not by his own powers, but by the strength of other animals, which he had subjugated to his use. Chariots were used in war, and wagons in agricul- ture, at a very remote period. Wheels. — The mechanical action of wheels, applied to locomotive carriages, is twofold. They diminish friction, and, also, surmount obstacles, or inequalities, of the road, with more advantage than bodies of any other form, in their place, could do. The friction is diminished, by transferring it from the surface of the ground to the cen- * This remark, of course, does not apply to situations in which fric- tion is obviated, as upon water, ice, rail-roads, &c. ROLLERS. SIZE OF WHEELS 13 tre of the wheel, or rather to the place of contact, between the axletree and the box of the wheel. So that it is les- sened, by the mechanical advantage of the lever, in the proportion, which the diameter of the axletre>3 bears to the diameter of the wheel. The rubbing surfaces, also, beiig kept polished, and smeared with some unctuous substance, are in the best possible condition to resist friction. In like manner, the common obstacles, that present themselves in the public roads, are surmounted by a wheel, with pecuhar facility. As soon as the wheel strikes against a stone, or similar hard body, it is converted into a lever, for lifting the load over the resisting object. If an obstacle, eight or ten inches in height, were presented to the body of a carriage, unprovided with wheels,- it would stop its progress, or subject it to such violence as would endanger its safety. But, by the action of a wheel, the load is lifted, and its centre of gravity passes over, in the direction of an easy arc, the obstacle furnishing the fulcrum, on which the lever acts. Rollers. ^R^oWers, placed under a heavy body, diminish the friction in a greater degree than wheels, provided they are true spheres, or cylinders, without any axis, on which they are constrained to move. If the rollers be perfectly elastic, and, also, the plane upon which they move, there will be no sliding friction, whatever ; whereas the wheel always rubs at its axis. But an offset for this advantage is found in the circumstance, that the wheel maintains its relative place, in regard to the load, while the roller constantly falls behind, and is obhged to be taken up and replaced, at an expense of power. A cyhndrical roller, likewise, occasions friction, whenever its path de- viates, in the least, from a straight line. Size of Wheels. — The mechanical advantages of a wheel are proportionate to its size ; and the larger it is, the more effectually does it diminish the ordinary resist- ances. A large wheel will surmount stones, and similar obstacles, better than a small one ; since the arm of the iever, on which the force acts, is longer, and the curve, described by the centre of the load, is the arc of a iar- II. 2 XII. 14 ARTS OF LOCOMOTION. ger circle, and, of course, the ascent is more gradual and easy.* A. further advantage is derived from the circumstance, that, in passing over holes, ruts, or excavations, a large wheel sinks less than a small one, and, consequently, occa- sions less jolting, and expenditure of power. The \v«ar, also, of small wheels, exceeds that of larger ones ; for, if we suppose a wheel to be three feet in diameter, it will turn round twice, while a wheel, six feet in diameter, turns round once. Of course, its tire will come twice as often in contact with the ground, and its spokes will twice as often have to support the weight of the load. So, that, by calculation, it should last but half the length of time. On these accounts, it would be advantageous to aug- ment the diameter of wheels to a great extent, were it not for certain practical limits, which it is not found useful to exceed. One of these is found in the nature of the ma- terials, which we are obliged to use, and which, if em- ployed to make wheels of great size, at the same time preserving the requisite strength, would render them cum- bersome, and too heavy for use.f Another reason, for regulating the size of wheels by a limited standard, arises from the relative size of the animals, commonly employed for draught. A wheel should seldom be of such dimen- sions, that its centre would exceed, in height, the breast of the horse, or other animal, by which it is drawn ; because, if this were the case, the horse would draw obhquely downward, as well as forward, and expend a part of his strength in acting against the ground. Line of Traction. — In practice, it is even found neces- sary, to place the point of draught, or centre of the wheels, lower than the middle of the horse's breast, for various reasons. 1. The shape of the animal's shoulders requires this direction. 2. The horse exerts a greater force, in proportion, as the line of draught passes near the fulcrum, * If the plane, on which a carriage moves, and the line of draught be both horizontal, the advantage, for surmounting an immovable obstacle of a given height, is as the square root of the radius of the wheel. — Se« Flayfair's Outlines of JVatural Philosophy, vol. i. p. 103. t See the article. Limit of Bulk, p. 48 BROAD WHEELS. 15 which is in his hind feet. 3. If a horse draws obliquely upward, a part of his force is employed in lessening the pressure on the ground, and, to answer this purpose most effectually, it has been remarked, that the inclination of the traces, or shafts, ought to be the same with that of a road, upon which the carriage would just descend by its own weight.* According to Dr. Gregory, a power, which moves a sliding body along a horizontal plane, acts with the greatest advantage, as far as friction is concerned, when the line of direction makes an angle of about eigh- teen and a half degrees with the plane. f M. Deparcieux states, from experiments with carriages, that the angle, made by the trace with a horizontal line, should be one of fourteen or fifteen degrees. 4. Another reason, for in- clining the hne of draught, is, that a horse depresses his body, in proportion to the force he is obliged to exert, in order that he may bring his own weight to act more advan- tageously upon the load. M. Deparcieux has demon- strated, that animals draw through the medium of their weight, in all our common vehicles ; and this fact becomes obvious, when we consider, that if a horse had no weight, he would be unable to draw, but would simply be raised on his hind feet, by any exertion to advance, while in his harness. In the foregoing considerations, it is necessary to re- collect, that the conditions, which enable a horse to exert his greatest force, are not those which promote his greatest velocity, and that the means of increasing his speed are obtained, as in other cases, by the sacrifice of power. When there are four wheels, the line of draught ought to be directed to a point between the two axletrees, or, rather, to a point directly under the centre of gravity of the load ; and such a line should always pass above the axle of the fore wheels. Broad Wheels. — Much controversy has existed in re- gard to the comparative utility of wheels having a broad, or a narrow, circumference. The disadvantages of broad wheels are, that they are* heavier than narrow ones, that * Young's Natural Philosophy, vol. i. p. 216. t Treatise on Mechanics, vol ii p. 18. 16 ARTS OF LOCOMOTION they are more expensive, and that they include in their path a greater number of stones, or projecting obstacles. Their advantages are, that they pass more easily over ruts and holes, and that^ in soft and sandy roads, they sink to a smaller depth.* But the great benefit which results from broad wheels is of an indirect kind, and arises from the improvement of the roads, which takes place under their use. They tend to prevent deep and narrow ruts, and act as rollers, in levelling the surface. Form of Wheels. — If roads w^ere, in all cases, level and smooth, wheels should be made exactly cylindrical, or with all their spokes parallel to the same plane. But, since the unequal surface of most roads exposes carriages to frequent and sudden changes of position, it is found advantageous to make the wheels a litde conical, or, as it is commonly termed, dishing, so that the spokes may all diverge, with their extremities from the carriage. In this case, whenever the carriage is thrown into an inclined position, and the centre of gravity shifted towards one wheel, the spokes on the under side of that wheel, become more nearly vertical, and are in a more advantageous position to sustain the pressure. This w^ill be seen in Fig. 94, on the opposite page. In muddy roads, there is a convenience attending the dished wheel, in having its circumference further from the body of the carriage, than that of a straight wheel, upon the same hubb,f would be. Some disadvantages, at the same time, attend upon this form of the w^ieel, the principal of which is, the increase of friction which it occasions. A conical wheel, if left to itself, tends to travel in a circle, round a point, where the apex of the cone would be situated. If it is obliged to advance in a straight line, it has a degree of lateral motion and friction, which increases in proportion as it deviates from the cyhndrical form. In common cases, a slight * The latter advantage, however, is of a more equivocal kind than appears at first view ; for although they sink less deeply, they displace more earth in sinking to the same depth. Still, however, the advan- tage, upon calculation, remains on the side of the broad wheel. t This word, instead of ?iai'C, is so generally used in this country, tha^ It would be a useless refinement to avoid it. The same is true of tlw woTd factory for manufactory, and also of many mechanical terms. AXLETREES SPRINGS, ETC. 17 degree of the dishing form is best, but it should never be carried to such an extent, as to create much friction, or endanger the bending of the spokes. In the annexed figure, (94,) A represents the cyhndri- cal, and B the dished, form of the wheel. Fis. 94. Axletrees. — When wheels are perfectly upright, the ends of the axles should be cylindrical ; but, in dished wheels, they are made conical, and inclined downward, so as to make their under surface horizontal. In this case, the wheels spread most at top, and the lower spokes are most nearly vertical. The ends of the axletree are often inclined a httle forward, which arrangement causes the wheels to run inward, and prevents them from pressing on the hnch-pin. The friction, however, is increased. In some locomotive carriages, the axle is fixed to both wheels, and turns with them. This mode of connexion causes great strain and friction, whenever the path is in any other than a straight hue, from the necessity, which IS produced, that the wheels should keep pace with each other, in their revolutions. Springs. — The effect of suspending a carriage on springs is, to equalize the motion, by causing every change to be- more gradually communicated to it, and to obviate shocks, by converting percussion into pressure.. Springs are not only useful for the convenience of passengers, but they also diminish the labor of draught ; for, whenever a wheel strikes a stone, it rises against the pressure of the spring, in many cases, without materially disturbing the load ; whereas, without the spring, the load, or a part of it, must rise with every jolt of the wheel, and will resist this change of place, with a degree o^ inertia proportionate to the weight and the suddenness of the percussion. IS ARTS OF LOCOMOTION. Hence, springs are highly useful, in baggage wagons, ard other vehicles, used for heavy transportation.* Attaching of Horses. — Horses draw most advantage • ously, when they are either single, or harnessed abreast of each other. When two horses draw side by side, they are equally near to the load, and have the same line of traction. If their traces are attached, as is frequently done, to hooks on the ends of a crossbar, which, in its turn, is connected to the carriage by a staple, projecting behind, a compensation will be thus made for any difference in the strength, or activity, of the animals. In Fig. 95, the cen- L Fig. 95. A. C B F tre, E, upon which the bar moves, is considerably behind the points of attachment, x\ and B. Hence, w^hen one end falls back, so that the arm, AB, assumes the poshion, CD, the foremost horse will have the disadvantage of acting by a lever equal only to EF, while the other horse acts by a lever equal to EC In the narrow streets of cities, a custom has arisen of harnessing draught horses before each other, in a single line, probably for the sake of room, and the convenience of the driver. But, in this situation, only the shaft horse has an advantageous hne of draught. The remaining horses draw nearly in a horizontal line, and, of course, at a disadvantage. Besides this, the foremost horses, being attached to the ends of the shafts, do not act directly upon the load, hut expend a part of their force Fig. 96. See a paper by Mr. Gilbert, in Brande's Journal, vol. xix. HIGHWAYS. ROADS. PAVEMENTS. 19 in vertical pressure, upon the back of the shaft horse, which is increased in drays, sleds, and all low carriages. This will be seen by inspecting Fig. 96, where it is obvious, that the hne of draught of the first horse cannot become direct, without crippling down the shaft horse. The best mode of remedying this difficulty, would apparently be, to attach the traces of the forward horse to a strong hook, project- ing downward from the end of each shaft, so as to bring the traces into the proper line of traction, by directing them more nearly towards the centre of the wheels. It is true, that the shaft horse derives a certain degree of mechani- cal advantage from vertical pressure, hke that which would result from an increase of his weight. Yet this, although useful in short exertions, is not so, when continued through a day's fatigue. HIGHWAYS. Roads. — Roads, intended for the passage of wheel-car- nages, are made more level, and of harder materials, than the rest of the ground. In roads, the travel on which does not authorize great expense, natural materials alone are em- ployed, of which the best are hard gravel and very small stones. The surface of roads should be nearly flat, with gutters at the sides, to facihtate the running ofFof water. If the surface is made too convex, it throws the weight of the load unequally upon one wheel, and also that of the horses on one side, whenever the carriage takes the side of the road. Hence, drivers prefer to take the middle, OBtop, of the road, and, by pursuing the same track, occasion deep ruts. The prevention of ruts is best effected by flat and solid roads, and by the use of broad wheels. It would also be further effected, if a greater variety could be intro- duced in the width of carriages. Embankments at the sides, to keep the earth from sHding down, are best made^ by piling sods upon each other, like bricks, with the grassy surface at right angles with the surface of the bank. But stone walls are preferable for this purpose, when the ma- terial can be readily obtained. Pavements. — Pavements are stone coveriiags ol the ground, chiefly employed in populous cities, and the most 20 ARTS OF LOCOMOTION. frequented roads. Among us, they are made of pebbles, of a roundish form, gathered from the sea-beach. They should consist of the hardest kinds of stone, such as gran- ite, sienite, &c. It flat stones are used, they require to be artificially roughened, to give secure foothold to horses. In Milan, and some other places, tracks for wheels are made of smooth stones, while the rest of the way is paved with small, or rough, stones.* The advantage of a good pavement consists, not only in its durability, but in the facility wuth which transportation on it is effected. Hors«s draw more easily on a pavement, than on a common road, because no part of their power is lost, in changing the form of the surface. The disadvan- tages of pavements consist in their noise, and in the wear which they occasion of the shoes of horses, and tires of wheels. They should never be made of pebbles so large as to produce much jolting, by the breadth of the interstices. f Wooden Pavements, made of hexagonal blocks of wood, have been introduced in some of our cities. They have been found more free from dust and noise than other pave- ments. They are placed with the grain of the wood per- pendicular to the ground, to prevent splintering, and give better foothold. The most hard and durable woods are best ; but the cheaper kinds are more used, for economy. McMam Roads. — The system of road-making, which takes its name from Mr. McAdam, combines the advan- tages of the pavement and gravel road. The McAdam roads ajre made entirely of hard stones, such as granite, flint, &c., broken up, with hammers, into small pieces, not exceeding an inch in diameter. These fragments are spread u^ron the ground, to the depth of from six to ten inches. At first, the roads thus made are heavy, and la- * The streets of many of the ancient cities were paved, as those of Rome, Pompeii, &c. But the streets of London were not paved in tne eleventh century, nor those of Paris in the twelfth. t Mr Telford has constructed, in England, a kind of paved road, in *vhich the foundation consists of a pavement of rough stones and frag- ments, having their points upward. These are covered with very small Btone fragments, and gravel, for the depth of four inches, the whole of which, when rammed down and consolidated, forms a hard, smooth, and durahle, road. BRIDGES. WOODEN BRIDGES. 21 borious to pass ; but, in time, the stones become consol- idated, and form a mass of great hardness, smoothness, and permanency. From the manner in which the stones overlap each other, each stone, at !he surface, may be considered as the apex of a pyramid, so that it cannot be driven downward, without carrying before it a base of, perhaps, a foot square, as will be seen by Fig. 97. The Fi^. 97. Stones become partly pulverized, by the action of carriage wheels, and partly imbedded in the earth beneath them. The consohdation seems to be owing to the angular shape of the fragments, which prevents them from rolling in tbeii beds, after the insterstices between them are filled. Mr. McAdam advises, that no other material should be added to the broken stones, apparently with a view to prevent the use of clay and chalk, which abound in England. It appears, however, that a little clean gravel, spread upon the stones, causes them to consolidate more quickly, and has the good effect of excluding the light street dirt, which, otherwise, never fails to become incorporated, in large quantities, among the stones. BRIDGES. The construction of small bridges is a simple process, while that of large ones is, under certain circumstances, extremely difficult, owing to the fact, that the. strength of materials does not increase in proportion to their weight, and that there are limits, beyond which no structure of the kind could be carried, and withstand its own gravity. Bridges differ, in their construction, and in the materials of which they are composed. The principal varieties are the following. 1. IVooden Bridges. — These, when built over sha\- 22 AKTS OF LOCOMOTION. low and sluggish streams, are usually supported upon piles, driven into the mud, at short distances, or upon frames of timber. But, in deep and powerful currents, it is ne- cessary to support them on strong 3tone piers, and abut- ments, built at as great a distance as practicable from each other. The bridge, between these piers, consists of a stifi' frame of carpentry, so constructed, with reference to its material, that it may act as one piece, and may not bend, or break, with its own weight, and any additional load, to which it may be exposed. When this frame is straight, the upper part is compressed^ by the weight of the whole, while the lower part is extended^ like the tie- beam of a roof. But the strongest wooden bridges are made with curved ribs, which rise above the abutments, in the manner of an arch, and are not subjected to a lon- gitudinal strain, by extension. These ribs are commonly connected and strengthened with diagonal braces, keys, bolts, and straps of iron. The flooring of the bridge may be either laid above them, or suspended, by trussing, un- derneath them. Wooden bridges are common in this country, and some of them are of large size. One of the most remarkable is the upper Schuylkill bridge, at Phil- adelphia, which consists of a single arch, the span of which is three hundred and forty feet. 2. Stone Bridges. — These, for the most part, consist of regular arches, built upon stone piers, constructed in the water, or upon abutments at the banks. Above the arches is made a level, or sloping, road. From the nature of the material, these are the most durable kind of bridges ; and many are now standing, which were built by the an- cient Romans. Several of the stone bridges across the Thames, at London, are distinguished for elegance and strength. The stone piers, on which bridges are support- ed, require to be of great solidity ; especially, when ex- posed to rapid currents, or to floating ice. Piers are usually built with their greatest length in the direction of the stream, and with their extremities pointed or curved, so as to divide the water, and allow it to glide easily past them. In building piers, it is often necessary to exclude the water, by means of a coffer-dam. This is a temporary CAST-IRON BRIDGES, ETC. 23 enclosure, formed by a double wall of piles and planks, having their interval filled with clay. The interior space is made dry by pumping, and kept so, till the structure is finished. 3. Cast Iron Bridges. — These have been constructed in England out of blocks, or frames, of cast-iron, so shap- ed, as to fit into each other, and, collectively, to form ribs and arches. These bridges possess great strength, but are hable to be disturbed by the expansion and contrac- tion of the metal with heat and cold. 4. Suspension Bridges. — In these, the flooring, or main body of the bridge, is supported, on strong iron chains, or rods, hanging in the form of an inverted arch, from one point of support to another. The points of support are the tops of strong pillars, or small towers, erected for the purpose. Over these pillars, the chain passes, and is attached, at each extremity of the bridge, to rocks, or massive frames of iron, firmly secured under ground. The great advantage of suspension bridges con- sists in their stability of equilibrium, in consequence of which, a smaller amount of materials is necessary for their construction, than for that of any other bridge. If a sus- pension bridge be shaken, or thrown out of equilibrium, it returns, by its weight, to its proper place ; whereas the reverse happens in bridges which are built above the level of their supporters. One of the most remarkable suspen- sion bridges, is that over the Menai strait, on the coast of Wales, the span of which, or rather the water-way, is five hundred feet, and the distance between the points of support, or centre of the piers, five hundred and sixty feet. It is suspended by four wrought-iron cables, which pass over rollers, on the tops of the pillars, and are fixed to iron frames, under ground, which are kept down by masonry. 5. Floating Bridges. — Upon deep and sluggish water, stationary rafts of timber are sometimes employed, ex- tending from one shore to another, and covered with planks, so as to form a passable bridge. In military op- erations, temporary bridges are often formed by planks laid upon boats, pontoons, and other buoyant supporters. 24 ARTS OF LOCOMOTION. RAIL-ROADS. In the best constructed public roads, a great amount of power is expended, in overcoming the disad^vantages which are inseparable from their construction, and the nature of their materials. The chief loss of power de- pends on the continual change of form, which carriages occasion in roads, by the crushing of stones, cutting of ruts, and other displacements of the material of which the load is made ; which processes serve to consume power, without forwarding the progress of the carriage. The object of a rail-road is to furnish a hard, smooth, and unchanging, surface, for wheels to run upon. These surfaces, in most cases, consist of parallel rails of iron, raised a little above the general level of the ground, and having a gravelled road between the rails, so that the rail- road combines the advantages of good foothold for horses, where it is necessary to use them, and of smooth, hard, surfaces, for the wheels to roll upon. The wheels are made smooth and true, and guides, or flanges, to prevent them from slipping off, are affixed, either to the wheels, or to the rails, — most commonly, to the former. Rail-roads are a modern invention, and their greatest improvements have been made within the present century. In comparing the effect of a rail-road with that of a com- mon turnpike-road, a saving is made, according to Mr. Tredgold,* of seven eighths of the power ; one horse on a rail-road~ producing as much eftect, as eight horses on a turnpike-road. In the effect produced by a given power, the rail-road is about a mean between the turnpike-road and a canal, when the rate is about three miles per hour ; but, when greater speed is desirable, the rail-road may equal the canal in effect, and even greatly surpass it. In the Winter season, when canals are liable to be frozen, rail-roads, if kept clear from snow and ice, may be al- ways passable. In the construction of rail-roads, it is desirable that they bhould be made as level as possible. For this purpose, the road is first graded^ by digging down the more ele- * Treatise on Rail-roads and Carriages, p, 3. EDGE RAIL-WAT. 25 vated parts, and raising those which are depressed. Hills are usually passed through by deep cuts; and, in some in- stances, perforated by tunnels, or hollow passages. Val- hes and marshes are raised by embankments of earth, and streams are crossed by wooden bridges, or by viaducts ol stone, constructed with arches of regular masonry. The earliest rail-roads appear to have been constructed of wood only. But, at the present day, iron is employed in all rails from which durability is expected. In ^sorne cities, tracks of hewn stone are laid for wheels, in the streets ; but these are seldom executed with sufficient ac- curacy, to deserve the name of rail-ways. Of the iron rail-road, there are three principal varieties. 1. The Edge rail. 2. The Tram road. 3. The Single rail. Edge Rail-way. — In this species, which is now prefer red to all others, and is, indeed, the only one now much in use, the rails are laid with the edge upward, and the carriage is retained upon them by a flange, or projecting edge, attached to the wheels, instead of the rail. These rails were originally made of cast-iron, about three feet long, and four or five inches deep in the middle, the out- line being curved on the under side, to produce equality of strength. Fig. 9S, represents a side-view of the old Fig. 98. cast-iron rail-way. The ends of the rails are received in a piece of cast-iron, called a chair, and these chairs are affixed to large blocks of stone, or logs of w^ood, called sleepers, which are previously placed in the ground, upon a proper level. Fig. 99, on the next page, is a section, or end view, of the rail-road, together with the wheels of a carriage, and the flange which serves to guide them. Rails are now almost universally made of wrought-iron. As this material is costly, when employed alone, it is some- times used in thin bars, as a covering to wooden rails, par- ticularly in this country, where timber is plenty, and iron II 3 XII. 26 ARTS OF LOCOMOTION. Fig. 99. expensive.* But the most common rails are of solid iron, rolled out in lengths of several yards, the edges, espec- ially the upper, being straight, and thicker than the other parts. Wrought-iron rails have the advantage of being longer, and, therefore, reducing the number of joints ; a circumstance which greatly increases the strength, as well as smoothness, of the road. Mr. Trautwine has published, in the Frankhn Journal, the following transverse sections of eight varieties of par- allel rails, employed on different rail-roads in the United States. They are drawn to a scale of one fourth the full * The durability of this combination of wood and iron, remains to be settled by longer experience. It must be greatly inferior to that of iron alone. TRAMS. SINGLE RAILS. 27 size, and accompanied by a statement of the weights, per lineal yard. Weights. No. 1. Columbia and Philadelphia, per yard, 41i lbs. a 2. " " " 33 " " 3. Germantown and Norristown, " 39 ',' " 4. Camden and Amboy, " 394 '^ " 5. Boston and Providence, " 54 " " 6. Wilmington and Susquehanna, " 40 " " 7. Alleghany Portage, " 40 '' " 8. Boston and Providence, " 40 " Tram-roads. — Tram-roads are flat rails, made usually of cast-iron, with an elevated edge, or flange, on one side, to guide the wheels of carriages in their path. Tram rails are weaker than edge rails, when made of the same amount of material, and it is sometimes necessary to strengthen them with ribs underneath. They are capa- ble of being used for ordinary wheel carriages, but the introduction of wheels which are not perfectly smooth, is always injurious to the road. Tram-roads are more lia- ble to be covered with dirt, than rails of other kinds, and are now httle used. Single Rail. — Carriages may be made to run upon a single rail, by deviating the rail from the ground, and sus- pending the load beneath it. In Mr. Palmer's rail-way, the rail is about three feet above the surface of the ground, and is supported by pillars, placed at distances of about nine feet from each other. The carriage con- sists of two receptacles, or boxes, suspended, one on each side of the rail, by an iron frame, and having two wheels placed one before the other. The rims of the wheels are concave, and fit the convex surface of the rail ; and the centre of gravity of the carriage, whether loaded or empty, is so far below the upper edge of the rail, that the receptacles hang in equilibrium, and will bear a con- siderable inequality of load without inconvenience, owing to the change of fulcrum, allowed by the breadth of the rail, which is about four inches. The alleged advantages of the single rail are, that it is more free from lateral fric- tion than the other kinds of rail-way, and that, being high- 28 ARTS OF LOCOMOTION. er from the ground, it is less liable to be covered with dust and gravel ; and, lastly, that it is more economical, the construction of one rail being less expensive than of two. It has not, however, been much introduced into use. Passings, or Sidings. — When the amount of travel on a rail-road is very great, it becomes necessary that the road should be double, one set of tracks being provided for carriages moving in each direction. Where there is less travel, a single road is sufficient, if it be provided with double places, called sidings, for carriages to pass each other, at convenient distances. The siding, or pas- sing place, is a short length of additional track, laid by the side of a line of rail- way, and connected with it, at each extremity, by suitable curves, the rails being constructed and disposed in such a manner, that the carriages can either proceed along the main hne, or turn into the sid- fng, as may be required. To accomplish this, the portion of rails, forming the junction of the siding with the main hne, is made mova- ble, so as to join either track-way. This portion is term- ed a switch, and the points where one rail crosses an- other, are termed crossing points. These last are gener- ally fixed or immovable ; suitable grooves being left, on their surface, for the passage of the flanges of the carriage wheels on either track-way. The Turn-plate, or Turn-table, is a contrivance for re- moving rail-way carriages from one line of rails to another. They are, generally, made for crossings at right angles with each other, but can be adapted to any angle that may be required. They consist of an iron framing, upon which iron gratings, or w^ood plankings, are laid, thereby forming a table, or platform, two pairs of rails being fixed on the surface of the same, crossing each other at right angles. This platform turns upon a centre pivot, wiiich rests upon another iron frame, set on masonry, friction rollers being inserted between them, at the extreme edges of the table. Curves. — The term curve is applied to a sudden bend, in a hne of road, canal, or rail-way. Curves, upon rail- ways of less than three fourths of a mile radius, should be PROPELLING POWER. LOCOMCJ I irfiS. 29 avoided, as the centrifugal force, arising upon them, lias a tendency to tlTrow the train off the rails. They also pro duce an injurious amount of friction, which wastes pow- er, and wears the flanges of the wheels. When the rail- way crosses a public road, it is made to pass at a lower level than the common surface, and is protected from carriage wheels, by an elevated edging of wood, or stone ; bridges are preferred, whenever the situa- tion permits them to be made. Rail-ways require to be free from dirt, which greatly increases the resistance. Mr. Palmer found, upon a tram-road, that it required nine- teen per cent, more power to draw the same carriages when the rails were slightly covered with dust, than when they were swept clean. The edge rail, however, being convex on its upper surface, retains but httle dust. Propelling Power. — Horses were originally employed for drawing loads upon rail-ways, a horse being supposed capable of drawing eight times as much, as upon a com- mon road. But Locomotive steam-engines are now gen- erally employed upon rail-ways, of any considerable length. They were, at first, made to propel carriages, by means of a toothed wheel, which acted upon a rack at- tached to one of the rails ; but, at the present day, they are made to act by the friction, only, of the carriage wheels upon the plain rail. These engines are always made of high pressure, since those of low pressure are rendered too heavy, by the w^eight of the water necessary for con- densation. Great improvements have lately been made in the construction of locomotive engines, in consequence of which, th^y have been enabled to attain the extraordi- nary speed of thirty or forty, and, in some short experi- ments, even of seventy, miles, per hour. (See Steam Engine.)* Locomotive Engines differ considerably from other steam-engines, in their mode of construction ; and numer ous modifications are found necessary, to render the ma chine suitable for a rapid transit, the principal of which are the combination of the engine and boiler in one, and a contrivance for the rapid generation of steam. * Franklin Journal, jcix. page 407, New Series. 3* 30 ARTS OF LOCOMOTION. It became necessary, to form the boiler of much smaller dimensions, in proportion to its power, than was before customary, and to reduce the size of the cylinders. A greater degree of strength was also required, in securing the several parts of the framing together, in order to ren- der the w^hole proof against the sudden shocks and strains, to which it is subjected. Locomotives were in a very imperfect state, previous to the opening of the Liverpool and Manchester rail-way, having merely one flue, passing through the boiler, and returned again to the fire-box, at which end the chimney was situated. A greater velocity than eight miles an hour could never be attained by them, owing to the small ex- tent of evaporating surface. They did not possess above one quarter the power of the present locomotives. The directors of that rail-way, having, in the year 1829, offered a premium of five hundred pounds for the best locomotive engine, the first stimulus was given to the subject. The Rocket engine, by Mr. G. Stevenson, prov- ed successful in obtaining this premium. Li the boiler of this engine, tubes were introduced, for the first time, which greatly increased the evaporating powers of the engine ; and, although locomotives have since been con- siderably modified, yet this has formed the basis of all the great improvements, which have taken place. A descrip- tion of it will be given, under the head of Steam Engine. Mr. Stevenson's engine weighed only four and a half tons, and the evaporating surface was three times the ex- tent of that in the former engines, which weighed up- wards of seven and a half tons. It attaine.d a speed of twenty-nine miles an hour, and an average velocity of four- teen and a half miles an hour. It was soon after found, that, by constructing engines of greater size, with increased evaporating powers, ample amends would be made for the additional weight. Heavier engines were introduced on the Liverpool and Manchester rail-way ; and the loco- motives, in general use, at the present time, weigh from nine to thirteen tons. The power of a modern locomo- tive engine, having tweh^e-incn cylinders, and an eighteen- STATIONARY ENGINES. 31 mch stvoke of piston, is computed at about thirty-eight or forty horse power, at high velocities, and seventy or eigh- ty horse power, at a slow rate of speed. The rapid generation of steam, in these locomotives, is owing to the great number of tubes, and to their thin- ness, whereby a large surface of water receives its heat quickly, through a thin partition. An advantage is sup- posed to be derived from the final escape of the steam, which is discharged into the chimney. Various improvements have been introduced into the locomotive engine, one of which consists in the use of six wheels, instead of four. In this country, many en- gines are constructed with six wheels, the first four of which are united by their axles, so as to form a kind of separate carriage, which is made to support one end of the locomotive. This carriage turns on a central bolt, like the fore axle of a wagon. It has the advantage, that the pressure is distributed more equally, and that the wheels accommodate themselves better, to curvatures of the road. Stationary Engines are used to draw up loads where the ascent is too steep for locomotives to ascend. Where the declivity of the road is great, loaded carriages sometimes descend, by their own gravity, and, at the same time, draw up the empty ones, by means of pullies. To prevent carriages from acquiring too great a velocity, in descending, a crooked lever, called a brake, or convoy, is apphed to the surface of the wheels, so as to retard them by its friction.* When loaded carriages are trans- ferred from one part of the road to another, of greater elevation, they are either drawn up an inchned plane, with ropes, by horses, or stationary engines ; or, in some cases, they may be lifted perpendicularly, by pullies. This meth- od, however, is seldom practised. * A retarding friction is produced, when necessary, in mountaincus countries, upon common roads, by chaining one of the wheels, when the carriage goes down hill, so as to prevent its turning. The same effect is produced, in a safer manner, by placing a wooden shoe, like a runner, under one of the wheels. 32 ARTS OF LOCOMOTION. CANALS. Canals are artificial channels for water, cut for the pur-" pose of admitting inland navigation. The great utility of canals, in facilitating transportation, has caused them to be constructed in all ages. The canals of the ancients were chiefly made on one level, so as to form merely artificial rivers, or creeks. Those of the moderns, by means of locks, are carried, indiscriminately, over ground which is depressed, or elevated. In level tracts of country, if the earth is of suitable character, canals are easily made. But, in loose and crumbling soils, in undulating, rocky, and mountainous, tracts, and in those which are intersected by large streams, their construction becomes expensive and difficult. To surmount these difficulties, loose soils are defended with firmer materials, vallies are passed by embankments, hills are penetrated by deep cuttings or tunnels, rivers are crossed with aqueducts, and declivities are ascended and descended by locks. In order that wa- ter may not be wanting in any part of the canal, a supply is ensured at the highest level, and this gradually passes off through the locks, to the lowest. The streams v.-hich furnish the water at this, and other, points, are called feeders. Embankments. — Canals are dug with sloping sides, to prevent the banks from caving in. The boats being, in almost all cases, drawn by horses, a firm, uninterrupted, towing path is formed on one of the banks. The banks are hable, in time, to become indented and washed away, by the constant agitation of the water, occasioned by the passage of boats. To prevent this, they are sometimes secured, by driving close rows of stakes against the banks ; but, the only effectual protection is found in waUing the banks with stone. When the canal crosses a section of country, the surface of which is lower than the intended surface of the water, the canal is raised to the proper level, by means of embankments. These are artificial baaks, or dykes, made of such materials as will not be liable to leak, and of such form and strength, that they will not be broken by the pressure of the water. The AQUEDUCTS. TUNNELS. 33 surface of these banks is of a sloping form, and is secured by sodding, and, in some instances, by piles, or stone walls. Where the nature of the earth renders leakage probable, it is common to cover the bottom and sides of the canal with a lining of puddle, which is formed from loam, or clay, and gravel, worked up with water. For additional security, a trench is dug, in each bank, to a greater depth than the bottom of the canal, and filled with puddle. It sometimes happens, that the embankments act as a dam, to prevent the land, on one side of the canal, from being properly drained. In this case, culverts, or sub- terranean passages, are constructed underneath the canal, but not communicating with it, to effect the necessary draining. Culverts are made of brick, or stone, and re- quire to be strong and tight. Aqueducts. — When a canal crosses a river, or a deep ravine, it is supported, at the proper level, by an aqueduct. This structure resembles a stone bridge, formed of strong piers and arches, of regular masonry, rendered as tight as possible, with hydraulic cement. Upon the top, a level channel for the water is formed. This is secured with strong and tight walls, on the sides, and lined within by a coating of clay. Room for the towing path must be preserv- ed, on one of the sides. In England, aqueducts have sometimes been made of casViron. Tunnels. — Tunnels are subterranean passages, most frequently cut through the base of hills, to afford a level water-course for canals. Tunnels are also made for the passage of rail-ways, and, in some cases, of highway-roads. When they are obHged to be cut through solid rock, which is done chiefly by blasting, their formation is difficult ; but they require no artificial security for their subsequent protection. But tunnels, which are made in soft earth, re- quire to be arched over, for their whole length, with stone, or brick ; and, in loose, springy ground, the bottom, like- wise, must be defended with an inverted arch. That tun- nels may be properly ventilated, especially while digging, shafts, or vertical passages, are sunk, at proper distances, in which fires are kept burning, to create a current for dis- 34 ARTS OF LOCOMOTION. charging the foul air. One of the most remarkable tun- nels is that at Worsley, on the Duke of Bridgewater's canal, which, with all its branches, is estimated at eigh- teen miles in length. Gates and Weirs. — As, all canals are liable to have their banks broken through, during violent rains and fresh- ets, it is important to lessen the injury, which results from such accidents, by retaining as much of the water in the canal as possible. To effect this object, safety-gates and stop-gates are placed, at suhable distances from each other, on the canal, so that, by closing them, at any time, in case of accident, the escape of that part of the water, which is beyond them, may be prevented. These gates are some- times attached to the sides, and sometimes lie upon the bottom. Certain parts of the banks, called Weirs, are made lower than the rest, to discharge the superfluous water, and keep the surface at a proper level. To prevent them from being gullied, or worn away, by the attrition of the water, they are commonly made of stone, or, sometimes, of wood. Locks. — When a canal changes from one level to an- other, of different elevation, the place, where the change of level occurs, is commanded by a Lock. Locks are tight, oblong enclosures, in the bed of the canal, fur- nished with gates, at each end, which separate the higher, from the lower, parts of the canal. When a boat passes up the canal, the lower gates are opened, and the boat glides into the lock ; after which, the lower gates are shut. A sluice, communicating with the upper part of the canal, is then opened, and the lock rapidly fills with water, ele- vating the boat on its surface. When the lock is filled to the highest water level, the upper gates are opened, and the boat, being now on the level of the upper part of the canal, passes on its way. The reverse of this process is performed, when the boat is descending the canal. Locks are made of stone, or brick, and, sometimes, ol wood. The walls are sometimes erected upon an inverted arch, and also upon piles, if the soil is alluvial, or loose. They are laid with hydraulic cement, and rendered im- pervious to water. The gates are commonly double, re- LOCKlS. 35 sembling folding doors, turning upon coin-posts ^ which are next the walls. They meet each other, in most instances, at an obtuse angle, and the pressure of the water serves to keep their contact more firm. The hydrostatic pressure, in these cases, being in full force, in a direction perpendic- ular to the surface of the gates, has a different action from that of the pressure of gravity, appHed to a roof, or simi- la.r structure, and gives to long gates a greater compara- tive disadvantage than to short ones. Cast-iron gates are sometimes used, in England, curved in the form of a hori- zontal arch, with their convex side opposed to the water. Valves are small sliding shutters, which admit a stream of water, for the purpose of gradually filling, or emptying, the lock, to prevent the shock of suddenly opening the gates. In situations, where there is a scarcity of water, the waste, occasioned by frequently opening the gates, for the passage of boats, is too great for the amount supplied to the canal. In these cases, to economize the water, re- servoirs are provided, at different heights, on each side of the lock. The water, in the upper parts of the lock, is discharged nito these reservoirs, and only that in the lower parts is suffered to escape into the lower canal. After- wards, the water in these reservoirs is used to fill again the lower parts of the lock, and thus, the same w^ater is made use of, a second time. In China, where inland navigation is much practised, it is said there are no locks, but boats are transferred, from one level to another, by means of inclined planes. This method is sometimes practised, in Europe, and it had a zealous advocate in the late Mr. Fulton. To effect this transfer most advantageously, two boats, passing in oppo- site directions, are connected together by a chain, passing over a pulley. One boat, in descending the plane, assists, by its weight, to draw the other upward. Sometimes, instead of inclined planes, perpendicular lifts have been proposed, by which the boats are hoisted directly, by pul- lies, from one level to another, or lowered, in the opposite direction, by the same means. The objection to all these modes exists in the strain, to which the boats are exposed, unsupported by the pressure of the water. Various ex- 36 ARTS OF LOCOMOTION. pedients have been proposed, for altering the level oi the water, and transferring boats, by means of large plungers, diving chests, &c.; but none oi uiem, as yet, appear to have been approved in practice.* Fig. 100. Boats. — Canal boats are made narrow, for passing each other, and draw water proportioned to the depth of the canal. Their length is limited only by that of the locks. They are drawn by horses, on the tow-path, being kept, by the rudder, from coming in contact with the bank. No species of oars, poles, or paddle-wheels, is allowed, on account of the injury done to the bottoms and banks, by their use. It is said, however, that the steam-engine has, in some cases, been used, without injury to the canal, by causing the paddle-wheels to work in a water passage, or casing, which passes through the boat, above its bottom. Size of Canals. — Canals differ greatly from each other, not only in their length, but their size, and the draught of water which they admit. One of the largest canals, as far as the volume of water is concerned, is the great Dutch canal, which connects the city of Amsterdam with the Helder, on the north coast of Holland. This canal is fifty miles in length, one hundred and twenty-four feet in width, at the surface of the water, thirty-six feet wide, at bottom, and about twenty-one feet deep. It is large enough to permit one frigate to pass another. ' The Cal- edonian canal extends from the Murray Frith, on the eastern coast of Scodand, to Loch Eil, on the western, and admits of the passage of large ships. It is one hun- dred and twenty feet wide, at the water surface, and fifty wide, at bottom. The depth of water is twenty feet. The distance, from sea to sea, is about fifty-nine miles, of which thirty-seven and a half is lake navigation, and * Repertory of Arts, vols. i. ii. and xxiii. SAILING. FORM OF A SHIP. 37 twenty-one and a half is cut.* The canal of Languedoc, in France, is sixty-four leagues in length, and connects the Atlantic ocean with the Mediterranean sea. It is sixty-four feet wide, at the surface, and navigable for ves- sels of one hundred tons. The great New York, or Erie, canal is three hundred and sixty miles long, and extends from the Hudson river, at Albany, to Lake Erie, at Buffalo. It is forty feet wide, at the surface, twenty-eight feet wide, at bottom, and has four feet depth of water. SAILING. Form of a Ship. — The movement of bodies through water, if performed within certain hmits of velocity, is at- tended with less resistance than that which takes place in most other modes of transportation. A body, however, of given size, will encounter a greater or less resistance from the water, according to its proportions, and the sort of surface which it opposes to the fluid. In calculating the proper form for a ship, it is necessary to consider the kinds of pressure, to which bodies, moving in fluids, are* subject. If we suppose an oblong square box, or paral- lelopiped, as ABCD, in Fig. 101, to move through the Fig. 101. C I? water, in the direction of its length, the pressure will be increased before, and diminished behind it, the surface of the water being elevated, at the anterior extremity, and depressed, at the posterior ; an efiect which increases, in a high ratio, as the velocity becomes greater. The prin- cipal part of the water, which is before the moving body, divides and passes off by the sides ; but a certain quantity of what is called dead water is pushed along, in advance of the moving body, nearly in the same manner as if it were * Supplement to the Encyclopedia Britannica, and Edinburgh Ency- clopedia. II. 4 XII. 38 ARTS OF LOCOMOTION. a part of ihe body itself. The shape of this dead water, at the surface, is found to be that of an irregular triangle, and hence it becomes advantageous to add to the moving body an extremity, or boic^ having nearly the same shape as the dead water, and occupying its place, as in the dot- ted line, BED. On the other hand, there occurs, behind the moving body, a depression of surface, and a partially empty space, which is also of a triangular, or wedge, form, consisting of the room which the moving body has just left, and into which the water, upon each side, has not yet flow- ed. The cavity, which is thus formed, resists the progress of the body, by its negative pressure. Its effect is readily understood, when we consider, that, if the water before the moving body be raised one foot, while the water behind it is depressed one foot, the difference of pressure, upon the two extremities, will be equal to that resulting from two feet. On this account, it is advantageous to add to the moving body a tapering, or wedge-shaped, extremity, be- hind, capable of occupying this cavity, and nearly answer- ng to it in shape, as represented by the dotted line, AGO. The consequence will be, that the water, which is advanc ing from both sides to fill up the vacuity, will meet the ta pering sides of the vessel soon enough to obviate, or great- ly diminish, the negative pressm^e. The form, produced by this general outline, varied by a proper curvature of the sides and bottom, corresponds nearly to that which is adop- ted in the construction of ships, and also to that pur- sued by Nature, in the structure of fishes. If a vessel be intended for a fast sailer, its proportionate length, and its sharpness, before and behind, must be increased, since both the positive and negative pressure, and the extent of the dead water and vacant space, will increase with the velocity. Keel and Rudder. — The use of the keel, which is a projecting timber, extending the whole length of the ship's bottom, is to assist in confining the motion of the ship to its proper direction, and, by its lateral resistance, to dimin- ish the disposition to roll, or vibrate, from side to side. The rudder, which is a perpendicular part attached, by braces, resembhng hinges, to the stern-post of the vessel. EFFECT OP THE WIND. 39 serves to govern the ship's course, by altering the relative resistance of its two sides. Thus, while the ship is under way, if the rudder is turned to one side, it receives an impulse from the water on that side, causing the stern to turn tow^ards the opposite side, where no such resistance exists, thus altering the directit)n of the keel, and the general course of the vessel. Effect of the Wind. — When a ship sails in the same direction as the wind, she is said to he. scudding, or sail- ing before the wind, and if she had but one sail, it would act with the greatest advantage, when perpendicular, or nearly so, to the wind. When a ship advances against the wind, and endeavors to proceed, in the nearest direction possible, to the point of compass from which the wind blows, she is said to be close-hauled. A large ship will sail against the wind with her keel at an angle of six points with the direction of the wind, and sloops, and smaller vessels, may sail much near er. When a ship is neither sailing before the wind, nor close-hauled, she is said to be sailing large. In this case, her sails are set in an obHque position, between the direction of the wind, and that of the intended course ; as represented in the various plans of vessels in Fig. 102, on page 40, where the direction of the wind is represented by the arrow, and the position of the yards and sails, which is necessary for^proceeding on the various points of com- pass, is shown by the transverse lines on each plan. The relation of the wind to the course of the vessel is deter- mined by the number of points of the compass, between the course she is steering, and the course which she w^ould be steering, if close-hauled. In Fig. 102, the ships, [a and 6,] are close-hauled, and the ships, [c and c?,] the for- mer steering east by north, and the latter west by north, have the wind one point large. The ships, [e and /,] one steering east, and the other west, have the wind two points large. In this case, the wind is at right angles with the keel, and is said to be upon the beam. The ships, [g and /i,] steering southeast, and southwest, have the wind six points large, or, as it is commonly termed, upon the quarter, and this is considered as a very favora- 40 ARTS OF LOCOMOTION. Fig. 102. ble manner of sailing, because all the sails cooperate to increase the ship's velocity ; whereas, Vhen the wind is directly aft, as in the vessel, [m,] it is partly intercepted by the after sails, and prevented from striking, with its full force, on those which are forward. The force of a wind which strikes obliquely upon the sails, supposing them flat surfaces, is resolvable into two forces, one of which tends to push the vessel ahead, and the other to push her sideways. If the form of the vessel, instead of being oblong, were circular, like a tub, she would move in the direction of the diagonal of a rectangle, representing these two forces, and her course would be at right angles with the position of the sail, or in the direction of the line AB, in Fig. 103. But, owing to the oblong shape of the vessel, and the influence of her keel, it requires about twelve STABILITY OF A SHIP. 41 times as much force to pusn her sideways, as to push her head foremost.* The obhque impulse, therefore, will carry her a great distance forward, in the time that she is drifting a short distance to the leeward, and it is this re- lative difference of progress, which enables a vessel to advance, even against the wind. The angular deviation of a ship's real course, from her apparent course, upon which her head is directed, is called the leeway. In the vessel, [Fig. 103,] with the wind blowing in the direction of the arrows, and the sails set as represented, if the ves- sel were moving in a rail-way, or unchangeable channel, her course would be BD ; but, in the water, she drifts so much to the leeward, that her real course is BC, and the angle, CBD, represents the amount of leeway. Stability of a Ship. — The masts of a ship, when acted upon by the pressure of the wind against the sails, are so many levers, tha tendency of which is, to overset her. To counteract this tendency, a sufficient weight of ballast, or cargo, is stowed in the bottom of the hold, to carry the centre of gravity into the lower part of the hull, so that this part will always preponderate, while the relative buoyancy of the upper part causes the vessel to right, as often as her position is disturbed. If the ballast is too light, or is stowed too high in the hold, the vessel is said to be too cranky and rolls more, and cannot carry so much sail, without danger of oversetting. On the other hand, if the ballast is too heavy, and placed too low, the vessel is said to be too stiff, and not only draws so much water as to impede her velocity, but is liable to have ♦ Robinson's Mechanhal Philosophy, vol. iv. p. 620. 4* 42 ARTS OF LOCOMOTION. her masts endangered, by the shocks which result from the suddenness of her motions. In regard to shape, an increase of the width of a shi{) increases her stabihty, but, at the same time, detracts from her power as a fast sailer. Steam Boats. — Experiments on the propulsion of ves- sels, by steam, were made in Europe, and this country, at different times, during the last century; but the first successful introduction of steam navigation, on a large scale, was made in America, by the late Mr. Fulton, about the year 1807. The application of the steam-en- gine to navigation, has given to vessels the advantage of greater speed and regularity, in the performance of their passages, without interruption from the ciiangeable, and often adverse, operation of the elements. In the action of the steam-engine, as in that of rowing, a vessel is pro- pelled by a succession of impulses, which act against the inertia of the water. A power acting within a boat, whether of men, of horses, or of steam, may be applied to the water, in va- rious ways. Some of the principal of these are the fol- lowing. 1. A system of oars, or paddles, has been made to act with alternating strokes, rising out of water at the end of each stroke. 2. An alternating paddle has been contrived, w4iich is continually immersed, and which folds up, like the foot of a w^ater-fowd, during the backward stroke. 3. It has been pr(^osed to drive a current of air, or a current of water, out at the stern of the vessel. 4. Spiral wheels and water-screws, or wheels with oblique vanes, hke those of a windmfll, have been made to turn under water, with their axes parallel to the keel of the vessel. 5. Obhque planes, acting with an alternate, instead of a revolving, stroke, were recom- mended by Bernoulli. 6. Paddle-wheels. These, from their simplicity, and advantageous mode of action, have, in common use, superseded all the rest. They consist of paddles, or float-boards, attached to the arms, or spokes, of a wheel, the axis of which is at right angles with the keel. Their common place is on the sides of the boat, as in Fig. 104, on the opposite page. The outline of the float-boards, or paddles, is com- STEAM-BOATS. Fig. 104. 43 monly rectangular, though ^Ir. Tredgold recommends that 'heir outer extremity should be parabolic. The best po- sition for the paddles is in a plane, passing through the axis of the wheels ; but with this position, they strike the water obliquely, in entering, and lift a considerable quantity, on quitting it ; both of which motions occasion loss of pow- er. Attempts have been made to correct this disadvant- age, by various mechanical arrangements, in which the paddles are made to enter and leave the water perpen- dicularly ; but want of simplicity, and objections of vari- ous other kinds, have prevented them from coming into use. It has be"en proposed to fix a series of paddles up- on longitudinal chains, passing round wheels, and parallel to each side of the vessel. By this mode, a number of perpendicular paddles would act upon the water at once ; but it will be seen, that, as no more of these paddles can operate usefully, than are sufficient to put the water be- tween. them into motion, a part of the series will be less useful, than if it acted upon water at rest. In wheels of the common form, it is advantageous to have a double row of paddles, one outside the other, and so placed, that the paddles of one series shall be opposite the intervals of the other, and thus enter the water successively, and in different places.* This plan is the one most generally adopted, in American steam-boats. In Perkins's propel- ling wheel, the paddles are placed obliquely, in regard to the axis of the wheel, and the w^heel itself is placed ob- * For examinations of the different propelling powers, see the Edin- burgh Encyclopedia, article ' Navigation Inland,' ascribed to Mr. Tel "ord ; also, Tredgold on the Steam Engine, p. 309. 44 ARTS OF LOCOMOTION. liquely, in regard to the keel of tb»-boat. This arrange ment is such, that the paddles enter and leave the water obliquely, but, at the time of their greatest immersion, they are at right angles with the keel, and in the most favora- ble position for propelling the boat. The average speed of a well-constructed steam -boat has been assumed at fourteen miles per hour, and the greatest speed at sixteen miles.* Steam-boats have been considered as best adapted to the navigation of rivers, and straits, or sounds, where the water is comparatively smooth. In the open sea, the vio- lence of the waves renders the action of the paddle-wheels irregular, and it was, for a long time, thought difficult for them to carry fuel sufficient to supply the engine, during long voyages. The steam-ship Savannah first crossed the Atlantic, in 1819, and was twenty-one days, from land * Mr. W. S. Redfield, of New York, has addressed to Lieutenant Hos- ken, the commander of the Great Western steam-ship, a letter, in which he says : " Tiiere is, if T mistake not, some misapprehension prevail ing, both in England and America, in regard to the ordinary, as well as maximum, speed of the best steam-vessels. This is mainly to be as cribed to three causes : 1st. The erroneous statements which often find their way into newspapers. 2d. To a mistaken estimate of the velo- city of the tides and currents. And, 3d, to the erroneous popular esti- mate of navigating distances, which, on nearly all internal, or coasting, routes, in both countries, so far as my knowledge extends, are habitu- ally overrated. This may explain, on one hand, the extravagant claims to velocity, which are sometimes stated of American steam-boats ; and, on the other hand, may account for the strange incredulity, which has been manifested by Dr. Lardner, and others, not well acquainted with the structure and performances of American steam-boats. The ac- quaintance which I have had with the navigation of the Hudson, by steam, during the last thirteen years, enables me to speak with confi- dence on some of the points involved. " The usual working speed of the best class of steam-boats, on the Hudson, may be estimated at fourteen statute miles per hour, through still water of good depth. That they are not unfrequently run at a lower speed, is freely admitted. But the maximum speed of these boats is, and has been, for several years, equal to about sixteen miles per hour. In regard to the " admitted four miles per hour tide up the Hudson," the admission is extremely erroneous. The average advan- tage to be realized, in a passage on flood-tide, from New York to Al- bany, is not more than one mile and a half per hour, or, at the most, say twelve miles, in a passage to Albany, — equal to about one twelfth of the distance, as performed under the most favorable circumstances " STEAM-SHIPS. DIVING-BELL, 45 to land, during eighteen of which, only, she was able to use her engine. Steam Ships. — The difficulties attendant on marine steam navigation, which, but a short time ago, were pro- nounced, by some distinguished authorities, to be insur- mountable, have been completely overcome by the intro- duction, in 1838, of steam-ships of extraordinary size, propelled by engines of great power. The Great West- ern, which arrived at New York, from Bristol, in April, 1838, measured, for her extreme length, two hundred and thirty-six feet, and in width, between the outside of the paddle-cases, fifty-eight feet. The British Queen, which followed in the next year, is two hundred and seventy- five feet long, which is stated to be thirty-five feet longer than any ship in the British navy. She has two engines, of two hundred and fifty horse power each. It is now settled, that the passage of the Atlantic may be made, safely and successfully, by vessels of this size, and ac- complished, under favorable circumstances, in less than a fortnight. The success attending these experiments has led to the multiplication of ocean-steamers, which are intended to ply upon all the great tracks of commerce, in the civil- ized world. 'The communication between Europe and the United States, as well as that with the West and East Indies, and, indeed, with most of the important sea-ports on the globe, may be considered as hereafter to be per- formed, in half the time which was formerly required, and with far greater certainty, in regard to the times of arrival and departure. Of the numerous steam-ships now building, or built, in Great Britain, to ply between that country and foreign ports, some are constructed entirely of iron. Some are of immense size, exceeding that of the British Queen, which has already been mentioned. DIVING-BELL. The diving-bell is an inverted vessel, containing air^ and used for the purpose of enabling persons to descend, with safety, to great depths uuder water. It is made tight 46 ARTS OF LOCOMOTION. at the top and sides, but is entirely open at bottom. Its principle is the same with that ot" a gasometer, and may be familiarly illustrated, by immersing an inverted tumbler in a vessel of water. The air cannot escape from the in- side of the vessel, being necessitated, by the order of spe- cific gravities, to occupy the upper part of the cavity. Diving-bells appear to have been first introduced, in the beginning of the sixteenth century. They were first known as objects of curiosity, only, but have been since applied to tlie recovery of valuable articles from wrecks, the blasting and mining of rocks, at the bottom of the sea, and the practice of submarine architecture. They may be made of almost any shape ; but the common form has been that of a bell, or hollow cone, m.ade of w^ooden staves, and strongly bound with hoops, having seats for the occu- pants, on the inside. It is suspended with ropes, from a vessel above, and is ballasted with heavy weights at bot- tom, which serve to sink it, and to prevent it from turn- ing over. More recently, diving-bells have been made of cast-iron. The kind of bell used at Howth, near Dub- hn,* is an oblong iron chest, six feet long, four broad, and five high, thicker at bottom than at top, and weighing four tons. It has a seat at each end, and is capable of holding four persons. The upper part is pierced with eight or ten holes, in which are fixed the same number of strong convex glasses, which transmit the hght. As the air in the bell becomes contaminated, by breathing, it is renewed, by letting down barrels, or small bells, of fresh air, which is transferred to the large bell ; or else, by keeping up a constant supply, through a pipe, by nieans of a forcing pump, which is worked by men at the sur- face. Persons who descend in diving-bells often experience a \iam in the ears, and a sense of pressure, occasioned by the condensation of the air, within the cavity of the bell. These symptoms gradually pass off, or habit renders the body indifferent to them, so that workmen remain under water, at the depth of twenty feet or more, for seven oj eight hours in a day, without detriment to the health. ♦Edinburgh Philosophical Journal, vol. v. p. 8. SUBMARINE NAVIGATION. 47 Submarine Js\ivigation. — A machine was invented, during the American Revolution, by Mr Bushnell, of Connecticut, which was capable of containing a person in safety, under water, and of being governed, and steered in any direction, at pleasure. It is described* as being a hollow vessel, of a spheroidal form, composed of curved pieces of oak, fitted together, and bound with iron hoops, the seams being caulked, and covered with tar, to render them tight. A top, or head, was closely fitted to the ves- sel, and served the purpose of a door. In this were in- serted several strong pieces of glass, to admit the light. The machine contained air enough to render it buoyant, and to support respiration. A quantity of lead was at- tached to the bottom, for ballast. The vessel was made to sink, by admitting water, and to rise, by detaching a part of the leaden ballast, or by expelling water with a forcing pump. It was propelled horizontally, by means of revolving oars, placed obliquely, like the sails of a wind- mill, on an axis which entered the boat through a tight collar, or water-joint, and was turned witli a crank with- in. A rudder was also employed, for steering the vessel When fresh air was required, the vessel rose to the sur- face, and took in air through apertures at the top. Tlie intention of this machine was, to convey a magazine of powder under ships of war, for the purpose of blowing them up. Several experiments were made with it, which, though unsuccessful in their object, nevertheless proved the practicability of this species of locomotion. The late Mr. Fulton made various experiments on sub- marine navigation, in a boat large enough to contain sev- eral persons, furnished with masts and sails, so as to be capaole of proceeding at the surface of the water, and, also, of plunging, when required, below the surface. f While under water, its motions were governed by two machines, one of which caused it to advance horizontal- ly, while the other regulated its ascent and descent, its depth below the surface being known, by the pressure on a barometer. A supply of fresh air was carried down in * Silliman's Journal, vol. ii. p. 94. t See Colden's Life of Fulton, 8vo. New York, 1810. 48 ARTS OF LOCOMOTION. the boat, condensed into a strong copper globe, by which the air of the boat was replaced, when it became unfit for respiration. Mr. Fulton's object was the destruction of ships of war, by bringing underneath them an explosive engine, called a torpedo. AEROSTATION. Balloon. — A Balloon is a sphere, or bag, formed ol some light material, such as silk, and rendered impervi- ous to the air, by covering it with elastic varnish. It is filled with a gaseous fluid, lighter than the surrounding atmospheric air, and has a car suspended, at the bottom. If the specific gravity of the whole mass is less than that of an equal bulk of the atmospheric air, which surrounds it, the balloon will ascend into the atmosphere, and re- main suspended, until, by the escape of its gas, or other means, it becomes heavier than the surrounding air, when it will again descend. Balloons were invented in France, by the Montgolfiers, about 1782. Those which were first employed by them were filled with common air, rarefied by heat ; but these required, that a fire should be constantly kept burning beneath them, to keep them afloat. Hydrogen gas was afterwards employed ; and this fluid, being permanently about fourteen times less dense than common air, is, undoubtedly, the best material for aeros tation. Carburetted hydrogen, though heavier than hy- drogen, has also been employed, of late, on account of its cheapness, being furnished, in large quantities, at the man- ufactories of illuminating gas. Balloons are made, by sewing together pieces of silk, the shape of which corresponds to that of the part includ- ed by two meridians of the artificial globe. They have also been made of linen, and of paper. They are var- nished with a solution of elastic gum, torrender them tight. A net-work is thrown over the top of the balloon, to which is attached, by strings, a car of wicker-work, un- derneath the balloon. The whole is kept down, by a sufficient quantity of ballast, and ascends into tiie atmo- sphere, when a part of the ballast is thrown over. It is made to descend again, by sufl^ering a part of the gas to escape through a valve, provided for the purpose. PARACHUTE. 49 The regulation of the ascent and descent of balloons is the extent of control, which has been hitherto obtained over them. All attempts to guide or propel them, by means of wings, sails, oars, &c., have hitherto failed, and the machine can only proceed at the mercy of the winds. The small degree of buoyancy, which balloons possess, does not permit them to carry sufficient weight of male- rial, to furnish the medium of an adequate propelling force. By taking advantage, however, of favorable winds, voy- ages have been made in them to the distance of three hundred miles ; and persons have ascended to the height of twenty thousand feet, and upwards. The velocity of balloons varies with that of the wind, but has, in some instances, amounted to the rate of seventy miles an hour.* Parachute. — The danger, which attends falling from great heights, is in consequence of the continual acceler- ation of velocity, which faUing bodies experience. When, however, the resistance of the atmosphere becomes equal to the force of gravity, the motion is no longer acceler- ated, but becomes uniform. A parachute is an appen- dage to a balloon, formed somewhat like an umbrella, and is designed to break the force of a fall, by means of the large surface which it opposes, in its progress, to the at- mosphere. It is made of silk or canvass, and is placed underneath the balloon, having the car suspended from it by cords. When the balloon is at any height in the air, the parachute may be detached from it, and will imme- diately fall with the car, to the ground. But the resistance of so large a surface to the atmosphere, causes the fall to be gradual and easy, so that a person may descend with a parachute, in safety, from the greatest heights. The size of the parachute, employed by M. Garnerin, and with which he descended from a height of two thousand feet, at Paris, in 1797, w^as twenty-five feet in diameter. The parachute was folded up, at the beginning oT the fall, * M. Gay-Lussac, on the 6th of September, 1804, ascended twen ';y-three thousand and one hundred feet above Paris. M. Garnerin, September 21st, 1827, passed, in seven hours and a half, from Paris to Mount Tonnere, a distance of three hundred miles. This voyage was performed in the night, and daring a storm. II. 5 XII 50 ELEMENTS OF MACHINERY. but soon expanded itself, by the resistance of the atmo- sphere. The only inconvenience, which was experienced> arose from a violent oscillating motion. Works of Reference. — Brewster's Edition of Ferguson Lectures on Mechanics, &c. 2 vols. 8vo. 1823 ; — ANSTiCE,on Whee Carriages ; — EdgewortHjOD Roads and Carriages, Svo ; — Depar- ciEUx sur letirage des chevaux, in the Mem. de VAcad. Paris, 1760 ; — Yovng's Lectures on Natural Philosophy ; — McAdam, on roads, Svo. 1823 ; — Blvnt and Stevenson's Civil Engineer, fol. 1834, &c. ; — Parnell, Treatise on Roads, 8vo. 1833 ; — Tredgold, on Rail Roads, Svo. 1825 ; — Wood, on Rail Roads, Svo. 1825 ; — Strickland's Reports on Canals, Rail Roads, &c., oblong fol. Phil ad., 1820 ; — Article Canal, in Rees' Cyclopedia, written by Mr. J. Farey ; Articles Navigation Inland, Railway, Bridges, Aeronautics, &c., in the Edinburgh Encyclopedia ; — Chapman, on Canal Naviga- tion, 4to. 1797 ; — Fulton, on Canal Navigation, 4to. 1796 ; — Smea- ton's Reports, 3 vols. Svo. 1812 ; — Prony, Architecture Hydrau- lique, 2 torn. 4to. 1790 ; — Belidor, Architecture Hydraulique, 4 torn. 4to. 1750 ; — De Cessart, Travaux HydrauliqueSy 2 torn. 4to. 1808 ; — Reports to the House of Commons on Roads, Steam Boats, &c., 1822, &c. ; — Article Seamanship, in the Encyclopedia Brittani- ca, by Prof. Robinson ; — Dupin, Voyage dans la Grand Bretagne, 6 vols. Svo. with plates, fol. 1825. CHAPTER XV. ELEMENTS OF MACHINERY. Machines, Motion. Rotary, or Circular, Motion, Band Wheels, Rag Wheels, Toothed Wheels, Spiral Gear, Bevel Gear, Crown- wheels, Universal Joint, Perpetual Screw, Brush Wheels, Ratchet Wheel, Distant Rotary Motion, Change of Velocity, Fusee. Al- ternate, or Reciprocating, Motion, Cams, Crank, Parallel Motion, Sun and Planet Wheel, Inclined Wheel, Epicydoidal Wheel, Rack and Segment, Rack and Pinion, Belt and Segment, Scapements. Continued Rectilinear Motion, Band, Rack, Universal Lever, Screw, Change of Direction, Toggle Joint. Of Engaging and Dis- engaging Machinery. Of Equalizing Motion, Governor, Fly Wheel. Friction. Remarks. JUachines. — By a machine, may be understood a com- bination of mechanical powers, adapted to vary the di- rection, apphcation, and intensity, of a moving force, sen circle, while the outline of the teeth of the other wheel is described, by the same curve rolling within the circle. It may also be produced, if the teeth of one wheel be straight, circular, or of any regular figure, whatever ; pro- vided the teeth of the other wheel be of a figure, com- pounded of that figure and of an epicycloid.* Of two wheels, which are unequal in size, the larger is called the wheel., and the smaller, the pinion. The act- ing portions of the wheel are called teeth ; and, of the * For investigations relating to the teeth of wheels, see Camus, on the Teeth of Wheels, translated, London, 8vo. 1806 ; — Buchanan, on Mill Work, chap. i. &c. ; — Brewster's Ferguson's Lectures, vol. ii. p. 119 ; — Gregory's Mechanics, vol. ii. p. 451 ; — also, a Treatise, by Mr. Blake, in Silliman's Journal, vol. vii. p. 86. *5 54 ELEMENTS OF MACHKNERY. pinion, more commonly, leaves. The name of lanterns is given to pinions with two heads, connected by cyhn- drical teeth, or trundles. In Fig. lOS, the line, joining Fig. 108 tho centres, B and F, of the wheel and pinion, is called the line of centres, and, when this line is divided into two parts, FA and BA, which are to each other, as the number of leaves in the pinion is to the number of teeth in the wheel, BA is called the primitive radius* of the wheel, and FA, the primitive radius of the pinion ; while the lines, or distances, Ff and Bb, are called the true radii. The circles, X AX and RAFt, are called the primitive cir- cumferences, and, by workmen, the pitch lines. Friction, to a certain extent, cannot be avoided, in teeth of the common kind, whose acting faces are at right angles with the plane of the wheels, to which they belong. It may, however, be much diminished, by making the teeth as small and as numerous, as is consistent with their strength ; for the quantity of friction necessarily increases, with the distance of the point of contact from the line of centres. ♦ Called the proportional radius, by Buchanan SPIRAL GEAR. 65 tSpiral Gear. — In common cases, the teeth of wheels are cut across the circumference, in a direction parallel to the axis. In the spiral gear, now much used in cotton mills, in this country, the teeth are cut obliquely, so that, if continued, they would pass round the axis, like the threads of a screw. In consequence of this disposition, the teeth come in contact only in the line of centres, and thus operate without friction. [Fig. 109 J The action of these wheels, it is true, is compounded of two forces, one of. which acts in the direction of the plane of the wheel, and the other in the direction of its axis. The latter force occasions a degree of friction, w'hich, being expended at the end of the axle, may be regarded as in- considerable. The remaining force goes to produce ro- tary motion. The spiral gearing has been apphed to clock-work, and has the peculiarity, that it admits of a smaller pinion than any other gearing. Thus, if a very small cylinder have a spiral groove so cut in it, as to extend once round its circumference, it will perform one revolution for every tooth of the wheel which drives it. The groove may be cut indefinitely near to the centre of the pinion, or cylin- der, without weakening it so much as would happen in other forms of the pinion.* * The spiral gear has been used at Waltham, Mass., and elsewhere, for about fifteen years, and is commonly considered, here, as the inven- tion of Mr. White. Something analogous to it, under the name of Inclined Plane Wheels, was published in London, by Mr. T. Shel- 'drake, in 1811. 56 ELEMENTS OF MACHINERY, Bevel Gear. — When wheels are not situated in the same plane, but form an angle with each other, the spur gearing, already described, is changed for teeth of a dif ferent description. In this case, the bevel gearing is commonly employed, consisting of wheels, which are frusta of cones, having their teeth cut obliquely, and con- verging toward the point, where the apex of the cone would be situated. According as the relative magnitude of the wheels varies, the angle of the bevel must be dif- ferent, so that the velocities of the wheels may be in the same proportion, at both ends of their oblique sides, or faces. For this purpose, the faces of all the teeth must be directed to the point, where the axes of the two wheels would meet. The bevel gearing is shown in Fig. 110, and Fig. 116. Fig. 110. Crown Wheels. — Circular motion is also communicat- ed, at right angles, by means of teeth or cogs, situated parallel to the axis of the wheel. Wheels, thus formed, are denominated crown, or contrate., w^heels. They act either upon a common pinion, or upon a lantern. The crown-wheel is represented in Fig. 111. It is less m use than the bevel-gear, before described, having more friction UNIVERSAL JOINT. PERPETUAL SCREW. 57 Universal Joint. — The contrivance called Hooke's universal joint, is sometimes used, instead of wheels, to communicate circular motion in an oblique direction. It consists of two shafts, or axes, each terminating in a semicircle, and connected together by means of a cross, upon which each semicircle is hinged. [Fig. 112.] It is Fk. 112. obvious, that when one shaft is turned, the other must re- volve likewise ; and this will be the case, whenever the angle, by which one shaft deviates from the direction of the other, does not exceed forty degrees. By means of a double universal joint, circular motion may be com- municated, at an angle of from fifty to ninety degrees. Perpetual Screw. — The perpetual, or endless, screw, sometimes called loorm^ by mechanics, is made use of to convey circular motion from an axle to a toothed wheel, situated in the direction of the same plane with the axle. The relative velocity of a wheel driven by a screw is very slow ; for, if the screw have only a single thread, the wheel will advance the breadth of one tooth, only, for eacb Fig. 113. kS aa 53 ELEMENTS OF MACHINERY. revolution of the screw. This mechanism is of great use in producing an equable slow motion, in machinery, and also, in increasing mechanical power. [Fig. 113.] The motion may be reversed, or conveyed from the wheel to the screw, if the obliquity of the threads be sufficiently increased. A spiral wheel and a toothed wheel may be made to turn, with equal velocity, or any desired propor- tion of velocity, by the construction represented in Fig. / ^4. A, is a wheel, seen edgeways, its axis being BC. B<: /^z^c Its circumference is furnished with spiral ridges, which, as the wheel turns, cause the pinion, D, to revolve in the plane of the axis, BC. Brush Wheels. — In light machinery, wheels sometimes turn each other by means of bristles, or brushes, fixed to their circumference. They may, also, communicate cir- cular motion, by friction only. In this case, the surface brought in contact is formed of the end-grain of wood, or it is covered with leather, or some other elastic substance, and the two wheels are pressed together, to increase the friction. Ratchet Wheel. — The ratchet, or detent, wheel is in- tended to prevent motion in one direction, while it per- mits it in another. For this purpose, the teeth are cut with their faces inclining in one direction, and a small lever, or catch, is so placed, as to enter the indentations, and stop the wheel, if it turns backward, but slides ovei the teeth, without obstructing them, if it moves forward. [Fig. 115.] Ratchet-wheels are generally employed to DISTANT ROTARY MOTION. 69 pres^ent a weight, raised by a machine, from descending, and to obviate other retrograde movements. Fig. 115. Distant Rotary Motion. — When it is required to trans- mit circular motion to a distance, for example, from one extremity, or story, of a building, to another, various meth- ods are employed. The most common is, by band-wheels, or drums, connected by leather belts of the requisite length. This mode is considered most economical. -When a precise velocity is required, a rolling shaft, geared at both ends, as in Fig. 116, is to be preferred. A double crank. Tier. 116. having its two parts at right angles with each other, and connected with a similar crank, by stiff rods, or bars, an- swers the same purpose. [Fig. 1 17.] If triple cranks are Fig. 117. used, cords will serve, instead of bars, for connection, be- cause, in this case, some part of the first crank will always be in a situation to draw the second, and a rigid medium will not be necessary. 60 ELEMENTS OF MACHINERY. Change of Velocity. — It is sometimes necessary, thai a machine should be propelled with a velocity which is not equable, but which continually changes, in a given ratio. This happens in cotton-mills, where it is neces- sary that the speed of certain parts of the machinery should continually decrease, from the beginning to the end of an operation. To effect this object, two cones, or conical drums, are used, having their larger diameters in opposite directions. They are connected by a belt, which is so governed, by proper mechanism, that it is gradually moved from one extremity of the cones to the other, thus acting upon circles of different diameter, causing a con- tinual change of velocity in the driven cone, with relation to that which drives it. [Fig. 118.] A change of speed is also effected, by a decreasing series of toothed wheels, placed, in the order of their size, upon a common axis, and fixed. A corresponding series, in an inverted order, are placed upon another axis, and not fixed, but capable of revolving about the axis, like loose pullies. The axis of this second series is made hollow, and contains a movable rod, which has a tooth, project- ing through a longitudinal slit in one side of the axis. This tooth serves to lock any one of the wheels, by entering a notch, cut for its reception. Only one wheel, however, can be locked at a time, the others remaining loose, so that the axis will revolve with a velocity, which is due to the relative size of the particular wheel which is locked, and of the wheel which drives it. By successively lock- ing the different wheels, an increase, or decrease, of speed is obtained.* [Fig. 119.] * A mechanism of this kind is used in the cotton factory at New- ton, Massachusetts, and there is one, nearly similar, in Bramah's plan- ing machine. CHANGE OF VELOCITY Fig. 119. 61 Another mode of changing speed is produced, by a large, and small, wheel, placed at right angles with each other, and acting by friction only. The edge of the smaller wheel is kept in close contact with the disc, or flat surface, of the larger wheel, so that the smaller wheel will revolve faster, or slower, according to the distance, at which it is kept from the centre of tLe larger wheel. The distance may be varied at pleasure [Fig. 120.] Fig. 120. It is sometimes requisite that a wheel, or axis, should move with different velocity, in different parts of a single revolution, as in orreries, &c. This may be effected, by an eccentric crown-wheel, acting on a long pinion as in l(. ¥11, 62 ELEMENTS OF MACHINERY. Fig. 121. It may also be accomplished in a different way, by a cone, furnished with spiral line of teeth, acting on another cone, the position of which is reversed. Fusee. — In the preceding arrangements for changing velocity, there is a corresponding change of force, which is in an inverse ratio to the change of velocity. They may, therefore, be employed for varying force, as well as speed. The fusee of a common watch is a contriv- ance, adapted to this purpose. "When a watch is recent- ly wound up, the spring, which propels it, is in the state of greatest tension. As this spring relaxes, or uncoils itself, its power decreases, and, in order to correct this inequal- ity, the chain, through which it acts, is wound upon a spi- ral fusee. The fusee, B, is an axis, surrounded by a spiral groove, the distance of the groove from the axis being made to increase gradually, from the top to the bottom, so that, in proportion as the force of the spring is diminished, it may act on a longer lever. The general outline of the fusee must be nearly such, that its thickness, at any part, may diminish, in the same proportion as it becomes more distant from the point, at which the force would cease altogether, the general curve being that of a hyperbole ; \)ut the workmen have, in general, no other rule, than that of habitual estimation. [Fig. 122.] Fig. 122. ALTERNATE, OR RECIPROCATING, MOTION. This name is applied to movements which take place continually, backwards and forwards, in the same path. An alternate motion may take place about a centre, in which case, the moving parts will describe arcs of circles, as in a tilt-hammer, or the beam of a steam-engine ; or it may be confined by guides, so as to pursue a rectilinear path, as in the saw of a saw-mill. In most complex ma- CAMS. 63 chines, both rotary and reciprocating motions occur, and these motions are convert"^d into each other, by any of the following contrivances. Cams. — If the axis of a wheel be situated in any other point than its centre, the wheel, thus rendered eccentric, may produce, by its revolution, an alternate motion in any part exposed to its action. Circles, hearts, ellipses, parts of circles, and projecting parts of various forms, are made to produce alternate motion, by continually altering the distance of some movable part of the machine, from the axis about which they revolve. Such projecting parts are called cams.* In the various forms which are shown in the figures, the part, removed by the cam, is supposed to return, by its own gravity, or by some other power, so as to keep up the alternate motion. In the circular ec- centric cam, or wheel, [Fig. 123,] the sliding, or recipro- cating, part, x\B, will ascend and descend, with an easy motion, being never at rest, unless at the instant of chang- ing its direction. Eccentric wheels, if surrounded by a hoop, as at H, in PI. IX. perform the same office as cranks. In the semicircular cam, [Fig. 124,] the recipro- cating part will remain at rest, on the periphery of the cam, during half the revolution, but, in the remaining half, it w'ill approach the axis, and return. In the quadrant cam, [Fig. 125,] the reciprocating part will remain at rest, on the periphery, during the first quarter of the revolution ; Fig. 123. A 1 Fig. 124. A o Fig. 125. A Fig. 126 A o Fig. 127. A ^B r-^B ^B^B S ^ ^ / :^ c * This word is spelt cam, camm, and camb, by different writers. In French came. — Borgni^. 64 ELEMENTS 01 MACHINERY, during the second, it will descend to the axis ; during the Third, it will be at rest upon the axis ; and during the fourth, it will return to its original situation. The narrow cam, [Fig. 126,] causes the reciprocating part to rise and fall, in one half the revolution, and to remain at rest, on the axis, during the other half. In these figures, the angles. of the cams are made sharp, for the sake of demonstration ; but, in practice, they are generally rounded, to produce more gradual changes of motion. The elhptical cam, [Fig. 127,] causes two alternate movements for each revolution ; and the triple cam, in Fig. 12S, apphed to a tilt, or trip, Fig. 128. hammer, causes three strokes for one revolution. In thi: case, the cams are called icipers, and it is common to accelerate the reciprocal motion, by adding to the action of gravitation, the elastic force of a spring, or by the re- coil of the handle from a fixed obstacle. A cam, in the form of a heart, called a heart-wheel^ is much used in cotton-mills, to cause a regular ascent and descent of the rail on which the spindles are situated.* When an easy motion is desired, as in most large ma- chinery, the acting outline of the cam should be curved . but, to produce a sudden stroke, it should be straight The number of cams may be indefinitely multiplied, if a rapid, or vibrating movement, is required. This is, in effect, done, when the teeth of a wheel act upon a spring, or weight, as in a watchman's rattle, or in the feeder of a grist-mill. * For an investigation of the curves proper for different cams and wipers, see Brewster's edition of Ferguson's Mechanics, vol. ii. p. 126, &c. For producing an easy and uniform motion, spiral, epicycloidal, and other curves, are requisite ; but, for abrupt, forcible, motions, such as occur in tilt-hammers, curves of equal action are to be avoided. CRANK. PARALLEL MOTION. 65 Crank. — The common crank affords one of the simp- lest and most useful methods, for changing circular into alternate motion, and vice versa. The single crank, [Fig. 129,] can only be used upon the end of an axis. The bell-crank, [Fig. 130,] may be used in any part of an axis. The double crank, [Fig. 131,] produces two alternate Fig. 129. Fig. 130. Fig. 131. M uT rt ir motions, reciprocating with each other. The alterna- ting parts, in all these cases, are attached to the crank by connecting rods, or by some of the kinds of mechan- ism, hereafter described. The motion, produced by cranks, is easy and gradual, being most rapid, in the mid- dle of the stroke, and gradually retarded, toward the extremes ; so that shocks and jolts, in the moving ma- chinery, are diminished, or wholly prevented, by their use. Parallel Motion. — The name of parallel motions is giv- en to those arrangements, which convert circular motion, whether continued or alternate, into alternate rectilinear motion, and vice versa. Thus, the beam of a steam-en- gine moves in circular arcs, while the piston moves in right lines. They cannot, therefore, be rigidly connect- ed together, without doing violence to the machine ; and it becomes necessary to convert one movement into the other, by the intervention of proper mechanism. A mov- able parallelogram is principally used, for this purpose, and will be described under the head of Steam Engine. A similar contrivance, of a more simple form, is shown in Fig. 132. CD, is a rod, moving back and forwards, in a right line. Every point of junction is a hinge, or joint. 66 ELEMENTS OF MACHINERY. GE, is a rod, movable about E, as a centre ; and FH, a rod of the same length, movable about F, as a centre ; these centres being equally distant from the path of CD. GH, is a bar, connecting these two rods, and havmg the rod, CD, attached, by a joint, to its centre. When the whole is set in motion, the joint, G, will describe the cir- cular arc, IK, and the joint, H, will describe the circulai arc, GH, while the joint, C, will pursue an intermediate, or rectihnear, course. Various other methods are practised, to insure a rectili- near motion, though most of them are attended with great Fig. 133. SUN AND PLANET WHEEL. 67 er friction than that last described. Thus, the alternating part is often confined to a'rectilinear path, by shding in grooves, guides, or holes, or between friction wheels ; a connecting rod uniting the straight and circular motions, as in the last instance. In Cartwright's steam-engine, the straight movement of the piston is secured, by con- necting it with two cranks, acting in opposition to each other, and having their axles geared together by wheels, as represented in Fig. 133, on page 6G, The connecting rod may be dispensed with, if a trans- verse groove, or slit, be cut in the alternating part, of a length equal to the diameter of the crank's revolution ; as in Fig. 1 34. The end of the crank, seen at [o,] in its Fig. 134. revolution, traverses the whole length of this groove, which is cut in the crossbar, AB, while the main bar, CD, has an alternate motion in the straight path to which it is con- fined. As the space of ascent, or descent, of the bar, CD, is always equal to the versed sine of the arc described by the crank, the motion of the bar will be accelerated, towards the middle of its oscillations, and retarded, to- wards the extremes. A more equal motion can be pro- duced, if desired, by substituting for the straight groove, a curvilinear groove, somewhat like the figure co ; but this method is attended with much friction, and little use. Sun and Planet Wheel. — The mechanism which bears this name, was invented by Mr. Watt, to convert 68 ELEMENTS OF MACHINERY. reciprocating into circular motion, in the steam-engine , the use of the crank, for this purpose, being, at one time, secured by patent to another individual. In Fig. 135, a view is given of the sun and planet wheel. A, is the end of a beam, having a reciprocating motion. B, is the fly- wheel of the engine, to which a rotary motion is to be communicated. Upon the axis of this fly-wheel, a small toothed wheel is firmly fixed. A second toothed wheel is connected to the first, by a loose crank, so as to be capable of revolving freely about it. This second wheel is firmly fixed upon the end of a connecting rod, which is attached, by a joint, to the beam of the engine. The two wheels being in gear, it is obvious, that as the beam. A, rises and falls, the second wheel, with the assistance of the fly, will revolve quite round the first ; and, if the num_ber of teeth be equal, the first, or sun-wheel, must perform two rotations on its axis, while the second, or planet-wheel, revolves once round it. The necessity of this will be more obvious, when we consider, that, if one tooth of the planet-wheel, were con- nected by a joint to one tooth of the sun-wheel, it would act as a simple crank, and cause one revolution. But an additional revolution is also necessary, because, during the circuit, all the teeth of the planet-wheel must act INCLINED WHEEL. EPICYCLOIDAL WHEEL. 69 upon those of the sun-wheel, thus turning it round, as in common wheel-work. Fig. 136. C E ■ tl D F Inclined Wheel. — In Fig. 136, AB, is a wheel, placed obliquely on its axis, CD. The edge, or periphery, of this wheel, is received in a notch, at B, of a sHding bar, EF. As the wheel revolves, the bar, EF, will move up and down once, during each revolution. This reciprocal motion may be indefinitely varied, by bending the edge of the wheel into different curves and angles. Epicycloidal Wheel. — A very beautiful method of con- verting circular into alternate motion, or alternate into cir- cular, is shown in Fig 137. AB is a fixed ring, or wheel, Fig. 137. toothed on its inner side. C, is a toothed wheel, of haft the diameter of the ring, revolving about the centre of the ring. While this revolution of the wheel, C , is taking place. 70 ELEMENTS OF MACHINERY. any point, whatever, on its circumference, will describe a straight line, or will pass and repass through a diameter of the circle, once, during each revolution. This is an elegant appHcation of the law, that, if a circle rolls on the inside of another of twice its diameter, the epicycloid de- scribed is a straight line. In practice, a piston, rod, or other reciprocating part, may be attached to any point on the circumference of the wheel, C. Rack and Segment. — If an alternating motion is requir- ed, the velocity of which shall be always equal, a rack is best adapted to produce this effect. In Fig. 138, AB Fig. 138. a a parallelogram, having a rack on two opposite sides. 0, is a half wheel, toothed on its curved side, and having its centre equally distant from the two racks. It is ob- vious, from inspection, that, as this half wheel revolves, its teeth will act successively upon the two racks, and cause the parallelogram to move back and forwards, with a uni- form motion. The change, however, from one direction to the other, will be nearly instantaneous, so that this plan will only answer in machinery which is very hght, or of slow motion. The teeth of the half wheel must cover somewhat less than half a circle, that they may not become engaged in one rack, before they are disengaged from the other. Rack and Pinion. — Another contrivance, which ren- ders the change more gradual, is represented in Fig. 139. AB, is a double rack, with circular ends, fixed to a beam, capable of moving in the direction of its length. The rack IS driven by a pinion, P, which is capable of moving up and down in a groove, [m?i,] cut in the cross-piece. When the pinion has moved the rack and beam, until it comes ta BELT AND SEGMENT. ^SCAPEMENTS. 71 Fig. 139. „ % P n V ar V» a ^u the end, B, the projecting piece [a] meets the spring, [5,] and the rack is pressed against the pinion. The pinion, then working in the circular end of the rack, will be forced down the groove, [mn,] until it works in the lower side of the rack, and moves the beam back in theopposite direction ; and, in this way, the motion is continued. The motion of the pinion in the groove will be diminished, if, instead of a double rack, we use a single row of pins, which are parallel to the axis of the pinion, as in some of the ma- chines, called mangles. Belt and Segment. — An alternate circular motion is converted into an alternate rectilinear motion, in fire-en- gines, dressing-machines, &c., by a belt, or chain, fasten- ed to each end of a segment, or other portion of a wheel. The two belts pass by each other, and are attached to the opposite ends of an alternating part. When the segment turns, in either direction, it draws after it the alternating par^,, in a straight line. [Fig. 140.] Fig. 140. Scapements. — In clocks and watches, an alternating motion is produced in the pendulum and balance-wheel, 72 ELEMENTS OF MACHINERY. by means of the mechanism called a scapement. In the more simple scapements, two teeth, called pallets, are made to vibrate on a common axis. They are connect- ed with a toothed wheel, in such a manner, that one pallet enters between the teeth of the wheel, whenever the other is thrown out of their reach. As the wheel revolves, its teeth successively impinge against one or the other of these pallets, and, by causing them successively to escape, communicate to their axis a vibrating, or alternate, motion. The crutch scapement, [Fig. 141,] is an arch, situated in the same plane with the scape-wheel, and parallel to the plane in which the pendulum vibrates. Its pallets suc- cessively enter and escape from the teeth of the wheel, and receive from it a vibrating motion. In the old, or com- mon, watch scapement, [Fig. 142,] a contrate, or crown, wheel is used as the scape-wheel, and the pallets [a and b] are placed upon the axis of the balance-wheel, so as to meet the teeth, successively, on opposite sides of the cir- cumference of the scape-wheel. A variety of other more complicated forms of the scapement are also in use. Fig. 141. Fig. 142. BAND. RACK. 73 CONTINUED RECTILINEAR MOTION. A long-continued rectilinear motion is not to be pro duced in the parts of a machine, except so far as it par- takes of the nature of a rotary, or a reciprocating, motion. Thus, a band, passing round pullies, is a modification of rotary motion, and a rack, which is obliged to return at intervals, has a reciprocatmg motion. But, to a certain extent, the motions of both may be regarded as conftti- iiously rectilinear. Band. — If it is required to produce motion, in a right line, which shall be always in one direction, as, for exam- ple, in the feeding parts of machines, a band, passing round pullies or drums, is the method most commonly practised, as in Fig. 105. If a precise velocity is required, the band may be perforated with holes, and received upon short pins, at the circumference of the wheels ; or the rag-wheel and chain, represented in Fig. 107, may be substituted. Rack. — If a slow rectilinear motion is required only for limited times, such a mechanism may be used, as will permit the moving part to retrace its own path, at inter- vals, and regain its original situation. [Fig. 143.] A rack, which is a straight bar, having teeth on one side, will move in this manner, if it be acted on by a toothed wheel, or by a perpetual screw. If the thread of a perpetual screw be formed of different obliquity, in different parts of its circumference, the progressive velocity of the rack will be unequal, instead of being uniform. And, if a part of the thread be in a plane, at right angles with the axis of the screw, the rack will be at rest, while that part of the screw revolves in contact with it. XII. 74 ELEMENTS OF MACHINERY. Universal Lever. — A rack is also propelled, by means of a catch, or dog, connected with some part of the ma- chine, which has an alternating motion. The catch caus- es the rack to advance, the length of one tooth, at each stroke of the alternating part. The universal lever, some- times called the lever of La Garousse, consists of a bar moving upon a centre, and havmg a movable catch, or hook, attached to each side, and acting upon the oblique te^h of a double rack, or of a ratchet-wheel, so that the alternating motion of the bar causes a progressive motion of the rack, or wheel. [Fig. 144.] Fig. 144. Screw. — A common screw is often made use of, to produce rectilinear movements, when the motion is in- tended to be very slow, or when great power is required. Change of Direction. — A change, from one path, or direction, to another, forming an angle with it, may be produced, by several of the mechanical powders. Thus, a cord, passing over a pulley, may change a perpendicular to a horizontal motion, as at P, [Fig. 159,] or to one at any other angle required. A bent lever, like that repre- sented by y z, in PI. III., produces the same effect, pro- vided the moving parts are confined, by guides, to their respective paths. An inclined plane, also, if it moves through the length of one side of a parallelogram, will cause another body to move through the length of the contiguous side, at right angles. This method, however, is attended with much friction. Toggle Joint. — The knee-joint^ ccmmonly called, in OP ENGAGING AND DISENGAGING MACHINERY. 75 this country, toggle-joint, affords a very useful mode of converting velocity into power, the motion produced be- ing nearly at right angles with the direction of the force. Its operation is seen in the iron joints which are used, to uphold the tops of chaises. It is also introduced into various modifications of the printing press, in order to obtain the greatest power, at the moment of the impres- sion. It consists of two rods, or bars, connected by a joint, and increases rapidly in power, as the two rods ap- proach to the direction of a straight line.* In Fig. 145, a moving force, applied in the direction CD, acts with great and constantly increasing power, to separate the parts, A and B. • C OF ENGAGING AND DISENGAGING MACHINERY. In many cases, particularly where numerous machines are propelled by a common power, it is important to pos- sess the means of stopping any one of them, at pleasure, and of restoring its motion, without interfering with the rest. To produce this effect, a great variety of combi nations have been invented, under the name of couplings. These, in most instances, are sHding boxes, which move longitudinally upon shafts or axles, and serve to engage, or lock, a shaft which is at rest, with one which is in mo- tion ; so as practically to convert the two into one, until * An investigation of the power of this combination, is given hy the late Professor Fisher, in Silliman's Journal, \ol. iii. p. 320. 76 ELEMENTS OF MACHINERY. they are again unlocked. Couplings are sometimes pro- vided with clutches, or glands, which are projecting teeth, intended to catch on other teeth, or levers, and thus lock the shafts together. Sometimes they have bayonets, or pins, adapted to enter holes. Sometimes, the connexion is produced by friction alone, by pressing together sur- faces, which are either flat, or conical. Sometimes, also, wheels are thrown into^ and out of, gear, which is done, by causing wheels to shde in the direction of their axles, or, in some cases, by elevating and depressing the axle itself. These methods, however, are difficult and un- safe. The live and dead pulley afibrd, perhaps, the sim- plest mode of engagement. They consist of two paral- lel band-wheels, on the same axle, one of which is fast, and the other loose, or capable of turning without the axle. The band, which communicates the power, is placed upon the loose pulley, when it is desired to stop the machine, and upon the fast pulley, when it is intend- ed to set the machine in motion. A common band may, also, be made to admit of motion or rest, according as it is rendered tense, or loose, by a tightening wheel, pressed against hs side by a lever. OF EQUALIZING MOTION. In most machines, both the moving force, and the re- sistance to be overcome, are liable to fluctuations of in- tensity, at different times. As such variations influence both the safety and efficiency of machines, it is necessa- ry to provide against them, by some appendage, which shall equalize either the supply, or the distribution, of the power. Governor. — The name of governor has been given to an ingenious piece of mechanism, which has been intro- duced, to regulate the supply of steam, in steam-engines, and of water, in water-mills, so as to render the power equable, and proportionate to the resistance to be sur- mounted. It is represented in Fig. 146, on the opposite page. x\B, and AC, are two levers, or arms, loaded with heavy balls, at their extremities, B and C, and suspended, by a joint, at A, upon the upper extremity of a revolv- GOVERNOR. 77 ing shau, AD. At [a,] is a collar, or sliding box, cou- nected to the levers, by the rods [a6, and ac,] with joints at their extremities. It follows, that when the weights, B and C, diverge, the collar [a] will move up- ward, on the shaft. AD, and vice versa. The governor, thus constructed, is attached to some revolving part of the machine. In this state, if it turns too rapidly, the balls, B and C, move outwards, by their centrifugal force, and draw upward the collar, [a.] If, on the other hand, the speed diminishes, the balls are allowed to subside, and the collar moves down upon the shaft. In the steam-engine, the collar has a circular groove, which receives the end of a forked lever. As the collar rises and falls, this lever turns upon its fulcrum, and acts, remotely, to open or close a throttle-valve, which is placed in the main steam-pipe.* Whenever, therefore, the machine moves too rapidly, the balls recede from the centre, the collar rises, the lever moves the valve, and, by partially closing the pipe, di- minishes the quantity of steam admitted from the boiler. If the machine moves too slowly, the reverse takes place, and a larger amount of steam is admitted. In water-wheels, where a greater power is necessary to control the supply of water, the governor is usually connected to the sluice-gate, by the intervention of wheel- work. This may be done in several ways, one of which * For a further account of the governor, see the article, Steam Eiu gine. 7* 78 ELEMENTS OP MACHINERY. IS as follows. The lower part of the shaft, AD, carries a wheel at D, acting upon two others beneath it, M and N. While the machinery moves with its proper speed, the wheels, M and N, are both unlocked, and turn loosely round their axles, and the gate is stationary. But, when the velocity increases or diminishes, the collar [a] rises or falls, and, by means of a cam, acts upon a lever above it, or upon another below it, so as to lock one of the wheels, M or N, by moving a clutch situated at [c?.] These wheels, being upon a common axle, are capable of turning this axle different ways. When, therefore, one wheel is locked to the axle, it acts by turning a perpetual screw, to open the sluice gate. When the other is locked, the axle and the screw turn in the opposite direction, and partially close the gate. The foregoing are some, out of various, modes in which the governor is appHed. In windmills, it is so adapted as to increase the feeding, or supply of corn, when the mill goes too fast, and also to vary the distance of the mill- stones from each other, if necessary. It has also been applied to clothe and unclothe the sails, in proportion to the strength of the wind. Fly Wheel. — It is an object of great importance, in machines, to have the means of accumulating power, when the moving force is in excess, and of expending it, when the moving force operates more feebly, or the resistance increases. This equahzalion of motion is obtained, by what is called a fly, which is generally made in the form of a heavy wheel, though, sometimes, in the form of arms, or crossbars, with weights at their extremities. A fly being made to revolve about its axis, keeps up the force, by its own inertia, and distributes it, in all parts of its rev- olution. If the moving power slackens, it impels the machine forward ; and if the power tends to move the machine too fast, it keeps it back. Fly-wheels are capable of accumulating power to a great extent. A small force, continually applied to the surface of a heavy revolving wheel, will eccelerate its ve- locity, till it shall be equal to that of a musket-ball, and ts momeatum almost irresistible. Fjy- wheels, to act FRICTION. 79 i^ith th6 Z^ Htrtrx Pump. — A pump, partaking of the nature til a forcing and a sucking pump, is sometimes called a mixed pump. In De La Hire's pump, which is of this kind, and shown in Fig. 168, the same piston is made to serve Fig. 168. a double purpose ; the rod woiking in a collar of leathers, and the water being admitted and expelled, in a similar manner, above and below the piston, by means of a double apparatus of valves and pipes. When the piston is de- pressed, the water enters the barrel at the valve. A, and goes out at B. When the piston is elevated, it enters at C, and escapes at D. For forcing-pumps, of all kinds, the common piston, with a collar of loose and elastic leather, is preferable to those of a more complicated structure. The pressure of the water, on the inside of the leather, makes it sufficiently- tight, and the friction is inconsiderable. In some pumps, the leather is omitted, for the sake of simpHcity, the loss of water being compensated by the greater durability of the pumps ; and this loss will be the smaller, in propor- tion, as the motion of the piston is more rapid. Hydrostatic Press. — This powerful machine is essen- tially a forcing-pump, aided, in its action, by the well-known properties of hydrostatic pressure. It appears to have been invented by Pascal, previously to 1664, and recom- mended by him, as a new mechanical power. It was, however, practically, lost sight of, till it was re-invented by 152 ARTS OF CONVEYING WATER. Mr. Bramah, more than a century afterwards. In tlin press, the water is forced, by a small pump, into a strong iron cylinder, in which it acts on a much larger piston ; consequently, this piston is urged by a force, as much greater than that which acts on the first pump-rod, as its surface is greater than that of the small one. In Fig. 169, the water is forced, by the pump. A, through the Fig. 169. FrTnl rnpl . pipe, B, into the cylinder, C, in which it acts, very pow- erfully, upon the large piston, D, and raises the bottom of the press, E. The upward force, by which the material, above E, is compressed, exceeds the force, which is ap- plied to the pump, as much as the surface of the piston, D, exceeds that of the piston of the pump. In practice, the cylinder, C, requires to be made much thicker than here represented.- Lifting Pump. — Where the height, through w^hich the water is to be raised, is considerable, some inconvenience might arise, from the length of the barrel, through which the piston-rod of a sucking-pump would have to descend, in order that the piston might remain within the hmits of atmospheric pressure. This may be avoided, by placing the movable valve, below the fixed valve, and introducing the piston, at the bottom of the barrel. It is then w^orked, by means of a frame, on the outside. Such a machine is called a lifting-pump. In common with other forcing- pumps, It has the disadvantage of thrusting the piston be- fore the rod, and thus tending to bend the rod, and pro- duce an unequal friction on the piston, while, in the suck- BA.a-PUMP. DOUBLE-ACTING PUMP. 153 ing-pump, the principal force always tends to straighten the rod. Bag Pump. — A bag of leather has sometimes been employed, for connecting the piston of a pump with the barrel, and, in this manner, nearly all friction is avoided. It is probable, however, that the want of durability would be a great objection to such a machine. In Fig. 170, A, represents a leathern bag, attached to a number of hoopb. This bag is alternately extended and contracted, like a bellows, by every stroke of the piston, and raises the wa- ter, without friction against the pump. Double-acting Pump. — The rod of a sucking-pump, may also be made to work in a collar of leather, at the top, as at A, in Fig. 171, and the water may be forced Fisr. 171. 154 ARTS OF CONVEYING WATER. through a valve, into an ascending pipe, B. By applying an air-vessel to this, or to any other, forcing-pump, as is done in fire-engines, its motion may be equalized, and its performance improved ; for, if the orifice be large enough, the water may be forced into the air-vessel, during the stroke of the pump, with any velocity that may be re- quired, and with little resistance, from friction ; whereas, the loss of force, from the frequent accelerations and re- tardations of the w^hole body of water, in a long pipe, must always be considerable. The condensed air, re- acting on the w^ater, expels it more gradually, and in a continual stream, so that the air-vessel has an effect, anal- ogous to that of a fly-wheel, in mechanics. Fig. 172. Rolling Pump. — A pump of this kind is formed, by a bavrel, or hollow cylinder, shown in section, in Fig. 172, naving two partitions. One of these, iVB, is fixed, and the other, CD, is composed of two wings, or valves, ca- pable of an alternate motion, about the axis of the cylin- der. When the partition, CD, turns in one direction, the water, in the cavity, C, is driven out at the orifice, [a,] and will rise in a pipe, attached to that orifice. At the eane time, the water, in the cavity, D, is forced out at the orifice, [d]. While this is taking place, fresh por- tions of water enter the remaining cavities, [at mand z]. When the partition, CD, has moved, as far as possible, it then returns, in the opposite direction, and drives out the water, through [y and a;,] and receives fresh water, through [b and c]. The orifices, which receive the water, have valves, opening inward, and those, which dis- charge it, have valves, opening outward. The machine ECCENTRIC-PUMP. 155 is worked by arms, attached to the axis of the cylinder, which, for this purpose, projects through a collar, in the ends of the vessel. For the sake of simplicity, a sector of a cylinder is sometimes used ; in which case, a single partition, or valve, like a door on hinges, traverses the whole cavity, and only half the number of orifices are necessary, to ad- ;*.it and discharge the water. Fire-engines, for project- ing water, have been constructed, in byoih these methods, by different inventors. Fig. 173. Eccentric Pump. — The eccentric pump, a section of which is shown at Fig. 173, consists of a hollow cylinder, [a(?,] in the interior of which, a solid cyhnder, [6,] of the same length, but of about half the diameter, is made to revolve, by its axle, passing through water-tight collars, in the ends of the exterior cylinder. The internal cyl- inder is so placed, that its surface comes in contact with some part of the internal surface of the larger cylinder. The surface of the small cylinder, is also furnished with four large valves, or flaps, turning on hinges, and par- takir.g of its own curvature ; so that, when they are, shut down, they form no projections, but appear as parts of the same cylinder. These valves are made to open, by springs, or otherwise ; so that, when one of them is brought, by the revolution of the internal cylinder, into the narrowest part of the internal space, it is pressed down, and shut ; but, as the inner cylinder moves on, tha 156 ARTS OF CONVEYING WATER. valve, being gradually carried forward, will continue to open, until it arrives at the widest part of the cavity. It is then pressed down again, by a continuation of the rev- olution. In this way, the water behind the valve is drawn up, from the feeding-pipe, by the atmospheric pressure, while that before the valve is forced upward, into the delivering pipe. As each of the valves performs the same operation, in its turn, this pump affords a constant supply of water. Rotative steam-engines have been constructed, by dif- ferent projectors, on the principle of this pump, as well as the following. Fig. 174. Another form of an eccentric pump, is seen in Fig. 174. The roller, or solid cylinder. A, revolving within the reservoir, or hollow cylinder, BF, carries with it the slider, DE, which is made to sweep the internal surface of this cyhnder, by revolving, in the direction from C to F, so that the water is drawn up, by the pipe, C, and dis- charged, by the pipe, F. An objection to all pumps of this sort is, that, if they are made tight enough to hold water, they occasion a great degree of friction, on account of the extensive con- tact. of the moving surfaces. The continual change, also, which takes place, both in the direction and velocity of the water, is productive of great resistance from inertia. The stream, at the delivering orifice, although never whol- ly intermitted, is, by no means, uniform in its velocity. Arrangement of Pipes. — The pipes, through which wa- ter is raised, by pumps of any kind, ought to be as short, and as straight, as possible. Thus, if we have to raise CHAIN-PUMP, ETC. 157 water, to a height of twenty feet, and to carry it, to a hor- izontal distance of one hundred, by means of a forcing- pump, it will be more advantageous to raise it first, ver- tically, into a cistern, twenty feet above the reservoir, and then to let it run along horizontally, or find its level in a bent pipe, than to connect the pump immediately with a single pipe, carried to the place of its destination. And, for the same reason, a sucking-pump should be placed as nearly over the well as possible, in order to avoid a loss of force, in working it. If very small pipes are used, they will much increase the resistance, by the friction which they occasion. Chain Pump. — Water has sometimes been raised by stuffed cushions, or by oval blocks of wood, connected with an endless rope, or chain, and caused, by means of two wheels, or drums, to rise, in succession, in the same oarrel, carrying the water in a continual stream before them. The magnitude, however, of the friction, appears to be an objection to this method. From the resemblance of the apparatus to a string of beads, it has been called a bead-pump^ or paternoster-work. When flat boards are united by chains, and employed, instead of these cushions, the machine has been denominated a cellular pump ; and, in this case, the barrel is usually square, and placed in an inclined position. There is, however, a considerable loss, from the facility with which the water runs back. The chain-pump, used in the Navy, is a pump of this kind, with an upright barrel, through which leathers, strung on a chain, are drawn in constant succession. These pumps are only employed, when a large quantity of water is to be raised, and they must be w^orked with considera- ble velocity, in order to produce any effect at all. The Chinese work their cellular pumps, or bead- pumps, by walking on bars, which project from the axis of the wheel, or drum, that drives them ; and, whatever objection may be made to the choice of the machine, the mode of communicating motion to it, must be allowed to be advantageous. Schemnitz Vessels, or Hungarian Machine. — The mediation of a portion of air is employed for raising wa- ll. 14 XII. 158 ARTS OF CONVEYING WATER. ter, not only in the spiral-pump, but also in the air-ves- sels of Schemnitz, in the manner, shown in Fig. 175. A column of water, descending through a pipe, C, into a closed reservoir, B, containing air, obliges the air to act, by means of a pipe, D, leading from the upper part of the reservoir, or air-vessel, on the water in a second res- ervoir, A, at any distance, either below or above it, and forces this water to ascend, through a third pipe, E, to any height less than that of the first column. The air- vessel is then emptied, the second reservoir filled, and the whole operation repeated. The air must, however, acquire a density, equivalent to the pressure, before it can begin to act ; so that, if the height of the columns were thirty-four feet, it must be reduced to half its dimensions, before any water would be raised ; and thus, half of the force would be lost. But, where the height is small, the force lost in this manner is not greater, than that which is usually spent in overcoming friction, and other imperfec- tions, of the machinery employed ; for the quantity of water, actually raised by any machine, is not often greater than half the power which is consumed. The force of the tide, or of a river, rising and falling with the tide, might easily be applied, by a machine of this kind, to the purpose of raising water. Thus, if, at low tide, the ves- HERO S FOUNTAIN, ETC 159 sel, A, was filled with air, then, at high tide, the w^ater, dewing down the tube, E, would cause the water in the vessel, B, to ascend in the pipe, C. Heroes Fountain, — The fountain of Hero, precisely re- sembles, in its operation, the hydrauHc vessels of Schem- nitz, which were probably suggested to their inventor, by (he construction of this fountain. It may be used, simply, to raise water, or to project it upwards, in the form of a pt, as in Fig. 176. The first reservoir, C, of the foun- Fig. 176. tain, is lowe^ 'han the orifice of the jet. A pipe descends horn it, to the air-vessel, B, which is at some distance below, and the pressure of the air is communicated, by dn ascending tube, D, to a third cavity. A, containing the water which supplies the jet. 1r this form of the ma chine, the water will continue to spout from the pipe, E, sintil all the water in the reservoir, C, has descended into the vessel, B. The principle of Hero's fountain has been applied, to raise oil in lampi- ; and one of its most simple forms has already been desofibed, under the head of Hydrostatic Lamp,, page 334, vol. I. Atmospheric Machines. — The spontaneous vicissitudes of the pressure of the air, occasioned by changes in the weight and temperature of the atmosphere, have been ap- plied, by means of a series of reservoirs, furnished wit^ proper valves, to the purpose of raising water, by degrees, to a moderate height. But it seldom happens, that such 160 ARTS OF CONVEYING WATER. changes are capable of producing an elevation m the water of each reservoir, of more than a few inches, or, at most, a foot or two, in a day ; and the whole quantity raised must therefore be inconsiderable. Hydraulic jRam.— The momentum of a stream of wa- ter, flowing through a long pipe, has also been employed, for raising a small quantity of water, to a considerable height. The passage of the pipe, being stopped by a valve which is raised by the stream, as soon as its mo- tion becomes sufficiently rapid, the whole column of fluid must necessarily concentrate its action, almost instantan- eously, on the valve. In this manner, it loses the charac- teristic property of hydraulic pressure, and acts, as if it were a single solid ; so that, supposing the pipe to be per- fectly elastic, and inextensible, the impulse may overcome any pressure, however great, that might be opposed to it. If the valve opens into a pipe, leading to an air-vessel, a certain quantity of the water will be forced in, so as to condense the air, more or less rapidly, to the degree that may be required, for raising a portion of the water, con- tained in it, to a given height. Mr. Whitehurst appears to have been the first that employed this method. It was afterwards improved by Mr. Boulton ; and the same ma- chine has attracted much attention, in France, under the denomination of the hydraulic ram of M. Montgolfier. Fig. 177. Fig. 177, represents this machine. When the water in the pipe, AB, has acquired sufficient velocity, it raises the valve, B, which immediately stops its further passage. The momentum, which the water has acquired, will ther OF PROJECTING WATER. FOUNTAINS. 161 force a portion of it, through the valve, C, into the air- vessel, D. The condensed air, at D, causes the water to rise into the pipe, E, as long as the effect of the horizon- tal column continues. When the water becomes quies- cent, the valve, B, will open again, by its own weight, and the current will be renewed, until it acquires force enough to shut the valve, and repeat the operation. OF PROJECTING WATER. If a degree of force, or pressure, be applied to water, sufficient to raise it, through a tube, to a given height, the same force would also cause it to spout through an ori- fice, in a continued stream, or jet, to nearly the same height, in common cases. The height, however, can never be fully as great, for various reasons. One of these is found, in the friction of the ajutage, or discharg- ing orifice, which acts as a retarding force. Another obstacle is, the resistance of the atmosphere, which in- creases, in a rapid ratio, as the velocity of the water be- comes greater, and which is also greatly augmented, as the w^ater divides, and spreads out a greater surface to the resistance of the air. A third obstacle consists, in the resistance which the water offers to itself. The parts first projected, being constantly retarded in their ascent, by gravity, and atmospheric resistance, oppose the pro- gress of the parts, which are last projected, and which have the greatest velocity. And, as fluids move, in all directions, this impulse, of different parts of the water, against each other, tends to widen, and, consequently, to shorten, the column. In a vertical jet, moreover, the weight of the falling water opposes the ascending col- umn ; and, hence, a fluid will spout higher, if the jet be turned a little to one side, than if it be perpendicular. Fountains. — Artificial fountains, which throw a per- petual jet of water, usually act by the pressure of a res- ervoir of water, situated at a greater height than that of the jet produced. The w^ater is conveyed from the res ervoir, to the place of the fountain, in pipes ; and, if the orifice, from which it issues, be directed upward, it will spout, to a height approaching tnat of the reservoir. Ii 14* 162 ARTS OF CONVEYING WATER. will always, however, fall short of this height, for the reasons already stated ; and the difference will be great- er, in jets of great height, than it is in lower ones ; since it is found, by experiment, that the differences between the heights of the jets and of the reservoirs, are as the squares of the heights of the jets themselves.* Foun- tains are chiefly used, for purposes of ornament, and, when of large size, require to be fed from the elevated parts of rivers, or bodies of water, having a high level. At Peterhoff, in Russia, there are two fountains, which spout a column of water, nine inches in diameter, to the height of sixty feet, and the fall of the returning water produces a concussion, sufficient to shake the ground. Fire Engines: — The engines used for extinguishing fires, in buildings, are, in effect, a species of forcing pumps, in which the water is subjected to pressure suffi- ciently strong to raise it, by a jet, or otherwise, to- the re- quired height. But, if the forcing pump were used alone, the water would issue only in intermitting jets, in conse- quence of the reciprocating motion of the pump, and thus, a great part of it would become ineffectual. In or- der to make the discharge uniform, and thus keep up a continual stream, a strong vessel, filled with air, is at- tached to the engine. Into this vessel, the water is forced, by the pumps ; and, as the air cannot escape, it is con- densed, in proportion as the water accumulates, until it reacts upon the surface of the water, with great power. If the air be condensed, into half the space which it orig- inally occupied, it will act upon the water with a pressure, equal to that of two atmospheres, and will be adequate to raise water, through a tube, to the height of thirty-three feet, or to project it, through the atmosphere, to nearly the same height. When the air is condensed, to one third of its former volume, in consequence of the air- vessel being two thirds filled with water, its elasticity will be three times greater than that of the atmosphere. It will therefore raise water, in a tube, to the height of six- ty-six feet, and would throw, it to nearly the same height, * Ascertained by Mariotte. — Bossut, Tom. ii § 615. THROWING-WHEEL. 163 were it not for the resistances, which have already been explained. The foregoing principle of the fire-engine has been variously modified, by adapting different kinds of pumps to the air-vessel, and by altering various details. In the engines of Newsham, and others, two cylinders, con- structed like forcing-pumps, are worked by the recipro- cating motions of transverse levers, to which the handles are attached. In this way, the water is forced into the air-vessel, from which it afterwards spouts, through a movable pipe. In some other engines, a single cylin- der is used, the piston-rod passing through a tight collar, as it does in Watt's steam-engine, thus alternately receiv- ing and expelling the water, at each end of the cylinder. In Rowntree's engine, and some others, a mechanism is used, hke that of the rolHng-pump, a part of the inside of a cylinder being traversed by a partition, like a door, hinged upon the axis of the cylinder, which drives the water, successively, from each side of the cyhnder, into the air vessel. A long flexible tube, made of leather, and known among firemen by the name of hose, is of great use in carrying the spouting orifice near to the flames, and thus preventing the water from being scattered too soon. It also serves an important purpose, in bringing water from distant reservoirs, by suction, created in the pumps of the engine. Throioing Wheel. — A throwing-wheel, otherwise call- ed a flash-wheel, or fen-wheel, is used for raising water, both by lifting and projecting it. Its structure resembles that of an undershot water-wheel, or, more properly, of a breast-wheel. Its under surface is received in a trough, or channel, which curves upward. When the wheel is made to revolve, it drives the water before it, and throws it out from the trough, at a considerable elevation. These wheels are used, for draining ponds, marshes, &c., and are turned by wind-mills, or any other power. If their movement is slow, they simply lift the water, and cause it to overflow, at the end of the trough. But, if they 164 COMBINING FLEXIBLE FIBRES. revolve vv'th much velocity, they are capable of throw- ing the water to a still higher level. VV^ORKs OF Reference. — Robison's Mechanical Philosophy, ar- ticles. Theory of Rivers, Water Works, &ic.; — Gregory's Mechan- ics, vol. i. ; — Young's Natural Philosophy, vol. i.; — Ilydraulia, or an Account of the Water Works of London, 8vo. 1835 ; — Bossut, Traitc Theoretique et Experimental d^ Hydrodynumique, 1771, &c. ; — Du BuAT Trait'ed^ Hydravlique, et Pyrodynamiquc, 1786, &c.; — Ven- TURi, Rlcherches Experimentales sur Ics Fluides, 1797; — Rees' Cyclopedia, article Water; — Edinburgh Encyclopedia, article Hydro- dynamics ; — and the Hydraulic Works of Mariotte, Guglielmi- Ni, MiCHALOTTi, D. and J. Bernoulli, D' Alembert, Fon- TANA, M. Young, Prony, Vince, Juan, Eytelwein, &c. CHAPTER XVIII. ARTS OF COMBINING FLEXIBLE FIBRES. Theory of Twisting, Rope Making, Hemp Spinning. Cotton Man nfacture. Elementary Inventions, Batting, Carding, Drawing, Rov- ing, Spinning, Mule Spinning, Warping, Dressing, Weaving, Twil- ling, Double Weaving, Cross Weaving, Lace, Carpeting, Tapestry, Velvets, Linens. Woollens. Felting. Paper Making. Book- binding. Theory of Tivisting. — The strength of cordage, which is employed in uniting bodies, and the utility of flexible textures, which serve for furniture, or for clothing, de- pend, principally, upon the friction, or lateral adhesion, produced by the twisting and intermixture of their constit- uent fibres. A twisting cord is not so strong as the fibres which compose it, supposing the fibres and cord to be of the same length. The object of twisting is, to connect sue cessive numbers of short fibres, in such a manner, that besides the mutual pressure which their own elasticity causes them to exert, any additional force, applied in the direction of the length of the aggregate, may tend to bring their parts into closer contact, and augment their adhesion .0 each other. The simple art of tying a knot, and the ROPE-MAKING. 165 more complicated processes of spinning, rope-making, weaving, and felting, derive most of their utility from this principle. By considering the effect of a force, which is counter- acted by other forces, acting obliquely, it will be seen, that the operation of twisting has a useful effect, in bind- ing the parts of a rope, or thread, together ; and also, that it has an inconvenience, in causing the strength of the fibres to act with a mechanical disadvantage. The great- er is the obliquity of the fibres, the greater will be their adhesion to each other, but the greater, also, will be their immediate strain, or tension, when a force acts upon them, in the direction of the whole cord. From this, it follows, that, after employing as much obliquity, and as much ten- sion, as is sufficient to connect the fibres firmly together, all that is superfluously added tends to w-eaken the cord, by overpowering the primitive cohesion of the fibres, in the direction of their length. The mechanism of simple spinning is easily understood. Care is taken, where the hand is employed, to intermix the fibres sufficiently, and to engage their extremities, as much as possible, in the centre ; for, it is obvious, that, if any fibre were wholly external to the rest, it could not be retained in the yarn. In general, however, the materials are, previously, in such a state of intermixture, as to ren- der this precaution unnecessary. Rope Making. — A single thread of yarn, consisting of fibres twisted together, has a tendency to untwist itself, the external parts being strained, by extension, and the internal parts, by compression ; so that the elasticity of all the parts resists, and tends to restore the thread to its natural state. But, if two such threads, similarly twisted, are retained in contact, at a given point of the circumfer- ence of each, this point is rendered stationary, by the opposition of the equal forces, acting in contrary direc- tions, and becomes the centre, round which both threads are carried, by the forces which remain ; so that they con- tinue to twist round each other, till the new combination causes a tension, capable of counterbalancing the remain- ing tension of the original threads. Three, four, or more, 166 COMBINING FLEXIBLE FIBRES. threads may be united, nearly in the same manner. A strand^ as it is called by rope-makers, consists of a con- siderable number of yarns, thus twisted together, gener- ally from sixteen to twenty-five ; a halser consists of three strands ; a shroud^ of four ; and a cable^ of three halsers, or shrouds. Shroud-laid cordage has the disadvantage of being hollow in the centre, or else of requiring a great change of form in the strands, to fill up the vacuity ; so that, in undergoing this change, the cordage stretches, and is unequally strained. The relative position, and the comparative tension, of all the fibres, in these complicated combinations, are not very easily determined by calcula- tion ; but, it is found, by experience, to be most advan- tageous for the strength of ropes, to twist the strands, when they are to be compounded, in such a direction, as to untw^ist the yarns, of w^hich they are formed ; that is, to increase the twist of the strands themselves ; and, proba- bly, the greatest strength is obtained, when the ultimate obhquity of the constituent fibres is least, and the most equable.* A very strong rope may, also, be made, by twisting five or six strands round a seventh, as an axis. In this case, the central strand, or heart, is found, after much use, to be chafed to oakum. • Such ropes are, however, considered unfit for rigging, or for any use, in which they are liable to be frequently bent. Ropes are most commonly made of hemp ; but various other vegetables are occasionally employed. The Chi- nese even use w^oody fibres ; and the barks of trees fur- nish cordage to other nations. In spinning the yarn, in the piocess of rope-making, the hemp is fastened round the waist of the workman ; one end of it is attached to a wheel, turned by an assistant, and the spinner, walking backwards, draws out the fibres with his hands. When one length of the walk has been spun, it is immediately reeled, to prevent its untwisting. The machines, employ- ed in continuing the process of rope-making, are mostly of simple construction ; but both skill and attention are * Young's Natural Philosophy, vol. i. Lect. xvi. HEMP-SPINNING. COTTON MANUFACTURE. 167 required, in applying them, so as to produce an equable texture, in every part of the rope. The tendency of two strands to twist, in consequence of the tension, arising from the original twist of the yarns, is not sufficient to produce ^n equilibrium, because of the friction and rigidity to be overcome. Hence, it is necessary to employ force, to assist this tendency, and the strands, or ropes, will after- wards retain, spontaneously, the form which has thus been given them. The largest ropes, even, require external force, in order to make them twist at all. The constituent ropes of a common cable, w^hen sepa rate, are stronger than the cable, in the proportion of about four to three ; and a rope, worked up from yarns, one hun- dred and eighty yards in length, to one hundred and thirty- five yards, has been found to be stronger, than when reduc- ed to one hundred and twenty yards, in the ratio of six to five. The difference is owing, partly, to the obliquity of the fibres, and, partly, to the unequal tension, produced by twisting.* Hemp Spinning. — The desideratum of spinning hemp, by machinery, has been attained by Mr. Treadwell, in his machines for that purpose, now at work, at the Charles- town Navy Yard, and elsewhere. By this invention, the hemp is drawn out to the requisite size, by a long series of teeth, fixed upon a revolving belt, and afterwards twist- ed, by the revolutions of the machine. The equality, or uniform size, of the yarn, is ensured, by a roller, or small wheel, which rests upon the part just twisted, and which rises, or is pushed up, if the twist becomes too large, and moves a comb, which immediately falls, and intercepts the superfluous part of the fibres. On the other hand, if the twist becomes too small, the roller descends, and, in so doing, increases the rapidity of the machine, and causes it to supply the hemp faster. COTTON MANUFACTURE. When the fibres of cotton, wool, or flax, are intended to be woven, they are reduced to fine threads, of uniform * Young's Natural Philosophy, vol. i. Lect. xvL 168 COxMBINING FLEXIBLE FIBRES. Size, by the well-known process o( spinning. Previous- ly to the middle ot the last century, this process was per- formed by hand, with the aid of the common spinning- wheel. Locks of cotton, or wool, previously carded, were attached to a rapidly-revolving spindle, driven by a large wheel, and were stretched or draw^n out by the hand, at. the same time that they were twisted by the spindle, upon which they were afterwards wound. Flax, the fibres of which are longer, and more parallel, was loosely wound upon a distaft', from which the fibres were selected, and drawn out by the thumb and finger, and, at the same time, were twisted by flyers, and wound upon a bobbin, which revolved with a velocity, somewhat less than that of the flyers. The manufacture of flexible stufls, by means of machin- ery, operating on a large scale, is an invention of the last century. Ahhough of recent date, it has given birth to some of the most elaborate and wonderful combinations of mechanism, and already constitutes, especially in Eng- land, and in this country, an important source of national wealth and prosperity. Elementary Inventions. — The character of the machin- ery which has been applied to the manufacture of cotton, at different times, has been various. There are, howev- er, several leading inventions, upon which most of the essential processes are founded, and which have given to their authors a greater share of celebrity than the rest. These are, 1. The spinning-jenny. This machine was invented by James Hargreaves,* in 1767, and, in its simplest form, resembled a number of spindles, turned by a common wheel, or cylinder, which was worked by hand. It stretched out the threads, as in common spin- ning of carded cotton. 2. The water spinning-frame^ 'nvented by Richard Arkwright, in 1769. The essen- tial, and most important, feature in this invention con- sists in the drawing out, or elongating, of the cotton, by causing it to pass between successive pairs of rollers, which revolve, with different velocities, and which act as * Mr. Guest, in a late work, attributes the invention, botli of the jen- »y, and water spinning-frame, to Thomas Highs, of Leigh, England BATTING. 169 substitutes for the finger and thumb, as applied in common spinning. These rollers are combined with the spindle and flyers of the common flax wheel. 3. The mule. This was invented by Samuel Crompton, in 1779. It combines the principles of the two preceding inventions, and produces finer yarn, than that which is spun in either of the other machines. It has now nearly superseded the jenny. 4. The power-loom for weaving, by water or steam power, which was introduced about the end of the eighteenth century, and has received various modifica- tions. The foregoing fundamental machines are used in the same, or different establishments, and for different pur- poses. But, besides these, various auxiliary machines are necessary, to perform intermediate operations, and to pre- pare the material, as it passes from one stage of the man- ufacture to another. The number of these machines, and the changes, and improvements, which have been made in their construction, from time to time, render it impossible to convey, in a work hke the present, any accurate idea of their formation, in detail. A brief view, however, of the offices which they severally perform, may be taken, by following the raw material, through the principal changes which it undergoes, in a modern cotton-factory, founded and improved upon the general principles of Arkwright. Batting. — The cotton, after having been cleared from its seeds, at the plantation, by the operation of ginning., described on page 111, Vol. I., is compressed into b^gs, for exportation, and arrives at the factory, in a dense and matted mass. The first operation to which it is submitted has, for its object, to disentangle the fibres, and restore the cotton to a light, open, and uniform, state. For this pur- pose, after being weighed out, it is submitted to the ope- ration of a machine, called a picker., or of another, de- nominated a batter. In some of these machines, it is subjected to the action of a series of pins ; in others, to a sort of blunt knives, revolving with great rapidity ; the effect of which is, to beat up and separate the fibres, to disengage their unequal adhesionS; and to reduce the whole to a very light, uniform, flocculent, mass. II. In XII. 170 COMBINING FLEXIBLE FIBRES. Carding. — The cotton next passes to the carding-ma- chines, of which, when there are two, the first is called the breaker, and the second, ihe finisher. In this opera- tion, the cotton is carried over the surface of a revolving cylinder, which is covered with card-teeth of wire, and which passes in contact with an arch, or part of a con- cave cylinder, similarly covered with teeth. From this cylinder, it is taken off by another, called the doffing cyl- inder, which revolves in an opposite direction ; and from this, it is again removed, by the rapid vibrating movement of a transverse comb, otherwise called the doffing -plate, moved by cranks. It then exists in the state of a flat, uniform, fleece, or lap, which, after passing the breaker, undergoes the process of plying, or doubling, by causing it to perform a certain number of revolutions upon a cyl- inder, or a perpetual cloth. It is then carded a second time, by the finisher, and the fleece, after being taken off from this machine, is draw^n by rollers, through a hollow cone, or trumpet mouth, which contracts it to a narrow band, or sliver, and leaves it coiled up in a tin can, ready for the next operation. The process of carding serves to equalize the substance of the cotton, and to lay its fibres somewhat in a more parallel direction. Drawing. — The slivers of cotton are next elongated, by the process of drawing. This operation is the ground- work, or principle, of Arkwright's invention, and is used in the roving, and spinning, as well as in the drawing- frame. It is an imitation of what is done by the finger and thumb, in spinning by hand, and is performed, by means of two pairs of rollers. The upper roller, of the first pair, is covered with leather, w^hich, being an elastic substance, is pressed, by means of a spring, or weight. The lower roller, made of metal, is fluted, in order to keep a firm hold of the fibres of cotton. Another similar pair of rollers are placed near those which have been de- scribed. The second pair, moving with a greater veloc- ity, pull out the fibres of cotton from the first pair of rol- lers. If the surface of the last pair move at twice, or thrice, the velocity of the first pair, the cotton will be di-awn twice, or thrice, finer than it was before. Thij ROVING. 171 relative velocity is called the draught ot the machine, This mechanism being understood, it will be easy to con- ceive the nature of the operation of the drawing-frame. Several of the narrow ribands, or slivers, from the cards, (sometimes termed card-ends ,) by being passed through a system of rollers, are thereby reduced in size. By means of a detached, single pair of rollers, the several re- duced ribands are pliedj or united into one sliver. The operations of drawing and plying serve to equalize, still further, the body of cotton, and to bring its fibres more into a longitudinal direction. These slivers are again combined, and drawn out, so that one sliver of the finished drawing contains many phes of card-ends. Hith- erto, the cotton has acquired no twist, but is received into movable tin cans, or canisters, similar to those used for receiving the cotton from the cards. Roving. — The operation of roving communicates the first twist to the cotton. It is performed by a machine, called the roving-frame ^ or double-speeder. The tin cans, containing the shvers of cotton, are placed upon this ma- chine, and are made to revolve, slowly, about their axes, so as to produce a shght degree of twisting. The slivers then pass again, through several pairs of rollers, moving with different speeds, and are thus still further attenuated, by drawing. They are then slightly spun, by the revolu- tion of flyers, and are wound upon the bobbins of the spindles, in the form of a loose, soft, imperfect, thi-ead, denominated the roving. The mechanism of the double speeder is complicated, and interesting, and great ingenuity has been displayed, in overcoming the difficulties of hs construction. In order that the yarn, or roving, may be wound upon the bobbins, in even, cylindrical, layers, it is necessary, that the spindle rail, or horizontal bar, which supports the spindles, should continually rise and fall, with a slow alternate motion This is effected by heart-wheels, or cams, in the interio* of the machine. Again, since the collective size of tht Dobbin is augmented, by the addition of each layer oi roving, it is obvious, that, if the axis of the bobbin re volved, always, with the same velocity, the thread of rov 172 COMBINING FLEXIBLE FIBRES. ing would be broken, in consequence of being wound up too fast. To prevent this accident, the velocity of the spindles, and, likewise, the motion of the spindle-rail, is obliged gradually to diminish, from the beginning to the end of an operation. This diminution of speed is effect- ed, by transmitting the motion, both to the spindle-rail, and to the bobbins, through two opposite cones, one of which drives the other with a band, the band being made to pass, slowly, from one end to the other of the cones, and thus continually to alter their relative speed, and cause a uniform retardation of the velocity of the moving parts.* As the roving is not strong enough to bear any violence, the spindles, which support the bobbins, are geared to each other, so as to prevent any deviation from the proper velocity. A more simple form of the roving-frame has been in- vented,! in which the gearing is dispensed with, as well as the pair of cones, which regulates the motion of the bobbins. In this machine, the bobbins are not turned by the rotation of their axes, but by friction, applied to their surface, by small wooden cylinders which revolve in con- tact with them. In this way, the velocity of the surface of the bobbin will always be the same, whatever may be its growth, from the accumulation of roving, so that the winding goes on, at an equable rate. To prevent the rov- ing from being stretched, or broken, in its passage from the drawing rollers to the bobbins, it is made to pass through a tube, w^hich has a rapid rotation, and which twists it, in the middle, into a cord of some firmness. It is again untwisted, as fast as it escapes from the tube, and is wound upon the bobbins, in the form of a dense, even, cord, but without any twist. Spinning. — The bobbins, which contain the cotton, in A state of roving, are next transferred to the spinning- frame. It is here once more drawn out by rollers, and twisted by flyers, so that the spinning is little more than * Instead of band c-oi.es, an ingenious mode of using geared cones, now introduced in several American factories, has already been de escribed, page 60. t By Mr. Danforth, of Massachusetts. MULE-SPINNING. 175 • a repetition of the process gone through, in making the roving, except that the cotton is now twisted into a strong thread, and cannot any longer be extended, by drawing. The flyers of the spinning-frame are driven by bands, which receive their motion, in some cases, from a hori- zontal fly-wheel, and, in others, from a longitudinal cylin- der.* As the thread is sufliciently strong not to break with a slight force, the resistance of the bobbins, by fric- tion, is rehed on to wind it up, instead of having tlie spin- dles geared together, and turned with an exact velocity, as they are in the common double-speeder. In the spin- ning frame, the heart-motion is retained, to regulate the rise and fall of the rail ; and, in those frames which spin the woof, or filling, it is applied, by a progressive sort of cone, the section of which is heart-shaped, and which acts, remotely, to distribute the thread, in conical layers, upon the bobbins, that it may unwind the more easily, when placed, afterwards, in the shuttle. Mule Spinning. — The processes of water-spinning, already described, are adequate to produce yarns, of suf- ficient fineness for ordinary fabrics. But, for producing threads of the finest kind, another process is necessary, which is called stretchings and which is analogous to that which is performed, with carded cotton, upon a commr^n spinniiag-wheel. In this operation, portions of yarn, sev- eral yards long, are forcibly stretched, in the direction r^ their length. It differs, therefore, from the operation €>*' drawing, in which a few inches, only, are extended at • time. The stretching is performed, with a view to elop- gate and reduce those places in the yarn, which have ^ greater diameter, and are less twisted, than the other parts so that the size and twist of the thread may become uni- form throughout. To effect the process of stretching, the spindles are mounted upon a carriage, which is moved, back and forwards, across the floor ; receding, when the tln-eads are to be stretched, and returning, when they are to be wound up. The yarn, produced by mule-spinning, is more perfect than any other, and is employed in the * The latter method, which had gone into disuse, is beginnmg to be revived, and to be considered most advantageous. 15* 174 COMBINING FLEXIBLE FIBRES. m fabrication of the finest artiJes. The sewing-thread, >pun by mules, is a combination of two, four, or six, con- stituent threads, or phes. Threads t>ave been produced, of such fineness, that a pound of cotton has been calculat- ed to reach one hundred and sixty-seven miles. IVarping. — The first step, preparatory to weaving, is to form a warp^ which consists of parallel threads, con- tinued through the whole length of the intended piece, and sufficient, in number, to constitute its breadth. It was, formerly, the practice to attach the threads to as many pins, and to draw them out, to the required length. But, as this method required too much room, a warping ma- chine was subsequently used, in which the mass of threads, intended to constitute a warp, w^as wound in a spiral course, upon a large revolving frame, which rose and fell, so as to produce the spiral distribution. These methods are now superseaeu, n this countiy by Moody's warping-machine,* an ingerious piece ot mechanism, in which a number of bobbins, eqjal to one eighth part of the number of threads in the intended warp, are arranged upon the surface of a con ".ave frame. The threads pass through a reed, which separates the alternate threads, as they are to be kept in the loom ; after which, they are wound upon a beam, with rods interposed at the end, to preserve the separation. But the most ir4/erest- ing part of the mechanism is a contrivance for stopping the machine, if a single thi^ead of the warp breaks. To effect this object, a small steel weight, or flattened wire, is suspended, by a hook, from each thread, so that it falls, if the thread is broken. Beneath the row of weights, a cylinder revolves, furnished with several projecting ledges . extending its whole length, parallel to the axis. Whe. one of the w^eights falls, by the breaking of its thread, i intercepts one of the ledges, and causes the cyhnder to exert its force upon an elbow, or toggle-joint, which dis- engages a clucch, and stops the machine. After the thread is tied, and the weight raised, the machine proceeds. * Mr. Paul Moody, formerly of Walthara, and now of Lowell, is the inventor of this machine ; likewise of the spinning-frame, which winda the woof in conical layers ; and of great improvements in the roving frame, the dressing-frame, &c. DRESSING. WEAVING. 176 Dressing. — As the threads, which constitute the warp, are Hahle to much friction, in the process of weaving, they are subjected to an operation, called dressing, the object of which is, to increase their strength and smoothness, by agglutinating their fibres together. To this end, they are pressed between rollers, impregnated with mucilage, made of starch, or some gelatinous material, and, immediately afterwards, brought in contact with brushes, which pass repeatedly over them, so as to lay down the fibres in one direction, and remove the superfluous mucilage from them. They are then dried, by a series of revolving fans, or by steam-cylinders, and are ready for the loom. Weaving. — Woven textures derive their strength from he same force of lateral adhesion, which retains the twis- ed fibres of each thread in their situations. The man- ner, in which these textures are formed, is readily under- stood. On inspecting a piece of plain cloth, it is found to consist of two distinct sets of threads, running perpen- dicularly to each other. Of these, the longitudinal threads constitute the warp., while the transverse threads are called the woof., t^^ft, or fillings and consist of a single thread, passing backwards and forwards. In weaving with the common loom, the warp is wound upon a cylindrical beam, or roller. From this, the threads pass through a har- ness,- composed of movable parts, called the heddles, of which there are two or more, consisting of a series of vertical strings, connected to frames, and having loops, through which the warp passes. When the heddles con- sist of more than one set of strings, the sets are called leaves. Each of these heddles receives its portion of the alternate threads of the warp ; so that, when they are moved, reciprocally, up and down, the relative position of the alternate threads of the warp is reversed. Each time that the warp is opened, by the separating of its al- ternate threads, a shuttle, containing the woof, is thrown across it, and the thread of a w^oof is immediately driven into its place, by a frame, called a lay, furnished with thin reeds, or wires, placed among the warp, like the teeth of a comb. The woven piece, as fast as it is completed, is wound up on a second beam, opposite to the first. 176 COMBJNING FLEXIBLE FIBRES. Power looms, driven by water, or steam, although a late invention, are now universally introduced into manu- factories of cotton and woollens. As the motions of the loom are, chiefly, of a reciprocating kind, they are produ- ced, in some looms, by the agency of cranks, and in oth- ers, by cams, or wipers, acting upon weights, or springs. Twilling. — In the mode of plain weaving, last describ- ed, it will be observed, that every thread of the warp crosses at every thread of the woof, and vice versa. In articles, which are twilled^ or 'ticeeled^ this is not the case ; for, in this manufacture, only the third, fourth, fifth, sixth, &c., threads cross each other, to form the texture. In the coarsest kinds, every third thread is crossed ; but, in finer fabrics, the intervals are less frequent, and, in some very fine twilled silks, the crossing does not take place, till the sixteenth interval. In Fig 178, is shown a magnified Fig. 178. section of a piece of plain cloth, in which the woof passes, alternately, over and under every thread of the warp. In Fig. 79, is a piece of twilled cloth, in which the thread Fk. 179. r and few subjects, connected with the mechanic arts, have called forth more inventive c.cuteness, elabor- ate experiment, and exact calculation. Before proceeding to a description of the entire me- chanism of a clock, or watch, it will be useful to attend to some of the general principles, and essential parts, of a timekeeper. These will be most easily made intelligi- ble, by directing the attention to the following subjects. 1. The maintaining power. 2. The regulating move- ment. 3. The method of connection. Maintaining Power. — The force, which is employed to sustain the motions of timekeepers, does not require to be of a pow^erful kind. It must, however, be steady and uniform, in its action. Gravity and elasticity, applied through the medium of weights and springs, are the only means now employed, to communicate motion to these machines. In clocks, the maintaining force is usually derived from a iceight. A weight acts with perfect uni- formity, from the beginning to the end of its descent, pro- vided the line, which suspends it, is of equal size through- out, and that this line is w^ound upon a true and perfect cylinder. In portable timekeepers, the weight, for ob- vious reasons, cannot be employed ; and the springs al- though a less perfect and equable power, is obliged to be substituted. From the oldest clocks which remain, it appears, that the spring was in use before the weight ; and one of the first, ever made, is still preserved at Brussels, in which the spring is an old sword-blade, from which a piece of catgut is wound upon the cylinder of the first wheel. The principal difficulty in the use of the spring is, that its action is unequal, and that the more it is bent, the greater force it exerts, to return to its natural situa- tion. The spring of a watch, as it is now used, is a long plate of steel, coiled up into a spiral form. From the outside of this, proceeds a chain, which is attached, not to a cylinder, as is done" willi ihc weight, but to a spiral REGULATING MOVEMENT. PENDULUM. 191 roller, called a fusee, which, by its conical form, gives- to the spring an increased mechanical advantage, in propor- tion as its power diminishes. The fusee has already been described, on page 62. In some of the watches which are now made, the fusee and the chain are dispensed with. The barrel, which incloses the spring, has a toothed circle on its outside, which turns round, as the spring unwinds, and gives mo- tion t:> the machinery. But, in this case, the spring is made larger than common, and only the middle part of its action is used, it being never wound up so far, as to call forth its greatest strength, nor suffered to run down, so far as to be materially weakened. Regulating Movement. — In the mechanism of clocks and watches, it is necessary, so far to retard the move- ment of the maintaining force, i. e., of the weight or spring, that it may be hours and days in expending itself, and that the timekeeper may require to be wound up, only at distant and convenient periods. This is, in part, ef- fected, by the successive combination of wheels and pin- ions, the last of which turns round many hundred times, while the first turns round once. But, if a timekeeper possessed only wheels and pinions, it would run down, with a rapidly accelerated motion, in the course of a few seconds. It becomes, therefore, necessary, to connect with it another motion, which cannot be accelerated, be- yond a certain degree, by any given force. This mo tion is obtained, in clocks, from the pendulum^ and, in watches, from the balance ; and it is the one which it was proposed to consider, as the second head, under the name of the regulating movement. Pendulum. — A pendulum is a weight, capable of vi- brating about a point, from which it is suspended. If the curve, in which the pendulum moves, be a circular arc, it is necessary, that the length of the vibrations should be exactly equal ; otherwise, the pendulum will not keep true time. But, if the curve be a cycloidal one, the pendulum will move, back and forward, in equal times, whatever be the length of its vibrations. In practice, it is found diffi- cult to make a pendulum move in a cycloidal path, with- l92 ARTS OF HOROLOGY. out too much friction. It is, therefore, customary, ni clocks, to use pendulums, moving in circular arcs, these arcs being made to approximate to cycloids, by being as short as possible. Pendulums, when set in mot'on, would continue to vi- brate forever, were it not for the retarding effect of fric- tion, and the resistance of the atmosphere. The former of these is partly obviated, by hanging the pendulum upon a thin spring, and the latter, by forming it with a sharp edge. Still, a considerable force is requisite to sustain the motion, and this force, in clocks, is derived from the weight. That pendulums may vibrate in equal periods, and thus furnish a correct measure of time, it is necessary, that they should always be of uniform length ; for pendulums of different lengths differ in their vibrations, as the square roots of their lengths. Now, such is the effect of heat, in expanding all known substances, particularly metals, that the same pendulum is always longer in summer than it is in winter, and sufficiently so, to affect the correctness of the timepiece, to which it is attached. To remedy this difficulty, various ingenious contrivances have been resort- ed to, the most common of which are, combinations of metals, so connected, as to expand in opposite directions, counterbalancing each other, so as to keep the centre oi oscillation in one place. This is sometimes effected, in the gridiron pendulum, by combining bars, or rods, of steel and brass ; and, in the mercurial pendulum, by en- closing a quantity of quicksilver, in a tube, near the bot- tom of the pendulum. Balance — As the pendulum depends upon the force of gravity, for its motions, it obviously cannot be employed for watches, or portable timekeepers, which are liable to change their position. A substitute is found in the bal- ance^ which is commonly a wheel, moving on an axis, and which, when thrown, backward and forward, by oppo- site appHcations of the moving force, performs its vibra- tions in equal times. The balance is liable to the same irregularities, from expansion and contraction, as the pen- dulum, and is corrected in a similar manner ; and watches SCAPEMENT. i93 go best, when they are kept in the uniform heat of the body. The quantity of matter, accumulated in the balance- wheel of a common watch, is so extremely small, that it seems impossible, that it should exert a perfect regula- ting power. The want of weight, however, is, in some measure, made up, by causing it to perform large vibra- tions, and to move with great velocity. The rim of the balance-wheel, in a good watch, frequently moves through ten inches in every second. This velocity is produced by the hair-spring, which throws the balance back to the point of equilibrium, as fast as it is thrown out, in either direction, by the moving force ; thus per- forming for the balance, what gravity does for the pen- dulum. If the hair-spring be taken away, a watch will lose more than twelve hours in twenty-four, and go much more irregularly. The operation of the common regula- tor of a watch is, to tighten, or relax, this hair-spring, by making its effective part longer or shorter, thus accelera- ting, or retarding, the speed of the balance. Scapement. — It remains to consider the third part, or scapement, by which the rotary motion of the wheels is converted into the reciprocating one of the pendulum and balance. In the scapement, a certain part, connected with the pendulum, or balance, is put in the way of the last, or most rapid, wheel, so that only one tooth of this wheel can escape by it, during each vibration. Thus, the pendulum, or balance, while it receives its motion from this wheel, becomes, in its turn, the regulator of its velo city. The crutch, or anchor-scapement, used in clocks, and the common pailet-scapement with a contrate-wheel, which is the kind most extensively used in watches, have been already explained, under the head of Machinery, page 72. The horizontal scapement. Fig. 183, con- sists of a wheel, A, with elevated teeth, the outer surface of which is curved obliquely. These teeth act upon the edges of a hollow half cylinder, C, the axis of which is parallel to that of the wheel, and carries the balance upon one of its extremities. When a tooth of the scape-wheel 11= 17 xn. 194 ARTS OF HOROLOGY. Fig. 183 Strikes the first edge of the cylinder, it causes it to re- cede, moving the balance in one direction. The tooth then enters the hollow part of the cylinder, and strikes upon the opposite side. Before it can escape, the cylin der is obliged to turn in the opposite direction, and thus a vibrating movement is kept up, in the cylinder and bal- ance. A multitude of other scapements have also been in troduced, by different artists, varying from each other, in the complication of their structure, and accuracy of their movements. But these must, necessarily, be omitted. The operation of the simpler forms, already described, will be more intelligible, taken in connexion with the wheel-work, next to be noticed. Description of a Clock. — In PI. IV. several views are given of the mechanism of a clock, consisting of the go- ing part^ which moves constantly, and carries the hands ; and the striking part., which announces the hour. Fig. 1, PI. IV. is an elevation of the clock, with the wheels seen edgewise, showing the going part ; the striking movements being omitted, in this figure, to avoid confu- sion. Fig. 2, is a front view of the wheel-work of both going and striking parts ; and Fig. 3, is the dial-work., or mechanism, immediately under the dial, or face of the clock, and is that part which puts the striking train in mo- tion, every hour. A clock of this kind contains two in- dependent trains of wheel-work, each with its separate first mover. One is constantly going, to indicate time, by the hands on the dial-plate ; the other is put in motion, once in an hour, and strikes a bell, to tell the hour at a distance. The part, marked [a,] in Figs. 1 and 2, is DESCRIPTION OF A CLOCK. 195 the barrel of the going part ; it has a catgut band, [6,] wound round it, suspending the weight, which keeps the clock in motion. The part, marked 96, is a wheel, call- ed the first, or great "u'lieel, of ninety-six teeth upon the end of a barrel, turning a pinion, 8, of eight leaves, on an arbor,* which carries the minute-hand ; also, 64, is a wheel of sixty-four teeth, on the same arbor, called the centre-wheel, turning the wheel, 60, by a pinion of eight leaves on its arbor. This last wheel gives motion to the pinion of eight, on the arbor of the swing-wheel, 30, which has thirty teeth. The parts [c?/i] are the pallets of the scapement, fixed on an arbor, [e,] Fig. 1, going through the back plate of the clock's frame, and carrying a long lever, [/.] This lever has a small pin, projecting from its lower end, going into an oblong hole, made in the rod, B, of the pendulum. The pendulum consists of an inflexible metalhc rod, sus pended by a very slender piece of steel spring, D, from a brass bar, E, screwed to the frame of the clock, having a weight at its lower end, not seen in the figure ; in the present case, thirty-nine and one eighth inches from the suspension, D. When this pendulum is moved from the perpendicular line, in either direction, and suffered to fall back again, it swings nearly as much beyond the perpen- dicular, on the contrary side, and then returns. This it will continue to do, for some time ; and each of these vi- brations will be performed in one second of time, when the pendulum is of the above length. This is the meas- urer of the time ; and the office of the clock is only to in- dicate the number of vibrations it has made, and to give it a small impulse, each time, to keep it going, as the re- sistance of the air, and elasticity of the spring, D, would otherwise, in a short time, cause it to stop. By the ac- tion of the weight, appHed to the cord, [6,] which is called the maintaining power, the wheels are all turned round ; * The terms arbor, shaft, axle, and axis, are synonymously used by mechanics, to express the bar, or rod, which passes through the centre of a wheel. The terminations of a horizontal arbor are called gud- geons, and of an upright one, frequently, pivots. The term axis, in a more exact sense, may mean merely the longest central diameter, or a diameter about which motion takes place. I9b ARTS OF HOROLOGY. and if the pallets [c? and h] were removed, the swing- wheel, 30, would revolve, with great velocity, in the direc- tion from 30 to [f/,] until the weight reached the ground. The teeth of these pallets are so placed, that one of them always engages the wheel, and prevents it from turning more than half a tooth at a time. In the figure, the pallet [d] has the nearest tooth of the w^heel resting on it, and the pendulum is on the side [/i] of the perpendicular. When it returns, it moves the pallet, [c/,] so as to allow the tooth of the wheel to slip off; but, in the mean time, the pallet [/i] has interposed its point, in the way of the tooth next it, and stops the wheel, till the next vibration, or second. The distance between the two pallets [d and /i] is so adjusted, that only half a tooth of the wheel escapes, at each vibration ; and, as the wheel has thirty teeth, it will revolve once in sixty vibrations, of one second each, or in one minute ; consequently, a hand, on the arbor of this wheel, will indicate seconds, on the dial-plate, F, which is a circle, divided into sixty. The pinion of eight, on its arbor, is turned by a wheel of sixty, which, conse- quently, will turn once in seven turns and a half of the other, or in seven minutes and thirty seconds, or, in one eighth of an hour. Its pinion of eight is moved by a wheel of sixty-four, or eight times itself, which will turn in one eighth part of the time. This will be an hour ; and, there- fore, the arbor of this wheel carries the minute-hand of the clock. The great wlieel of 96, being twelve times the number of the pinion eight, will turn once in twelve hours, and the barrel, [a,] with it. The cord of catgut goes round sixteen times, so that the clock w^ill go eight days. The hour-hand of the clock is turned by the wheel- work, shown in Figs. 1 and 3. On the end of the arbor of the centre wheel, 64, a tube is fitted, so as to go round with it, by friction. This carries the minute-hand ; and, if the clock should require correction, the hand may be slipped round, without moving the wheels. This tube has a pinion of forty teeth on its lower end, indicated by a dotted circle. This turns another wheel, 40, of forty teeth, which has a pinion of six teeth on its arbor, turning a wheel, 72, of seventy-two teeth. The two wheels, 40, STRIKING PART. 197 will both turn in an hour ; and 72, in twelve hours. The arbor of this wheel has the hour-hand, and is a tube, going over the arbor of the minute-hand, so that the two hands are concentric. The barrel [a] is fitted to an arbor, com- ing through the plate of the clock, and filed square, to put on a key, to wind up the weight. The great wheel, 96, is not fixed fast to the arbor, but has a click on it, which takes the teeth of a ratchet-wheel, cut on the barrel ; so that the barrel may be turned in one direction, to wind up the weight, without the wheel ; but, by the descent of the weight, the wheels will be turned with the barrel, by the click. Striking Part. — Having now considered the going part of the clock, it remains to dfscribe the mechanism by which the hour is struck. In Fig. 2, 78, is a great wheel of seventy-eight teeth, provided with a barrel and chck, as in 96 ; it turns a pinion of eight. On the same arbor is a wheel, 64, turning a pinion of eight, on the arbor of the wheel [o] of forty-eight. This turns another pinion of eight, and w-heel [j)] of forty-eight, which turns a pin- ion of six, on the sam.e arbor, with a thin vane of metal, seen edgewise, which is called the fly, and which, by the resistance of the air to its motion, regulates the velocity of the wheels. The wheel, 64, has eight pins projecting from it, which raise the tail [n] of the hammer, as they revolve. The hammer is returned, violently, when the pins leave its tail, by a spring; [?7i,] pressing on the end of a pin, put through ts arbor, and strikes the bell. The hammer and bell are behind the plate, and, therefore, unseen. There is a short spring, [/,] which the other end of the pin through the ar- bor touches, just before the hammer strikes the bell. Its use is, to lift the hammer off the bell, the instant it has struck, that it may not stop the sound. The pins in the wheel, 64, must pass by the hammer-tail seventy-eight times, in striking the twelve hours, l-f2-t-3+4-f-5-|-6+ 7+8+9+10+11+12=78 ; and, as its pinion has eight leaves, each leaf of the pinion answers to a pin in the wheel, 64. Now, as the great wheel has seventy-eight teeth, it will turn once in twelve hours, the same as the 17* 108 ARTS OF HOROLOGY. Other great wheel, 96. In the wheel, 64, eight of its teeth correspond to one of the pins of the hammer, and, as the pinion of the wheel [oj has eight teeth, it (wheel o) will turn once, for each stroke of the hammer. By the remaining wheels, one, [o,] multiplying six times, and the other, [p, ] eight times, the fly will turn 6X8=48 times, for one turn of [o,] which answers to one stroke of the hammer. Fig. 3, is also mechanism, relating to the striking part. Behind [r,] there is a small pinion, of one tooth, called the gathering-pallet J on the arbor of the wheel, [o,] which, consequently, turns once, for each stroke of the hammer. The part, marked [Sra;,] is a portion of a large wheel, and is called the rack. The part [t] is an arm attached to the rack, whose end r«sts against a spiral plate, V, called the snail, which is fixed on the tubular arbor, be- fore described, of the hour-hand and wheel, 72, and turns round with it once in twelve hours. The snail is divided into twelve equal angles, of thirty degrees each, and, as it turns, each of these answers to an hour. The circular arcs, forming the circumference of the snail, are struck from the centre of the arbor, between each division, with a different radius,' decreasing a certain quantity, each time, in the order of the hours. The circular part of the rack, 14, is cut intx) teeth, each of which is of such a length, that every step upon the snail shall answer to one of them. At [^0,] is a spring, pressing against the tail of the rack, and acting to throw the arm of the rack against the snail. The part Ig] is a click, called the hawk's-bill, taking into the teeth of the rack, and holding it up, in opposition to the spring, [io.~\ The part [ik'] is a three-armed detent, called the warning-piece. The arm [/c] is bent at its end, and passes through a hole, in the front plate of the clock, so as to catch a pin, placed in one of the arms of the wheel, [p,] Fig. 2, and which describes the dotted circle, in Fig. 3. The other arm [i~\ stands, so as to fall in the way of a pin, in the wheel, 40. In the pre- sent position of the figure, the wheels of the striking train are in motion, and would continue turning, until the gath- ering-pallet at \r] which turns once, at each stroke of the hammer, by its tooth lifts the rack, [s,] in opposition STRIKING PART. 199 to ihe spring, [tc,] one tooth, each turn ; and the hawk's- bill [g] retains the rack, until a pin, in the end of the rack, is brought in the way of the lever of the gathering- pallet, [r,] and stops the wheels from turning any further. It is in this position, with the rack wound up, till its pin arrests the tail, [r,] that we shall begin to describe the operation of the striking of the clock. The wheel, 40, as has been said before, turns'once in an hour ; and, consequently, at the expiration of every hour, the pin in it takes the end, [i,] and moves it to- wards the spring near it. This depresses the end, [/c,] until it falls in the circle of the motion of the pin, in the wheel, [p,] Fig. 2. At the same time, the short tail de- presses one end of the hawk's-bill, and raises the other, [^,] so as to clear the teeth of the rack, [5.] Immedi- diately, the spring [10] throws the rack back, until the end of its tail [f] touches that part of the snail which is nearest it. When the rack falls back, the pin in it is mov^d clear of the gathering-pallet, [r,] and the wheels are set at hberty. The maintaining power puts them in motion ; but, in a very short time, before the hammer has struck, the pin in the wheel [p] falls against the end of [fc,] and stops the whole. This operation happens, a few minutes before the clock strikes, and this noise of the wheels turning is called the warning. When the hour is expired, the wheel, 40, has turned so far, as to allow the end of [i] to slip over its pin, as in the figure. The small spring, pressing against it, raises the end, [/c,] so as to be within the circle of the pin, in the wheel, [p,] Fig. 2. Every obstacle is now removed, and the w^heels run on the pinion ; the wheel, 64, raises the hammer, [r,] and it strikes on the bell ; the gathering-pallet [r] takes up the rack, one tooth at each turn, the hawk's-bill [g] re- taining it, until the pin [x] in the rack, comes under the gathering-pallet, [r,] and stops the motion of the whole machine, till the pin in the wheel, 40, at the next hour, takes the warning piece, [i/c,] and repeats the operation we have now described. As the gathering-pallet turns once, for each blow of the hammer, and its tooth gathers up one tooth of the rack, at each turn, it is evident, that 200 ARTS OF HOROLOGY. the number of teeth, which the rack is allowed to fall back, hmits the number ot strokes the hammer will rauke. This is done by the rack's tail, [f,] resting on the snail. Each step of the snail answers to one tooth of the rack, and one stroke of the hammer. At each hour, a fresh step of the snail is turned to the tail of the rack, and, by tliis means, the number of strokes is made to increase one, at each time, from one to twelve. Description of a Watch. — In PI. V., several views are given of the construction of a common portable watch. Fig. 1, represents the wheel-work, immediately beneath the dial-plate, and also its hands, the circles of hours and minutes being marked, though the dial, on which these are engraved, is removed. Fig. 2, is a plan of the wheel- work, all exhibited at one view, for which purpose, the upper plate of the watch is removed. Fig. 3, is a plan of the balance, and the work situated upon the upper plate. Fig. 4, shows the great wheel, and the pottance-wheel, detached. Fig. 5, the spring-barrel, chain, and fusee, detached ; and Fig. 6, is an elevation of all the move- ments together, the works being supposed to be opened out into a straight line, to exhibit them all at once. Fig. 7, is a detached view of the balance, together with the scapement, in action. The principal frame, for supporting the acting parts of the watch, consists of two circular plates, marked C and D, in the figures. Of these, the former is called the upper plate, and the latter, the pillar-plate, from the cir- cumstance that the four pillars, EE, which unite the two plates, and keep them a proper distance asunder, are fas- tened firmly into the lower plate ; while the other ends pass through holes, in the upper plate, C, and have small pins put through the ends of the pillars, to keep the whole together. By drawing out these pins, the watch may be taken to pieces. The pivots of the several wheels being received in small holes, made in these plates, they, of course, fall to pieces, as soon as the plates are separated. The maintaining power is a spiral steel spring, which is coiled up close, by a tool used for the purpose, and put into a brass box, called the barrel. It is marked A, in DESCRIPTION OF A WATCH. 201 all the figures, and is shown separate, in Fig. 5, with the spring in it. The spring has a hook, at the outer end of its spiral, which is put through a hole, [a,] Fig. 5, in the side of the barrel, and riveted fast to it. The inner end of the spiral has an oblong opening, cut through it, to receive a hook upon the barrel arbor, B, Fig. 5. The pivots of this arbor pass through the top and bottom of the barrel, and one of them is filed square, to hold a ratchet-wheel, [6,] Figs. 1 and 6, which has a click, and keeps the arbor from turning round, except in one direc- tion. The two pivots of the arbor are received in pivot- holes in the plates, CD, of the watch, and the pivot, which has the ratchet-wheel upon it, passes through the plate. The wheel marked [6,] Figs. 1 and 6, with its chck, is, therefore, on the outside of the pillar-plate, D, of the watch. The top of the barrel has a cover, or lid, fitted into it, through which the upper pivot of the arbor pro- jects ; thus, the arbor of the barrel is to be considered as a fixture, the click of the ratchet-wheel preventing it from turning round, while the interior end of the spiral spring, being hooked, assists in rendering it stationary. The barrel, thus mounted, has a small steel chain, [f/,] Figs. 2 and 6, coiled round its circumference, and attached to it by a small hook of the chain, which enters a little hole, made in the circumference of the barrel, at its upper end. The other extremity of this chain is hooked to the lower part of the fusee, marked F, Figs. 2, 5, and 6, and the chain is disposed, either upon the circumference of the barrel, or in the spiral groove, cut round the fusee for its reception, the arbor of which has pivots at the ends, which are received into pivot-holes, made in the plates of the watch. One pivot is formed square, and projects through the plate, to fit the key, by which the watch is wound up. It is evident, that, when the fusee is turned by the watch-key, it will wind the chain, off the circumference of the barrel, on itself; and, as the outer end of the spring is fastened to the barrel, and the other is hooked to the barrel-arbor, which, as before mentioned, is prevented from turning, by the click of the ratchet-wheel, [a^,] the spring will be coiled up into a smaller compass than be- 202 AKTS OF HOROLC»¥. fore. Its reaction, therefore, when the key is taken off, will turn the barrel, and, by the chain, turn the fusee, and give motion to the wheels of the watch. The fusee has a spiral groov^e cut round it, in which the chain lies ; this groove is cut by an engine, in such a form, that the chain shall pull from the smallest part, or radius, of the fusee, when the spring is quite wound up, and, therefore, acts with its greatest force on the chain. From this point, the groove gradually increases in diameter, so that, as the spring unwinds, and acts with less power, the chain oper- ates on a larger radius of the fusee ; and the effect, upon the arbor of the fusee, or the toothed wheel attached to it, will always be equal, and cause the watch to go with regularity. To prevent too much chain being wound upon the fu see, and, by that means, breaking the chain, or over- straining the spring, a contrivance, called a guard-gut^ is added. It is a small lever, [e,] Fig. 2, moving on a stud, fixed to the upper plate, C, of the watch, and press- ed downwards by a small spring, [/.] As the chain is wound up, upon the fusee, it rises in the spiral groove, and lifts up the lever, until it touches the upper plate. It is then in a position to intercept the edge, or tooth, [^,] of the spiral piece of metal, seen on the top of the fusee, and thus stops it from being wound up any further. The power of the spring is transmitted to the balance, by means of several toothed wheels, which multiply the number of revolutions, which the chain makes on the fu- see, to such a number, that, though the last, or balance- wheel, turns nine and one half times every minute, the fu- see will, at the same time, turn so slowly, that the chain will not be drawn off from it, in less than, twenty-eight or thirty hours, and it will make only one turn, in four hours This assemblage of wheels is called the train of the watch. The first toothed wheel, G, is attached to the fusee, and is called the great wheel. It is shown separa- ted from the fusee, in Fig. 4, having a hole through the centre, to receive the arbor of the fusee, and a projecting ring upon its surface. The under surface of the base of the fusee is shown in Fig. 5, at F, having a circular DESCRIPTION OF A WATCH. 203 cavjiy cut in it, to receive the corr^|ponding ring upon the great wheel, G, Fig. 4. A ratchet-wheel [i] is fixed fast upon the fusee arbor, and sunk within the cav- ity, excavated in the lower surface of the fusee. When the wheel and fusee are put together, a small chck, [/i,] Fig. 4, takes into the teeth of the ratchet, [i.] As the /iisee is turned by the watch-key, to wind up the watch, tl.s click slips over the sloping slides of the teeth, with- out turning the great wheel ; but, when the fusee is turned the other way, by drawing the chain from the spring-bar- rel, the click catches the teeth of the ratchet-wheel, and causes the toothed wheel to turn with the fusee. The great wheel ^ G, has forty-eight teeth on its cir- cumference, which take into, and turn, a pinion of twelve teeth, fixed on the same arbor with the Centre-wheel^ H, so called, from its 5atuation in the centre of the watch ; it has fifty-four teeth, to turn a pin- ion of six leaves, on the arbor of the Third wheel, I, which has forty-eight teeth. It is sunk ni a cavity, formed in the pillar-plate, and turns a pinion of six, on the arbor of the Contrate-wheel, K, which has forty-eight teeth, cut parallel with its axis, by which it turns a pinion of six leaves, fixed to The halance-wheel, L. One of the pivots of the arbor of this wheel turns in a frame, M, called the pottance, or potence, fixed to the upper plate, and shown separately, in Fig. 4. The other pivot runs in a small piece, fixed to the upper part, called the counter potlance, not shown in any of the figures ; so that, when the two plates are put together, the balance-wheel pinion may work into the teeth of the contrate- wheel, as shown in Fig. 6. The balance-wheel, L, has fifteen teeth, by which it impels the balance, [op.] The arbor of the balance, which is called the verge, has two small leaves, or pallets, projec- ting from it, nearly at right angles to each other. These are acted upon by the teeth of the balance-wheel, L, in such a manner, that, at every vibration, the balance re- ceives a slight impulse to continue its motion ; and every vibration, so made, suffers a tooth of the wheel to escape, 204 ARTS OF HOROLOGY. or pass by ; whMpjB this part is called the scapement oi the watch, and constitutes its most essential part. The wheel, L, is sometimes called the scape-wheel^ or crown- wheel. Its action is explained by Fig. 7, which shows the wheel, and balance, detached. Suppose, in this view, the pinion [h] on the arbor of the balance-wheel, or crown-wheel, [i/c,] to be actuated by the main-spring, which forms the maintaining- power, by means of the train of wheel-work, in the direction of the arrow, while the pallets, [m and n,] attached to the axis of the balance, and standing at right angles to each other, or very nearly so, are long enough to fall in the way of the ends of the sloped teeth of the wheel, when turned round, at an angle of forty-five degrees, so as to point to opposite directions, as in the figure. Then a tooth in the wheel below, for instance, meets with the pallet, [n,] supposed to be at rest, and drives it before it, a certain space, till the end of the tooth escapes. In the meantime, the balance, [ospr,'] attached to the axis of the pallets, continues to move in the direction [rosp,] and winds up the small spiral, or hair-spring, [9,] one end of which is fast to the axis, and the other to a stud, on the upper plate of the frame. In this operation, the spring opposes the mo- mentum, given to the balance, by this push of the tooth upon the pallet, and prevents the balance going quite round ; but, the instant the tooth escapes, the upper pal- let [m] meets with another tooth, at the opposite side of the wheel's diameter, moving in an opposite direction to that below. Here, this pallet receives a push, which carries the balance back again, its momentum, as yet, being small in the direction [ospr,'] and aids the spring, which now unbends itself, till it comes to its quiescent position, then swings beyond that point, partly, by the im- pulse from the maintaining powder on the pallet, [m,] and partly, by the acquired momentum of the moving balance, particularly when this pallet [m] has escaped. At length, the pallet [w] again meets with the succeeding tooth, and is carried backward by it, in the direction in which the balance is now moving, till the maintaining power and force of the unwound spring, together, overcome the mo- DESCRIPTION OF A WATCH? 205 mentum of the balance, during which time, the recoil of the balance-wheel is apparent, and, also, of the second- hand, if the watch has one, its place being on the arbor of the contrate-wheel. Then the wheel brings the pallet [n] back again, till it escapes ; and the same process takes place w^ith the pallet, [??i,] as has been described with re- spect to pallet, [n.] Thus, two contrary excursions, or oscillations, of the balance take place, before one tooth has completely escaped ; and, for this reason, there must always be an odd number of teeth in this wheel, that a space on one side of the wheel may always be opposite to a tooth on the other, in order that one pallet may be out of action, while the other is in action. The upper pivot of the verge is supported in a cover, screwed to the upper plate, as shown at N, in Fig. 6, which extends over the balance, and protects it from vio- lence. The lower pivot works in the bottom of the pot- tance, M, at [?,] Fig. 4. The socket, for the pivot of the balance-wheel, is made in a small piece of brass, [v,] which slides in a groove, made in the pottance, as shown in Fig. 4 ; so that, by drawing the slide in or out, the teeth of the balance-w^heel shall just clear one pallet, be- fore it takes the other ; and, upon the perfection of this adjustment, which is called the scaping of the watch, the performance of it very greatly depends. It now remains to show the communication of this mo- tion to the hands of the watch, which indicate the time on the dial-plate. The hands are moved by the central arbor, which comes through the pillar-plate, and projects a considerable length. It has a pinion of twelve leaves, called The common pinion, \_w,] Fig. 6, fitted upon it, the axis of which is a tube, formed square at the end, to fix on the minute-hand, W. It fits tight upon the projecting arbor of the centre-wheel ; and, therefore, turns with it, but will slip round to set the hands, wlien the watch is wrong, and requires to be rectified. The common pin- ion is situated close to the pillar-plate, and its leaves en- gage the teeth of The minute-wheel, X, Figs. 1 and 6, of forty-eight II. 18 XII. 206 ARTS OF HOROLOGY. teeth, \^hich is fitted on a pin fixed in the plate, and Its pinion, [x,] of sixteen leaves, which is fixed to it, turns The hour-icheel, Y, of forty-eight teeth. The arboi of this is a tube, which is put over the tube of the cannon- pinion^ carrying the minute-hand, and has the hour-hand, Z, fixed on it, to indicate the time upon the dial-plate. Thus, by the cannon-pinion, [lo,] which is to the minute- wheel, X, as one is to four, and the pinion [x] of this, which is to the hour-wheel, Y, as one is to three, the hour- wheel, Y, and its hand, [2:,] though concentric with the cannon-pinion and minute-hand, make but one revolution, during twelve revolutions of the other ; therefore, one turns round in an hour, and the other turns round once in twelve hours, as the figures on the dial show. It is necessary to have some regulation^ by which the rate of the watch's movement may be adjusted ; for, hith- erto, we have only spoken of making the watch keep al- ways to a uniform, or certain rate of, motion ; but it is necessary to make it keep true time. This can be done by two means ; either by increasing or diminishing the force of the main-spring, which increases or diminishes die arc which the balance describes ; or it may be done, by strengthening or weakening the hair-spring, which will cause the balance to move quicker or slower. The hair-spring, otherwise called the pendulum- springs [ In order to penetrate into the interior of the earth, and to extract from it the objects of his toils, the miner has at his disposal several means, which may be divided into three classes ; 1. manual tools, 2. gunpowder , and 3. fire. The tools used by the miners of Cornwall and Devonshire are the following : The pick. It is a light tool, and somewhat varied in shape, according to circumstances One side, used as a hammer, is called the poll, and is employed to drive in the gads, or to loosen and detach prominences. The point is of steel, carefully tempered, and drawn under the ham- mer to the proper form. The French call it pointerolle. The gad. It is a wedge of steel, driven into crev- ices of rocks, or into small openings made with the point of the pick. The minerh shovel. It has a pointed form, to ena- ble it to penetrate among the coarse and hard fragments of the mine rubbish. Its handle being somewhat bent, a man's power may be conveniently applied, without bend- ing his body. The blasting, or shooting, tools are, a sledge or mallet, borer, claying-bar, needle or nail, scra- per, tamping-bar. Besides these tools, the miner requires a powder-horn, rushes to be filled with gunpowder, tin car- tridges, for occasional use in wet ground, and paper rubbed over with gunpowder, or grease, for the smifts, or fuses. The borer is an iron bar, tipped with steel, formed like a thick chisel, and is used by one man holding it straight in the hole, with constant rotation on its axis, while another strikes the head of it, with the iron sledge, or mallet. The hole is cleared out, from time to time, by the scraper, which is a flat iron rod, turned up at one end. If the ground be very wet, and the hole gets full of mud, it is cleaned out by a stick, bent at the end into a fibrous brush, called a swab-stick. The hole must be rendered as dry as possible, which is effected very simply, by filling it partly with tenacious flay, and then driving into it a tapering iron rod, which MINES. 291 nearly fills its calibre, called the claying-har. This be- ing forced in with great violence condenses the clay into all the crevices of the rock, and secures the dryness of the hole. Should this plan fail, recourse is had to tin cartridges, furnished with a stem, or tube, through which the powder may be inflamed. When the holt is dry, and the charge of powder introduced, the nail^ a small taper rod of copper, is inserted, so as to reach the bottom of the hole, which is now ready for tamping. By this difficult and dangerous process, the gunpowder is confined, and the disruptive effect produced. Different substances are employed for tamping ^ or cramming the hole, the most usual one being any soft species of rock, free from sili- cious, or flinty, particles. Small quantities of it only are introduced at a time, and rammed very hard, by the tamp- ing-bar^ which is held steadily by one man, and struck with a sledge by another. The hole being thus filled, the nail is withdrawn, by putting a bar through its eye, and striking it upwards. Thus, a small perforation, or vent, is left for the rush which communicates the fire. Besides the improved tamping-bar, faced with hard cop- per, other contrivances have been resorted to, for dimin- ishing the risk of those dreadful accidents that frequently occur in this operation. Dry sand is sometimes used as a tamping material ; but there are many rocks, for the blasting of which it is ineffective. Tough clay will answer better, in several situations. For conveying the fire, the large and long green rushes, which grow in marshy ground, are selected. A slit is made in one side of the rush, along which the sharp end of a bit of stick is drawn, so as to extract the pith, when the skin of the rush closes again, by its own elasticity. This tube is filled up with gunpow- der, dropped into the vent-hole, and made steady with a bit of clay. A paper smift., adjusted to burn a proper time, is then fixed to the top of the rush tube, and kindled, when the men of the mine retire to a safe distance. Gunpowder is the most valuable agent of excavation , possessing a power which has no limit, and which can act every where, even under water. Its introduction, in 1615, caused a great revolution in the mining art. 292 APPENDIX. It is employed in mines, in different manners, and in different quantities, according to circumstances. In all cases, however, the process resolves itself into boring a hole, and enclosing a cartridge in it, which is afterwards made to explode. The hole is always cylindrical, and is usually madf by means of the borer, a stem of iron ter- minated by a blunt-edged chisel. It sometimes ends in a cross, formed by two chisels set transversely. The work- man holds the stem in his left hand, and strikes it w^ith an iron mallet, held in his right. He is careful to turn the punch a very little round, at every stroke. Several punches are employed, in succession, to bore one hole ; the first shorter, the latter ones longer, and somewhat thinner. The rubbish is whhdrawn, as it accumulates at the bottom of the hole, by means of a picker, which is a small spoon, or disc of iron, fixed at the end of a slender iron rod. When holes of a large size are to be made, several men must be employed ; one, to hold the punch, and one or more, to wield the iron mallet. The perforations are sel- dom less than an inch in diameter, and eighteen inches deep ; but they are sometimes tw^o inches wide, with a depth of fifty inches. The gunpowder, when used, is most commonly put up in paper cartridges. Into the side of the cartridge, a small cylindrical spindle, or piercer^ is pushed. In this state, the cartridge is forced down to the bottom of the hole, which is then stuffed, by- means of the tamping-bar, with bits of dry clay, or friable stones coarsely pounded. The peircer is now withdrawn, which leaves in its place a channel, through which fire may be conveyed to the charge. This is executed, either by pouring gunpowder into that passage, or by inserting into it, reeds, straw-stems, quills, or tubes of paper, filled with gunpowder. This is explod- ed by a long match, which the workmen kindle, and then retire to a place of safety. As the piercer must not only be slender, but stiff, so as to be easily withdrawn when the hole is tamped, iron spindles are usually employed, though they occasionally give rise to sparks, and, consequently, to dangerous acci- dents, by their friction against the sides of the hole. Brass MINES 5?^3 piercers have been sometimes tried, but they twist and break too readily Each hole bored in a mine should be so placed, in ref- erence to the schistose-structure of the rock, and to its natural fissures, as to attack and blowup the least resisting masses. Sometimes, the rock is prepared, beforehand, for splitting in a certain direction, by means of a narrow chan nel, excavated wath the small hammer. The quantity of gunpowder should be proportional to the depth of the hole, and the resistance of the rock ; and merely sufficient to spht it. Any thing additional w^ould serve no other purpose than to throw the fragments about the mine, without increasing the useful effect. Into the holes of about an inch and a quarter diameter, and eigh- teen inches deep, only two ounces of gunpowder are put. It appears, that the effect of the gunpowder may be augmented, by leaving an empty space above, in the mid- dle of, or beneath, the cartridge. In the mines of Sile- sia, the consumption of gunpowder has been eventually reduced, without diminishing the product of the blasts, by mixing saw^dust with it, in certain proportions. The hole has also been filled up with sand, in some cases, ac- cording to Mr. Jessop's plan, instead of being packed with stones, which has removed the danger of the tamp- ing operation. The experiments, made in this way, have given results very advantageous, in quarry blasts, with great charges of gunpowder ; but less favorable, in the small charges employed in mines. Water does not oppose an insurmountable obstacle to the employment of gunpowder ; but when the hole cannot be made dry, a cartridge bag, impermeable to water, must be used, provided with a tube, also impermeable, in which :he piercer is placed. After the explosion of each mining charge, wedges and levers are employed, to drag away, and break down, what has been shattered. Wherever the rock is tolerably hard, the use of gun powder is more economical, and more rapid, than any tool' work, and is, therefore, always preferred. A gallery, for example, a yard and a half high, and a yard wide, the 25* 294 APPENDIX. piercing of which, by the hammer, formerly cost from five to ten pounds sterling the running yard, in Germany, is executed, at the present day, by gunpowder, at from two to three pounds. When, however, a precious mass of ore is to be detached ; when the rock is cavernous, which nearly nullifies the action of gunpowder ; or when there is reason to apprehend that the shock, caused by the explo- sion, may produce an injurious fall of rubbish, hand-tools alone must be employed. In certain rocks and ores, of extreme hardness, the use, both of tools and gunpowder, becomes very tedious and costly. Examples to this effect are seen in the mass of quartz, mingled with copper pyrites, worked at Rammels- burg, in the Hartz ; in the masses of stanniferous granite of Geyer and Altenberg, in the Erzgebirge of Saxony, &c. In these circumstances, fortunately very rare, the action of fire is used with advantage, to diminish the cohesion of the rocks and the ores. The employment of this agent is not necessarily restricted to these difficult cases. It was formerly applied, very often, to the working of hard substances ; but the introduction of gunpowder into the mining art, and the increase in the price of wood, occa- sion fire to be little used as an ordinary means of excava- tion, except in places, where the scantiness of the popula- tion has left a great extent of forest-timber, as happens at Kongsberg in Norway, at Dannemora in Sweden, at Fel- sobanya in Transylvania, &c. The action of fire may be applied to the piercing of a gallery, or to the advancement of a horizontal cut, or to the crumbling down of a mass of ore, by the successive upraising of the roof of a gallery already pierced. In any of these cases, the process consists in forming bonfires, the flame of which is made to play upon the parts to be attacked. All the workmen must be removed from the mine, during, and even for some time after, the combus- tion. When the excavations have become sufficiently cool to allow them to enter, they break down with levers and wedges, or even by means of gunpowder, the masses which have been rent and altered by the fire. To complete our account of the manner in which man MINES. 295 may penetrate into the interior of the earth, we must point out the form of the excavations that he should make in it. In mines, three principal species of excavations may be distinguished, viz.; shafts, galleries ^ and the cavities of greater or less magnitude, which remain in the room of the old workings. A shaft, or pit, is a prismatic, or cylindrical, hollow space, the axis of which is either vertical, or much inclin- ed to the horizon. The dimension of the pit, which is never less than thirty-two inches in its narrowest diameter, amounts, sometimes, to several yards. Its depth may ex- tei]yd to one thousand feet, and more. Whenever a shaft is opened, means must be provided to extract the rubbish, which continually tends to accumulate at its bottom, as well as the waters, which may percolate down into it ; as also to facilitate the descent and ascent of the workmen For some time a wheel and axle, erected over the mouth of the opening, which serve to elevate one or two buckets, of proper dimensions, may be sufficient for most of these purposes. But such a machine becomes, ere long, inad- equate. Horse-whims, or powerful steam-engines, must then be had recourse to ; and effectual methods of support must be employed, to prevent the sides of the shaft from crumbling, and falling down. A gallery is a prismatic space, the straight or winding axis of which does not usually deviate much from the hor- izontal line. Two principal species are distinguished ; the galleries of elongation, which follow the direction of a bed, or a vein ; and the transverse galleries, which in- tersect this direction under an angle, not much different from ninety degrees. The most ordinary dimensions of galleries are a yard wide, and two yards high ; but many, still larger, may be seen, transversing thick deposites of ore. There are few, whose width is less than twenty-four inches, and height less than forty; such small drifts serve merely as temporary expedients in workings. Some gal- leries are several leagues in length. We shall cescribe, in the sequel, the means which are, for the most part, necessary to support the roof and the walls. The rubbish is removed by wagons, or wheel-barrows, of various kinds; 296 APPENDIX. It is impossible to advance the boring of a shaft, or gal lery, beyond a certain rate ; because only a limited set of workmen can be made to bear upon it. There are some galleries which have taken more than thirty years to perforate. The only expedient for accel- erating the advance of a gallery, is, to commence, at sev- eral points of the line to be pursued, portions of galleries, which may be joined together on their completion. Whether tools, or gunpowder, be used, in making the excavations, they should be so applied, as to render the labor as easy and quick as possible, by disengaging the mass out of the rock, at two or three of its faces. The effect of gunpowder, wedges, or picks, is then much more powerful. The greater the excavation, the more impor- tant is it to observe this rule. With this intent, the work- ing is disposed in the form of steps, (gradins,) placed like those of a stair ; each step being removed, in succes- sive portions, the whole of which, except the last, are disengaged on three sides, at the instant of their being at- tacked. The substances to be mined occur in the bosom of the earth, under the form of alluvial deposits, beds, pipe- veins or masses, threads or small veins, and rake-veins. When the existence of a deposit of ore is merely sus- pected, without positive proofs, recourse must be had to labors of research, in order to ascertain the richness, na- ture, and disposition, of a supposed mine. These are divided into three kinds ; open workings, subterranean workings, and boring operations. 1 . The working by an open trench has for its object to discover the outcropping, or basset edges of strata, or veins. It consists in opening a fosse of greater or less width, which, after removing the vegetable mould, the alluvial deposits, and the matters disintegrated by the at mosphere, discloses the native rocks, and enables us to distinguish the beds, which are interposed, as well as the veins which traverse them ; the trench ought always to be opened in a direction perpendicular to the line of the sup posed deposit. This mode of investigation costs little DEPTH OP MINES. 297 Dut it seldom gives much insight. It is chiefly employed for verifying the existence of a supposed bed, or vein. The subterranean workings afibrd much more satisfac- tory knowledge. They are executed by different kinds of perforations ; viz. by longitudinal galleries^ hollowed out of the mass of the beds or veins themselves, in fol- lowing their course ; by transverse galleries, pushed at right angles to the direction of the veins ; by inclined shafts, which pursue the slope of the deposits, and are excavated in their mass ; or, lastly, hy perpendicular pits. If a vein or bed unveils itself on .the flank of a moun- tain, it may be explored, according to the greater or less slope of its inclination, either by a longitudinal gallery, opened in its mass from the outcropping surface, or by a transverse gallery, falling upon it in a certain point, from which either an oblong gallery, or a sloping shaft, may be opened. If our object be to reconnoitre a highly inclined stra- tum, or a vein in a level country, we shall obtain it, with sufficient precision, by means of shafts, eight or ten yards deep, dug at thirty yards distance from one another, ex- cavated in the mass of ore, in the direction of its depo- sit. If the bed is not very much inclined, only forty-five degrees, for example, vertical shafts must be opened in the direction of its roof, or of tffe superjacent rocky stra tum, and galleries must be driven from the points in which they meet the ore, in the line of its direction. When the rocks, w^hich cover valuable minerals, are not of very great hardness, as happens generally with the coal formation, with pyritous and aluminous slates, sal gem, and some other minerals of the secondary strata, the bor- er is employed with advantage, to ascertain their nature. This mode of investigation is economical, and gives, in such cases, a tolerably exact insight into the riches of the interior. The method of using the borer has been de- scribed under Artesian Wells. — Ure''s ' Diet. ofJlrts,'^ Sf^c. III. — Depth of Mines. At the third meeting of the British Association, Mr. Taylor exhibited a section, showing the depths of shafts 298 APPENDIX. of the deepest mines in the world, and their position in relation to the level of the sea. The absolute depths of the principal ones were : Feet. 1. The shaft, called Roehrobichel, at the Kitspiihl mine, in the Tyrol, 2764 2. At the Sampson mine, at Andreasberg, in the Hartz, .... 2230 3. At the Valenciana mine, at Guanaxuato, Mexico, 1770 4. Pearce's shaft, at the Consolidated mines, Cornwall, .... 1464 5. At Wheal Abraham mine, Cornwall, 1452 6. At Dolcoath mine, Cornwall, 1410 7. At Ecton mine, Staffordshire, 1380 8. Woolf's shaft, at the Consolidated mines, 1350 These mines are, however, very differently situated, with regard to their distance from the centre of the earth ; as the last on the list, Woolf's shaft, at the Consolidated mines, has twelve hundred and thirty feet of its depth be- low the surface of the sea ; while the bottom of the shaft of Valenciana, in Mexico, is near six thousand feet in absolute height above the tops of the shafts in Cornwall. The bottom of the shaft, at the Sampson mine, in the Hartz, is but a few fathoms under the level of the ocean ; and this, and the deep mine of Kitspiihl, form, therefore, intermediate links between those of jSlexico and Cornwall. Mr. Taylor stated, that, taking the diameter of the earth at eight thousand miles, and the greatest depth un- der the surface of the se^ being twelve hundred and thir- ty feet, or about one fourth of a mile, it follows, that we have only penetrated to the extent of ^^^-^tj P^^^t of the earth's diameter. IV. — Canals in the United States. The Americans have not rested satisfied with the nat- ural inland navigation afforded by their rivers and lakes, nor made the bounty of Nature a plea for idleness, or want of energy ; but, on the contrary, they have been zealously engaged in the work of internal improvement ; and their country now numbers, among its many wonderful artifi- cial lines of communication, a mountain rail-way, which, in boldness of design, and difficulty of execution, I can compare to no modern works I have ever seen, except- ng, perhaps, the passes of the Simplon, and MontCenis, CANALS IN THE UNITED STATES. 299 in Sardinia ; but even these remarkable passes, viewed as engineering works, did not strike me as being more wonderful than the Alleghany rail-way, in the United States. The objects, to which that enterprising people have chiefly directed their exertions for the advancement of their country in the scale of civilization, are, the removal of ob- s-rructions in navigable rivers ; the junction of different tracts of natural navigation ; the connection of large towns ; and the formation of lines of communication from the At- lantic ocean to the great lakes, and the valleys of the Mississippi, Missouri, and Ohio. The number and ex- tent of canals and rail-ways which they have executedj in effecting these important objects, sufficiently prove, that their exertions, during the short time they have been so engaged, have been neither small nor ill-directed. The aggregate length of the canals, at present in operation in the United States alone, amounts to upwards of two thou- sand seven hundred miles, and that of the rail-ways, already completed, to sixteen hundred miles. Nor are the labors of the people at an end ; for, even now, there are no few- er than thirty-three rail-ways in an unfinished state, whose aggregate length, when completed, will amount to upwards of two thousand five hundred miles. The zeal with which the Americans undertake, and the rapidity with which they carry on, every enterprise, which has the enlargement of their trade for its object, cannot fail to strike all, w^ho visit the United States, as a charac- teristic of the nation. Forty years ago, that country was almost without a lighthouse, and now, no fewer than two hundred are nighdy exhibited on its coast ; thirty years ago, it had but one steamboat, and one short canal, and now, its rivers and lakes are navigated by between five and six hundred steamboats, and its canals are upwards of two thousand seven hundred miles in length ; ten years ago, there were but three miles of rail-way in the country, and now, there are no less than sixteen hundred miles in oper- ation." These facts appear much more wonderful, when it is considered, that many of these great lines of commu- nication are carried for miles in a trough, as it were, cut 300 APPENDIX. through thick and almost impenetrable forests, where it is no uncommon occurrence to travel for a whole clay, with- out encountering a village, or even a house, excepting, perhaps, a few log-huts, inhabited by persons connected with the works. The routes of the principal canals and rail-roads in North America are not wholly confined to the seaward and more thickly-peopled States, but extend far into the in- terior. The stupendous canals, which have already been executed, enable vessels, suited to the inland navigation of the country, to pass from the Gulf of St. Lawrence to the Gulf of Mexico, and also from the city of j\ew York to Quebec, on the St. Lawrence, or to New Orleans, on the Mississippi, without encountering the dangers of the Atlantic ocean. But, that the reader may be able fully to understand the nature of lines of inland navigation, so enormous, I shall give, in detail, the route from New York to New Orleans, which is constantly made by per sons travelling between those places. Miles. From New York to Albany, by the River Hudson, the dis- tance is, ....... . 150 ♦' Albany to Buffalo, by the Erie Canal, . . . .363 ♦' Buffalo to Cleveland, by Lake Erie, . ... 210 " Cleveland to Portsmouth, by the Ohie Canal, . . 309 ■ ' Portsmouth to New Orl^ns, by the Ohio and Mississippi Rivers, . 1670 Total distance, . . 2702 This extraordinary inland journey, of no less than two thousand seven hundred and two miles, is performed en- tirely by means of water-communication ; six hundred and seventy-two miles of the journey are performed on canals, and the remaining two thousand and thirty miles of the route is river and lake navigation. The internal improvements of the United States are placed under the management either of the Legislatures of the States, in which the works are situate, or of joint- stock companies. The works constructed by the Legis- latures of the States, are called State Works, and are conducted by commissioners, chosen from the different CANALS IN THE UNITED STATES. 301 Legislatures, who publish annual reports on the works committed to their charge. The joint-stock companies, on the other hand, are composed of private individuals, who receive a charter from the Government, investing them with powe'r to execute the work, and afterwards to conduct the affairs and transact the business of the com- pany. The public works in the British dominions in North America have been executed, partly, at the ex- pense, and under the direction, of the British Govern- ment, and partly, by companies of private individuals. It is believed that canals, which were, until very lately, the only mode of conveyance employed in North Ameri- ca, were in use in Egypt, China, Ceylon, Italy, and Hol- land, before the Christian era ; but the period, at which the first artificial water-communication w^as formed, and the country, in which the construction of a canal was first attempted, are equally unknown. The earliest canal con- structed in France was the Languedoc, connecting the Bay of Biscay with the Mediterranean Sea, w^hich was completed in the year 1681 ; and the first formed in Great Britain was that of Sankey Brook, in Lancashire, completed in 1760. Several short canals were made, for improving the river navigation, in the United States, about the end of the last century ; but the first work of any importance, in that countr^jr, was the Santee canal, in the State of South Carolina, which was opened in the year 1802 ; and the first, in the British dominions in Amer- ica, was the Lachine canal, in Lower Canada, opened in the year 1821. At the end of this chapter is a table of the principal canals in the United States. The table, which is compiled from the American a/manacs, and the annual reports of the canal commissioners, contains the names of all the canals of any importance, now in opera- tion in the country ; together with such information, regard- ing their size and expense, as these documents contain. The great length of many of the A-merican canals is one remarkable feature in these astonishing works. In this respect, they far surpass any thing of the kind hith- erto constructed in Europe. The longest canal in Eu- rope is the Languedoc, which has a course of one hun- II. 26 XII. 302 APPENDIX. dred and forty-eight miles ; and the most extensive in the United States is the Erie canal, which is no less than three hundred and sixty-three miles in length. But the cross-sectional area of the American canals is by no means so great as that of many in Europe. The North Holland Ship canal, for example, between the Zuyder Zee, at Amsterdam, and the Holder, which I lately visited, has a larger cross-sectional area, than any other European work of the same description. It measures one hundred and twenty-four feet six inches, at the water-line, and affords sufficient breadth to allow large vessels to pass each other with perfect ease. It is fifty-six feet in breadth, at the bottom, and has a depth of water of no less than twenty- one feet. This remarkable canal, which is nearly fifty miles in length, undoubtedly ranks as one of the greatest works of the kind that has ever been executed. It was constructed for the purpose of facihtating the passage of vessels to and from the port of Amsterdam ; and, by means of the sheltered inland passage which it affords, the intri- cate and dangerous navigation of the Zuyder Zee is avoid- ed. At the time when canals were introduced into Amer- ica, however, the trade of the country was small, and did not warrant the expenditure of large sums of money in their construction, the chief object being to form a com- munication, with as little loss of time, or outlay of capital, as might be consistent with a due regard for the safety and stability of the work. It is not to be expected, therefore, that the American works, although on an extensive scale, should be constructed in the same spacious style as those of older and more opulent countries. The dimensions of many of the canals in the United States are no-w found to be inconveniently small, for the increased traffic which they have to support ; and the great Erie canal, as well as some others, is at present undergoing extensive altera- tions, by which its breadth will be increased from forty to sixty feet, and its depth from four to seven feet. It is doubtful whether the increased depth will, on the whole, j)rove advantageous, especially for quick transport. Ac- cording to Mr. Russell, the velocity of the wave due to a depth of four feet, making allowance for the sloping sides CANALS IN THE UNITED STATES. 303 of the canal, is about seven miles an hour ; and if the boat is dragged in the top of the wave, the horses must travel at somewhat more than this rate, in order to keep before Jt. If, on the other hand, the depth of the canal be seven feet, the velocity of the wave will be about nine miles an hour ; a speed which it would be difficult for horses regular- ly to keep up. The boat would, consequently, travel at a less speed than the wave, which is shown by Mr. Rus- sell, in his ' Researches in Hydrodynamics,' to be very disadvantageous. English and American engineers are guided by the same principles in designing their works ; but the differ- ent nature of the materials employed in their construc- tion, and the climates and circumstances of the two coun- tries, naturally produce a considerable dissimilarity in the practice of civil-engineers in England and America. At the first view, one is struck with the temporary and ap- parently unfinished state of many of the American w^orks, and is very apt, before inquiring into the subject, to im- pute to want of ability what turns out, on investigation, to be a judicious and ingenious arrangement to suit the circumstances of a new country, of which the climate is severe, — a country, where stone is scarce, and wood is plentiful, and where manual labor is very expensive. It is vain to look to the American works for the finish, that characterizes those of France, or the stability, for which those of Britain are famed. Undressed slopes of cut- tings and embankments, roughly-built rubble-arches, stone parapet-walls coped with timber, and canal-locks whol- ly constructed of that material, every where offend the eye accustomed to view European workmanship. But it must not be supposed that this arises from want of knowl- edge of the principles of engineering, or of skill to do them justice in the execution. The use of wood, for example, which may be considered, by many, as wholly inapplicable to the construction of canal-locks, where it must not only encounter the tear and wear occasioned by the lockage of vessels, but must be subject to the destruc tive consequences of alternate immersion in water and exposure to the atmosphere, is yet the result of delioer- 304 APPENDIX. ate judgement. The Americans have, in many cases, been induced to use the material of the country, ill adapt- ed though it be, in some respects, to the purposes to which it is applied, in order to meet the wants of a ris- ing community, by speedily, and perhaps superficially, completing a work of importance, which would otherwise be delayed, from a want of the means to execute it in a more substantial manner ; and, although the works are wanting in finish, and even in sohdity, they do not fail for many years to serve the purposes for which they were constructed, as efficiently as works of a more lasting de- scription. When the wooden locks on any of the canals begin to show symptoms of decay, stone structures are generally substituted ; and materials, suitable for their erection, are with ease and expedition conveyed from the part of the country where they are most abundant, by means of the canal itself to which they are to be applied ; and thus the less substantial work ultimately becomes the means of facilitating its own improvement, by affording a more easy, cheap, and speedy transport of those durable and expensive materials, without the use of which, perfectioi is unattainable. One of the most important advantages of constructing the locks of canals, in new countries, such as America, of wood, unquestionably is, that, in proportion as improve ment advances, and greater dimensions, or other changes, are required, they can be introduced at little cost, and without the mortification of destroying expensive and substantial works of masonry. Some of the locks on the great Erie canal are formed of stone ; but, had they all been made of wood, it would, in all probability, have been converted into a ship-canal, long ago. But the locks are not the only parts of the American canals in which wood is used. Aqueducts, over ravines or rivers, are generally formed of large wooden troughs, resting on stone pillars ; and even more temporary expe- dients have been chosen, the ingenuity of which can hard- ly fail to please those who view them as the means of carrying on improvements, which, but for such contriv- CANALS IN THE UNITED STATES. 305 ances, might be stopped by the want of funds necessary to complete them. Mr. M'Taggart, the resident engineer for the Rideau canal in Canada, gave a good example of the extraordi- nary expedients often resorted to, by suggesting a very novel scheme for carrying that work across a thickly wooded ravine, situate in a part of the country where materials for forming an embankment, or stone for build- ing the piers of an aqueduct, could not be obtained but at a great expense. The plan consisted of cutting across the large trees in the line of the works, at the level of the bottom of the canal, so as to render them fit for sup- porting a platform on their trunks, and on this platform the trough containing the water of the canal was intended to rest. I am not aware whether this plan was carried into effect ; but it is not more extraordinary than many of the schemes to which the Americans have resorted, in con- structing their pubhc works ; and the great traffic sus- tained by many of them, notwithstanding the temporary and hurried manner in which they are finished, is truly wonderful. The number of boats navigating the Erie canal, in 1836, was no less than three thousand one hun- dred and sixty-seven, and the average number of lockages, one hundred and eighteen per day ; facts which clearly prove the efficiency, as well as the utihty, of the work. With the exception of some few works, in the most southern States of the Union, the artificial navigation of North America, as well as that of the northern rivers and lakes, is completely suspended during a period of from three to five months, every year. During that time, the water is always withdrawn from the canals and feed- ers. This precaution is absolutely necessary, as the in- tense frost, with which the country is then visited, very soon proves destructive to the locks and aqueducts, by the expansion of the water, which, if permitted to re- main in them, is speedily converted into a mass of ice. The rate of travelling, which has been adopted on the American canals, the charges for the conveyance of passengers and goods, and the general laws for regulating canal transport, are fixed by the commissioners who have 26* 306 APPENDIX. charge of the different works, and are not exactly the same in every State. The following observations, how- ever, regarding the mode of travelling on the Pensylva- nia State canals, are generally applicable to all others in the country. The tolls paid to the State, by the persons who have boats on the§e canals, are three halfpence per mile for each boat, and three farthings per mile for each passenger conveyed in them. The passenger-boats vary from twelve to fifteen feet in breadth, and are eighty feet in length ; the large-sized boats weigh about twenty tons, and cost £250 each, and, when loaded with a full complement of passengers, draw twelve inches of w^ater. They are dragged by three horses at once, which run ten-mile sta- ges. The length of the tow-hne, generally used, is about one hundred and fifty feet, and the rate of travelling is from four to four and a half miles per hour. The works, which have been employed in forming the inland lines of water-communication in America, are of two kinds, called slackwater-navigation, and canals. The slackw^ater-navigation is the more simple of these operations, and can generally be executed at less expense. It consists in improving the navigation of a river by the erection of dams, or mounds, built in the stream, which have the effect of damming up the water, and increasing its depth. If there be not a great fall in the bed of the river, a single dam often produces a stagnation in the run of the water, extending for many miles up the river, and forming a spacious navigable canal. The tow-path is formed along the margin of the river, and is elevated above the reach of flood- water. The dams are passed by means of locks, such as are used in canals. This method of forming water-communication, has been extensively and successfully introduced in America, where limited means, and abundance of rivers, rendered it peculiarly applicable. One of the most extensive works, on this principle, in the country, was constructed by the Schuylkill Navigation Company, in the State of Pennsylvania, and consisted in damming up the water of the river Schuylkill. It ex- tends from Philadelphia to Readii^, and is situate in the CANALS IN THE UNITED STATES. 307 lieart of a country abounding in coal, from the transport of which, the Company derives its chief revenue. It is one hundred and eight miles in length, and its construc- tion cost about .£500,000. This line of navigation is formed by numerous dams thrown across the stream, with twenty-nine locks, which overcome a fall of six hundred and ten feet. It is navigated by boats of from fifty to sixty tons burden. These dams are constructed some- what on the same principle as that erected on the Schuyl- kill, at Fairmount Water-works, near Philadelphia. One great objection, to this mode of forming inland navigation, is the necessity of constructing works of great strength, sufficient to enable them to withstand the floods and ice, to which they are exposed, and by which they are very apt to be damaged, or even carried away. Acci- dents of this kind, however, may be in a great measure guarded against, by making a judicious selection of situa- tions for the dams and locks, and placing them in such a manner in the bed of the river, that the current may act on them in the direction least detrimental to their sta- bility, as has been done in the dam at Fairmount Water- works, just alluded to. The number of boats, which passed through the locks of the Schuylkill navigation, in 1836, was twenty-four thousand four hundred and seventy, the tolls on which amounted to £14,043. The various articles taken up the river, during that year, weighed sixty-one thousand and seventy-nine tons, and those brought towards the sea, five hundred and seventy thousand and ninety-four tons, of which four hundred and thirty-two thousand and forty-five tons were anthracite coal, from the State of Pennsylvania. Slackwater-navigation also occurs at intervals on many of the great lines of canal. About seventy-eight miles of ihe Rideau canal, in Canada, are formed in this way ; and in the United States, it is met with on the Erie, Oswego, Pennsylvania, Frankston, Lycoming, and Lehigh canals. The works which have been executed, in forming most of the water-communications, in America, however, are not generally of the slackwater kind, but resemble the canals in use in Europe, being, in fact, artificial trenches 308 APPENDIX. or troughs, with locks to enable vessels to pass from one evel to another. The locks are furnished with boom-- gates, which are opened and shut by a long lever fixed to the tops of the quoin and mitre posts. The sluices, by which the water is admitted into the locks, are placed in the lower part of the gates. They are, in general, com- mon hinge-sluices, opened by means of a rod extending to the top of the gates, and worked by a crank handle. The canals of this construction, in the United States, are so very numerous, and resemble each other so much, that I do not consider it necessary to give a detailed de- scription of the various works which have been executed on all of them, but shall content myself with giving a briel sketch of the Erie canal, which was the first in America, on which the conveyance of passengers was attempted, and is the longest canal in the world, regarding wdiich we possess accurate information. The Erie canal was commenced in 1817, and com- pleted in 1825. The main line, leading from Albany, on the Hudson, to Buffalo, on Lake Erie, measures 363 miles in length, and cost about ^1,400,000 sterling. The Champlain, Oswego, Chemung, Cayuga, and Crook- ed Lake, canals, and some others, join the main line, and, including these branch canals, it measures five hun- dred and forty-three miles in length, and cost upwards of £2,300,000. This canal is forty feet in breadth, at the water line, twenty-eight feet, at the bottom, and four fpet in depth. Its dimensions have proved too small for the extensive trade which it has to support, and workmen are now employed in raising its banks, so as to increase the depth of water to seven feet, and the extreme breadth of the canal to sixty feet. The country through which it passes, is admirably suited for canal-navigation, and there are only eighty-four locks on the main line. These locks are each ninety feet in length, and fifteen in breadth, and have an average lift of eight feet two inches. The total rise and fall is six hundred and ninety-two feet. The tow-path is elevated four feet above the level of the water, and is ten feet in breadth. The Erie canal begins at Buffalo, on Lake Erie, and extends for a distance of CANALS IN THE UNITED STATES. 309 about ten miles along the banks of Lake Erie and the river Niagara, as far as Tonawanda creek. By means of the slackwater-navigation, formerly described, the channel of the Tonawanda is rendered navigable for the distance of twelve miles, and the canal is then carried through a deep cutting, extending seven and a half miles, to Lockport. Here it descends sixty feet, by means of five locks excavated in solid rock, and afterwards pro- ceeds, on a uniform level, for a distance of sixty-three miles, to Genesee river, over which it is carried on an aqueduct having nine arches, of fifty feet span, each. Eight and a half miles from this point, it passes over the Cayuga marsh, on an embankment two miles in length, and, in some places, seventy feet in height. It then passes through Lakeport and Syracuse, and, at this place, the " long level" commences, which extends for a distance of no less than sixty-nine and a half miles, to Frankfort, without an intervening lock. After leaving Frankfort, the canal crosses the river Mohawk, first by an aqueduct, of seven hundred and forty-eight feet in length, supported on sixteen piers, elevated twenty-five feet above the sur- face of the river, and afterwards, by another aqueduct, one thousand one hundred and eighty-eight feet in length, and at last reaches the city of Albany. Albany is the capital of the State of New York, and con- tains a population of about thirty thousand. It is situate on the west, or right, bank of the Hudson, at the head of the natural navigation of the river ; but some improve- ments have been made, which enable vessels of smaP burden to ascend as far as Waterford, thirteen miles above Albany. One of these improvements has been efi^ected by the erection of a dam across the Hudson, eleven hundred feet in length, and nine feet in height, at a cost of up- wards of ^£18,000. The lock, connected with this dam, measures one hundred and fourteen feet in length, and thirty feet in breadth. Albany, however, may be said to monopolize the trade of the river, and, in addition to the interest it possesses as a place of great commerce, it is important from its position at the outlet of the Erie canal, and as the seat of a large basin, or depot, for the 310 APPENDIX. accommodation of the boats navigating it. This basin, which has an area of thirty-two acres, is formed by an enormous mound, placed lengthwise with the stream of the river Hudson, and enclosing a part of its surface. The mound is composed, chiefly, of earth, and is four thousand three hundred feet in length, and eighty feet m breadth, and, being completely covered with large warp- houses, it now forms a part of the city of Albany, w^itn which it is connected by means of numerous drawbridges The place has, in consequence, very much the same ap- pearance as many of the Dutch towns. The lower ex- tremity of the mound is unconnected with the shore, ? large passage being left for the ingress and egress of ves- sels ; but its upper end is separated from the bank oi the river, by a smaller opening, which is closed, when necessary, to prevent ice from injuring the craft lying in the basin. A stream of water is generally allowed to enter at the upper end, which, flowing through the basin, acts as a scour, and prevents it from silting up. The mound is surrounded by a wooden wharf, like those of New York and Boston, at which vessels discharge and load their cargoes. This admirable basin forms a part of the Erie canal works, and cost about £26,000. According to the Report of the Canal Commissioners, dated March, 1837, the number of boats, registered in the Comptroller's office, as navigating the Erie canal and its branches, was. In 1834, . 2,585 " 1835, . 2,914 Increase, 329 " 1836, . 3,167 " 253 The total number of clearances, or trips made during the same years, was, In 1834, . 64,794 *' 1835, . 69,767 " 1836, . 67,270 The average number of lockages, per day, at each lock was. In 1834, . 95i " 1835, . 112 " 1836. . lis CANALS IN THE UNITED STATES. 311 The whole tonnage, transported on the canal, during the year 1836, was 1,310,807 tons, the value of which amounted to §67,643,343, or £13,526,868. The pro- portion between the weight of freight, conveyed from the Hudson to the interior of the country, and that con- veyed from the interior of the country to the Hudson, was in the ratio of one to five. The tolls, collected in 1836, for the conveyance of goods and passengers, amounted to £322,867. The rates of charge, accord- ing to which the tolls are collected, are annually changed, to suit the circumstances of the trade, and are not the same throughout the whole line of the canal, which ren- ders it difficult to give a view of them. In 1836, the passage-money from Albany to Buffalo, in the packet- boat, w^as £S 35., being at the rate of nearly 2d. per mile ; and in a line-boat, which is an inferior conveyance, £1 1 8s., being at the rate of one penny and two tenths per mile. The expenditure for keeping the canal and iis branches in repair, during 1836, w'as §410,236, or about £82,047 ; which, taking the whole length at five hundred and forty-three miles, gives an average of £151 per mile. The average cost of repairs, for the six preceding years, amounted to £136 per mile. Before leaving the subject of canals, I must not omit to mention the Morris canal, in the State of New Jer- sey. This canal leads from Jersey, on the Hudson, to Easton, on the Delaware, and connects these two rivers. The breadth, at the water hne, is thirty-two, and at the bottom, sixteen, feet, and the depth is four feet. It is one hundred and one miles in length, and is said to have cost about £600,000. It is peculiar, as being the only canal in America, in which the boats are moved from dif ferent levels by means of inclined planes, instead of locks , a construction, which was first introduced on the Duke of Bridgewater's canal, in England. The whole rise and fall, on the Morris canal, is one thousand five hundred and fifly-seven feet, of w^hich two hundred and twenty- three feet are overcome by locks, and the remaining one thousand three hundred and thirty-four feet, by means of twenty- three inclined planes, having an average lift of 312 APPENDIX. fifty-eight feet each. The boats, which navigate this canal, are eight and one half feet in breadth of beam, from sixty to eighty feet in length, and from twenty-five to thirty tons burden. The greatest weight ever drawn up the planes is about fifty tons. The boat-car used on this canal, consists of a strongly made wooden crib, or cradle, on which the boat rests, supported on two iron wagons running on four wheels. When the car is wholly supported on the incHned plane, or is resting on a level, the four axles of the wagons are all in the same plane ; but when one of the w^agons rests on the inclined plane, and the other on the level surface, their axles no longer remain in the same plane, and their change of position produces a tendency to rack the cradle, and the boat which it supports ; but this has been guarded against, in the construction of the boat-cars on the Morris canal, by introducing two axles, on which the whole w^eight of the crib and boat are supported, and on which the wagons turn, as a centre. The cars run on plate-rails, laid on the inclined planes, and are raised and lowered by means of machinery driven by water-wheels. The rail-way, on which the car runs, extends for a short distance from the lower extremity of the plane, along the bottom of the canal. When a boat is to be raised, the car is lowered into the water, and the boat being floated over it, is made fast to the part of the framework which projects above the gunwale. The machinery is then put in motion ; and the car, bearing the boat, is drawn by a chain to the top of the inclined plane, at which there is a lock for its recep- tion. The lock is furnished with gates, at both extremi- ties ; after the car has entered it, the gates next the top of the inclined plane are closed, and, those next the canal being opened, the w^ater flows in and floats the boat off the car, when she proceeds on her way. Her place is supplied by a boat travelling in the opposite direction, which enters the lock, and the gates next the canal being closed, and the water run off, she grounds on the car. The gates next the plane are then opened, the car is gen- tly lowered to the bottom, when it enters the w^ater, and the boat is again floated. The principal objection, urged CANALS IN THE UNITED STATES. . 313 against the use of inclined planes, in canal navigation, for moving boats from different levels, is founded on the in- jury which the boats are apt to sustain in supporting great weights, while resting on the cradle, during its passage over the planes. It can hardly be supposed that a shm- ly-built canal-boat, measuring from sixty to eighty feet in length, and loaded with a weight of twenty or thirty tons, can be grounded, even on a smooth surface, without strain- ing and injuring her timbers ; a circumstance which is a decided objection to this mode of construction, and has operated powerfully in preventing its introduction in many situations, both in this country and in America. But, notwithstanding this objection, the twenty-three inclined planes on the Morris canal are in full operation, and act exceedingly well. No pains have been spared to render the machinery connected with them as perfect as possible, and the greatest credit is due to the engineer for the suc- cess which has hitherto attended the operation. — Steven- son^s ' Sketches of Civil Engineering in Mrth America.^ II. 27 XII. 314 APPENDIX c •> p c- c s o T3 o 0) ,_H C3 O ;n o C 01 o J3 CJ bJO O 'i ^ 11 -^e; o a T3 s^ ^6 c h:i . rn -^ ^ s ^•- 114 H o O isl * no ..^-g .5-^ « J2 •TJ G Q^ o ^ P-i °J S 0] 35^ S CJ ^S5 r1 "t::^ S^fl O P rt JS W oT.g H • g ^ ^ • 5 ^ 2 a -s ;$ £ rt o c bS E-«' 2§ ft S -S :h2 (rt ffi z^ J_ fll (1) 1 eg , COT o 2 M.2 te 03. SO 1^; on S . » S b tf « 2 CANALS IN THE UNITED STATES. 315 §"5 Ci o ^ o» o ^ CI O U-; X) £> Lr! ^ -o O t '^ Ci lO C< ?l CO «+^ = «5 ^ » sac 1-1 t^ ^ WT}< OO OD CO CO • 3 fa 316 APPENDIX. §•0 Pi "H t3 o OJ •a c « 2 ^ « 502 CSS to «> -H 01 ^S" T 2^ 'i^ .3 O ^ ° s" - PS «J C3< 'S'^ft'^rt «c o S'^S 5 ^ os C5 u 5 t S(5£ «p2 Q'- iss a o o a, • S ej J .20 5 -a « 83^ «H ^.2 a .2 r oT a u > ) O 4) > o o )00 O |«§ J2 O O ii is "3 es .0 2 « CANALS IN THE UNITED STATES. 317 Pi ; at**, ;/2 :c 5-1 jc 02 O H lis" 9 2 = s I "SO cs « a o o"2 tC 1^ O h5 QD J O C3 d si cl CS 27= 318 APPENDIX. V. — Rail-ways in the United States. Within a very (ew years, a wonderful change has been effected in land-communication throughout Great Brit- ain and America, where rail-ways have been more ex- tensively and successfully introduced than in any other parts of the world. As early as the sixteenth century, wooden tram-roads were used in the neighborhood of many of the collieries of Great Britain. In the year 1767, cast-iron rails were introduced at Colebrookdale, in* Shropshire. In IS 11, malleable iron rails were, for the first time, used in Cumberland, and the locomotive en- gine, on an improved construction, was successfully in- troduced on the Liverpool and Manchester line, in 1830. Little progress has hitherto been made in the formation of rail- ways on the Continent of Europe. A small one has been in existence, for some time, in the neighborhood of Lyons ; but the only rail-road, constructed in France, for the conveyance of passengers by locomotive power, is that from Paris to St. Germains, which was opened only in 1837. In Bohemia, the ChevaHer Gerstner, about eight years ago, constructed a rail-way of eighty miles in length, leading from the river Muldau to the Dan- ube. In Belgium, the rail-way from Antwerp to Ghent has been in use for some time ; and some lines are at pres- ent being constructed in Holland and Russia. But the purpose of the present article is to describe the state of this wonderful improvement in communication, in the United States. The Quincy rail-road, in Massachusetts, .was the first constructed in America. It was intended for the con- veyance of stone from the Quincy granite-quarries to a shipping port, on the river Neponset, a distance of about four miles. At the end of this article is given a tabular list of the principal rail-roads which are already finished, and also of those that have been begun in the United States, which show the rapid increase of these works since 1827, the date at which the Quincy rail-road was completed. From these tables it appears that, in 1840, there were no fewer than seventy-one rail-ways completed. RAIL-WAYS IN THE UNITEL STATES. 319 and in full operation, whose aggregate length amounts to about twenty-three hundred miles ; and also, that twenty- three rail-ways were then in progress, which, when com- pleted, will amount to about twenty- eight hundred miles. In addition to this, upwards of one hundred and fifty rail- way companies have been incorporated ; and the works of many of them will, in all probability, be very soon commenced. The Boston and Lowell rail-way, in Massachusetts, is twenty-six miles in length, and is laid with a double line of rails. The breadth between the rails, which is four feet eight and a half inches, is the s.ame in all the Ameri- can rail-roads, and the breadth between the tracks is six feet. The supporters are granite blocks, six feet in length, and about eighteen inches square. These are placed transversely, at distances of three feet apart, from centre to centre, each block giving support to l30th of the rails. This construction was first introduced in the Dublin and Kingstown rail-way, in Ireland, but was found to pro- duce so rigid a road, that great difiiculty was experienced in securing the fixtures of the chairs. From the difficulty, also, of procuring a solid bed for stones of so great di- mensions, most of them, after being subjected for a short time to the traffic of the rail-way, were found to be split. Another construction has been tried on this line, con- sisting of longitudinal trenches, two feet six inches square, and four feet eight and a half inches apart, from centre to centre, formed in the ground, and filled with broken stone, hard punned down with a wooden beater, as a foundation for the stone blocks on which the rails rest. These blocks measure two feet square, and a foot in thickness, and a transverse sleeper of wood, two feet eight inches and a half in length, one foot in breadth, and eight inches in th'ckness, is placed between the blocks, to prevent them from moving. The plan of resting the rail-way on a foundation of brok en stone was adopted, in the expectation that it might be sunk to a sufficient depth below the surface of the ground, to prevent the frost from affecting it ; bat subsequent 320 APPENDIX. experience has shown that many of those rail-ways, whose construction was more superficial, have resisted the ef- fects of frost much better. The New York and Patterson rail-way is sixteen and a half miles in length, and extends along a marshy tract of ground. The foundation of the road consists of a line of pits under each rail, eighteen inches square,. and three feet in depth. They are placed three feet apart, from centre to centre, and filled with broken stones. On this foundation, transverse wooden sleepers, measuring eight inches square, and seven feet in length, are firmly bedded, on w^hich rest the longitudinal sleepers, measur- ing eight inches by six. To these, plate-rails of mallea- ble iron, two and a half inches wide, and half an inch thick, weighing about thirteen pounds per lineal yard, are fixed by iron spikes. In the Saratoga and Schenectady rail-way, the paral- lel trenches are eighteen inches square, and four feet eight and a half inches apart, from centre to centre. They extend throughout the whole line of the rail-way, and are firmly punned full of broken stones. Longitudinal sleep- ers of wood, measuring eight by five inches, are placed on these trenches, which support the transverse wooden sleepers, measuring six inches square, and placed three feet apart, from centre to centre. Longitudinal runners, measuring six inches square, are firmly spiked to the transverse sleepers, and the whole is surmounted by a plate-rail, half an inch thick, and two and a half inches wide, weighing about thirteen pounds per lineal yard. The Newcastle and Frenchtown rail- way, which is sixteen miles in length, and forms part of the route from Philadelphia to Baltimore, is constructed in the same way as that between Schenectady and Saratoga, excepting that the plate-rail is two and a half inches broad, and five eighths of an inch thick, and weighs nearly sixteen pounds per lineal yard. The Baltimore and Washington rail- way is also constructed in the same manner, as regards the foundation and arrangement of the timbers ; but edge-rails are employed on that line, three and a half inches in breadth at the base, and two inches in height. RAIL-WAYS IN THE UNITED STATES. 321 Several experiments have been made on the Columbia rail-road, in Pennsylvania, which is eighty-two miles in length, and is under the management of the State. Part of the road is constructed with trenches measuring two feet six inches in breadth, and two feet in depth, excava ted in the ground, and filled with broken stone. In these, the stone blocks, two feet square, and a foot in thickness, are imbedded, at distances of three feet apart, to which the chairs and rails are spiked, in the ordinary manner. The rails on each side of the track are connected togeth- er by an iron bar. This attachment is rendered absolute- ly necessary, on many parts of the Columbia rail-road, by the sharpness of the curves, which, at the time when the work was laid out, were not considered so prejudicial on a rail-way, as experience has shown them to be. Another plan tried on this road has a continuous line ot stone curb, one foot square, resting on a stratum of broken stone, instead of the isolated stone blocks. A plate-rail, half an inch thick, and two and a half inches broad, is spiked down to treenails, of oak or locust wood, driven into jumper-holes bored in the stone curb. The Boston and Providence rail-way is forty-one miles in length. Pits, measuring eighteen inches square, and one foot in depth, are excavated under each hne of rail, at intervals of four feet apart. They are filled with broken stone, and form a foundation for the transverse wooden sleepers, measuring eight inches square, on which the chairs and rails are fixed in the usual manner. One of the tracks, in very general use in America, is met with on the Philadelphia and Norristown. the New York and Haerlemand the Buffalo and Niagara rail-roads ; and has been mtroduced on many others. It consists of two lines of longitudinal wooden runners, measuring one foot in breadth, and from three to four inches in thickness, bedded on broken stone, or gravel. On these ^runners, transverse sleepers are placed, formed of round timber, with the bark left on, measuring about six inches in diameter, and squared at the ends, to give them a prop- er rest. Longitudinal sleepers, for supporting the rails, are notched into the transverse sleepers. The rail is flat. 322 APPENDIX. made of wrought-iron, and varies in weight from ten to fif- teen pounds per lineal yard. It is fixed down to the sleep- ers, at every fifteen or eighteen inches, by spikes four or five inches in length, the heads of which are countersunk in the rail. The rails used on the Camden and Amboy rail-way, w^hich is sixty-one miles in length, are parallel edge-rails, and are spiked to transverse sleepers of wood, and, in some places, to w^ood treenails driven into stone blocks. Their breadth is three and a half inches at the base, and two and a half at the top, and their height is four inches. They are formed in lengths of fifteen feet, and secured at the joints by an iron plate on each side, with two screw- bolts passing through the plates and rails. On the Phila- delphia and Reading rail-road, rails of the same form have been adopted. On several of the rail-roads, with a view to counteract the effects of frost, round piles of timber, about twelve inches in diameter, are driven into the ground as far as they will go, at the distance of three feet apart, from cen- tre to centre. The tops are cross-cut, and the rails are spiked to them in the same way as in the Camden and Amboy Rail-way. The heads of the piles are furnished with an iron strap, to prevent them from splitting ; and the rails are connected together, at every five feet, by an iron bar. The Brooklyn and Jamaica rail-road is exceedingly smooth, and is said to resist the effects of frost very suc- cessfully. It consists of transverse sleepers, measuring eight by six inches, supported on slabs of pavement, two feet square, and six inches thicli. The wooden runner ;s spiked on the inside of the chairs, to render tnem firm This rail rests on the cheeks^ or sides, of tne cnair, ana not on the bottom, as is generally the case. The rail-road between Charleston and Augusta, and many others in the southern States, where there is a scar- city of materials for forming embankments, are carried over low-lying tracts of marshy ground, elevated on struc- tures of wooden truss-work. The framing is nsed in sit- uations where the level of the rails does not require to be RAIL-WAYS IN THE UNITED STATES. o2o raised more than ten or twelve feet above the surface of the ground. Piles, from ten to fifteen inches in diameter, are driven into the ground by a piling engine, and, in places where the soil is soft, their extremities are not pointed, but are left square, which makes them less liable to sink under the pressure of the carriages. The struts are attached to the tops of the piles, and are also fixed i*> dwarf piles driven into, the ground. Their effect is to prevent lateral motion. It is evident, however, that these structures are by no means suitable or safe, for bearing the weight of locomotive engines or carriages ; and, as may naturally be expected, very serious accidents have ocjasionally occurred on them. They are, besides, gen- erally left quite exposed, and, in some situations, when they are even so much as twenty feet high, no room is left for pedestrians, who, if overtaken by the en- gine, can save themselves only by making a leap to the ground. These varieties of construction were all in use in the United States in 1837 ; but the American engineers had not, at that time, come to any definite conclusion, as to which of them constituted the best rail-way. It seemed to be generally admitted, however, that the wooden struc- tures were, in most situations, more economical than those formed of stone, and were also less liable to be affected by the frost. Structures of wood also possess a great advantage over those of stone, from the much greater ease with which the rails supported by them are kept in repair. Wooden rail-roads are more elastic, and bend under great weights, while the rigid ana unyielding nature of the rail roads laid on stone blocks causes the impulses, producec oy the rapia motion of locomotive carriages, or heavily loaded wagons, over the surface, to be much more severe- ly felt, both by the machinery of the engine, and by the rails themselves. Experience, both in this country and in America, has shown the truth of these remarks. On the Liverpool and Manchester rail-way, for example, on which a large sum is annually expended in keeping the rails in order, the part of the road which requires least repair !s that extending over Chat Moss, where the rails are laid 324 APPENDIX. on wooden sleepers, and the weight of passing trains ol loaded wagons produces a sensible undulation in the sur- face of the rail-way, which at this place actually floats on the moss. These considerations are worthy of attention ; and, since the introduction of Kyan's patent anti-dry-rot preparation, wood is beginning to be more generally em- [)loyed for the construction of rail-ways in this country. The rails of the Dublin and Kingstown road are now laid on wood, and it has also been extensively employed on the Great Western rail-way, now in progress. The rails used in the United States are of British man- ufacture. They are often taken to iVmerica as ballast ; and the Government of the United States having remov- ed the duty from iron imported for the purpose of forming rail-ways, the rails are laid down on the quays of New York nearly at the same cost, as in any of the ports of Great Britain. Those of the Brooklyn and Jamaica road, which are in lengths of fifteen feet, and weigh thirty-nine pounds per lineal yard, are of British manufacture, and cost at New York, when they were landed, in 1836, £S per ton ; the cast-iron chairs, which are also of British manufacture, weigh about fifteen pounds each, and cost <£9 per ton. There is a great abundance of iron ore in America, and some of the veins in the neighborhood of Pittsburg are at present pretty extensively worked ; but the Americans know that it would be bad economy to attempt to manufac- ture rails, so long as those made at Merthyr Tydvil Iron- works, in Wales, can be laid down at their sea-ports at the present small cost. The stone blocks, in use on some of the rail-wavs. are inade of granite, which is found in many parts of the United States. Yellow pine is generally employed for tne longitudinal sleepers, and cedar, locust, or white-oaK, for the transverse sleepers on which the rails rest. Cedar, however, if it can be obtained, is generally preferred for the transverse sleepers, because it is not liable to be split by the heat of the sun, and is less affected than perhaps any other timber, by dampness and exposure to the at- mosphere. The cedar sleepers used on the Brooklyn and Jamaica rail-way, measuring six inches by five, and RAIL-WAYS IN THE UNITED STATES. 325 seven feet in length, notched, and in readiness to receive the rails, cost ^s. S^d. each, laid down at Brooklyn. It is a costly timber, and is not very plentiful in the United States. It has also risen greatly in value, since the intro- duction of rail-ways, for the construction of which it is peculiarly applicable. For all treenails, locust-wood is universally employed. The American rail-roads are much more cheaply con- structed than those in England, which is owing chiefly to three causes ; firsts they are exempted from the heavy expenses often incurred in the construction of English rail- ways, by the purchase of land, and compensation for dam- ages ; second, the works are not executed in so substantial and costly a style ; and, third, wood, which is the prin- cipal material used in their construction, is got at a very small cost. The first six miles of the Baltimore and Ohio rail-road, which is formed "in an expensive man- ner, on a very difficult route," has cost, on an average, about £12,000 per mile. The rail-roads in Pennsylva- nia cost about £5000 per mile ; the Albany and "Sche- nectady rail-road, upwards of £6000 per mile ; the Sche- nectady and Saratoga rail- way, £1800 per mile ; and the Charleston and Augusta rail-road, about the same.* Mr. Moncure Robinson, in a report relative to the Philipsburg and Juniata rail-road, states, that the first ten miles of the Danville and Pottsville rail-road, formed for a double track, but on which a single track only was laid, cost, on an average, £4400 per mile, and that the Honesdale and Carbondale rail-road, sixteen and one third miles in length, laid with a single track, and executed for a considerable Dortion of its length on truss-work, is understooa, wiin niacnmery, to have averaged £3600 per mile. The average cost of these rail-ways, constructed m diflx;renk parts of the United States, is £4942 per mile. This contrasts, strongly, with the cost of the rail-ways constructed in Great Britian. The Liverpool and Man- chester rail-way cost £30,000 per mile ; the Dublin and * Facts and suggestions relative to the New York and Albany rail way. New York, 1833. II. 28 XII. 326 APPENDIX. Kingstown, £40,000 ; and the rail- way between Liverpod and London is expected to cost upwards of £25,000. The following extract, embodying an estimate from Mr. Robinson's Report, will give some idea of the cheapness with which many of the American works are construc- ted : — " The following plan," says Mr. Robinson, '-is pro- posed for the superstructure of the Philipsburg and Juni- ata rail-road. " Sills of white or post oak, seven feet ten inches long, and twelve inches in diameter, flattened to a width of nine inches, are to be laid across the road, at a distance of five feet apart, from centre to centre. In notches formed in these sills, rails of white-oak or heart-pine, tive inches wide by nine inches in depth, are to be secured, four feet seven inches apart, measured within the rails. On the inner edges of these rails, plates of rolled iron, two inches wide by half an inch thick, resting at their points of junction on plates of sheet iron, one twelfth of an inch thick and four and a half inches long, are to be spiked, with five-inch wrought-iron spikes. The inner edges of the wooden rails to be trimmed slightly level- ling, but flush at the point of contact with the iron rail, and to be adzed down, outside the iron, to pass off rain- water. " Such a superstructure, as that above described, would be entirely adequate to the use of locomotive engines of from fifteen to twenty horses' power, constructed without surplus weight, or similar to those now in use on the little Schuylkill rail-road in this State. (Pennsylvania,) or tne Petersburg rail-road m Virgmia : and it will be observea mat only tlie sills, which constitute but a very slight item in its cost, are much exposed to the action of those causes which induce decay in timber. It is particularly recom- mended for the Philipsburg and Juniata rail-road, by the great abundance of good materials, along the line of the improvement, for its construction, and the consequent economy wuth which it may be made. " The following may be deemed an average estimate of the cost of a mile of superstructure, as above described. RAIL-WAYS IN THE UNITED STATES. 327 1056 trenches, 8 feet long, 12 inches wide, and 14 inches Uolls. deep, filled with broken stone, at 25 cents each, . 264 Same number of sills, hewn, notched, and imbedded, at 50 cents each, ....... 528 10,912 lineal feet of rails, (allowing 33^ per cent, for waste,) at 4 cents per lineal foot, delivered, . . 436.43 2112 keys, at 2^ cents each, 52.80 10,560 lineal feet of plate rails, 2 inches by ^ inch, weight 3^ lb. per foot, ISy'^^g- tons, delivered at 50 dollars (£10) per ton, 785 50 1509 lbs. of 5-inch spikes, at 9 cents per pound, . . 135 81 Sheet iron under ends of rails, ..... 30.21 Placing and dressing wood, and spiking down iron rails, 280 Filling between sills with stone, or horse-path, . . 180 2692 dollars, or about £540. , 2692.80 It was found rather difficult to obtain much satisfactory information regarding the expense of upholding the Amer- ican rail-ways. It is stated in a report made by the Di- rectors of the Boston and Worcester rail-road, that Mr. Fessenden, their engineer, estimates the annual expendi- ture for repairing the road, carriages, and engines, and pro- viding fuel and necessary attendance for forty-three and a half miles of rail-way, at £6829 per annum, which is at the rate of £157 per mile. The expense of the repairs on the Utica and Schenectady rail-road, which is about seventy- seven miles in length, amounts to £23,000 per annum, be- ing at the rate of about £363 per mile. These sums for keeping rail-roads in repair are exceedingly small, compar- ed with the amount expended in this country for the same purpose. On the Liverpool and Manchester rail-way, for example, the expense annually incurred, in keeping the engines in a working state, and the rail-wav in repair. amounts to upwards of £30,000, or £1000 per miJt^ This difference in the cost arises, m a a^reat measure, iron, tne comparatively slow speed at which the engines work- ing on the American rail-ways are propelled, which, in the course of my own observation, never exceeded the aver- age rate of 6fteen miles per hour. On the State rail-ways, and also on many of those under the management of in- corporated companies, fifteen miles an hour is the rate of travelling fixed by the administration of the rail-way, and •his speed is seldom exceeded. 328 APPENDIX. On some of the American rail-ways, where the line is short, or the traffic small, horse power is employed ; but locomotive engines for transporting goods and passen- gers, are in much more general use. In New Ycrk, Brooklyn, Philadelphia, Baltimore, and other places, which have lines of rail-way leading from them, the depot, or station for the locomotive engines, is generally placed at the outskirts, but the rails are continued through the streets, to the heart of the town, and the carriages are dragged over this part of the line by horses, to avoid the inconvenience and danger, attending the passage of loco- motive engines, through crowded thoroughfares. The fuel used on most of the rail-ways is wood, but the sparks vomited out by the chimney are a source of constant annoyance to the passengers, and occasionally set fire to the wooden bridges on the line, and the houses in the neighborhood. Anthracite coal, as formerly no- ticed, has been tried, but the same difficulties which at- tend its use in steam-boat furnaces, are experienced, to an equal extent, in locomotive engines. In situations where the summit-level of a rail-way can- not be attained, by an ascent sufficiently gentle for the employment of locomotive engines, or where the forma- tion of such inclinations, though perfectly practicable, would be attended with an unreasonably large outlay, transit is generally effected by means of inclined planes, worked by stationary engines. This system has been introduced on the Portage rail-way, over the Alleghany Mountains, in America, on a more extensive scale, than in any other part of the world. The Portage or Alle- ghany rail-way forms one of tiie links of the great Penn sylvania canal and rail-road communication, from Phila- delphia to Pittsburg, — a work ot so difficult and vast a nature, and so pecuhar, both as regards its situation and details, that it cannot fail to be interesting to every engi- neer, and I shall, therefore, state at some length the facts which I have been able to collect regarding it. This communication consists of four great divisions, the Columbia rail-road, the Eastern Division of the Penn- sylvania canal, the Portage or Alleghany railroad, and RAIL-WAYS IN THE UNITED STATES. 329 the Western Division of the Pennsylvania canal. These works form a continuous line of communication from Phil- adelphia, on the Schuylkill, to Pittsburg, on the Ohio, a distance of no less than three hundred and ninety-five miles. Commencing at Philadelphia, the first Division of this stupendous work is the Philadelphia and Columbia rail- road, which was opened in the year 1S34. It is eighty- two miles in length, and was executed at a cost of about £666,025, being at the rate of £8122 per mile. There are several viaducts of considerable extent on this rail-way, and two inclined planes worked by stationary engines. One of these inclined planes is at the Philadelphia end of the line. It rises at the rate of one in 14.6 for two thousand seven hundred and fourteen feet, overcoming an elevation of one hundred and eighty-five feet. The other plane, which is at Columbia, rises at the rate of one in 21. '2 for a distance of one thousand nine hundred and fourteen feet, and overcomes an elevation of ninety feet. A very large sum is expended in upholding the inclined planes, and surveys have lately been made with a view to avoid them. The cost of maintaining the stationary power, and superintendence of the Philadelphia inclined plane, is said to be about £8000 per annum, and that of the Columbia plane, about £3498 per annum. Locomo- tive engines are used between the tops of the inclined planes. The steepest gradient on that part of the line is at the rate of one in one hundred and seventeen ; but the curves are numerous, and many of them very sharp, the minimum radius being so small as three hundred and fifty feet. This line of rail-way was surveyed and laid out, before the application of locomotive power to rail- way conveyance had attained its present advanced state, — at a period when sharp curves and steep gradients were not considered so detrimental to the success of rail-ways, as experience has since shown them to be. The passenger-carriages on the Columbia rail-road are extremely large and commodious. They are seated for sixty passengers, and are made so high in the roof, that the tallest person may stand upright in them, without in- convenience. There is a passage between the seats ex- 28* 330 APPENDIX. tending from end to end, with a door at both extremities ' and the coupling of the carriages is so arranged, tha* the passengers may walk from end to end of a whole train, without obstruction. In winter, they are heated by stoves. The body of each of these carriages measures from fifty to sixty feet in length, and is supported on two four-wheeled trucks, furnished with friction-rollers, and moving on a vertical pivot, in the manner formerly alluded to, in describing the construction of the locomotive en- gines. The flooring of the carriages is laid on longitudinal beams of wood, strengthened with suspension-rods of iron. At the termination of the rail-way at Columbia, is the commencement of the Eastern Division of the Pennsyl vania canal, which extends to HolHdaysburg, a town s'lU uate at the foot of the Alleghany Mountains. This canal is rather more than one hundred and seventy-two miles in length, and was executed at an expense of £918,829, being at the rate of <£5342 per mile. There are thirty-three aqueducts, and one hundred and eleven locks, on the line, and the whole height of lockage is 585.8 feet. A considerable part of this canal is slack- water-navlgatlon, formed by damming the streams of the Juniata and Susquehanna. The canal crosses the Sus- quehanna at its junction with the Juniata, at which point it attains a considerable breadth. x\ dam has been erec- ted in the Susquehanna, at this place, and the boats are dragged across the river by horses, which walk on a tow- path attached to the outside of a wooden bridge, at a lev- el of, about thirty feet above the surface of the water. HolHdaysburg is the western termination of the East- ern Division of the Pennsylvania canal. The town stands at the base of the Alleghany Mountains, which ex- tend in a southwesterly llrectlon, from New Brunswick, to the State of Alabama, a distance of upwards of eleven hundred miles, presenting a formidable barrier to commu- nication between the eastern and western parts of the United States. The breadth of the Alleghany range va- ries from a hundred to a hundred and fifty miles, but the peaks of the mountains do not attain a greater height than four thousand feet above the medium level of the sea. RAIL-WAYS IN THE UNITED STATES. 331 They rise with a gentle slope, and are thickly wooded to their summits. " The Alleghany Mountains present what must be considered their scarp, or steepest side, to the east, where granite, gneiss, and other primitive rocks, are seen. Upon these repose, first, a thin forma- tion of transition rocks dipping to the westward, and next, a series of secondary rocks, including a very extensive coal formation."* The National road, which has al- ready been noticed, was the first line of communication formed by the Americans over tliis range ; and in the year 1831, an Act was passed for connecting the Eastern and Western Divisions of the Pennsylvania canal, by means of a rail-road. This important and arduous work, which cost about £526,871, was commenced within the same year in which the Act for its construction was grant- ed, and the first train passed over it on the 26th of Novem- ber, 1833 ; but it was not till 1835, that both the tracks were completed, and the rail-way came into full operation. The rail-way crosses the mountains by a pass called *' Blair's Gap," where it attains its summit-level, which is elevated two thousand three hundred and twenty-six feet above the mean level of the Atlantic ocean. Mr. Robin- son surveyed a line of rail-way from Philipsburg to the river Juniata, which is intended to cross the Alleghany Mountains by the pass called " Emigh's Gap." The summit-level of this line is stated, in a report by the di- rectors, to be two hundred and ninety-two feet lower than that of the Portage rail- way. The preliminary operation of clearing a track for the passage of the rail-way, from a hundred to a hundred and fifty feet in breadth, through the thick pine forests with which the mountains are clad, was one in which no small difiiculties were encountered. This operation, which is called grubbing, is litde know^n in the practice of engi- neering in this country, and is estimated by the Ameri- can engineers, in their various rail- w^ay and canal reports, at from £40 to £80 per mile, according to the size and quantity of the timber to be removed ; an estimate which, from the appearance of American forests, must, in many * Encyclopaedia Britannica, article America. 332 APPENDIX. instances, be much too low. The timber removed from the line of the Alleghany rail-way is chiefly spruce and hemlock pine, of very large growth. The line is laid with a double track, or four single lines of rails, and is twenty-five feet in breadth. For a con- siderable distance, the rail-way is formed by side-cutting along steep sloping ground, composed of clay-slate, bitu- minous coal, and clay, part of the' breadth of the road be- ing obtained by cutting into the hill, and part by raising embankments, protected by retaining walls of masonry. The rail-way is consequently liable to be deluged, or even entirely swept away, by mountain torrents, and the thor- ough drainage of its surface has been attended with great expense and difficulty. The retaining walls,- by which the embankments are supported, are in some places not less than a hundred feet in height ; they are built of dry- stone masonry, and have a batter of about one half to one, or six inches horizontal to twelve inches perpendic- ular. There are no parapet or fence walls on the rail- way, and on many parts of the line, especially at the tops of several of the inclined planes, the trains pass within three feet of precipitous rocky faces, several hundred feet high, from which the large trees, growing in the ra- vines below, almost resemble brushwood. One hundred and fifty-three drains and culverts, and four viaducts, have been built on the rail-way. One of the viaducts crosses the river Conemaugh, at an elevation of seventy feet above the surface of the water. There is also a tunnel on the line nine hundred feet in length, twenty feet in breadth, and nineteen feet in height. The inclined planes are, however, the most remarka- ble works which occur on this line. The rail- way extends from Hollidaysburg on the eastern base, to Johnstown on the western base, of the Alleghany Mountains, a distance of thirty-six miles ; and the total rise and fall, on the whole length of the line, is 2571.19 feet. Of this height, 2007.02 feet are overcome by means of t^n inclined planes, and 564.17 feet by the slight inclinations given to the parts of the railway which extend between these planes. The distance from Hollidaysburg to the summit-level is about RAIL-WAYS IN THE UNITED STATES. 333 ten miles, and the height is 1398.31 feet. The distance from Johnstown to the same point is about twenty-six miles, and the height 1172.88 feet. The height of th? summit-level of the rail-way, above the mean level of the Atlantic, is 2326 feet. The machinery by which the inclined planes are work ed consists of an endless rope passing round horizontal, grooved wheels, placed at the head and foot of the planes which are furnished with a powerful break, for retarding the descent of the trains. The ropes were originall}' made seven and a half inches in circumference, but they have lately been increased to eight inches, to prevent a tendency, which the)' formerly had, to slip in the grooved wheels, occasioned by their circumference being too small for the size of the groove, or hollow in the wheel. Two stationary engines, of twenty-five horses' power each, are placed at the head of the inclined planes, one of which is in constant use in giving motion to the horizontal wheels round which the rope moves, while the trains are passing the inclined planes. Two engines have been placed ar each station, that the traffic of the rail-w^ay may not be stopped, should any accident occur to the machinery of that which is in operation ; and they are used alternately, for a week at a time. Water for supplying the boilers has been conveyed, at a great expense, to many of the sta- tions, in wooden pipes upwards of a mile in length. The planes are laid with a double track of rails, and an ascending and a descending train are always attached to the rope at the same time. Many experiments have been made, to procure an efficient safety-car, to prevent the trains from running to the foot of the inclined plane, in the event of the fixtures, by which they are attached to to the endless rope, giving way. Several of these safety- cars are in use, and are found to be a great security. The trains are attached to the endless rope simply by two ropes of smaller size made fagt to the couplings of the first and last wagons of the train, and to the endless rope by a hitch or knot, formed so as to prevent it from slipping. Locomotive engines are used on the parts of the road between the inclined planes. — Stevenson^ s ' Sketch of Civil Engineering in J^orth America.'' 334 APPENDIX, Table of the Principal Rail-ways in operation in the United States, in 1840. NAME. counsE. When Length Whole length a. opened Miles. in each State. Maine. Bangor and Orono, . From Bangor to Orono, 1836 10 10 New Hampshire. Nashua and Lowell, Nashua to Lowell, Massachusetts. 1838 15 1 15 ! Quincy, C Quincy Quarries to Nepon- l set River, . J 1827 4 Boston and Lowell, . Boston to Lowell, . 1835 26 Andovcr and Wilmington, C Andover to the Boston and I Lowell Rail-road, |l836 n Andover and Haverhill, Andover to Haverhill, . 1838 10 Boston and Providence, Boston to Providence, 1835 41 Dedham Branch, . C Boston and Providence R. \ Road to Dedham, . |l835 2 Taunton Branch, C Boston and Providence I Rail-road to Taunton, 1 1836 11 Boston and Worcester, Boston to Worcester, . 1835 45 Western Rail-way, . Worcester to Springfield, 1839 54 Worcester and Norwich, Worcester to Norwich, 1839 59 Eastern Rail-road, Boston to Newburyport, 1839 36 2951 Rhode Island. Providence & Stonington, Providence to Stonington, 1837 47 47 Connecticut. Hartford and New Haven, Hartford to New Haven, 1839 40 Housatonic, Bridgeport to New Milford, • • 40 New York. 80 1 Mohawk and Hudson, C Between the Rivers Mo- l hawk and Hudson, . |l832 16 Saratoga & Schenectady, Saratoga to Schenectady, 1832 22 Rochester, . Rochester to Carthage, 1833 3 Ithaca and Oswego, Ithaca to Oswego, . 1834 29 1 Rensselaer and Saratoga, Troy to Ballston, 1835 24^ iUtica and Schenectady, Utica to Schenectady, . 1836 77 j Buffalo and Niagara, . Buffalo to Niagara Falls, 1837 21 'Haerlem, New York to Haerlem, 1837 7 iLockport and Niagara, Lockport to Niagara Falls, 1837 24 i Brooklyn and Jamaica, Brooklyn to Jamaica, 1837 12 JAuburn and Syracuse, Auburn to Syracuse, . . 26 jCatskill and Canajoharie, Catskill to Canajoharie, 68 Hudson and Berkshire, C Hudson to the Boundary of I Massachusetts, i' 30 Tonawanda, Rochester to Attica, 45 404^ New Jersey. Camden and Amboy, Camden to Amboy, 1832 61 Paterson, . Paterson to Jersey, . 1834 16i 1 New Jersey, . C Jersey City to New Bruns- l wick, Morristown to Newark, jl836 31 Morris and Essex, . . 20 PennsylvanA.. 128i jColumbia, . Philadelphia to Columbia, . 82 Alleghany, ... CHollidaysburg to Johns- \ town, over the Alleghanies, }• • 36 Mauch Chunk, . C Mauch Chunk to the Coal- l mines, .... J 1828 5 Room Run, . Mauch Chunk to the mines, Carried forward, ■ ■ 5k 128i 1980* RAIL-WAYS IN THE UNITED STATES. 335 NAME. COURSE. When Length in Whole length opened Miles. in each State. Brought forward,'" ■• . 12Si 960J Pennsylvania, contirf^ed. Mount Carbon, . MountCarbon to the mines, 1830 7^ Schuylkill Valley, . (Port Carbon to Tuscarora,' ) I with numerous branches, 5 " * 30 Schuylkill, . 13 Mill Creek, . . Port Carbon to Mill Creek, , 7 xMinehill and Schuylkill, 20 Pine-grove, Pine-grove to Coal-mines, 4 Little Schuylkill, . Port Clinton to Tamaqua, isai 23 Lackawaxen,. . C Lackawaxen Canal to the I River Lackawaxen, I- • 16J Westchester, C Westchester to Columbia I Rail-road, . h832 9 Philadelphia and Trenton, Philadelphia to Trenton, 1833 26i Philadelphia&Norristown Philadelphia to Xorristown 1837 19 Central Rail-way, Pottsville to Danville, 51J Philadelphia and' Reading, Philadelphia to Reading, • • 40 i Philadelphia & Baltimore, Philadelphia to Baltimore, 93 489 Delaware. Newcastle & Frenchtown, Newcastle to Frenchto^m, 1832 16 16 Maryland. Baltimore and Ohio, C Completed to Harper's I Ferry, with branches, J 1835 86 Winchester, C Harper's Ferry to Win- l Chester, 30 Baltimore & Port-Deposit, Baltimore to Port-Deposit, 34i Baltimore & Washington, Baltimore to Washington, i83.5 40 Baltimore & Susquehanna, Baltimore to York, . Virginia. (Richmond to Chesterfield ( Coal-mines, . 1837 59i 249* Chesterfield, 13 Petersburg and Roanoke, ( Petersburg to Blakely, on I the Roanoke, . 59 Winchester and Potomac, (Winchester to Harper's \ Ferry, .... Portsmouth to Weldon, 30 Portsmouth and Roanoke, T7i Richmond, Fredericks- ? burg, and Potomac, j (Richmond to Fredericks- l burg, .... 58 Manchester, Richmond to Coal-mines, South Carolina. 13 250i South Carolina Rail-road, ( Charleston to Hamburg on I the Savannah, Georgia. |l833 136 136 Alatamaha «fe Brunswick, Alatamaha to Brunswick, • • 12 12 Alabama. Tuscumbia and Decatur, ( Mussel-Shoals, Tennessee I River, Louisiana. 46 46 Pen tchar train, ( New Orleans to Lake Pont- \ chartrain. |l831 5 Carrollton, New Orleans to Carrollton, Kentucky. ' 6 11 Lexington and Ohio, . Lexington to Frankfort, 29 Frankfort and Louisville, 1 Frankfort to Louisville, Total length in miles, 50 79 2270 S36 APPENDIX. List of the other Rail-ways now in progress in ths United States. Haverhill and Exeter, Newburyport and Ports- mouth, Old Colony, Western, Western, . Long Island, New York and Erie, Saratoga and Washington, Elizabethtown&Belvidere Burlington &Mount Holly. Oxford, Tioga, Greensville and Roanoke, Charleston and Cincinnati, Augusta and Athens, . Macon and Forsyth, Central Rail-road, Montgomery and Chat- i tahoochee, . . . ' Mississippi Rail-road. . Bowling Green and Bar- ) ren River, . . > Mu-i River and Lake Erie, Sandusky & Monroeville, Detroit and St. Joseph, New Hampshire. Haverhill to Exeter, Newburyport to Portsmouth, . Massachusetts. Taunton to New Bedford, Springfield to New York line, . Connecticut. Hartford to Springfield, New York. Jamaica to Greenport, New York to Lake Erie, Saratoga to Whitehall, New Jersey. Elizabethtown to Belvidere, Burlington to Mount Holly, . Pennsylvania. Columbia Rail-road to Port Deposit, Chemung Canal to Tioga Coal-mines, Virginia. South Carolina. Charleston to Cincinnati, . Georgia. Augusta to Athens, . . . . Macon to Forsyth, .... Savannah to Macon, . . . . Alabama. Mississippi. Natchez to Canton, Kentucky. Bowling Green to Barren Biver, . Ohio. Dayton to Sandusky, .... Sandusky to Monroeville, Michigan. Detroit to the River St. Joseph, Total length, MANUFACTURE OF MAPLE SUGAR. 337 VI. — Manufacture of Maple Sugar. The following account of the manufacture of sugar, from the sap of the maple tree, is copied from the North American Sylva of Michaux. The work is commonly taken in hand in the month of February, or in the beginning of March, while the cold continues intense, and the ground is still covered with snow. The sap begins to be in motion at this season, two months before the general revival of vegetation. In a central situation, lying convenient to the trees, from which the sap is drawn, a shed is constructed, called, a sugar-camp, which is destined to shelter the boilers, and the persons who attend them, from the weather. An auger, three quarters of an inch in diameter, small troughs to receive the sap, tubes of elder or sumac, eight or ten inches long, corresponding in size to the auger, and laid open for a part of their length, buckets for emptying the troughs and conveying the sap to the camp, boilers of €fteen or eighteen gallons capacity, moulds to receive the sirup when reduced to a proper consistency for being <"ormed into cakes, and, lastly, axes to cut and split the fuel, are the principal utensils employed in the operation. The trees are perforated in an obliquely ascending di- rection, eighteen or twenty inches from the ground, with two holes, four or five inches apart. Care should be tak- en that the augers do not enter more than half an inch within the wood, as experience has shown the most abun- dant flow of sap to take place at this depth. It is also recommended to insert the tubes on the south side of the tree ; but this useful hint is not always attended to. The troughs, which contain two or three gallons, are made in the Northern States, of white pine, of white or black oak, or of maple ; on the Ohio, the mulberry, which is very abundant, is preferred. The chestnut, the black walnut, and the , butternut should be rejected, as they impart to the liquid the coloring matter and bitter principle, with which they are impregnated. A trough. is placed on the ground, at the foot of each tree, and the sap is, every day, collected and temporarily II. 20 XII. 338 APPENDIX. poured into cask J, from which it is drawn out to fill the boilers. The evaporation is kept up by a brisk fire, and the scum is carefully taken ojBf during this part of the ])ro- cess. Fresh sap is added, from time to time, and the heat is maintained, till the liquid is reduced to a sirup, after which it is left to cool, and then strained through a blanket, or other woollen stuff, to separate the remaining impurities. Some persons recommend leaving the sirup, twelve hours, before boiling it for the last time ; others proceed with it immediately. In either case, the boilers are only half filled, and by an active, steady heat, the hquor is rapidly reduced to the proper consistency for being poured into the moulds. The evaporation is known to have pro- ceeded far enough, when, upon rubbing a drop of the sirup between the fingers, it is perceived to be granular. If it is in danger of boihng over, a bit of lard or of but- ter is thrown into it, which instantly calms the ebullition. The molasses being drained off from the moulds, the sugar is no longer dehquescent, like the raw sugar of the West Indies. Maple sugar, manufactured in this way, is lighter colored, in proportion to the care with which it is made, and the judgement wnh which the evaporation is conducted. It is superior to the brown sugar of the Colonies, at least, to such as is generally used in the United States ; its taste is as pleasant, and it is as good for culinary purposes. When refined, it equals in beauty the finest sugar consumed in Europe. The sap continues to flow for six weeks ; after which, it becomes less abundant, less rich in saccharine matter, and sometimes even incapable of crystallization. In this case, it is consumed in the state of molasses, which is superior to that of the West India Islands. After three or four days exposure to the sun, maple sap is converted into vinegar, by the acetous fermentation. The amount of sugar manufactured in a year varies, from different causes. A cold and dry winter renders the trees more productive than a changeable and humia season. It is observed, that when a frosty night is follow- ed by a dry and brilliant day, the sap flows abundantly : MANUFACTURE OF BEET SUGAR 339 and two or three gallons are sometimes yielded oy a single tree, in twenty-four hours. Three persons are found sufficient to tend two hundred and fifty trees, which give one thousand pounds of sugar, or four pounds from each tree. But this product is not uniform, for many farmers on the Ohio do not commonly obtain more than two pounds from a tree. Trees, which grow in low and moist places, afford a greater quantity of sap, than those, which occupy rising grounds, but it is less rich in the saccharine principle. That of insulated trees, left standing in the middle of fields, or by the side of fences, is the best. It is also re- marked, that in districts which have been cleared of othei trees, and even of the less vigorous sugar maples, the pro- duct of the remainder is proportionally more considerable. VII. — Of the Manufacture of Beet Sugar. The following account of this manufacture, in France, is extracted from a work compiled, in 1836, by Mr. Ed- ward Church. Cleansing of the Beet Roots. The object of this operation is, to separate from the loots the green parts of the neck, w^hich may not have been removed, the radicles, the defective parts, and the earth and the gravel which may adhere to these ; when this is properly done, the washing, should it be required, (which is not the case in many places,) is easily and quickly performed. In all cases, the cleansing should be effectually done, otherwise the gravel and earth (should there any remain) will injure the rasps. "Women and children perform this operation in France. For this pur- pose, each hand is provided with a sharp knife, from two to three inches broad, and ten long. With this tool, seated near a pile of beets, the laborer takes the beets one after another, scrapes them lengthwise, to detach the earth and stones, takes off the neck all round, and even a thin shce, when this has not been already done. When a beet is too large to be applied conveniently to the rasp, the workmen should cut it in two, or in quarters, 340 APPENDIX. according to its dimeisions. This must always be done longitudinally. The cleaning of the beets should always take place in a room near the rasps and presses, in order that these dif- ferent operations may follow conveniently and quickly. The place should be, w^hen possible, a building sufficient- ly large to contain beets enough for the consumption of the works for at least four or five days, and leave room enough besides for the laborers to do their w^ork easily. As fast as the roots are cleansed, they should be thrown into baskets about eighteen inches high, and a foot w-ide, of a conical shape, with handles. When several of these are filled they are carried to the rasp ; there they leave the full baskets and take back the empty ones. Two women, in France, who understand their business, can clean easily from three to three and one half tons of roots in twelve hours' work, and carry them to the rasp. The wages of these women, in some parts of France, do not exceed twelve or fifteen cents each, per day ; at this rate, the cleaning of a ton of beets would not cost over ten cents. It, of course, reduces the weight of the beet ; the loss is estimated, usually, at from six to seven per cent. The operation of washing the roots is, (as we before said,) by no means generally requisite ; and a careful cleansing, as described above, is decidedly preferable, and it is not always, that water in sufficient quantity can be con- veniently obtained. When a little stream is at hand, and they can be placed in baskets in the water, and remain till the earth is washed off by its motion, such a peculiar ad- vantage should never be neglected ; but this of rare occur- rence. This washing is the more difficult, too, as it must be executed in the winter, and the water frequently may be frozen. A general opinion once prevailed, that the cleans- ing with water was indispensable, and that the manufacture of sugar could not be undertaken without a locality which supplied an abundance of it ; but this supposed necessity is groundless, for there are few spots where a sufficiency of water may not be found for the inconsiderable wants of a beet sugar manufactory. MANUFACTURE OF BEET SUGAR. 341 Rasping the Beets. The first idea of the famous Achard, when in search of the best mode of extracting the sugar from beets, was to boil them and reduce them to paste ; but he soon found insuperable difficulties in the way of this process. The simple pressure without rasping has been repeatedly tried, and recently again by an improved press, and the rasp is as yet the only effectual mode employed, and too much care cannot be used in having this operation well done, as on it depends, in a great measure, the more or less sugar that is obtained. The^e is a great diversity in the con- struction of this machine, but the cylindrical rasp'of Mo- lard appears to have the preference. The cylinder is of cast-iron, into which one hundred and twenty saw plates are inserted. Asa description of this would probably be unintelligible without a representation of it by an engrav- ing, I will not attempt it. A man presses the beets en- closed in a box against the circumference of the cyhnder, another w^orkman, on the opposite side of the machine, re- moves the pulp, and, with the ladle with which he removes it, fills bags, as we shall more particularly explain hereaf- ter. From eighty to one hundred pounds of beet are re- duced to pulp, in one minute. The rasping requires, as well as every other operation of this manufacture, great activity ; and, as much as possi- ble, the rasping more beets than are immediately wanted, must be avoided, as a prejudicial change takes place in the pulp, from a quarter to a half hour, at most, after it is 'produced. A blackish color, which gradually increases, is the indication of this change. It is therefore prudent that no more should be rasped than can be immediately pressed. The rasp must be kept perfectly clean by repeated wash- ings. Once a day, at least, every part of the machine, and all the tools appertaining to it, should be carefully cleansed, because every portion of juice, or pulp, which is suffered to remain on them, would soon serve as a leaven to excite fermentation. It is immaterial what power is used to drive the rasps ; 29* 342 APPENDIX. animal, water, and steam, power, and even wind, is some- limes used in France. Extraction of the Beet Juice. A variety of machines, and of power, has been used, for the pressing of the pulp, as well as for raspjng the roots. Of late the Hydraulic press has superseded almost every other, for this last operation, at least, in large man- ufactories. The pulp, enclosed in bags, is submitted to the action of this machine ; the bags are usually made of Russia duck. The cloth, though required to be strong, must not be so close that the juice cannot easily pass through it, or they will otherwi^ burst ; on the other hand, it must be sufficiently so, to prevent the pulp passing through the tissue. This last defect, however, is less to be feared than the first, so that the caution, most to be attended to, is, to avoid too close a texture ; and it must be recollected that it will become-closer when saturated with the juice. The size of the bags may be varied, but, generally speaking, half a yard wide and one yard long is a convenient di- mension ; they should not be more than three fourths filled. The bags must be kept perfectly clean, and they should be washed every day in boiling water^ with a small addi- tion of the-sub-carbonate of soda. Wicker-work frames, on which the bags are to be piled, must be provided ; they should be made strong, and proportioned to the size of the platform of the press, that is, of the same dimen- sions ; they serve to support the piles of bags in their vertical position, on the hand-wagon, with which they are removed from the rasp to the press, and are themselves kept in place, when on the press, by stanchions, fixed to the platform of the press at the lower end, the other sliding through a groove fixed to the frame-work. These wicker- frames and bags are placed alternately under the press, usually to the number of thirty of each. As re- gards these frames, the caution of the cleanliness is re- newed, and, in a word, must be applied to every branch of this manufactory. A Reservoir is next to be provided, to receive the MANUFACTURE OF BEET SUGAR. 343 juice from the press, to be subsequently conveyed to the defecating boiler ; it must be supplied with pipes of com- munication with the press, and a pump to convey the juice it contains to the defecating boiler ; it should be placed on a lower level than the press, and receive the juice by an inclined plane. It must be made substantial- ly of wood, and lined wnth copper, having a concavity in the centre, into which the bottom of the pump must be inserted, so as to empty it completely. The capacity must, of course, depend on the extent of the manufactory. Mode of operating with the Press. When the bags and wicker-frames have been pded as before described, alternately, to the number of thirty or more of each, on the platform, and the stanchions placed, the weight of the pulp alone causes a pretty plentiful flow of juice ; if the press used is a screw press, a workman takes hold of the lever, and turns it, then a second man assists, and then a third. When they have exerted their united strength on the lever, the job is done, and, after al- lowing the bags to drain, whilst they are filling others, the press is unscrewed, the bags removed, the pulp cakes disposed of, the bags cleansed, and the operation first de- scribed is continued, till the whole quantity of pulp pre- pared is disposed of. Defecation of the Juice. The juice of the beet, as it comes from the press, car- ries with it all the soluble parts of the root. It contains, in this state, not only sugar and icater, but other compo- nent parts, which cannot be separated by evaporation alone ; they must be precipitated by chemical agents. Ma- ny and experfiive experiments were made in search for these, which I shall not here attempt to explain. The present process is as follows : Suppose a boiler contain- ing four hundred gallons of juice ; add,^e/o?'e lighting the fire, eight pounds sulphuric acid at sixty-six degrees, one part acid, three parts water, diluted, mix quickly and thoroughly with the juice, then take nine pounds of quick- lime, weighed before it is slaked, then slake with warm 344 APPENDIX. water to the consistency of milk, throw this also into the juice, and stir the whole completely ; the fire is now to be kindled under the boiler, and its contents raised to the temperature of one hundred and ninety degrees of Fah- renheit ; then animal carbon, that has been employed in clarification, is added, and well mixed, and a portion of diluted ox blood stirred in carefully ; the fire is withdrawn, the juice allowed to settle, and is drawn off clear, through a cock placed near the bottom of the boiler. It is im- portant to observe that the juice, when the sulphuric acid is added, must not be warm. This process has failed in the hands of some imitators of M. Crespel, from a mis- take on this point. M. Dubrunfaut acknowledges that he himself committed it. Concentration of the Juice. For this purpose, one or more boilers are necessary, with which the evaporation is begun and finished ; in these the juice from the defecating boiler is received clear ; then a slow fire is kept up m the beginning, and some al- buginous matter, (white of eggs, or blood,) added, if it should seem to be required. After this, a man must at- tend closely to the boiler, and manage the fire. When froth appears, it will be his duty to throw a small piece of but- ter, or other grease, (which he should have near him,) into the vessel, which will immediately cause it to subside ; he should also have a ladle to stir it when required. When th() juice has reached the proper point, that is to say, twenty-six degrees of Baumes's areometer, when boiling, that is thirty degrees, when cold, it is time to proceed to the operation of clarifying. Clarifying. The object of this is, to separate the sirup concen- trated to thirty degrees, or near it, from the extraneous matter which it Rolds in suspension, and moreover to de- prive it, by clarifying agents, of all coloring matter, and other foreign substances which ivere in the juice, or have formed there whilst under the preceding operation, all which matter is injurious to the sugar. Clarification mav MANUFACTURE OF BEET SUGAR. 345 be divided into two distinct branches, the one chemical, having for its object, by clarifying agents, such as animal carbon, albumine, &c., to purify the sirup ; the other, me- chanical, having for its object to separite from the same, the carbon and other sohd bodies agglomerated by the al- bumine. The first is managed with a boiler, only because the action of the chemical agents employed require to be aided by heat Of all the means hitherto devised for clarification, none has been found so simple and so effective as that offered by the use of animal carbon, and albuginous or caseous matter.* We will here suppose that the object in view is to clarify the portion of sirup, supphed by the defecation of one hundred gallons of juice, that is, sixteen and a half gallons of sirup concentrated to twenty-six degrees boil- ing and thirty degrees cold ; (it follows that for any other quantity it is only required to follow the same proportion ;) to do this, we must proceed to weigh eight pounds of ani- mal carbon, and throw it into the boiler ; the sirup, when boiling, should be well stirred with the ladle, then with the skimmer ; the black agglomerated matter which rises to the surface should be broken up, and mixed again with the liquid ; when it is apparent that the carbon is sufficiently separated and mixed with the sirup, it may be left to boil for a few minutes. The sirup now assumes a turbid and murky appearance ; whilst this operation is proceeding, s quart of ox blood, or the white of four eggs, should be beat up, and diluted with water, or otherwise, two quarts- of skimmed milk- This mixture must now be thrown into the boiler, taking care to mix the whole, well together. The ebullition will, of course, have been stopped by this addition ; and it is proper, till it begins again to boil, tiiat it should be constantly stirred, to prevent the precipitation of the ingredients ; the ebullition must be kept up for a few minutes, and the sirup is then prepared for filtration. * The process we are about to describe is varied by different man ufacturers. By some, the acid is omitted altogether, and other agents ■ubstituted. vM6 APPENDIX. Filtration. This is an exceedingly simple operation ; a flannel cloth fixed to a frame is all that is required. Sirup at the density of thirty degrees cold, as it comes from the filterer, is not sufficiently concentrated to crystal- lize ; it is therefore necessary to submit it to another boil- ing, to evaporate the superabundant water it still contains, and so to produce the required crystallization. This operation is only a continuation of the concentra- ting process, and also its completion ; the same boiler, which is suitable for the first part of this process, is the one now again required, the fire must be carefully attend- ed to, the sirup skimmed when required, and, if it rises in foam, must be stopped, as before, by a piece of grease ; when the proof shows ninety and one half to ninety-one of Reaumer, two hundred and thirty-six degrees Fahren- heit, which point it may reach, if the sirup is very good, it is time to stop and empty the boiler. It would be more prudent to do so at eighty-nine and one half; the sugar would purify more easily, and, as the molasses must neces- sarily be reboiled, this supports the operation, all the bet- ter, for being a little richer in sugar. The sixteen and one half gallons, with which we began our experiment, will new be reduced to ten and one half gallons. In this state it may be turned into a vessel, to cool gradually, where it may stay for ten or twelve hours, when it will fall to the temperature of one hundred and seventy degrees, or one hundred and eighty degrees, Fah- renheit, and then may be put into the pots for crystalliza- tion. These usually contain six to eight gallons. In turning It 'nto these, masses of the crystals will be found, already, at the bottom and sides of the vessel. If the sirup is good, some attention is necessary in this operation, that the sirup should not be left to get too cold, before it is turned into die pots ; as this would, in some degree, impede the crys- tallization. These should be kept in a close room, and at a steady temperature. The pots are of a conical form, with a hole in the bottom, which is stopped with a cork or clay. Thirty-six or forty hours after the sirup has remained in MANUFACTURE OF BEET SUGAR. 347 them, and when the temperature is reduced to seventy- seven degrees, Fahrenheit, or thereabout, the cork is re- moved, and the point of the cone placed over a vessel into which the molasses (which begins immediately to run) is received. In about fifteen days, in a temperature of from sixty to sixty-five degrees, Fahrenheit, they have furnished above two thirds of their molasses. In this degree of heat L e ichole of the molasses will not separate from the sugar ; the pots are therefore removed to another room, where the temperature is kept at from one hundred and twenty to one hundred and forty degrees, Fahrenheit. There they are again placed over the recipients ; but, before doing. this, a rod is. thrust through the hole in the point of the cone, to break the incrustation of sugar within, and facilitate the draining of the molasses. After remaining here fifteen days, the sugar must be completely freed from the molas- ses, and must now be taken out. For this purpose, the cone is placed on its base, shook against the platform on which it stands, and, in an hour or so, the sugar is de- tached in the form of the cone ; the point of this is im- pregnated with molasses, and is to be removed. It makes an inferior sort of brown sugar. The rest of the product will be generally fine, light colored sugar, which is found to produce a larger proportion of refined sugar to the weight, than any made from the cane, and is, therefore, much preferred by refiners. The sugar made at the be- ginning of the season is easier made, and better than that made later. The molasses collected in the process of crystallization, is reboiled, and subjected to the same process as the sir- up, and a certam portion of sugar is the result ; the re- siduum is used for many purposes, and is especially use- ful for cattle. For further particulars, see the w'ork cited ; also, a man- ual translated from portions of the treatise of M. M. Blachette, Zoega, and J. De Fontenelle, and published by Marsh, Capen, Lyon, and Webb, and a more recent work, on the same subject, by David Lee Child. 348 APPENDIX. VIII. — Voltaic Electrical Engraving. The following account of the process of engraving in relief, upon copper-plates, by means of voltaic electricity, is from the London Atheneum, for October 27, 1839. A previous number of this paper contained a letter from M. Jacobi, detailing his experiments on the subject ; and it appears that Mr. Thomas Spencer, of Liverpool, had also devoted much attention to the subject, and had noi only succeeded in doing all that M. Jacobi had done, but had surmounted difficulties which M. Jacobi could not. Mr. Spencer proposes, by means of voltaic electricitv, " to engrave in rehef upon a plate of copper ; deposit a voltaic copper-plate, having the lines in relief; obtain a facsimile of a medal, reverse or obverse, or of a bronze' cast ; to obtain voltaic impression from plaster, or clay , and to multiply the number of already-engraved copper- plates." The results which he has already obtained are said to be very beautiful. Take a plate of copper, such as is used by an engrav- er ; solder a piece of copper wire to the back part of it, and then give it a coat of wax; (this is best done by heat- ing the plate, as well as the wax ;) then write or draw the design on the wax, with a black lead pencil, or a point. The wax must now be cut through with a graver, or steel point, taking special care that the copper is thoroughly exposed, in every line. The shape of the tool or graver employed must be such, that the lines made are not V- shape, but, as nearly as possible, with parallel sides. The plate should next be immersed in dilute nitric acid ; say three parts water to one of acid. It will at once be seen whether it is strong enough, by the green color of the so- lution, and the bubbles of nitrous gas evolved from the copper. Let the plate remain in it long enough for the exposed lines to get slightly corroded, so that any minute portions of wax, which might remain, may be removed. The plate, thus prepared, is placed in a trough, separat- ed into two divisions by a porous partition of plaster of Paris, or earthenware ; the one division being filled with a saturated solution of sulphate of copper, and the othei VOLTAIC ELECTRICAL ENGRAVING. 349 with a saline, or acid, solution. The plate to be engrav- ed is placed in the division containing the solution of the sulphate of copper, and a plate of zinc, of equal size, is placed in the other division. A metallic connection is .hen made between the copper and zinc plates, by means of the copper wire soldered to the former ; and the vol- taic circle is thus completed. The apparatus is then left for some days. As the zinc dissolves, metalhc copper is precipitate J, from the solution of the sulphate on the copper-plate, wherever the wax has been removed by the engraving tool. After the vohaic copper has l^en deposited in the lines engraved in the wax, the surface of it will be found to be more or less rough, according to the quickness of the action. To remedy this, rub the surface with a piece of smooth flag, or pumice-stone, with water. Then heat the plate, and wash off the wax ground, with spirits of turpentine and a brush. The plate is now ready to be printed from, at an ordinary press. In this process, care must be taken that the surface of the copper in the lines be perfectly clean, as otherwise, the deposited copper will not adhere with any force, but is easily detached w^hen the wax is removed. It is in order to insure this perfect cleanness of the copper, that it is immersed in dilute nitric acid. Another cause of imperfect adhesion of the deposited copper, which Mr. Spencer has pointed out, is the presence of a minute portion of some other metal, such as lead, which, by be- ing precipitated before the copper, forms a thin film, which prevents the adhesion of the subsequently deposit- ed copper. This circumstance may, however, be turn- ed to advantage, in some of the other applications of Mr. Spencer's process, where it is desirable to prevent the adhesion of the deposited copper. In copying a coin, or medal, Mr. Spencer describes two methods. The one is by depositing voltaic copper on the surface of the medal, and thus forming a mould, from which, facsimiles of the original medal may readily be ob- tained, by precipitating copper into it. The other is even more pxpeditious. Two pieces of clean milled II. 30 XII. 350 APPENDIX. sheet lead are taken, and the medal being placed between them, the whole is subjected to pressure in a screw-press, and a complete mould, of both sides, is thus formed in . the lead, showing the most delicate lines, (in reverse.) Twenty, or even a hundred, of these, may be so formed on a sheet of lead, and the copper deposited by the vol- taic process, with the greatest facility. Those portions of the surface of the lead, which are between the moulds, may be varnished, to prevent the deposition of the lead, or, a whole sheet of voltaic copper having been deposi- teci^ the medals may afterwards be cut out. When cop- per is to be deposited on a copper mould, or medal, care must be taken to prevent the metal deposited adhering. This Mr. Spencer effects by heating the medal, and rubbing a small portion of wax over it. This wax is then wiped off, a sufficient portion always remaining to pre- vent adhesion. Enough has been said, to enable any one to repeat, and follow up, Mr. Spencer's interesting experiments. The variations, modifications, and adaptations, of them, are endless ; and many new ones will naturally suggest themselves to every scientific reader. IX. — Photogenic Drawing. Some account of Photography, or Photogenic drawing has been introduced in the previous pages of this work The following article, containing a description of the pro- cess, is from a work on this subject, published by M. Da- guerre, and translated by Mr. Memos, in 1839. The designs are executed upon thin plates of silver, plated on copper. Although the copper serves princi- pally to support the silver foil, the combination of the two metals tends to the perfection of the effect. The silver must be the purest that can be procured. As to the cop- per, its thickness ought to be sufficient to maintain the perfect smoothness and flatness of the plate, so that the images may not be distorted by the warping of the tablet; but unnecessary thickness, beyond this, is to be avoided, on account of the weight. The thickness of the two metals united ought not to exceed that of a stout card PHOTOGENIC DRAWING. 351 The process is divided into five operations. 1. The first consists in polishing and cleaning the plate, in order to prepare it for receiving the sensitive coating, upon which the light traces the design. 2. The second is to apply this coating. 3. The third is the placing the prepared plate, proper- ly, in the camera obscura, to the action of hght, for the purpose of receiving the image of Nature. 4. The fourth brings out this image, which, at first, is not visible, on the plate being withdrawn from the camera obscura. 5. The fifth, and last, operation has, for its object, to remove the sensitive coating on w^hich the design is first impressed, because this coating would continue to be af- fected by the rays of light, a property w^hich would ne- cessarily and quickly destroy the picture. First Operation. — Preparing the Plate. The requisites, for this operation, are, A small phial containing olive oil. Some very finely-carded cotton. A small quantity of very fine pumice powder, ground with the utmost care, tied up in a bag of muslin, suffi- ciently thin to allow the powder to pass through, when the bag is shaken. A phial of nitric acid, diluted with water, in the pro- portion of one pint of acid, to sixteen pints of distilled water. These proportions express volume, not weight. A frame of iron wire, upon which to place the plate, in order that it may be heated by means of a spirit-lamp. Lastly, a small spirit-lamp. As already stated, these photographic delineations are executed upon silver, plated on copper. The size of the plate will depend, of course, on the dimensions of the camera. We must begin, by polishing it carefully. To accomplish this, the surface of the silver is powdered all over with the pumice, by shaking the bag, without touch- *ng the plate. Next, with some cotton dipped in a little olive oil, the operator rubs die plate gently, rounding his strokes. Dur- 352 APPENDIX. « ing this operation, the plate must be laid flat upon several folds of paper, care being taken to renew these, from time to time, that the tablet be not twisted from any inequality in the support. The pumice must be renewed, and the cotton changed^ several times. The mortar, employed for preparing the pumice, must be of porphyry. The powder is afterwards finished, by grinding upon polished glass with a glass muller, and very pure water. And lastly, it must be perfectly dried. It will be readily apprehended, of what importance it is to attend to these directions, since upon the high polish of the silver, depends, in a great measure, the beauty of the future design. When the plate is well polished, it must next be cleaned, by powdering it all over, once more, with pumice, and rubbing with dry cot- ton, always rounding and crossing the strokes, for it is impossible to obtain a true surface by any other motion of the hand. A little pledget of cotton is now rolled up, and moistened with the diluted acid already mentioned, by applying the cotton to the mouth of the phial, and in- verting it, pressing gently, so that the centre only of the cotton may be wetted, and but slightly, care being taken, not to allow any acid to touch the fingers. The surface of the plate is now rubbed equally, all over, with the acid, applied by the pledget of cotton. Change the cot- ton, and keep rubbing, rounding as before, that the acid may be equally spread, yet in so small a quantity, as just to skim the surface, so to speak. If, as frequently hap- pens, the acid run into small drops, from the high polish, change the cotton repeatedly, and break down the glob- ules as quickly as possible, but always by gently rubbing, for if allowed to rest, or to run upon the plate, they will leave stains. It will be seen when the acid has been properly diffused, from the appearance of a thin veil, spread regularly over the whole surface of the plate. Once more powder over pumice, and clean it with fresh cotton, rubbing as before, but very slightly. The plate is now to be subjected to a strong heat. It is placed upon the wire frame, the silver upwards. The spirit-lamp is applied below the hand, moving it round. PHOTOGENIC DRAWING. 353 the flame touching and playing upon the copper. This operation being continued at least five minutes, a white strong coating is formed all over the surface of the silver, if the lamp has been made to traverse with proper regu- larity. The lamp is now withdrawn. A fire of charcoal may be used instead of the lamp, and is, perhaps, prefera- ble, the operation being sooner completed. In this latter case, the wire frame is unnecessary, because the plate may be held by one corner with pincers, and so held over the fire, moving it at the same time, till all is equally heat- ed, and the veil appear, as before described. The plate is now to be cooled, suddenly^ by placing it on a cold substance, such as a mass of metal, or stone, or, best of all, a marble table. When perfectly cold, it is to be again polished, an operation speedily performed, since the gummy appearance merely has to be removed, which is done by the dry pumice and cotton, repeated several times, changing the cotton frequently. The polishing being thus completed, the operation of the acid is to be repeated three diiferent times, dry pumice being powder- ed over the plate, each time, and polished off very gen- tly with the cotton, which must be very clean, care being taken not to breathe upon the plate, or to touch it with the fingers, or even with the cotton upon which the fingers have rested ; for the slightest stain upon the surface will be a defect in the drawing. When the plate is not intended for immediate use, the last operation of the acid is not performed. This allows any number of plates to be kept prepared, up to the last slight operation ; and they may be purchased in this state, if required. It is, however, indispensable, that a last operation by acid, as described, be performed on every plate, immediately before it be placed in the camera. Lastly, every particle of dust is removed, by gently cleaning the whole edges, and back, also, with cotton. Second Operation. — Coating the Plate. For this operation, we require, A box. A small board. 30* 354 APPENDIX. Four small metallic bands, the same substance as the })lates. A small handle, and a box of small tacks. A phial of iodine. The plate is first to be fixed on the board, by means of the metallic bands, with their small catches and tacks. The iodine is now put into a little dish at the bottom of the box. It is necessary to divide the iodine into pieces, in order to render the exhalation the more extensively and more equally diffused ; otherwise, it would form cir- cles in the centre of the plate, which would destroy this essential requisite. The board is now fitted into its po- sition, the plate face downwards, the whole being support- ed by small brackets projecting from the four corners of the box, the lid of which is then closed. In this posi- tion, the apparatus remains till the vaporization of the iodine, which is condensed upon the plate, has covered its surface with a fine coating of a yellow gold color. If this operation be protracted, the gold color passes into violet, which must be avoided ; because in this state the coating is not so sensitive to the impressions of hght. On the contrary, if the coating be too pale, the image of \ature in the camera will be too faint to produce a good picture. A decided gold color, — nothing more, nothing less, — is the only assurance that the ground of the future picture is duly prepared. The time for this cannot be determined, because it depends on several circumstances. Of these, the two principal are the temperature of the apartment, and the state of the apparatus. The opera- tion should be left entirely to spontaneous evaporation of the iodine ; or, at all events, no other heat should be used, than what can be applied through the temperature of the room, in which the operation takes place. It is also very important, that the temperature of the inside of the box be equal to that of the air outside ; for, otherwise, a depo- sition of moisture takes place upon the plate, a circum- stance most injurious to the final result. Secondly, as respects the state of the apparatus ; the oftener it has been used, the less time is required, because, in this case, the interior of the box being penetrated with the vapors PHOTOGENIC DRAWING. 355 of iodine, these arise from all sides, condensing thus more equally and more rapidly upon the surface of the plate ; a very important advantage. Hence, it is of consequence to leave always a small quantity of iodine in the cup, and to protect this latter from damp. Hence, likewise, it is obvious, that an apparatus of this kind, which has been some time in use, is preferable to a new box ; for, in the former, the operation is always more expeditiously performed. Since, from these causes, the time cannot be fixed, a priori, and may vary from five minutes to half an hour, rarely more, unless the weather be too cold, means must be adopted for examining the plate, from time to time. In these examinations, it is important not to allow the fight to fall directly upon the plate. Also, if it appear that the color is deeper on one side of the plate than the other, to equalize the coating, the board must be re- placed, not exactly in its former position, but turned one quarter round, at each inspection. In order to accom- plish these repeated examinations, without injuring the sensibility of the ground, or coating, the process must be conducted in a darkened apartment, into which the light is admitted sideways, never from the roof ; the door left a little ajar answers best. When the operator would inspect the plate, he raises the lid of the box, and, lifting the board with both hands, turns up the plate quickly, and very fittle fight suffices to show him the true color of the coating. If too pale, the plate must be instantly replaced, till it attain the proper gold tone ; but if this tint be passed, the coating is useless, and the operations must be repeated from the commencement of the first. From description, this operation may, perhaps, seem difficult ; but with a little ])ractice, one comes to know, pretty nearly, the precise interval necessary to produce the true tone of color, and also to inspect the plate with great rapidity, so as not to allow time for the light to act. When the coating has reached the proper tone of yel- low, the plate, with the board to w^hich it is fixed, is slip- ped into the frame, and thus adjusted, at once, in the ca- mera. In this transference, care must be taken to protect 356 APPENDIX. the plate from the light. A taper should be used ; and even with this precaution, the operation ought to be per- formed as quickly as possible, for a taper will leave traces of its action, if continued for any length of time. We pass now to the third operation, that of the ca mera. If possible, the one should immediately succeed the other ; the longest interval between the second and third ought not to exceed an hour. Beyond this space, the action of the iodine and silver no longer possesses the requisite photogenic properties. Observanda. — Before making use of the box, the oper- ator should clean it thoroughly, turning it bottom upwards, in order to empty it of all the particles of iodine which may have escaped from the cup, avoiding, at the same time, touching the iodine with the fingers. During the operation of coating, the cup ought to be covered with a piece of gauze stretched on a ring. The gauze regulates the evaporation of the iodine, and also prevents the com- pression of the air, on the lid being shut, from scattering the particles of iodine, some of which, reaching the plate, would leave large stains on the coating. For the same reason, the top should always be let down with the great- est gentleness, not to raise the dust in the inside, the par- ticles of which, being charged with the vapor of the io dine, would certainly reach and damage the plate. Third Operation. — The Camera. The apparatus, required in this operation, is limited tt the camera obscura. This third operation is that, in which, by means ol light, acting through the camera. Nature impresses an image of herself on the photographic plate, enlightened by the sun, for then the operation is more speedy. It is easy to conceive that this operation, being accom- plished only through the agency of light, will be the more rapid in proportion as the objects, whose photographic images are to be delineated, stand exposed to a strong illumination, or in their own nature present bright lines, and surfaces. After having placed the camera in front of the land PHOTOGENIC DRAWING. 357 scape, or facing any other object of which it may be desi- rable to obtain a representation, the first essential is a per- fect adjustment of the focus, that is to say, making your arrangements, so as to obtain the oudines of the subject with great neatness. This is accomplished, by advancing or withdrawing the frame of the obscured glass, which re- ceives the images of natural objects. The adjustment being made with' satisfactory precision, the movable part of the camera is fixed by the proper means, and the ob- scured glass being withdrawn, its place is supplied by the apparatus, with the plate attached, as already described, and the whole secured by small brass screws. The light is, of course, all this time excluded by the inner doors. These are now opened, by means of two semicircles, and the plate is disposed, ready to receive its proper impres- sions. It remains only to open the aperture of the ca- mera, and to consult a watch. This latter is a task of some nicety, inasmuch as noth- ing is visible, and it is quite impossible to determine the time necessary for producing a design, this depending entirely on the intensity of the light on the objects, the imagery of which is to be reproduced. At Paris, for ex- ample, this varies from three to thirty minutes. It is likewise to be remarked, that the seasons, as well as the hour of the day, exert considerable influence on the celerity of the operation. The most favorable lime is from seven to three o'clock ; and a drawing which, in the months of June and July, at Paris, may be taken in three or four minutes, will require five or six, in May or August ; seven or eight, in April and September ; and so on, in proportion to the progress of the season. These are only general data for very bright, or strongly illumin- ated, objects ; for it often happens, that twenty minutes are necessary, in the most favorable months, when the objects are entirely in shadow. After what has just been said, it will readily occur to the reader, that it is impossible to specify, with precision, the exact length of time necessary to obtain photographic designs. Practice is the only sure guide ; and, with this advantage, one soon comes to appreciate the required 358 APPENDIX. time, very correctly. The latitude is, of course, a fixed element in this calculation. In the south of France, for example, and generally in all those countries, in which light has great intensity, as Spain, Italy, &c., we can easily understand that these designs must be obtained with greater, promptitude, than in more northern regions. It is, however, very important, not to exceed the time nec- essary, in different circumstances, for producing a design ; because, in that case, the lights in the drawing will not be clear, but will be blackened by a too-prolonged solariza- tion. If, on the contrary, the time has been too short, the sketch will be very vague, and without the proper details. Supposing that he has failed in a first trial, by with- drawing the tablet too soon, or by leaving it too long ex- posed, the operator, in either case, should commence with another plate immediately ; the second trial, being corrected by the first, almost insures success. It is even useful, in order to acquire experience, to make some es- says of this kind. In this stage of the process, it is the same as for the coating ; we must hasten to the next operation. When the plate is withdrawn from the camera, it should imme- diately be subjected to the subsequent process ; there ought, at most, not to be a longer interval than an hour, between the third and fourth operations ; but one is al- ways surest of disengaging the images, when no space has been allowed to intervene. Fourth Operation. — Mercurialj or Disengaging, Process. Here are required, a phial of mercury, containing at least three ounces. A lamp, with spirit of wine. An iron vessel, prepared with apparatus for receiving he plate, and submitting it to the vapor of mercury. A glass funnel with a long neck. By means of the funnel, the mercury is poured into the cup, at the bottom of the larger vessel. The quan- tity must be sufficient to cover the bulb of a thermome- ter. Afterwards, and throughout the remaining opera- nons, no light, save a taper, can be used. PHOTOGENIC DRAWING. iibi The board, with the plate affixed, is now to be with- drawn from the frame already described, as adapted to the camera. The board and plate are placed within the ledges of the black iron vessel, at an angle of forty-fire degrees, the tablet with sketch downwards, so that it can be seen through the glass. The top is then gently put down, so as not to raise up particles of the mercury. When all things are thus disposed, the spirit lamp is lighted, and placed under the cup containing mercury. The operation of the lamp is allowed to continue till the thermometer, the bulb of which is covered by the mer- cury, indicates a temperature of sixty degrees centigrade, [140°, Fahrenheit.] The lamp is then immediately with- drawn. If the thermometer has risen rapidly, it will con- tinue to rise without the aid of the lamp ; but this elevation ought not to exceed seventy-five degrees centigrade, [167° Fahrenheit.] The impress of the image of Nature existy upon the plate, but it is invisible. It is not till after the lapse cf several minutes, that the faint tracery of objects begins to appear, of which the operator assures himself, by looking through the glass, by the light of a taper, using it cau- tiously, that its rays may not fall upon, and injure, the nas- cent images of the sketch. The operation is continued till the thermometer sink to forty-five degrees centigrade, [113°, Fahrenheit;] the plate is then withdrawn, and this operation completed. When the objects have been strongly illuminated, or when the action in the camera has been continued rather too long, it happens that this fourth operation is completed before the thermometer has fallen even to fifty-five degrees centigrade. One may always know this, however, by ob- serving the sketch through the glass. It; is necessary, after each operation, to clean the inside of the apparatus carefully, to remove the slight coating of mercury adhering to it. When the apparatus has to be packed, for the purpose of removal, the mercury is with- drawn by a small cock, inclining the vessel to that side. One may now examine the sketch, by a feeble light, in order to be certain that the processes hitherto have sue- 360 APPENDIX. ceeded. The plate is now detached from the board, and the little bands of metal, which held it there, are carefully cleaned with pumice and water, after each experiment ; a precaution rendered necessary from the coating both of iodine and mercury, which they have acquired. The plate is now deposited in the grooved box, until it undergoes the fifth and last operation. This may be deferred, if not con- venient ; for the sketch may now be kept for months, in its present state, without alteration, provided it be not too frequently inspected by the full daylight. Fifth Operation. — Fixing the Impression. The object of this final process, is to remove from the tablet the coating of iodine, which, continuing to decom- pose by light, would otherwise speedily destroy the de- sign, when too long exposed. For this operation, the re- quisites are, A saturated solution of common salt, or a weak solu- tion of hyposulphite of pure soda. An apparatus of japanned white iron, for washing the designs. Two square troughs, of sheet copper. A vessel for distilled w^ater. In order to remove the coating of iodine, common salt is put into a bottle, with a wide mouth, which is filled one fourth with salt and three fourths with pure water. To dissolve the salt, shake the bottle, and, when the whole forms a saturated solution, filter through paper. This solution is prepared in large quantities, beforehand, and kept in corked bottles. « Into one of the square troughs, pour the solution, filling it to the height of an inch ; into the other, pour, in like manner, your water. The solution of salt may be re- placed by one of hyposulphite of soda, which is even preferable, because it removes the iodine entirely, which the saline solution does not always accomplish, especially when the sketches have been laid aside for some time, be- tween the fourth and fifth operations. It does not require to be warmed, and a less quantity is required. First, the plate is placed in common water, poured into PHOTOGENIC DRAWING. 361 a trough, plunging and withdrawing it immediately, the surface merely requiring to be moistened ; then plunge it into the saline solution, which latter would act upon the drawing, if not previously hardened by the washing in pure water. To assist the effect of the sahne solutions, the plate is moved about in them, by means of a little hoop of coppei wire. When the yellow color has quite disap- peared, the plate is lifted up with both hands, care being taken not to touch the drawing, and plunged again into the first trough of pure water. Next, the apparatus and the bottle having been previ- ously prepared, made very clean, and the bottle filled with ' distilled water, the plate is withdrawn from the trough, and being instantly placed upon the inclined plane, distilled water, hot, but not boiling, is made to flow in a stream over its whole surface, carrying away every remaining portion of the saline wash. If hyposulphite has been used, the distilled water need not be so hot, as when common salt has been em- ployed. Not less than a quart of distilled water is required, when the design is, in its dimensions, eight and a half by six and a half inches. The drops of water, remaining on the plate, must be removed by forcibly blowing upon it, for otherwise, in drying, they would leave stains on the drawing. Hence, also, will appear the necessity of using very pure water ; for if, in this last washing, the liquid con- tain any admixture of foreign substances, they will be de- posited on the plate, leaving behind numerous and per- maq^nt stains. To be assured of the purity of the wa- ter, let a drop fall upon a piece of polished metal ; evaporate by heat, and if no stain be left, the water is pure. Distilled water is always sufficiently pure, without this trial. After this washing, the drawing is finished ; it remains only to preserve it from the dust, and from the vapors that might tarnish the silver. The mercury, by the ac- tion of which the images are rendered visible, is par- tially decomposed ; it resists washing, by adhesion to tho silver, but cannot endure the slightest rubbing. II. 31 • XII. 362 APPENDIX. To preserve these sketches, then, place them in squaies of strong pasteboard, with a glass over them, and frame the whole in wood. They are thenceforth unalterable, even by the sun's light. In travelling, the collector may preserve his sketches in a box ; and, for greater security, may close the joints of tlie lid with a collar of paper. It is necessary to state, that the same plate may be em- ployed for several successive trials, provided the silver be not polished through to the copper. But it is very im- portant, after each trial, to remove the mercury immedi- ately, by using the pumice powder with oil, and changing the cotton frequently during the operation. If this be neglected, the mercury finally adheres to the silver ; and fine drawings cannot be obtained, if this amalgam be pres- ent. They always, in this case, want firmness, neatness, and vigor of outline, and general effect. \ A number of experiments, with prepared paper, have been made by different individuals, with various degrees of success, in Great Britain. From among the notices ■)f these experiments, as they have appeared in different ournals, the following selections have been made. In the spring of 1834, Mr. Talbot began a series of experiments, with the hope of turning to useful account the singular susceptibility evinced by the nitrate of silver, when exposed to the rays of a powerful light. He says, " In the course of my experiments directed to that end, I have been astonished at the variety of effects, whk^ I have found produced, by a very limited number of differ- ent processes, when combined in various ways ; and also, at the length of time, which sometimes elapses, before the full effect of these manifests itself with certainty. For I have found, that images formed in this manner, which have appeared in good preservation, at the end of twelve months from their formation, have nevertheless somewhat altered, during the second year." He was in- duced, from this circumstance, to watch more closely the progress of this change, fearing that, in process of time. PHOTOGENIC DRAWING. 363 all his pictures might be found to deteriorate. This, how ever, was not the case, and several have withstood the action of the Hght, for more than five years. The images, obtained by this process, are themselves white, but the ground is differently and agreeably color- ed ; and, by slightly varying the proportions, and some tri- fling details of manipulation, any of the following colors were readily obtained ; light blue, yellow, pink, brown, black, and a dark green, nearly approaching to black. The first objects, to which this process was applied, were leaves and flowers, which it rendered with extraor- dinary fidelity, representing even the veins and minute hairs with which they were covered, and which were fre- quently imperceptible, without the aid of a microscope. Mr. Talbot goes on to mention, that the following con- siderations led him to conceive the possibility of discov- ering a preservative process. Nitrate of silver, which has become darkened by exposure to the light, is no lon- ger the same chemical substance as before ; therefore, if chemical re-agents be applied to a picture, obtained in the manner already mentioned, the darkened parts will be acted upon in a different manner from those which re- tain their original color, and, after such action, they will probably be no longer affected by the rays of the sun, or, at all events, will have no tendency to assimilate b} such exposure ; and, if they remain dissimilar, the pic- ture will continue distinct, and the great difficulty be over come. The first trials of the inventor, to destroy the suscepti- bility of the metallic oxide, were entirely abortive ; but he has at length succeeded, to an extent equal to his most sanguine expectations. The paper, employed by Mr. Talbot, is superfine writing-paper ; this is dipped into a weak solution of common salt, and dried with a towel, till the salt is evenly distributed over the surface ; a solu- tion of nitrate of silver is then laid over one side of the paper, and the whole is dried by the heat of the fire. It is, however, necessary to ascertain, by experiment, the exact degree of strength requisite in both the ingredi- ents ; for, if the salt predominates, the sensibility of the 364 APPENDIX. paper gradually diminishes, in proportion to this excess, till the effect almost entirely disappears. In endeavoring to remedy this evil, Mr. Talbot discov- ered, that a renewed application of the nitrate not only obviated the difficulty, but rendered the preparation more sensitive than ever ; and, by a repetition of the same pro- cess, the mutability of the paper will increase to such a degree, as to darken of itself, without exposure to the light. This shows, that the attempt has been carried too far, and the object of the experimentalist must be to ap- proach, without attaining this condition. Having prepar- ed the paper, and taken the sketch, the next object is, to render it permanent, by destroying the susceptibility of the ingredients for this purpose. Mr. Talbot tried am- monia, and several other re-agents, with little success, till the iodine of potassium, greatly diluted, gave the desired result : this hquid, when applied to the drawing, produ- ced an iodine of silver, a substance insensible to the ac- tion of light. This is the only method of preserving the picture in its original tints ; but it requires considerable 'licety, and an easier mode is sufficient for ordinary pur- poses. It consists in immersing the picture in a strong solution of salt, wiping ofi' the superfluous moisture, and drj^ing it by the heat of the fire ; on exposure to the sun, the white parts become of a pale lilac, which is per- manent and immovable. Numerous experiments have shown the inventor, that the depth of these tints depends on the strength of the solution of sah. He also mentions, that those prepared by iodine become a bright yellow, un- der the influence of heat, and regain their original color ^on cooling. Without the application of one of these preserv- atives, the image will disappear, by the action of the sun ; but, if enclosed in a portfoho, will be in no danger of altera- tion : this, Mr. Talbot remarks, will render it extremely convenient to the traveller, who may take a copy of any object he desires, and apply the preservative at his leisure. In this respect, Mr. Talbot's system is superior to that of M. Daguerre, since it would be scarcely possible for a traveller to burden himself with a number of metallic plates, which, in the latter process, are indispensable. PHOTOGENIC DRAWING. 365 An advantage of equal importance exists in the rapid- ity with which Mr. Talbot's pictures are executed ; for which half a second is considered sufficient ; a circum- stance that gives him a better chance of success in delin- eating animals, or fohage. — Foreign Quarterly Review. J^otice of a cheap and simple method of preparing pa- per for Photograpic Drawings in which the use of any salt of silver is dispensed with : by Mungo Ponton, Esq., F. R. S. E., Foreign Secretary Society of Arts for Scotland. Communicated by the Society of Arts.* While attempting to prepare paper with the chromate of silver, for which purpose I used first the chromate of potash, and then the bichromate of that alkah, I discov- ered, that, when paper was immersed in the bichromate of potash alone, it was powerfully and rapidly acted on b'y the sun's rays. It accordingly occurred to me, to try paper so prepared, to obtain drawings, though I did not at first see how they were to be fixed. The result ex- ceeded my expectations. When an object is laid in the usual way on this paper, the portion exposed to the light speedily becomes tawny, passing more or less into a deep orange, according to the strength of the solution, and the intensity of the light. The portion covered by the ob- ject retains the original bright yellow tint, which it had before exposure, and the object is thus represented yellow upon an orange ground, there being several gradations of shade, or tint, according to the greater or less degree of traasparency in the difierent parts of the object. In this state, of course, the drawing, though very beau- tiful, is evanescent. To fix it, all that is required is careful immersion in water, when it will be found that those portions of the salt, which have not been acted on by the light, are readily dissolved out, while those which have been exposed to the light are completely fixed in the paper. By this second process, the object is obtained white, upon an orange ground, and quite permanent. If exposed, for many hours together, to strong sunshine, the * Read before the Society of Arts for Scotland, 29th May, 1839. 31* 366 . APPENDIX. color of the ground is apt to lose in depth, but not moie so than most other coloring matters. The action of light, on the bichromate of potash, dif- fers from that upon the salts of silver. Those of the lat- ter, which are blackened by light, are of themselves in- soluble in water ; and it is difficult to impregnate paper with them, in an equable manner. The blackening seems to be caused by the formation of oxide of silver. In the case of the bichromate of potash, again, that salt is ex- ceedingly soluble, and paper can be easily saturated with it. The agency of light not only changes its color, but deprives it of solubility, thus rendering it fixed in the pa- per. This action appears to me to consist in the disen- gagement of free chromic acid, which is of a deep red color, and which seems to combine with the paper. This is rendered more probable, from the circumstance, that the neutral chromate exhibits no similar change. The active power of the light, in this instance, resides principally in the violet rays, as is the case with the black- ening of the salts of silver. To demonstrate this, three similar flat bottles w^re filled, one with ammoniuret of copper, which transmits the violet rays, one with bichro- mate of potassa, transmitting the yellow rays, the third, with tincture of iodine, transmitting the red rays. The paper was readily acted on through the first, but scarcely, if at all, through the seconc and third ; although much more light passed through the bottle filled with bichromate of potassa, than through the one filled with ammoniuret of copper. The best mode of preparing paper with bichromate of potash is, to use a saturated solution of that salt ; soak the paper well in it, and then dry it rapidly, at a brisk fire, excluding it from daylight. Paper, thus prepared, acquires a deep orange tint, on exposure to the sun. If the solution be less strong, or the drying less rapid, the color will not be so deep. A pleasing variety may be made, by using sulphate of indigo along with the bichromate of potash, the color of the object, and of the paper, being then of different shades PHOTOGENIC DRAWING. 367 of green. In this way, also, the object may bq repre- sented of a darker shade than the ground. Paper, prepared with bichromate of potash, is equall}/ sensitive with most of the papers, prepared with salts of silver, though inferior to some of them. It is not suffi ciently sensitive for the camera obscura, but answers quite well for taking drawings from dried plants, or for copying prints, &c. Its great recommendation is, its cheapness, and the facility with which it can be prepared. The price of the bichromate of potash is 2s. 6d. per lb., whereas, of the nitrate of silver, only half an ounce can be obtained for that sum. The preparing of paper, with the salts of silver, is a work of extreme nicety, whereas, both the preparing of the paper with the bichromate of potash, and the subsequent fixing of the images, are matters of great simplicity ; and I am therefore hopeful, that this method may be found of considerable practical utility, in aiding the operations of the lithographer. — Jameson's Journal^ Apiil to July, 1839 GLOSSARY. Many words, not contained in this Glossary, will be found de* fined or described, in the body of the Work, in their proper places. For these, see Index. Acescent, becoming sour. Acetate, a salt, containing acetic acid. Acetic acid, a vegetable acid which exists in vinegar. Acetous, having the character of vinegar. Acetous fermentation, the fermentation which produces vinegar. Acicular, shaped like needles. Acid, a substance, or fluid, which turns vegetable blues to a red, and forms saline compounds with alkalies, &c. Most of the acids con- tain oxygen. Albumen, a. fluid found in living bodies, which coagulates by heat. White of egg is an example. Alkali, a substance in chemistry, which turns vegetable blues to a green, and combines with acids, forming salts. Alloy, a compound of different metals. Alumine, an earth, which exists in clay, alum, &c. Aluminium, a metal, which is the basis of alumine. Amalgam, a compound of mercury with another metal. Ammonia, volatile alkali. Amorphous, not having a determinate or certain form. Argillaceous, containing clay, or resembling it. Argillaceous schist, common slate. Arseniuret, a compound with arsenic. Barilla, the ashes of certain maritime plants. Barometer, an instrument for measuring the weight of the atmosphere. Base, an ingredient in a chemical compound. Thus, sulphuric acid is found combined with various bases, such as soda, magnesia, &c. Bichloride, a double chloride. A compound, having two proportionals of chlorine. Boracic acid, a compound of oxygen and boron, which last is a simple combustible substance. Borates, compounds of boracic acid with a base. Brake, or Break, a lever, which is occasionally pressed down upon the wheel of a carriage, to retard its velocity. Bromide, a compound of bromine and some other substance. Bromine, an elementary substance, related to iodine and chlorine, and found in sea water. 370 ' GLOSSARY. Camera lucida, > optical instruments, by which the images of ob- Cainera obscura,) }ects, as, for example, buildings or trees, are thrown upon a paper, or other plane surface. Carbonaceous, containing carbon or coal. Carbon, a simple inflammable body, forming the principal part of wood and coal, and the whole of the diamond. Carbonate, a compound or a salt, containing carbonic acid. Carbonic acid, a compound gas, consisting of carbon and oxygen. It has lately been obtained in a solid form. Carbonic oxide, a gas composed of carbon combined with the smal- lest quantity of oxygen. Carbojiization, conversion into coal. Carburetted hydrogen, a gas, composed of carbon and hydrogen ; as coal gas. Carburet, a name given to certain compound substances, of which carbon forms a part. Caseous, having the consistence of cheese. Centre of gravity, that point in a body, about which all the parts are equally balanced. Centrifugal, tending to fly off" from the centre. Chloride, a compound of chlorine and some other substance. Chlorine, a simple substance, formerly called oxymuriatic acid. In its pure state, it is a gas, and, like oxygen, supports the combustion of some inflammable substances. Chromate, a combination of chromic acid. Chromium, a brittle metal, of a yellowish white color. Chromic acid, an acid of which chromium is the basis. Chromate, a compound of chromic acid with some other substance, or base. Clay schist, common slate. Cohesive attraction, the force by which the particles of a body cohere together. Coluber, a snake, having plates on the belly and scales on the tail. Comparative anatomy, the science which treats of the structure of other animals, compared with that of man. Concentric, having the same centre. Conic sections, the curves produced by cutting across a cone, in diff*er ent directions. Cupreous, containing copper. Cycloid, the curve described by a point in the circumference of a cir- cle, \^hile the circle rolls along a straight line. Cylinder, a figure with circular ends and straight, parallel sides. A round ruler and a wafer box are rough examples of the cylindrical Debris, fragments, or remains, of disintegrated rocks. Deliquescent, dissolving by fluid absorbed from the atmosphere. Disintegrated, broken up or crumbling, for the most part, by the ac- tion of air and moisture. Eccentric, or excentric. This term is applied to a wheel, the axis of which is not in its centre. Effervescence, a motion resembling boilini;. GLOSSARY. * 371 Efflorescence, the conversion of crystals into powder by the loss of their water of crystallization. Electro-magnetism, a science which shows the connexion of elec- tricity and magnetism. Epicycloid, the curve described by a point in the circumference of one circle, while rolling upon the circumference of another. Flange, or Flanch, a rim, or part projecting from the whole circum- ference. Flanges are used in the wheels of rail-road cars, to pre- vent them from slipping off the track ; also, at the ends of iron pipes, to enable them to be screwed together. Flocculent, resembling locks of down, or cotton. Fluate of lime, or Fluor spar, lime combined with fluoric acid. At Derbyshire, in England, it is found in crystalline masses, beautifully variegated with purple. Flush, even, or in the same surface. Friction, the rubbing of surfaces together. Friction rollers, little wheels, or cylinders, used to diminish friction. Fulcrum, the point of support on which a lever rests. Gallate, a salt, formed of gallic acid and a base. Gallic acid, an acid obtained from nutgalls. Gear, the teeth of wheels, by which one moves another. Gelatin, an animal substance which is dissolved by hot water, ana which forms common glue. Geognostic, appertaining to a knowledge of the earth's structure. Geological strata, the natural layers which are met with in penetra ting the earth. Gneiss, stratified granite. Gobelins, the name of a celebrated manufactory of tapestry in Paris , so called, after two brothers of that name, who founded the manufac- tory in the reign of Francis I. Gravity, the general property by which bodies are attracted towards each other, as seen in a stone falling towards the earth. Graywacke, a kind of rock, of a gray or brown color, comp >sed of grains and fragments of different materials. HcBmatite, an ore of iron. Hydrate, a solid compound with water. Hydrate of lime, a solid compoimd of lime with water. Hydraulics, the science which treats of the motion of fluids. Hydraulic cement^ mortar, which hardens underwater. Hydrochlorate, a salt containing hydrochloric, or muriatic, acid. Hydrochloric acid, see Muriatic acid. Hydrodynamics, the science which treats of the power or force of water. Hydrogen, a very light, inflammable gas, of which water is, in part, composed. It is used to inflate balloons. Hydrostatic pressure, the property of fluids by which they press equally in all directions. Hydrostatics, the science which treats of the pressure of fluids. Hydrosulphuret, a compound of hydrogen and sulphur with another body. Hyperbola, one lould3 for casting, 233. Meaning of the word, as ap- plfed to glass, 248, note, 250. Employed as coloring materials for glass, 258. See Ores. Mexico, depth of a mine in, 298. Miea-slate, 232. Milling coins, 219. Mills, drawing in, by horses, 85.' Barker's, or Parent's, 96. Wind, 97. Post, 99. Hori- zontal wind, 100. Fulling, 181. Mineral veins, see Lodes and Veins. Mineralized metals, 209 Mineralizer, 209. Miners, distinction of mineral veins by, 283. Aided by geology, 287. Means of, for penetrating into the interior of the earth, 290. Shovels of, 290. See Mines. Mines, copper, 222, 286. Ure's Dictionary on, 279. Indications of metallic, 285. Geology a guide in the investigation of, 287 — 289. Instruments em- ployed in, 289. Tools used in, 290. Value and use of gun- powder in, 291. Use made of fire in, 294. Depth of several, 297, 298. See Earth, Excava- tion, Lodes, Miners, Ores, and Veins. ' Mint in England, 220. Minute-hands of clocks, 196. ; Minute-wheels of watches, 205. 3Iirrors, silvering of, 230. \ Mixed pumps, 151. I Money, coinage of, 219. I Montgolfier invented balloons, 48. ^Monument of Lysicrates, 265. j Moody, Paul, 174, and l'^4, note Moreys' engines, 123, 128. 3Iorris canal, 311, 315. Motion, 51. Rotary, or circular, i 51. Distant rotary, 59. Change of velocity in, 60. Alternate, I or reciprocating^2. Parallel, i 65. Continuedrectilinear, 73. i Change of direction in, 74. On ;j equalizing, 76. Rotary, in Bar- ' ker's mill, 96. Parallel, intro- i duced into steam-engines, 122. \Motion of animals, 9, 10. I Moulding glass, 254. Moulds, paper, 184. For casting jj metals, 233. For glass, 254, || 255. For casting pottery, 269 ' Saggars, 269. Movement, the regulating, of time- ; pieces, 191. I Moving forces used in the arts, 81; kludge on speculum-metal, 226 Mule°s, 169. |: Mule-spinning, 173. ii Mummies, glass found with, 261 388 INDEX. Murray's engine, 116, 123. Muscular power, 82. Of men, 82. Of horses, 84. Muskets, manufacture of, 239. N. Nail, a rod used by, miners, 291. Nail-making, 239. Nap of broadcloths, 182. Napoleon, reward offered by, 180. National road, 331. Native state of metals, 209. Natural steel, 241. Naves of wheels, 16, note. Navigation, steam, 42, 45. Sub- marine, 47. Inland, in Ameri- ca, 299, 314. Slack-water, 306, 314. Needles, polishing, 246. Negative indications of metallic deposits, 288. Nests, in geology, 280. Newcastle rail-way, 320, 335. Newcomen's atmospheric engine, 115, 120. New Orleans, see New York. NewsUam's fire-engines, 163. New York, route and distances from, to New Orleans, 300. New York canal, see Erie. New York rail-way, see Haerlem and Paterson. Niagara andAiffalo rail-way, 321, 334, Niokel, localities of, 287. Nodules, in geology, 280. Non-condensing engines, see High- pressure engines. Noria, 143. No.ristown rail-road, 321. O. Oars, propulsion of boats by, 42. Obstruction of pipes, 139. Off-cast veins, direction of, 285. Ohio rail-road, 325, 335. Open trench, working by, in min- ing, 296. Open workings, in mining, 296. Ores, 209. Locality of, 282, 285. Value of geology for finding, 287. -See Mines. Overflowing wells, see Artesian. Overshot-wheels, 85. Pressure of the atmosphere on, 88. Most advantageous velocity of, 90. Oxides metallic, 249, 256. Pacos, 289. Paddles, pro^^alsion of boats by, 42, 43. Paddle-wheels, 42. Painted glass, 257. See Stained Pakfong, Chinese, 226. Pallets, of scapements, 72. In clocks, 196. Gathering, of a clock, 198, 199. Palmer, rail-way of, 27. On dust on rail-ways, 29. Pantheon, Rotunda of the, brick, 262. Paper, materials for, 183. Man- ufacture of, 183. Sized, 184. Blotting, 184. Hot-pressed, 184. ^lachines for manufactur- ing, 184. Rapidity of manufac- turing, 185. Preparation of, for photographic drawing, 365 Parachutes, 49. Parallel motion, 65, 122. Parent's mill, 96. Paris, first paved, 20, note. Parkes, metallic baths of, 244. On supplying the Chinese with cobalt, 270, note. Parting gold, 213. Party-gold, 216. Pascal, hydrostatic press by, 151. Passenger-boats, see Boats. Passenger-cars, 329. Passey, paper in the possession of, 185. Passings, in rail-ways, 28. Paste gems, 258. Paternoster-work, 157. Paterson rail-way, 320, 334. Patterns, for castings, 233. Pavements, 19. Wooden, 20. In ancient cities, 20, note. Tel- ford's, 20, 7wte. Peace, Temple of, 262. Pearl buttons, brass eyes of, 224. Pearson, on gun-metal, 226, note. [NDEX. 389 Pebbles, use of, in pavements, 20, Pendulums of clocks, 191, 195. Remedies for the effect of heat on, 192. See Hair-springs. Penknives, 244, 245. Pennsylvania canal, 315, 328, 330, 331. Pennsylvania State canals, travel- ling' on the, 306. Perkins, propelling wheel of, 43. On getting rid of back-water, 92. Generators in the engines of, 113, 7iote. Steam-gun by, 129. Inventions by, 129, note. Perpendicular pits, 297. Perpetual screws, 57. Persia, ancient bricks in, 262, Persian wheels, 143. PeterhofF, fountains at, 162. Phials, Bologna, 251. Philadelphia rail-way, see Colum- bia and Xorristown. Photogenic drawing, 350, Prepar- ing the plate for, 351. Coating the plate for, 353. Use of the camera obscura in, 356. Sea- sons for, 357. 3Iercurial, or dis- engaging, process in, 358. Fix- ing the impression in, 360. Talbot's experiments in, 362. Ponton's method of preparing paper for, 365. Photography, 350. See Photo- genic drawing. Pick, used by miners, 290, 296. Picker, cotton, 169. Piercers, of cartridges, 292. Piers, of bridges, 22. Pig-iron, 2337 Piles, in rail-roads, 322, 323. Pinchbeck, 224. Pinion, 53. Leaves of, 54. Lan- terns to, 54, 56. Rack and, 70. In watches, 205. Cannon, 206. Pins, 225, Pipe clay, 267, Pipe-veins, 283, 284. P'lpes, steam, 117, Eduction, 118. Water*, 136. Wooden, 137. Iron, 137. Copper, 137. Lead, 137,227. Stone, 138. Earthen, 138. Friction of, 138. Quan- tity of water conveyed in, 138, 139 . Velocity of water in , 138, Size and form of, 138, 139. Curves in, to be avoided, 139,140. Obstruction of, 1.39. Arrangement of, 156. Pistons, of steanj-engnies, 117, 118, 122, 123. lor pumps, 151, 152. Pitch lines, 54. Pits, perpendicular, 297. Pivots, meaning of, 195, yioie. Planchets in coining, 219. Planet wheels, 67, Plate slass, 253. Plated^ baskets, 222. Plates, tin, 229, 230, 237. Plating with silver, 220, 222. Plunger pumps, 149. Plyin^g cotton, 170, 171. Po'interolle, 290. Polishing, silver, 219. Cutlery 246. Plate glass, 254. Poll of a pick, 290. Pompeii, pavements in, 20, note. Glass found at, 261. Pompey introduces the clepsydra into the Senate House, 188. Ponton, 3Iungo, 365. Porcelain, Reaumur's, 259. In- gredients of, 265. Manufacture of, 266. Drawings on, 270. Chi nese, 271. Eultpean, 271. Earths, in the United States, 272. Gilding, 272. Magic, 273. Portage, see Alleghany. Portland vase, 273. Imitated, 273. Positive indications of metallic de- posits, 288. Post-mills, 99. Potence, in a watch, 203. Pottance, in a watch, 200, 203. Pottery, 265. Operations in, 266 Glazing, 267, 270. Throwing, 268. Pressing, 269. Casting, 269. Burning, 269. Printing. 270. See Porcelain. Pottsville rail-road, 325, 335. Powder, see Gunpowder, Power, sources of, 81, Vehicles of, 81. x\nimal, 82. Water, 85, Viind, 97, Steam, 100 390 NDEX Of the steam-engine, 124. Of gunpowder, 130. The main- taining, of time-pieces, 190. Power-looms, 169, 176. Powers acting within a boat, 42. Precious stones, in watches, 207. Press, hydrostatic, 151. Pressed bricks, 263. Pressingof glass, 255. Of pottery, 269. Primary rocks, 279. Primitive, radius, 54. Circum- ferences, 54. Prince's metal, 224. Printing ware, 270. Projecting water, 161. Prongs of forks, 245. Propelling power, on rail-ways, 29. Propelling wheel of Perkins, 43. Proportional radius, 54, 7iote. Providence rail-way, 321, 334. Proximate positive indications of metallic deposits, 288. Puddle for lining canals, 33 Puddling-furuaces, 235. Pulleys, 76. Pulp for paper, 184, 185. Pumps, in steam-engines, 118. Rope, 143. Spiral, 145. Cen- trifugal, 146 Common, 147. Household, or sucking, 148. Forcing, 149. Plunger, 149. De la Hi«s, 151. Mixed, 151. Lifting, 152, Bag, 153. Dou- ble-acting, 153. Rolling, 154. Eccentric, 155. Chain, 157. Bead, 157. Cellular, 157. Punt, or punting-iron, 251, note. Puppet valves, 121. l*yramids, 125, 263, note. Uuadrupeds, locomotion of, 10. Swimming of, 11. Quartation of gold, 214. Ciuarter, wind upon the, 39. Q,uicksilver, alloys of, 211. Ex- traction of gold by amalgama- tion with, 212. See Mercury. Quilts, Marseilles, 177. Quincy rail-way, 318, 334. R Rack, and segment, 70. And pin ion, 70. Of a wheel in clocks, 198, 199. Racks, 73. Radius, 54, and 54, note. Rag wheels, 52. Rags for making paper, 183. Rails, materials of, 25. Weigh* of, 27. Introduction of cast- iron, 318 ; of malleable iron, 318. In the United States, 324. Rail-ways, object of, 24. Modern, 24. Compared with turnpikes, and canals, 24. On the con- struction of, 24, 323. The dif- ferent varieties of, 25. Pas- sings, or sidings, in, 28. Turn- plates in, 28. Curves in, 28. Crossing public roads, 29. Dirt on, 29. Propelling power on, 29. Locomotives for, 29. Sta- tionary engines, and inclined planes on, 31, 328, 332. Am- erican, 298, 299, 318, 334. Foreign, 318. The sleepers in, 324. Cost of American. 325, 326 ; of English, 32.5 Annual expenses of, 327, 329 Horses on, 328. Fuel, 328. Grubbing, 331. Machinery for working inclined planes on, 333. Tables of, in the United States, 334—336. Raising water, 142. See Water. Rake-veins, 283, Rams, hydraulic, 160, Rasping beets for sugar, 341. Ratchet wheels, 58. Razors, 244, 245. Reaumur, porcelain of, 259, On glass thread, 260. Receivers, in pressing glass, 255. Reciprocating motion, 62. Rectilinear motion, continued, 73. Redfield, W. S., 44, 7iote. Reduction of metals, 210, Refining metal, 210, Regulating movement of time- pieces, 191 Regulator of a watch, 193 INDEX. 391 Remote positive indications of me- tallic deposits, 288. Rents, in geological strata, 281. Reservoirs for beet juice, 342. Retarding wheels, 31. Rideau canal, 305, 307. Roads, hints on, 19. Me Adam, 20. Loss of power on, 24. The National, 331 Roasting ores, 210. Robinson, Moncure, on the cost of rail-ways, 325. Cited, 326. Robison, John, on the overshot wheel, 86. On the escape of air and water through a hole, 88. Describes a machine, 89. Rocket engines, 30. Rocks, 134. See Blasting. Rollers, 13. Rolling and slitting iron, 237. Rolling pumps, 154. Roman coins, 226, note. Romans, aqueducts among the, 136. Windows among the, 261. Rome, paved, 20, note. The first sun-dial at, 188;, The clepsy- dra brought to, 188, note. Ancient bricks at, 262. Roofs, covered with tiles, 264. Rope-^umps, 143. Ropes, 165. Rotary, or circular,motion,51. Dis- •tant, 59. In Barker's mill, 96. Rotary valves, 121. Rotative engines, 126. Rotunda of the Pantheon, 262. Rouge d' Angleterre, 246. Routes of canals and rail-roads in North America, 300, 314, 334. Roving-frames, 170, 171. Sim- pler form of, 172, Ilovvutree's engines, 163. Roy, on expansion of glass, 261. Rubies, in watches, 207. Rudder of a ship, 38. Rupert's drops, 251. Russel, on the velocity of wave in canals, 302. Russia, fountains in, 162. S. Safety gates in canals, 34. Safety-valves, 112. Saggars, 269. Before the wind, 39 Sailing, 37. Sails of windmills, 97. Angle for, 98. Adjustment of, 98. St. Austle, steam-engine at, 125. Sampson mine, shaft at the, 298. Sand,formoulds,233. Inglas3,24S. Sankey Brook canal, 301. Santee canal, 301, 317. Saratoga and Schenectady rail way, 320, 334. Cost of the,325. Sarcophagi, glass found on, 261. Savannah, steam-ship, 44. Sawdust, with gunpowder, 293. Saws, 244, 245. Saxony, the porcelain of, 272. Scapements, 71. Pallets of, 72 Crutch, 72. Watch, 72. Of time-pieces, 193, 200, 204. Scape-wheels, 193, 204. Schemnitz vessels, 157. Schenectady, see Albany, Sarato ga, and Utica. Schists, gold found in, 286. Schuylkill, bridge, 22. Slackwatei navigation, 306, 316. Scissors, 244, 245. Scoop wheels, 142. Scoria, 232. Scotland, canal in, 36. Screws, propulsion ^f boats by, 42 Perpetual, or endless, 57. De- finition of, 74. Archimedes' 144. The water, 145. Scudding before the wind, 39. Secondary rocks, 279. Segment,rack and.70 Beltand,71. Semicircle, used by miners, 289. Separating metal, 209. Serpents, locomotion of, 11. Setting the edges of cutlery, 246. Severus, Alexander, Portland vase discovered in the tomb of, 273. Sevres, porcelain made at, 271. Sewing-thread spun by mules, 174. Shafts, to ventilate canal tunnels, 33. Means of, 195, note. In mining, 295. Depths of, 297. Shanks of brass buttons, 224 Shearing cloths, 182- 392 INDEX. Shear-steel, 241. Sheet lead, 227. Sheldrake, T., inclit'.ed plane wheels by, 55, note. Shifts, in mineral veins, 285. Ships, form of, 37. Bows of, 38. Keels and rudders of, 38. Ef- fects of wind on, 39. Stability of, 41. Crank, 41. ToostifF,41. Shooting tools of miners, 290. Shot, manufacture of leaden, 228. Shovels, miners,' 290. Shrouds, 166. Shuttles, 175. Sidings, in rail-ways, 28. Silesia, use of sawdust in, 293. Silver, extraction of, 217. Eliqua- tion of, 218. Working, 218. Solder used for, 219. Polishing, 219. Alloyed, 219. Coining, 219. Milling, 219. Plating with, 220, 222. Edges, 221. Ger- man, 226. Use of, for coloring glass, 258. Localities of, 286. Silvering of mirrors, 230. Of look- ing glasses, 230. Of glass globes, 231. Silver-lustre ware, 273. Silversmiths' work, 218. Simplon and Mount Cenis, 298. Singing cotton fabrics, ISO. Single rail-wav'S, 27. Size, of wheels, 13. Of canals, 36. Sizing paper, 184. Slackwater navigation, 306, 307. In canals, 307, 314, 330. Slag, 232. Sleepers, used on rail-roads, 324. Sliding valves, 121. Slip, used in pottery, 269. Slitting iron, 237, 238. Sliver, cotton in, 170. Slubbing machine, 181. Smeaton, on muscular power, 84. On the velocity of wheels, 90, 91. On float-boards, 91. Smelting, metal, 210. Iron, 232. Smifts, used in blasting, 290, 291. Snails, water, 144. In clocks, 198. Snifting-valves, 118. Solder, for silver, 219. In pla- ting copper, 221. Sorting metal, 209. Sources of power, 81. See Power Sparry iron-ore, 241. Speculum-metal, 225, 226, 230. Speed, of steam-boats, 44, and 44, note. See Velocity. Spencer, on voltaic electrical en- graving, 348—350. Spindle-rails, 171. Spinning, mechanism of simple, 165, 168. Hemp, 167. Cotton, 172. Mule, 173. Glass, 260. Spinning-frames, 168, 173. Spinning-jenny, 168. Spiral gear, 55, and 55, note. . Spiral pumps, 145. Spiral wheels and water-screws, propulsion of boats by, 42. Spoon, of the Zurich machine, 146. Spouting wells, see Artesian wells. Springs, of carriages, 17. Of watches, 190,191,200,201,204. Spur-gearing, 53. Stability of a ship, 41. Staffordshire, mine in, 298. Stained glass, 256, 258. Stamping metal, 209. Started veins, 285. State works, 300. Stationary engines. See Inclined. Steam, propulsion of vessels by, 42. Expansion of water, when converted into, 100. Atnws- pheric weight upon, 101, 102, Increase of, after separation from water, 101. Three meth- ods of obtaining power from, 103. Application of, to engines, 114. Use of, at high tempera- tures, 126 ; at low tempera- tures, 127. Substitution of, for gunpowder, 129. Steam-boats, 42. Speed of, 44. Steam-carriages, 129. Steam-engines, 42. Cartwright's, 67,122. Governors in, 76, 110, 117. Estimation of the power of, by horses' power, 84. Ear- liest attempts at forming, 103. Remarks on, 107. Boilers in, 108. Appendages to, 110 Brathwaite and Ericsson's, 113 INDEX. S93 Application of steam to, 114. Newcomen's atmospheric, 115, 120. Description of the double- acting, 116. Expansion, 119. Condensers in, 120. Valves of, 121. Pistons, 122. Parallel motion in, 122. Estimates on the power of, 124. At St. Austle, in Cornwall, 125. Pro- jected improvements in, 126. Rotative, 126. See High-pres- sure, Inclined plants. Locomo- tive, and Low-pressure. Steam-guages, 110. Steam-guns, 129. Steam-navigation, 42, 45. Steam-pipes, 117. Steam-power, 100. Steam-ships, the Atlantic first cros- sed by, 44. The Great Wes- tern, 44, note, 45. The Brit- ish Queen, 45. Steel, gilding on, 217. Hardness and tenacity of, 232. Iron re- combined with carbon, 240. The iron used in, 240, 241. Ce- mentation of, 240. Blistered, 240. Tilted, 240. Shear, 241. Cast, 241. Natural, 241. Al- loys of, 241. Stodart's and Faraday's experiments on, 241. Indian, 241. Quantity of car- bon in, 241, note. Case-har- dening, 242. Tempering, 242. Cutlery, 245. Conversion of cast-iron into, 246. Steps, in mining galleries, 296. Stevenson, G., rocket-engine by, 30. On canals in North Ameri- ca, 298. On rail-ways, 318. Stodart, on steel, 241. Stoddart, on gilding, 217, note. Stone, bridges, 22. Pipes, 138. Stones, factitious, employed by the ancients, 263. Rail-ways laid on, 319, 321, 323. Stone-ware, manufacture of, 267. Stop-gates, in canals, 34. Stourbridge clay, crucibles of, 265. Strainers, for water pipes, 139. Strand of a rope, 166. Stratiform deposits, 279. Strength of man, 84, 150. Stretching, the process of, 173. Strikes, used in manufacturing sheet-lead, 227. Striking part of a clock, 194, 197. Submarine navigation, 47. Subteri-anean operations, instru- ments for, 289. Wjrkings, in mining, 296, 297. $ee Mines. Sucking-pumps, 148. Sugar, maple, 337. See Beet. Sulphate of soda may be employed in glass-making, 249. Sulphur, lead mineralized by, 226. Sun and planet wheels, 67. Sun-dials, 187. Superstructure for rail-roads, 326 Supporters of rail-ways, 319, 323. Suspension bridges, 23. Swab-sticks of borers, 290. Sweden, copper mines in, 222. Swimming, of fishes, 10. Of land animals, 11. Of birds, 11. Swimming bladders, 11, note. Switch, in rail-roads, 28. Swords, tempering of, 244, note. Syphons, 141. T. Table, of canals in the United States, 314 ; of rail-ways, 334. Table-forks, 244, 245. Prongs of, 245. ^. Table-knives, 244, 245. Tail-water, remedies for, 92, 93. Talbot, experiments by, 362. Tamping, by miners, 291. Tamping-bars, 291. Tapestry, 179. Taunton spindle, see Danforth's. Taylor, on depths of mines, 297. Teazles, 182. Teeth of wheels, 53. The cut of, 55, 56. Telescopes, speculum-metal used in, 225, 226, 230. Telford, paved road by, 20, note. Temperatures, use of steam at high, 126; of vapors of low, 127. Tempering steel, 242. By metallio 39'1 INDEX. baths, 244. By Ferrara, 244, note. Temple of Peace, 262. Tenders, see Locomotive. Terra-cotta, 264. Terre-cuite, 264. Test-bars, 240. Thames, bridges across the", 22. Thenard, on steel, 242. Theory of twisting flexible fibres, 164. Thermae, of brick, 262. Third wheel of a watch, 203. Thread, gold, 217. Glass, 260. Throttle-valves, 121. Throwing, in pottery, 268. Throwiug-wheels, 163. Tides, velocity of, 44, note. Tightening wheels, 76. Tiles, 264. Tilt-hammers, 236. Tilted-steel, 240. Timepieces, 189. Essential parts of, 190. Maintaining power of, 190. Regulating movement of, 191. Pendulums of, 191. Bal- ances of, 192. Scapemeuts of, 193, 200, 204. See Clocks and Watches. Tin, in bronze, 225. Extraction of, 229. Block, 229. Foil, 229. Plates, 229,237. Silvering with, 230, 231.- Localities of, 285. Tin-foil, 229. Tinning, copper, 223. Plates, 229, 230. Tinstone, 229. Toggle joint, 74. Tombac, 224. Toothed wheels, 53. Torpedo, Fulton's, 48. Tower of the Winds, 188. Traction, line of, 14, 18, 84. Train of a watch, 202. Tram-roads, 27, 318. Transition rocks, 279, 283. Transit^ on rail-ways, 328. Transverse galleries, 295, 297. Trautwine, sections of rail by, 26. Travelling, on canals, 306. Tread well, on using steam, 113. Condensers by, 121. Machines by, for spinning hemp, 167. Tredgold, 24, 43. Trench, working by an open, in mining, 296. True radii, 54. Trundles, in machinery, 54. Tub-wheels, 95. Tunnels, for rail-roads, 25. For canals, 33. At Worsley, 34. Turkey carpets, 179. Turnpikes jnd rail-roads, 24 Turn-plates, on rail-ways, 28 Turn-tables, on rail-ways, 28. Tweeled-cloth, 176. Twilled fabrics, 176. Twilling, 176. Twisting, theory of, 164. U. Undershot wheels, 85, 90. Ve- locity of, 91. Size of, 91. Float-boards of, 91. Universal, joint, 57. Lever, 74. Utica and Schenectady rail-road, 327, 334. Valenciana mine, depth of, 298. Valves, in canal-gates, 35. Of steam-engines, 112, 117, 118. Different kinds of, 121. Vapors of low temperature, 127. Vases, 273. Vehicles of power, 81. Veins, 282. Rake, 283. Pipe, 283,284. Flat, or dilated, 283, 284. The interlaced mass, 283, 285. Shifts, or faults, in, 285. Direction of offcast, 285. Heaved, 285. Started, 235. Exploring, 296. See Lodes and Mines. Velocity, change of, in machinery, 60. Of overshot-wheels, 90. Of undershot-wheels, 91. Of water in pipes, 138. In cotton machines, 170. Velvets, 179. Venetian carpets, 178. Ventilation of tunnels, 33. INDEX. 395 Verge of a balance-wheel, 203, 207. Vertical windmills, 97. Vessels, Schemnitz, 157. Viaducts, 25, 332. Vitrification, arts of, 247. Voltaic electrical engraving, 348. W. Wagons, 12. Retarding, 31, noie. Wales, bridge in, 23, 125. Walking, 10. Ware, Biddery, 229. Wedge- wood's, 265, 267. Earthen, 265, 266. Common crockery, 265. Glazing, 267, 270. Stone, 267. White, 267. Throw- ing, 268. Pressing, 269. Cast- ing, 269. Burning, 269. Print- ing, 270. China, 271. See Porcelain. Warning-piece, in clocks, 198. Warp, 175. Warping cotton, 174. Warping-machines, Moody's, 174. Washing metal, 209. Washington, see Baltimore. Watch scapements, 72. Watches, fusees of, 62, 191, 200 — 202. Essential parts of, 190. Maintaining power of, 190. Springs of, 190, 191, 200, 201 —204. Chains of, 190, 191, 200,201. Barrebin, 191, 195, 197, 200, 201. Regulating movement of, 191, 206. Bal- ances of, 191, 192, 203. Hair- springs of, 198, 204, 206. Reg- ulators of, 193. Scapements of, 193, 200. Description of, 200. Wheel-work of, 200, 203. Guard-gut of, 202. Train of, 202. Minute wheel in, 205. Hour-wheel of, 206. Cannon- pinion in, 206. Curb in, 206. Addition of jewels to, 207. Number of pieces in, 208. Number of trades employed in, 208. Water, movrnient of bodies through, 3T. Dead, 37. Va- riations in the fall of, 88. Great- est effect of the action of, on machinery, 91. Delivering, on an undershot-wheel, ft2, 94. Back, or tail, 92. On breast- wheels, 94. On horizontal oi «tub-wheels, 95. In Barker's, or Parent's, mills, 96. Expan- sion of, when converted into steam, 100. For boilers of steam-engines, 108. Arts of conveying, 135. Subterranean passages for, 136. Pipes for transmitting, 136 Velocity of, in pipes, 138. Obstruction of, in pipes, 139. Conveyed in sy- phons, 141. Raising, 142 ; by the scoop-wheel, 142 ; by the Persian wheel, 143 ; by the noria, 143 ; by the rope-pump, 143 ; by hydreole, 144 ; by Archimedes' screw, 144 ; by the spiral pump, 145 ; by t!ic centrifugal pump, 146 ; Lv common pumps, 147 5 by the forcing pump, 149 ; by the plunger pump, 149 ; by De La Hire's pump, 151 ; by the hy- drostatic press, 151 ; by the lifting pump, 152 ; by the bag- pump, 153 ; by the double-act- ing pump, 153 ; by the rolling pump, 154 ; by the eccentric pump, 155. Arrangement of pipes for raising, 156. Raising by the chain-pump, 157 ; by Schemnitz vessels, or the Hun- garian machine, 157 ; by He- ro's fountain, 159 ; by atmos- pheric machines, 159 ; by the hydraulic ram, 160. Project- ing, 161 ; by fountains, 161 ; by fire-engines, 162. Lifted and projected by throwing wheels, 163. Rise of, in Arte- sian wells, 276. Water-clocks, 189. Water-pipes, 136. See Pipes. Water-power, 85. Water-screws, 42, 145. Water-snails, 144. 396 INDEX. Water spinning-frame, 168. Water-wheels, governors in, 77. Watt, James, inventor of the sun and planet wheel, 67. On a horse's power, 84. Form of boilers used by, 107. Conden- ser invented by, 116, 120. Double-acting engine of, 116. Parallel motion introduced into engines by, 122. Coining ma- chinery by, 220. Weaving, l''o. Double, 177. Cross, 177. Wedgewood, ware of, 265, 267. Manufactory of, 267. Imitated the Portland vase, 273. Weft of cloth, 175. Weight, animals draw through the medium of, 15. Of rails for rail-ways, 27. Of locomotives, 30. Weights, raising of, by human power, 84 ; by horse's power, 84. Of clocks, 190, 195. Weirs, in canals, 34. Wells, Artesian, 275. Wheel-carriages, 12. Wheel-work, of a clock, 194. Of a watch, 200, 203. Wheels, mechanical action of, 12. Size of, 13. Attaching horses to, 14, 18,84. Broad, 15. Form of, 16. Cut of, 17. Perkins's propelling, 43. Band, in ma- chinery, 51. Rag, 52. Toothed, 53. Spiral gear, 55. Bevel gear, 56. Crown, or contrate, 56. Universal joir.i instead of, 67. Perpetual screw, 57. Brush, 58. Ratchet, 58. Change of velocity in, 60. Fusee, 62, 191, 200 — 202. Eccentric, 63. Cams for, 63. Heart, 64. Cranks in, 65. Sun and planet, 67. In- clined, 69. Epicycloidal, 69. Rack and segment, 70. Rack and pinion, 70. Thrown into, and out of, gear, 76. Tightening, 76. Fly, 78. Horses on, 85. Over- shot, 85. Breast, 85, 94. Un- dershot, 85, 90. Chain, 88. Besant's, 93. Lambert's, 94. Horizontal, or tub, 95. Scoop, 142. Persian, 143. Throwing, flash, or fen, 163. Of clocks, 194. Of watches, 200—206. For making ware, 266, 268. White, inventor of the spiral gear, 55, note. White-metal buttons, 224. White ware, manufacture of, 267. Wind, effect of the, on ships, 39. Action of, on wind-mills, 97. Windage, in guns, 132. Windmills, vertical, 77. Hori- zontal, 100. Windows, 261. Wind-power, 97. Winds, Tower of the, 188. Wipers, 64, Curves for, 64, 7iole Wire, gilt, or gold, 217. Wire-drawing, 238. Wirtz, Andrew, machine by, 146. Wooden, pavements, 20. Bridges, 21. Pipes, 137. Woof, of cloth, 175. Wool, remarks on, 181. Woolf, engines of, 103, 106, 120. Woolf's shaft, depth of, 298. Woollens, 181. Wootz, 241. Worcester rail- way, 327, 334. Working, of gold, 215. Of silver 218. Of copper, 223. Worm, the, 57. Worsley, tunnel at, 34. Worsted, 181. Wrought-iron, 235. Wrought-nails, 239. Y. Young, Dr., spiral pump, used by, 146. On the greatest effect produced by a laborer, 150. Z. Zinc, 223, 287. Zurich machine, 146. END OF VOL. li J''!/! ^ r/ri 2. m u •E r^-r ' ^^^ It ., V ,-ri i i i 1 L • i \jj i !., A. s/^ ?>>/. / />>/. ,2*. Fify 4 -/>^. 6\ A 000'797S"« ' .) /J 1 i i 1 5 \ \ < ' 1 .-.v i