03 O U) ? S DO g oc < LJ ^ OC LJ ^ O z ^^ < o LJ "S i 5 2 => . Strain on Hoisting Chains and Cables 172 37. Strength of Cable Chains 173 38. Wroiifjht-iron or Clinch Nails, Length and Number to the Pound. . .. 175 XV XVI UST OK TABLKS. PA(1B 89. Out Nails, Length and Number to th Pound 176 l<>. Turks, Si/.<- . and N limber per Pound 176 41. Wire Nails. L*iiglh and Numb:i- to Mir Pound 177 42. Wrought Spikes, Size and Number to the Pound 178 4:1. Wire Spikes, Si/.'- and Number to the Pound 178 M. Track Spikes, Si/o and Number per Keg 179 45. Street-railway Spikes, Size and Number per Keg 179 46. Dimensions of Wood Screws 180 47. Lag Screws, Size and Weight 181 48. Holding Power of Screws 181 49. Drift-bolts, Holding Power'of 184 50. Standard Dimensions of Screws, Heads, and Nuts 186 51. Weight of Bolts and Nuts 186 52. Weight and Strength of Bolts 187 58. Thickness and Weight of Washers 187 54. Length of Rivet-shank required to Form Head 189 55. Weight of Rivets 191 56. Natural Slopes of Earth 199 57. Lengths and Angles of Slopes 199 58. Amount of Cement and Sand required for One Cubic Yard of Mortar 245 59. Weight of Flat Dense-tile Arches 304 60. Weight of Porous Tile Arches 304 61 . Number and Weight of Shingles per Square 309 62. Dimensions and Number of Slates per Square 312 63. Galvanized Iron, Weight per Square Foot. . 313 64. Weight of Roof. coverings 314 65. Weight of Lead Waste-pipe 317 66. Weight and Thickness of Lead Pipe ... :518 67. Weight of Plain and Galvanized Iron Pipe 319 68. Weight of Block-tin Pipe 320 69. Weight of Cast-iron Koil-pipu :}i>0 70. Quantity of Materials required for Plastering 335 71. Area covered with Our Cubic Foot of Cement and Sand 335 7. TbickpeM nd Weight of Sheet Qlasa 339 73. Thickness and Weight of Skylight Glass 339 74. Dimensions and W-i^)i I of Cast-iron Pipes 360 75. Weight of Standard Specials 362 76. Weight of Lead and Gasket required for Each Joint of Cast-iron Pipe 363 77. Length of Sewer-pipe One Barrel of Cement will lay 370 78. Weight of Salt-glazed Sewer-pipe 370 79. Inches in Decimals of a Foot 394 80. Specific Gravity and Weight of Materials 396 81. Areas and Circumference of Circles 411 82. Square and Cube Roots of Numbers 416 83. Logarithms of Numbers , 433 84. Natural Sines, Tangents, and Secants 468 85. Tangents and Cotangents 487 INSPECTION OF THE MATERIALS AND WORKMAN- SHU' EMPLOYED IN CONSTRUCTION. CHAPTER I. DUTIES OF INSPECTORS. THE duty of the inspector is to see that the work on which he is placed is constructed in accordance with the plans and specifi- cations therefor and such written or verbal instructions as he may from time to time receive from his superior officer. To perform his duty efficiently he must make himself thoroughly acquainted with the requirement* of the specifications, a copy of which should always be in bis possession. The details of the inspector's duty will vary with the character of the work. In a general way it may be divided into three parts, as 1. Inspection of the materials to be employed. 2. Inspection of the methods used in preparing the materials. 3 Inspection of the construction, or placing of the prepared materials in the structure. To efficiently perform each of these functions the inspector must be familiar with the characteristics of the materials with which lie has to deal, the methods employed in preparing and placing them in the work, and he must also know whether the finish'*! work is what is required or expected. In performing the first section of his duty the inspector is re quired to pass upon the quality of the materials delivered, and dKerrnine whether they meet the requirements of the specifications or not, rejecting all that are defective. In marking rejected material he must be vareful to so place the 2 DUTIES OF INSPECTORS. marks that they cannot be readily erased. As a distinguishing mark, the letter " R " or " C " may be used. It will not be sufficient only to mark the rejected material and rely upon its being removed by the contractor. He must see that it is removed. If this precaution is not taken, the chances are that part if not all of it will find its way into the work. A careful record of all material rejected should be kept, stating the kind, character of the defects, and amount. Under the second division of his duty the inspector has to watch the methods employed in preparing the materials, to see that the quantities called for are used, and that the dimensions of all manu- factured pieces correspond to those marked on the plans. The right of the inspector to require special methods of manu- facture to be followed is not always clearly defined It is customary to allow the contractor to follow his own methods, so long as such methods cause no injury to the material and produce the required results. But when such methods cause injury or fail to produce the required results the inspector should have them stopped. To efficiently perform his duty under the third section the in- spector must be familiar with the methods employed by the vari- ous craftsmen in executing their work. To provide against slighting by careless and indifferent work- men constant vigilance is necessary, especially in such parts of the work which are difficult of access or will be covered up. A close scrutiny of each workman's manner of doing his work will be a great aid in directing attention to defective workmanship Every craftsman whose workmanship is once found defect : ve should be closely watched, and if found to persist in doing defec- tive work his removal should be ordered. The specifications and plans for each particular work must be the inspector's guide as to the character of the materials and work- manship required, and in case of any discrepancy between them, or doubt as to the meaning of any of the clauses, the matter must be submitted without delay to the engineer or architect for an explanation. The inspector should keep a diary recording the state of the weather, the number and trade of the workmen employed, the orders received and given, the amount and kind of material delivered, accepted, and rejected, the progress made, accidents, and any other incident which circumstances may suggest. At the periods directed by his chief he will send in his report. DUTIES OF INSPECTORS. This report is made up from the record of daily events, and should give such full derails, figures, and descriptions as will enable the chief to judge of the progress of the work. The inspector should so arrange his work as to inconvenience the contractor as little as possible. He should be on hand at all times so that workmen can consult him about any questionable points as they arise, and in this way avoid a great deal of friction which might occur if they proceeded in the way that seemed best to them. On the failure of the contractor or any of his workmen to comply with the requirements of the specifications, the inspector should notify him or his representative of the defective work and allow him a reasonable time in which to make it good. If at the end of this time the rectification is not made, or if he refuses to comply with the notice, the inspector must immediately acquaint his chief with the full particulars of the case, description of tlie defective work, character of the order given, and reasons advanced by the contractor for refusing to conform to it. The inspector should avoid arguments and disputes, and before raising objections or making complaints he should be quite sure of his case, then in as few words as possible make the complaint known. When complaint is necessary it should be promptly made; the longer it is put off the more difficult will be the rectification. The disagreements most frequent between inspectors and con- tractors and their agents are caused chiefly by complaints of the former of non-performance of the work in accordance with the .specifications, and, on the part of the latter, complaints of undue severity This complaint is to be expected; the best of men are reluctant to change what has already been done, and if inadver- tence or temporary convenience has led them into an obvious violation of the specifications, they will mince the truth in their explanations and excuses. The adjusting of these disagreements the inspector, unless he be possessed of a large fund of amiability and common sense, will find a very trying and unpleasant task. He who can distinguish between a mere blemish and a real defect, and thoroughly under- stands his position and can maintain it with firmness, will be less likely to have bad work thrust at him than one who errs in his decisions or is irresolute in his position. CLASSIFICATION OF STONES. CHAPTER II. STRUCTURAL MATERIALS. I. NATURAL STONES. Classification of Stones. The rocks from which the stones for building are selected are classified according to (1) their geological position, (2) their physical structure, and (3) their chemical composition. GEOLOGICAL CLASSIFICATION. The geological position of rocks has but little connection with their properties as building materia's. As a general rule, the more ancient rocks are the stronger and more durable ; but to this there are many notable exceptions. According to the usual geological classification rocks are divided into three classes, viz. : Igneous, of which greenstone (trap), basalt, and lava are ex- amples. Metamorphic, comprising granite, slate, marble, etc. Sedimentary, represented by sandstones, limestones, and clay. PHYSICAL CLASSIFICATION. With respect to the structural character of their large masses, rocks tire divided into two great classes : (1) the unstratified, (2) the stratified, according as they do or do not consist of flat layers. The unstratified rocks are for the most part composed of an aggregation of crystalline grains firmly cemented together. Granite, trap, basalt, and lava are examples of this class. All the unstrati- fied rocks are composed as it were of blocks which separate from each other when the rock decays or when struck violent blows. These natural joints are termed the line of cleavage or rift, and in all cutting or quarrying of unstratified rocks the work is much facilitated by taking advantage of them. The stratified rocks consist of a series of parallel layers, evidently deposited from water, and originally horizontal, al- though in most cases they have become more or less inclined and curved by the action of disturbing forces. It is easier to divide REQUISITES FOR GOOD BUILDING STONE. 5 them at the planes of division between these layers than else where. They are traversed by veins or cracks, sometimes empty, sometimes containing crystals, sometimes filled with " dikes," or masses of unstratified rock. These veins or dikes are often ac- companied by a "fault" or abrupt alteration of the level of the strata. Besides its principal layers or strata, a mass of stratified rock is in general capable of division into thinner layers ; and, although the surfaces of division of the thinner layers are often parallel to those of the strata, they are also often oblique or even perpendicular to them. This constitutes a laminated structure. Laminated stones resist pressure more strongly in a direction perpendicular to their laminae than parallel to them; they are more tenacious in a direction parallel to their laminae than per- pendicular to them ; and they are. more durable with the edges than with the sides of their laminre exposed to the weather. Therefore in building they should be placed with their laminae or " beds " perpendicular to the direction of greatest pressure, and with the edges of these laminae at the face of the wall. CHEMICAL CLASSIFICATION. The stones used in building are divided into three classes, each distinguished by the pre- dominant mineral which forms the chief constituent, viz. : Silicious stones, of which granite, gneiss, and trap are examples. Argillaceous stones, of which clay, slate, and porphyry are examples. Calcareous stones, represented by limestones and marbles. Requisites for Good Building Stone. The requisites for good building stone are durability, strength^ cheapness, and beauty. DURABILITY The durability of stone is a subject upon which there is very little reliable knowledge. The durability will de- pend upon the chemical composition, physical structure, and the position in which the stone is placed in the work. The same stone will vary greatly in its durability according to the nature and ex- tent of the atmospheric influences to which it is subjected. The sulphur acids, carbonic acid, hydrochloric acid, and traces of nitric acid, in the smoky air of cities and towns, and the carbonic acid in the atmosphere of the country ultimately decompose any stone of which either carbonate of lime or carbonate of magnesia forms a considerable part. Wind has a considerable effect upon the durability of stone. 6 TESTS FOR STOKE. Pligh winds blow sharp particles against the face of the stone and thus grind it away. Moreover, it forces the rain into the pores of the stone, and may thus cause a considerable depth to be sub- ject to the effects of acids and frost. In winter water penetrates porous stones, freezes, expands, and disintegrates the surface, leaving a fresli surface to be similatly acted upon. STRENGTH is generally an indispensable attribute, especially under compression and cross -strain. CHEAPNESS is influenced by the ease with which the stone can be quarried and worked into the various forms required. Cheap- ness is also affected by abundance, facility of transportation, and proximity to the place of use. APPEARANCE. The requirement of beauty is that it should have a pleasing appearance. For this purpose all varieties contain- ing much, iron should be rejected as they are liable to disfigure- ment from rust-stains caused by the oxidation of the iron under the influence of the atmosphere. Tests for Stone. The relative enduring qualities of different stones are usually ascertained by noting the weight of water they absorb in a given time. The best stones as a rule absorb the smallest amount of water. To determine the absorptive power, dry a specimen and weigh it carefully, then immerse it in water for 24 hours and weigh again. The increase in weight will be the amount of absorption. TABLE 1. ABSORPTIVE POWER OF STONES. Percentage of Water absorbed. Granites 0.06 to 0.15 Sandstones 0.41 " 5.48 Limestones 0.20 " 5.00 Marbles 0.08 " 0.16 EFFECT OF FROST (Brard's Test}. To ascertain the effect ot frost, small pieces of the stone are immersed in a concentrated boiling solution of sulphate of soda (Glauber's salts), and then hung up for a few days in the air. The salt crystallizes in the pores of the stone, sometimes forcing PRESERVATION OF STONE. 7 off bits from the corners and arrises, and occasionally detaching larger fragments. The stone is weighed before and after submitting it to the test. The difference of weight gives the amount detached by disintegra- tion. The greater this is, the worse is the quality of the stone. EFFECT OF THE ATMOSPHERE (Acid Test). Soaking a stone for several days in water containing 1 per cent of sulphuric and hydrochloric acids will afford an idea as to whether it will stand the atmosphere of a large city. If the stone contains any matter likely to be dissolved by the gases of the atmosphere, the water will be more or less cloudy or muddy. A drop or two of acid on the surface of a stone will create an in- tense effervescence if there is a larje proportion present of carbon- ate of lime or magnesia. Preservation of Stone. There are a great many preparations that have been used for the prevention of the decay of building stones, as paint, coal-tar, oil, beeswax, rosin, paraffine, soft-soap, soda, etc. All of the methods are expensive, and there is no evidence to show that they afford permanent protection to the stone. RANSOME'S PROCESS consists in coating the surface of the stone first with a solution of silicate of soda or potash, and then with a solution of chloride of calcium or barium. The chemical reaction produces insoluble silicate of lime and chloride of sodium, which washes out. The surface of the stone to be coated is made thoroughly clean and dry, all decayed parts being cut out and replaced by good. The silicate is diluted with from 1 to 3 parts of soft water until it is thin enough to be absorbed by the stone freely. The less water that is used the better, so long as the stone Is thoroughly penetrated by the solution. The solution is applied with an ordinary whitewash brush. After about a dozen brushings over, the silicate will be found to enter very slowly. When it ceases to go in, but remains on the surface glistening, although dry to the touch, it is a sign that the stone is sufficiently charged ; the brushing on should stop just short of this appearance. No excess must on any account be allowed to remain on the face. After the silicate has become perfectly dry the solution of chloride of calcium is applied freely (but brushed on lightly, without making it froth) so as to be absorbed with the sili- cate into the structure of the stone. 8 STLICIOUS STONES. Special care must be taken not to allow either of the solutions to be splashed upon windows or painted work, as the stains can- not be removed. The brushes or jets used for the silicate must not be used for the chloride, or vice versa. About four gallons of each solution is required for every hun- dred square yards of surface, but this will depend upon the porosity of the stone treated. II. DESCRIPTION OF BUILDING STONES. Silicious Stones. GRANITE is an unstratified rock composed of silica or quartz, feldspar, and mica. In addition to these essential constituents one or more accessory minerals may be present ; the more com- monly occurring are hornblende, pyroxene, epidote, garnet, tour- maline, magnetite, pyrite, and graphite. The character of the rock is often determined by the presence of these accessory con- stituents in quantity. Granite varies in texture from very fine and homogeneous to coarse porpliyritic rocks in which the individual grains are an inch or more in length. The color is also dependent upon the minerals present ; if the feldspar is the orthoclase (potash spar), it communicates a red color; the soda-spar produces gray. The mica also plays an important part in the modification of color ; if it is the white muscovite, it produces no change, but if the black biotite mica be present, it modifies the color accordingly. Horn- blende gives a dark mottled appearance ; pyroxene also gives a dark appearance ; epidote communicates a green color. The durability of the granites is closely related to their miner- alogical composition. The presence or absence of certain species influences the hardness and homogeneous nature of the stone. Although popularly regarded as the most durable stone, there are some notable exceptions. The quartzose varieties are brittle, the feldspathic are easily decomposed; feldspar in excess causes rapid decay and disintegration in consequence of the action of air and water on the potasli which seems to be removed, and the residue falls into a white powder composed chiefly of silica and alumina. The micaceous varieties are easily laminated. The durability and hardness of granites are greater the more SILICIOUS STONES. 9 quartz and hornblende predominate, and the less the quantity of feldspar and mica, which are the more weak and perishable in- gredients. Smallness and lustre in the crystals of feldspar in- dicate durability, largeness and dulness the reverse. If the mica or feldspar contains an excess of lime, iron, or soda, the granite is liable to decay. The quantity of iron either as the oxide or in combination with sulphur will affect the durability. The iron can generally be seen with a good glass; and a very short exposure to air, especially if assisted in dry weather by sprinkling with water to which has been added 1 per cent of nitric acid, will reveal it. The name " granite " as popularly used is not restricted to rock species of this name in geological nomenclature, but includes what are known as gneisses (foliated and bedded granites), syenite, gabbro, and other crystalline rocks whose uses are the same; in fact, the similar adaptability and use have brought these latter species into the class of granites. The name is also often im- properly applied to the diabase and trap rocks. The term "syenite" is usually restricted by modern petrog- raphers to a rock which is an aggregate of orthoclase and horn- blende; in other words, a granite in which the quartz has dis- appeared, while the mica has been superseded by hornblende. GNEISS AND MIC A- SLATE consist of the same materials as granite, but in a stratified form. They are found in the neighbor- hood of granite, in strata much inclined, bent, and distorted, and often form great mountain masses. Gneiss resembles granite in its appearance and properties, but is less strong and durable. Mica-slate is distinguished by containing little or no feldspar so that it consists chiefly of quartz and mica. TRAP (GREENSTONE) AND BASALT. These are unstratified metamorphic rocks, and consist of granular crystals of hornblende or augite with feldspar. In trap the grains are considerably finer than in granite; in basalt they are scarcely distinguishable. Trap breaks up into small blocks, basalt into regular prismatic columns Both these rocks are very compact, hard, tough, and durable; being generally without cleavage or bedding they are exceedingly intractable under the hammer or chisel, and conse- quently their use in masonry is very limited. The " Palisades " on the western shore of the Hudson River, opposite and above New York, are composed of trap rock, which 10 SILICIOUS STONES. splits easily into small blocks much used for paving under the naiue of "Belgian block." Crushed trap rock is also exten- sively used for making macadam pavements. SANDSTONES are stratified rocks consisting of grains of sand, that is, small crystals of quartz cemented together by silicious, ferruginous, calcareous, or argillaceous material. From the nature of the cementing material the rocks are variously designated as ferruginous, calcareous, etc. The hardness, strength, and durability depend upon the nature of the cementing material; if it be one which decomposes readily, as in the argillaceous and calcareous varieties, the whole mass is soon reduced to sand. When composed of m-arly pure silica and well cemented, sandstones are as resistant to weather as granite, and very much less affected by the action of fire. When quarried they are usually saturated with quarry-water (a weak solution of silica) and are very soft, but on exposure to the air (called "seasoning") they become harder by the precipitation of the soluble silica. The COLOR of sandstone is determined by the cementing material. A stone composed exclusively of grains of quartz, without foreign matter, is snow-white. The various shades of red and yellow are produced by the iron oxides; the purple tints a:e due to oxide of manganese; the gray, blue, and green tints are produced by iron in the form of ferrous oxide, carbonate, or silicate ; the brown color is produced by the hydrated oxide of iron. Sandstones are in general porous and capable cf absorbing much water, but they are comparatively little injured by moisture, except when built with the layers set on edge, in which case the expansion of water in freezing between the layers makes them split or " scale " off from the face of the stone; when built on the natural bed any water which may penetrate between the edges of the layers has room readily to expand or escape. When there is much lime in the cementing matter of the sand- stone it decays rapidly in the atmosphere of the seacoast, and in that of towns where much coal is burned; in the former case the lime is dissolved by muriatic acid, in the latter by sulphuric acid. Crystals of sulphuret of iron are sometimes embedded in the stone, which, when exposed to air and moisture, decompose and cause disintegration. These crystals are easily recognized by their yellow or yellowish-gray color and metallic lustre. On account of its easy working qualities it has been named ARGILLACEOUS STONES. 11 " freestone " by stone-cutters. A great variety of other names are applied, derived from the appearance of the stone and the uses to which it is put. Argillaceous Stones. SLATE. CLAY-SLATE is a primary stratified rock of great hard- ness and density, with a laminated structure making in general a great angle with the planes of its stratification. It splits readily along planes called "planes of slaty cleavage." This facility of cleavage is one of the most valuable characteristics, as it enables masses to be split into slabs and -plates of small thickness ard great area. The color of slates varies greatly; tho--e most frequently met with are dark blue, bluish black, purple, gray, bluish gray, and green. Red and cream-colored slates are also occasionally found. Some slates are marked with bands or patches of a different color; e.g., dark purple slates often have large spots of light green upon them. These are generally considered not to injure the durability of the slate, but they lower its quality by spoiling its appearance. Ribs or veins are dark marks running through some slates. They are always objectionable, but particularly when they run in the direction of the length of the slate, for it will be very liable to split along the vein. These veins arid ribbons are frequently soft and of inferior quality to the slate proper. On exposure to the weather they effloresce and show signs of decomposition due to the sulphate of iron contained in them. Such slates should not be allowed in good work. Calcareous Stones. LIMESTONES are composed of carbonate of lime combined with various minerals. There are many varieties, which differ in color, composition, and value for engineering and building purposes. The several kind 4 * are usually designated by the name of the principal combined minerals. Thus, if it contains much sand it is called sUicious limestone; if the silica is very fine grained it is called hor n stone ; if the silica is distributed in nodules or flakes, either in seams or throughout the mass, it is cherty limestone ; if it contains silica and clay in about 12 CALCAREOUS STONES. equal proportions it is hydraulic limestone ; if clay alone is the principal ingredient it is argillaceous limestone ; if iron is the principal impurity it is ferruginous limestone ; if iron und clay exceed the lime it is ironstone; if the ironstone is decomposed and the iron hydrated it is rottei intone; if carbonate of magnesia forms one third or less it is magnesian limestone; if carbonate of mag- nesia forms more than one third it u dolomitic limestone. GhiANULAii LIMESTONE consists of carbonate of lime in grains, which are in general shells or fragments of shells, cemented together by some compound of lime, silica, and alumina, and often mixed with a greater or less quantity of sand. It is always more or less porous. It is found in various colors, especially white and light yellowish brown. In many cases it is so soft when first quarried that it can be cut with a knife, and hardens by exposure to the air. It is found in various strata, especially the oolitic formation. COMPACT LIMESTONE consists of carbonate of lime, either pure, or mixed with sand and clay. It is generally devoid of crystalline structure, of a dull earthy appearance, and of a dark blue, gray, black, or mottled color. In some cases, however, it is crystalline and full of organic remains. It is then known as crystalline limestone. MAGNESIAN AND DOLOMITIC LIMESTONES. Whei the carbon- ate of magnesia is present in limestone to the amount of one third or less it is called magnesian limestone; when the carbonate of magnesia forms one third or more it is call* d dolomitic lime- stone. Both kinds are found in various conditions, from the com- pact crystalline to the porous granular condition. The durability depends mainly on the texture; when that is compact they are extremely durable. When sand is present in the magnesian variety the weathering qualities are greatly injured. Some varieties are peculiarly subject to the attacks of sulphuric acid, which forms a soluble sulphate of magnesia easily washed away. MARBLE is the purest form of carbonate of lime (except stalac- tites), and is an earlier formation of limestone, with a pressure which retained the carbonic acid. The name marble is generally applied to any limestone which will take a good polish. Marbles exhibit great diversity of color and texture; they are chiefly used for ornamentation and interior decorations. NATURAL STONE. 13 TABLE 2. SPECIFIC GRAVITY, WEIGHT, AND RESISTANCE TO CRUSHING OF VARIOUS STONES. Granites. Localities. Min. Max. Specific Gravity. 2.60 2.80 Average Weight. Pounds per Cubic Foot. 163 176 Resistance to Crushing. Pounds per Square Inch. 12,000 35,000 2 66 166 Q5 nnn Lord's Island ' 24 000 2 63 164 22 250 New Haveii ' q 7*0 Millstone Point ' 2 70 169 1fi 187 Milford ' 22 600 New London, ' Sharkey's Quarry, Me 2.66 2.72 166 170 12,500 22 1^5 Hurricane Island " 2 67 167 15 000 Fox Island (blue) " 14 875 13 000 to 18 000 Huron Island Micli ... . . . . 20 650 Duluth (dark) Minn 17 750 (light), " 19,000 East St Cloud " .... 28 000 Quincy (dark) Mass .. .. 2 66 166 19 500 " (light) " 14 750 Fall River (gray), " 15,937 Cape Ann " j 12, 423 Port Deposit Md 1 19,500 19 750 2.64 163 5,340 Jersey City N J . 3 03 189 20 750 Passaic Co (gray) N J 24 040 Chaumont Bay, N Y 2 65 162 22 700 \Vestchester Co " 2 65 166 18 250 Gflrrison's (gray) " 2 58 161 13 370 Staten Island (blue) " 2 86 179 22,250 Keene (bluish gray), N. H 2.65 166 12,875 CJunnison Colo .... ... . 13 000 Platte Canon (red), Colo 164 14 600 J2.72 170 14,100 Westerly (gray) HI... (2.63 2 67 164 167 21,250 14937 Burnet Co., Tex 2.82 176 11,891 Aberdeen, Scotland (gray) 2 62 163 10,900 " " (red) 2 62 165 10 760 Gneiss Conn 2 70 168 19 600 Syenite, Fourth Mountain, Ark.. Trap, Jersey City, N. J " Palisades " 2.64 3.03 167 {178 (189 30,740 20,000 24,000 19 700 ' ' Staten Island, N. Y 2.86 178 22,250 14 NATURAL STONE. SPECIFIC GRAVITY, WEIGHT, AND RESISTANCE TO CRUSHING OF VARIOUS STONES. (Continued.) Sandstones. Localities. Miu. Max. Specific Gravity. 2.23 2.75 Average Weight. Pounds per Cubic Foot. 137 170 Resistance to Crushing. Pounds per Square Inch. 5,000 18,000 Potsdam (red) NY... 2.60 2.75 2.41 2.68 2.42 2.25 2.71 2.13 2.26 2.57 2.16 2.24 2.14 2.39 j 2.36 \ 2.62 2.63 2.32 2.22 2.53 2.61 162 171 151 167 151 141 169 133 147 148 160 135 140 134 149 147 163 164 145 138 158 157 140 173 42,804 17,725 13,500 9,850 13,472 4,350 11,700 13,310 j 7,250 "j 10,250 8,850 8,750 6,800 6,650 5,000 9,687 6,950 13,000 9,150 10,700 6,250 8,750 6,250 7,450 5,714 j 7,000 \ 14,000 12,810 j 6,000 \ 11,000 11,505 11,707 Maiden (bluestone) Medina (pink) \Varsaw (bluestone) Albion (brown) . Little Falls (brown), Oxford (bluestone) Haverstraw (red) .... Belleville (gray) N. J . . . . " (brown), " Berea (drab), Ohio Vermilllou (drab), Massillon (yellow drab), Cleveland (olive-green), .... North Amherst, .... Seneca (red brown), Warrensburg (bluish drab), Mo.. Middletown (Portland), Conn.. . . Dorchester (brown), New Bruns- wick Kasota (pink) Minn Frontenac (light buff) " .... Fond du Lac " Fond du Lac (purple) Wis Marquette Mich Bristow Va Long Meadow (reddish brown), Mass Manitou (light red) Colo . St. Vrain, " Fort Collins (gray) " SLATE. Northampton Co., Pa NATURAL STONE. 15 SPECIFIC GRAVITY, WEIGHT, AND RESISTANCE TO CRUSHING OF VARIOUS STONES. (Continued.) Limestones. Localities. Min. Max. Specific Gravity. 1 90 2.75 Average Weight, Pounds per Cubic Foot. 118 175 Resistance to Crushing. Pounds per Square Inch. 7.000 20,000 Glens Falls N Y. 2 70 169 11 475 North lliver " . . 2 71 169 13425 Lake Cli am plain ' 2 75 172 25 000 Canajoharie, ' Erie Co (blue) ' . 2.68 2 64 168 165 20,700 12 250 Kingston ' .... . 2 69 108 13 900 Garrison's ' 2 63 165 18503 Joliet (white) 111 2 54 159 16 900 Grafton (magnesian), 111 17 000 Marblehead (white) Ohio 2 40 150 12 600 Marquette (drab) Mich 2 34 146 8 050 2 50 156 j 18,000 Billingsville Mo / 25,000 7,250 Cooper Co (dark drab) Mo 2 32 141 6 650 Bardstown (dark) K.y 2 69 168 16,250 Sturgeon Bay (bluish drab), Wis.. Bedford Ind 2.78 174 21,500 i 6,000 ] 10, 000 8,625 Ked \Ving Minn . . 23,000 Stillwater " 10,750 A von dale (gray) Pa 18,000 " Hiffht) " . 12,112 j 14.090 \ 16,340 Marbles. Min Max. East Chester NY 2.62 2.95 2 87 165 ITU 179 8,000 20,000 13 504 Hastings " 18 941 Dorset Vt 2 63 165 7 612 Kutland " . 10 746 Mill Creek 111 2 57 172 9 687 Montgomery (blue) Pa j 9,590 North Bay Wis 2 80 175 ( 13,70 20 02o Montgomery Va 8 950 Lee Mass (20,504 Stockbridge Mass { 22, 700 10 382 Colton Cal 17,783 Italy 2.69 168 13,425 16 NATURAL STONE. Inspection of Stone. The fitness of stone for structural purposes may be determined approximately by examining a fresh fracture, the appearance and characteristics of which are as follows : The even fracture occurs when the surfaces of division are planes in definite positions, and indicates a crystalline structure. The uneven fracture presents sharp projections, and is character- istic of a granular structure. The slaty fracture occurs when the planes of division are par- allel to the lamination and are uneven for other directions of division. The conchoidal fracture presents smooth concave and convex surfaces, and is characteristic of a hard and compact structure. The earthy fracture leaves a rough dull surface, and indicates softness and brittleness. Stones which contain "drys," i.e., seams containing material not thoroughly cemented together, or " crowfoots " i.e., veins containing dark-colored uncemented material, should be rejected. To test the soundness of any stone, strike it smart blows with a light hammer on both beds ; if it rings clearly, it is sound ; if the sound is dull, it is seamy and should be rejected. Stones to be used for face work should be closely examined for seams, the effect of which is to allow rain-water to penetrate to the interior of the stone and, under the action of frost, to split and crack it. THE DEFECTS OF GRANITE are termed knots, sap, shakes and rot. Knots are lumps of different color from the main body they are usually black or white. Sap is the name given to discolorations or stains. Shakes are seams which usually have discolored edges the name given to stone which crumbles easily. SANDSTONES AND LIMESTONES must be closely examined for ' The appearance of good sandstone is characterized by tie sharp of the grains, smallness of the cementing material, and acle-.r shining, translucent appearance on a newly broken surface Rounded grains and a dull mealy surface indicate soft and perish' able stone. NATUKAL STONE. 17 QUARRYING. In quarrying stone for building purposes there should be as little blasting as possible, as it shakes the stone. Stone showing powder- cracks should be rejected. Weather-worn stone and stone from the outcrop or capping of a quarry should not l,e used in good work. Stone should if pos- sible be worked at once aftt-r being quarried, for it is then easier to cut. The quarrying of limestone, marble, and sandstone during winter is not advisable, as they are liable to be injured by the freezing of the contained water. SEASONING. Stones of a porous nature which contain water when quarried are said to be green or sappy. Such stones must be exposed to the drying action of the air before using them, otherwise they will be split and fractured by the action of frost upon the con- tained water. 1 ARTIFICIAL STORES. in. ARTIFICIAL STONES. Brick. Brick is an artificial stone made by submitting clay, which has been suitably prepared and moulded into shape, to a temperature of sufficient intensity to convert it into a semi-vitrified state. The quality of the brick depends upon the kind of clay used and upon the care bestowed on its preparation. The clays of which brick is made are chemical compounds con- sisting of silicates of alumina, either alone or combined with other substances, such as iron, lime, soda, potash, magnesia, etc., all of which influence the character and quality of the brick, ac- cording as one or the other of those substances predominates. Iron gives hardness and strength ; hence the red brick of the Eastern States is often of better quality than the white and yellow brick made in the West. Silicate of lime renders the clay too fusible and causes the bricks to soften and to become distorted in the process of burning. Carbonate of lime is at high tempera- tures changed into caustic lime, renders the clay fusible, and when exposed to the action of the weather absorbs moisture, promotes disintegration, and prevents the adherence of the mor- tar. Magnesia exerts but little influence on the quality ; in small quantities it renders the clay fusible ; at 60 Fahr. its crystals lose their water of crystallization, and cold water decomposes them, forming an insoluble hydrate in the form of a white powder. In air-dried brick this action causes cracking. The alkalies are found in small quantities in the best of clays; their presence tends to promote softening, and this goes on the more rapidly if it has been burned at too low a temperature. Sand mixed with the clay in moderate quantity (one part of sand to four of clay is about the best proportion) is beneficial, as tending to prevent excessive shrinking in the fire. Excess of sand destroys the cohesion and renders the brick brittle and weak. MANUFACTURE OF BRICK. The manufacture of brick may be classified under the following heads : Excavation of the clay, either by manual or mechanical power. Preparation of the day consists in (a) removing stones and me- chanical impurities ; (&) tempering and moulding, which is now BRICK. 19 done almost wholly by machinery. There is a great variety of machines for tempering and moulding the clay, which, however, may be grouped into three classes, according to the condition of the clay when moulded : (1) soft-mud machines, for which the clay is reduced to a soft mud by adding about one quarter of its volume of water ; (2) stiff-mud machines, for whicli the clay is reduced to a stiff mud ; (3) dry-clay machines, with which the dry or nearly dry clay is forced into the moulds by a heavy pressure without having been reduced to a plastic mass. These machines may also be divided into two classes, according to the method of filling the moulds ; (1) those in which a continuous stream of clay is forced from the pug-mill through a die and is afterwards cut up into bricks ; and (2) those in which the clay is forced into moulds moving under the nozzle of the pug-mill. Drying and Burning. TLie bricks, having been dried in the open air or in a drying-house, are burned in kilns ; the time of burning varies with the character of the clay, the form and size of the kiln, and the kind of fuel, from six to fifteen days. COLOR OF BRICKS. The color of bricks depends upon the composition of the clay, the moulding sand, temperature of burning, and volume of air admitted to the kiln. Pure clay free of iron will burn white, and mixing of chalk with the clay will produce a like effect. Iron produces a tint ranging from red and orange to light yellow, according to the proportion of the iron. A large proportion of oxide of iron mixed with pure clay will produce a bright red, and where there is from 8 to 10 per cent, and the brick is exposed t > an intense heat, the oxide fuses and produces a dark blue or purple, and with a small volume of man- ganese and an increased proportion of the oxide the color is darkened even to a black. A small volume of lime and iron produces a cream color, an in- crease of iron produces red, and an increase of lime brown. Magnesia in presence of iron produces yellow. Clay containing alkalies and burned at a high temperature pro- duces a bluish green. CLASSIFICATION OF BRICK. Bricks are classified according to (1) the way in whicli they are moulded ; (2) their position in the kiln while being burned ; and (3) their form or use. 20 ARTIFICIAL STOKES. I. The method of moulding gives rise to the following terms : SOFT- MUD BRICK. One moulded from clay which has been reduced to a soft mud by add ng water. It may be either hand- moulded or machine-moulded. STIFF-MUD BRICK, One moulded from clay in the condition of stiff mud. It is always machine- moulded. PRESSED BRICK. One moulded from dry or semi-dry clay. RE-PRESSED BRICK. A soft-mud brick which, after being par- tially dried, has been subjected to an enormous pressure. It is also called, but less appropriately, pressed brick. The object of the re-pressing is to render the form more regular and to increase the strength and density. SLOP BRICK. In moulding brick by hand, the moulds are some- times dipped into water just before being filled with clay, to pre- vent the mud from sticking to them. Brick moulded by this process is known as slop brick. It is deficient in color and has a comparatively smooth surface, with rounded edges and corners. This kind of brick is now seldom made. SANDED BRICK. Ordinarily, in making soft-mud brick, sand is sprinkled into the moulds to prevent the clay from sticking ; the brick is then called sanded brick. The sand on the surface is of no advantage or disadvantage. In hand-moulding, when sand is used for this purpose, it is certain to become mixed with the clay and occur in streaks in the finished brick, which is very undesir- able. MACHINE-MADE BRICK Brick is frequently described as " machine-made " ; but this is very indefinite, since all grades and kinds are made by machinery. II. When brick was generally burned in the old-style up- draught kiln, the classification according to position was important; but with the new styles of kilns and improved methods of burning, the quality is so nearly uniform throughout the kiln that the classification is less important. Three grades of brick are taken from the old-siyle kiln : ARCH OR CLINKER BRICKS. Those which form the tops and sides of the arches in which the fire is built. Being overburned and partially vitrified, they are hard, brittle, and weak. BODY, CHERRY, OR HARD BRICKS. Those taken from the in- terior of the pile. The best bricks in the kiln. SALMON, PALE, OR SOFT BRICKS. Those which form the ex- terior of the mass. Being underburned, they are too soft for ordinary work, unless it be for filling. The terms salmon and pale. BRICK. 21 refer to the color of the brick, and hence are not applicable to a brick made of a clay that does not burn red. Although nearly all brick-clays burn red, yet the localities where the contrary is true are sufficiently numerous to make it desirable to use a different term in d signating the quality. There is not necessarily any relation between color, Mid strength and density. Brick-makers naturally have a prejudice against the term soft brick, which doubtless ex- plains the nearly universal prevalence of the less appropriate term salmon. III. The form or use of bricks gives rise to the following classi- fication : COMPASS BRICK. Those having one edge shorter than the other. Used in lining shafts, etc. FEATHER-EDGE BRICK Those of which one edge is thinner than the other. Used in arches ; and more properly, but less frequently, called voussoir brick. FRONT OR FACE BRICK. Those which, owing to uniformity of size and color, are suitable for the face of the walls of buildings. Sometimes face bricks are simply the best ordinary brick ; but gen- erally the term is applied only to re-pressed or pressed brick made especially for this purpose. They are a little larger than ordinary bricks. SEWER BRICK. Ordinary hard brick, smooth, and regular in form. KILN-RUN BRICK. All the brick that are set in the kiln when burned. HARD KILN-RUN BRICK. Brick burned hard enough for the face of outside walls, but taken from the kiln unselected. RANK OF BRICKS. In regularity of form re-pressed brick ranks first, dry-clay brick next, then stiff-mud brick, and soft-mud brick last. Regularity of form depends largely upon the method of burning. The compactness and uniformity of texture, which greatly in- fluence the durability of brick, depend mainly upon the method of moulding. As a general rule, hand-moulded bricks are best in this respect, since the clay in them is more uniformly tempered before being moulded; but this advantage is partially neutralized by the presence of sand-seams. Machine-moulded soft-mud bricks rank next in 'Compactness and uniformity of texture. Then come machine-moulded stiff-mud bricks, which vary greatly in dura- bility with the kind of machine used in their manufacture. By VI ARTIFICIAL STOKES. some of the machines the brick is moulded in layers (parallel to any face, according to the kind of machine) which are not thoroughly cemented, and which separate under the action of frost. The dry-clay brick come last. However, the relative value of the products made by different processes varies with the nature of the clay used. GLAZED AND ENAMELLED BRICKS. GLAZED BRICKS Bricks are glazed by means of a composition of porcelain or glass which fuses and renders the surface vitreous. This may be done by applying a flux or a chemical solution to the surface Pigments of metallic oxides are added to the composition, which give it any desired color or shade. The coloring is done either under the glaze or in the glaze. When the application is to be made under the glaze it is customary to dip the bricks previ- ously burned into a " slip" of colored clay composed, in most in- stances, of one part colored glass, ground, and two parts clay, the latter causing adhesion of the slip; the brick is then fired, or, after being allowed to dry, is coated with a transparent glaze and then fired. When the color is to be applied in the glaze the brick is dipped into a transparent colored glaze made of silicious sand, salt, and oxide of lead combined with the required coloring pig- ment. The composition is prepared by pulverization to a homo- geneous mass, then calcined, pulverized again, and made appli- cable by dissolving in water to the consistency of cream. The faces of the brick to be glazed are dipped in this solution or are coated with it by brushes, after which the brick is subjected to a temperature sufficient to fuse the glaze on the surface. ENAMELLED BRICKS are generally made of a particular quality of clay, containing a considerable proportion of fire clay. The enamel may either be applied to the unburnt brick or to the brick after it is burnt. In burning the enamel fuses and unites with the body of the brick, but does not become transparent, ?md there- fore shows its own color. It is claimed that an enamelled brick is more durable than a glazed brick, and will not so readily chip or peel. The enamel is also the purest white. An enamelled surface may be distinguished from a glazed sur- face by chipping off a piece of the brick. The glazed brick will show the layer of slip between the glaze and the brick ; the enamelled brick will show no line of demarcation between the body of the brick and the enamel. BRICK. 23 TABLE 3. SIZE AND WEIGHT OF BRICKS. The variations in the dimensions of brick render a table of exact dimensions impracticable. As an exponent, however, of the ranges of their dimensions, the following averages are given : Baltimore front \ Wilmington " j- 8" X 4|" X 2f " Washington " , ) Croton " 8" X 4" X 2" Maine ordinary 7|" X 3f" X 2|" Milwaukee" 8f X 4" X 2|" North River, N. Y 8" X 3" X 2J" English 9" X 4|" X 2" The Standard Size as adopted by the National Brickmakers' Association and the National Traders and Builders' Association is or common brick 8 X 4 X 2 inches, and for face brick $| x 4 X 2 inches. He-pressed Brick weighs about 150 Ibs. per cubic foot, common brick 125, inferior soft 100. Common bricks will average about 4^ Ibs. each. Hollow Brick, used for interior walls and furring, are usually of the following dimensions : Single, 8 in. long, 3f in. wide, 2f in. thick. Double, 8 " " 7* " " 4* " " Treble, 8 " " 7j " " 7^ " " Roman Brick, 12 in. long, 4 to 4 in. wide, l in. thick. TABLE 4. SPECIFIC GRAVITY, WEIGHT, AND RESISTANCE TO CRUSHING OF BRICK. Designation of Brick. Specific Gravity. Weight per Cubic Foot. Pounds. Resistance to Crushing. Pounds per Square Inch. Best pressed . 2 4 1*>0 *> 000 to 14 97 Common hard Soft 1.6 to 2.0 1 4 125 100 5.000 to 8,000 450 to 600 24 ARTIFICIAL STONES. BRICK. Inspection of Brick. The characteristics of good brick are : 1. Soundness ; that is, freedom from cracks and flaws. 2. Hardness, to enable it to withstand pressure and strain. 3. Regularity of shape and size; it should have plane faces, parallel sides, and sharp right angled edges. 4. Should show when broken a compact uniform structure, hard and somewhat glassy, and free from air-bubbles, cracks, cavities, and lumps. 5. Should emit a clear ringing sound when struck a sharp blow. 6. Should not absorb more than about -^ of its weight of water. 7. The specific gravity should be 2 or more. 8. The crushing strength of a half brick, when ground flat and pressed between thick metal plates, should be at least 7000 Ibs. per square inch. 9. The modulus of rupture should be at least 1000 Ibs. per square inch. Good bricks are generally of a dark reddish-brown color, and sometimes show vitrified spots on the surface; it is not well, how- ever, to depend upon this fact, for it is only an indication of the amount of heat to which the brick has been subjected, while the clay of which the brick is made may be impure and ill prepared. Bad bricks are generally recognized by their reddish-yellow color, but still more by the dull sound which they emit when struck. Their grain being soft they crumble easily and absorb water with avidity. All brick intended for building that does not take up a small percentage of water is too much burned, and the mortar will adhere to it imperfectly. When a brick left in water either scales or swells, it is of bad quality and contains caustic lime. A brick which being made red hot and then having water poured over it does not crack is of excellent quality. The strength of building brick, both transverse and crushing, varies in tolerably close inverse ratio with the quantity of water absorbed in 24 hours. The strongest bricks absorb least water. Good building brick absorb from 6 to 12 per cent of water in 24 hours, and with no greater absorption than 12 per cent will ordi- narily show from 7000 to 10,000 or more pounds per square inch of ultimate crushing strength, and a transverse modulus of 700 to 1200 Ibs. or more. ARTIFICIAL STOCKS. -Fl HE-BRICK. 25 Poor building brick will absorb from i to of their weight of water in 24 hours, and average a little more than half the trans- verse' and crushing strength of good brick. An immersed brick is neaily saturated in the first hour of immersion ; in the remaining 24 hours the absorption is only 0.5 to 0.8 per cent of its weight, as a rule. The strength of bricks in the kiln is least in the top courses, and increases quite rapidly for the first 10 or 12 courses and afterwards more slowly down to the arch bricks. Bricks made by the dry process are, as a rule, notably less porous and stronger than those iiiade by the wet mud process. To this rule, however, there are some exceptions. EFFECT OF FHOST. To ascertain if bricks will withstand the action of frost, boil one for half an hour in a solution of sulphate of soda, allow to remain in the solution until cold, then suspend it by a string over the vessel in which it has been boiled. In 24 hours the surface of the brick will be covered with small crystals; the brick is then to be immersed in the solution until the crystals disappear, and again suspended. Repeat this operation for five days. If after this treatment a number of particles of brick are found at the bottom of the vessel, the bricks are incapable of re- sisting the effects of frost. Fire-brick. Fire-brick is used wherever high temperatures are to be resisted. They are made from fire-clay by processes very similar to those adopted in making ordinary brick. Fire-clay may be defined as native combinations of hydrated silicates of alumina, mechanically associated with silica and alumina in various states of subdivision, and sufficiently free from silicates of the alkalies and from iron and lime to resist vitrification at high temperatures. The presence of oxide of iron is very injurious, and, as a rule, the presence of 6 per cent justi- fies the rejection of the brick. The presence of 3 per cent of com- bined lime, soda, potash, and magnesia should be a cause for rejection. The sulphide of iron pyrites is even worse than the substances first named. A good fire-clay should contain from 52 to 80 per cent of silica and 18 to 35 per cent of alumina and have an uniform texture, a somewhat greasy feel, and be free from any of the alkaline earths. 26 ARTIFICIAL STONES. TKIIKA-COTTA. Good fire brick should be uniform in size, regular in shape, homogeneous in textuie and composition, easily cut, strong, *uid infusible. A properly burnt fire-brick is of an uniform color throughout its mass. A dark central patch and concentric rings of various shades of color is due mainly to the different states of oxidation of the iron and partly to the presence of unconsumed carbonaceous mat- ter, and indicates that the brick was burned too rapidly. Fire-brick are made in various forms to suit the required work. A straight brick measures 9 X 4 X 2| inches and weighs about 7 Ibs., or 120 Ibs. per cubic foot ; specific gravity 1.93. One cubic foot of wall requires 17 9-inch bricks ; one cubic yard requires 460. One ton of fire-clay should be sufficient to lay 3000 ordinary bricks. English fire-bricks measure 9 X 4^ X 2f inches. To secure the best results fire-brick should be laid in the same clay from which they are manufactured. It should be used as a thin paste, and not as mortar: the thinner the joint the better the furnace wall. The brick should be dipped in water as they are used, so that when laid they will not absorb the water from the clay paste. They should then receive a thin coating of the prepared fire-clay, and be carefully placed in position with as little of the fire-clay as possible. Terra-cotta. Terra-cotta is largely used as a substitute for stone in the ornamental part of buildings. It is composed of mixed clays, to which sometimes is added a large proportion of ground glass, pottery, and sand. After being properly kneaded it is forced into moulds smeared with soft soap; it is then carefully dried, and gradually baked in a pottery-kiln, and then slowly cooled. When properly prepared and burnt it is not affected by the atmosphere or acid fumes. Terra-cotta is subject to unequal shrinkage in baking, which sometimes causes the pieces to be twisted. When this is the case great care must be taken in laying the blocks; otherwise the long lines of a building, such as those of string-courses or cornices, which are intended to be straight, are apt to be uneven, and the faces of the blocks are often in winding. Twisted and warped blocks are sometimes set right by chiselling, but this should be avoided, for if the vitrified skin on the surface ARTIFICIAL STONES. TERRA-COTTA. 27 be removed the material will not be able to withstand the attacks of the atmosphere, etc. Terra-cotta is made in several colors, depending chiefly upon the amount of heat it has gone through, White, pale gray, pale yellow or straw color indicate a want of firing. Rich yellow, pink, and red varieties are generally well burned. A green hue is a sign of absorption of moisture and of bad material. Inferior terra-cotta is sometimes made by overlaying a coarsely prepared body with a thin coating of a finer and more expensive clay Unless these bodies have been most carefully tested and assimilated in their contraction and expansion, they will in the course of time destroy one another; that is, the inequality in their shrinkage will cause hair cracks in the outer skin, which will retain moisture, and cause the surface layer to fall off in scales after winter frosts. Another very reprehensible custom is that of coating over the clay, just before it goes into the kiln, with a thin film of some ochreish paint mixed with a finely ground clay, which produces a sort of artificial bloom which speedily wears off after exposure to the action of the atmosphere. Terra-cotta, whether plain or ornamental, is generally made of hollow blocks formed with webs inside, so as to give extra strength and keep it true while drying. This is necessitated because good, well- burned terra-cotta cannot safely be made of more than about l inches in thickness, whereas when required to bond with brickwork it must be at least four inches thick. When extra strength is needed these hollow spaces are filled with concrete or brickwork, which greatly increases the crushing strength of the terra-cotta, although alone it is able to bear a very heavy weight. A solid block of terra-cotta of one foot cube has borne a crushing strain of 500 tons and over. TABLE 5. RESISTANCE TO CRUSHING OF TERRA-COTTA. Tons per Cubic Foot Solid block 523 Hollow block (unfilled) 186 " (slightly made and unfilled) 80 Solid " 2-inch square, red 492 buff 449 " " " gray 369 28 ARTIFICIAL STONES. TILES. The safe working strength of unfilled blocks may be taken at 5 tons per square foot, and for blocks filled solid with concrete or brickwork at 10 tons per square foot. The weight of terra- cotta in solid blocks is 122 pounds per cubic foot; the weight of hollow blocks 1^ inches thick varies from 65 to 85 pounds per cubic foot. Porous terra-cotta roofing 3 inches thick weighs 16 pounds per square foot, and 2 inches thick 12 pounds. POROUS TERKA-COTTA is made of a mixture of clay and some combustible material, such as sawdust, charcoal, cut straw, etc. When baked the combustible material is consumed, leaving the terra-cotta full of small holes. It is fireproof, of light weight, great tenacity, strong, can be cut with edge-tools, will hold nails driven in, and gives a good surface for plastering. Tiles, COMMON TILES are made of the same materials as bricks; they are used for paving and roofing. ENCAUSTIC TILES are those in which the colors are produced by substances mixed with the clay. PAVING TILES are of many shapes and sizes, and about one inch thick. ROOFING TILES are of many forms and sections, such as plain, corrugated, Venetian, ridge, etc. FLAT TILES 6|" X 10|" X I" weigh from 15 to 18 Ibs. per square foot of roof, the lap being one half the length of the tile. Tiles with grooves and fillets weigh from 7 to 9 Ibs. per square foot of roof. PAN TILES 14|" X W laid 10" to the weather weigh about 8 Ibs. per square foot. Inspection of Tile. The inspection and testing of tiles should embrace : 1. Examination of dimension, appearance, and soundness. 2. Weight and specific gravity. 3. The real and apparent absorption of water. 4. Presence of constituents soluble in water. 5. Strength. ARTIFICIAL STONES. 29 Stones made by Patented Processes. Several kinds of artificial stone are manufactured under patented processes. They are all a combination of hydraudc cement, sand, pebbles, stone-dust, etc., with or without the addi- tion of some indurating material, as baryte, litharge, etc. They are manufactured either in place or in form of blocks at a factory. Such stones are extensively employed in architecture and for the paving of cellars, areas, footpaths, etc. 30 LIME. IV. CEMENTING MATERIALS. The cementing materials employed in building are produced by the calcination of calcareous minerals. As these minerals differ greatly in their composition, ranging from pure carbonate of lime to stones containing variable proportions of silica, alumina, mag- nesia, oxide of iron, manganese, etc., they confer different prop- erties upon the calcined product, which render necessary certain precautions in its manipulation and treatment, and furnishes a basis of classification, as follows : 1st. Common or fat limes. 2d. Poor or meagre limes. 3d. Hydraulic limes. 4th. Hydraulic cements, which may be divided into three classes, viz. : Portland, Rosendale, and Pozzuolana, The first two differ from the third in that the ingredients of which the former are composed must be roasted before they acquire the property of hardening under water, while the ingredients of the latter need only be pulverized and mixed with water to a paste. The hydraulic cements do not slake after calcination, differing materially in this particular from the limes proper. They can be formed into paste with water, without any sensible increase in volume, and little, if any, disengagement of heat, except in cer- tain instances among those varieties which contain the maxi- mum amount of lime. They do not shrink in hardening, like the mortar of rich lime, and can be used with or without the addition of sand, although for the sake of economy sand is combined with them. The hydraulic activity of some of them is so ener- getic as to set under water at 65 F, in three or four minutes, although others require as many hours. Limes. RICH LIMES. The common fat or rich limes are those obtained by calcining pure or very nearly pure carbonate of lime. In slaking they augment to from two to three and a half times that of the original mass. They will not harden under water, or even in damp places excluded from contact with the air. In the air they harden by the gradual formation of carbonate of lime, due to the absorption of carbonic acid gas. LIME. 31 The pastes of fat lime shrink in haidcning to such a degree that they cannot be employed for mortar without a large dose of sand. POOR LIMES. The poor or meagre limes generally contain silica, alumina, magnesia, oxide of iron, sometimes oxide of man- ganese, and in some cases traces of the alkalies, in relative pro- portions, which vary considerably in different localities. In slaking they proceed sluggishly, as compared with the rich limes the action only commences after an interval of from a few minutes to more than an hour after they are wetted ; less water is required for the process, and it is attended with less heat and increase of volume than in the case of fat limes. HYDRAULIC LIMES. The hydraulic limes, including the three subdivisions of limes, viz., slightly liydraulic, hydraulic, and eminently hydraulic, are those containing after calcination suf- ficient of such foreign constituents as combine chemically with lime and water to confer an appreciable power of setting or hard- ening under water without the access of air. They slake still slower than the meagre limes, nd with but a small augmentation of volume, rarely exceeding 30 per cent of the original bulk. Inspection of Lime. QUALITY. The quality of good lime is indicated by the per- fect ness with which the lumps fall to powder when water is applied. No mashing of the lumps or stirring should be neces- sary, though the slaking will be somewhat hastened by so doing. Freshly burned lime may be known by its being in hard lumps rather than in powder or easily crumbled lumps. PRESERVATION. Lime, on account of it i affinity for moisture, and, when moist, for carbonic acid, absorbs them gradually from the atmosphere, and returns somewhat to the state of carbonate of lime; this process is termed "air-slaking" and weakens the setting quality of the lime. To protect it from this deteriorat- ing action it should be packed in close casks and stored in a dry place until required for use, and then quickly used; therefore the best lime for use is that which has been recently burned. Lime, when thoroughly slaked and mixed into a paste, may be kept for an indefinite time in that condition without deterioration if protected from contact with the air so that it will not dry up. It is customary to keep the lime paste in casks, or in the wide shallow boxes in which it was slaked, or heaped up on the ground, 32 LIME. covered over with the sand to be subsequently incorporated with it in making tlie mortar, SLAKING. Slaking is the process of chemical combination of quicklime with water ; one equivalent of water combines with one equivalent of lime, and forms slaked lime, or, in chemical lan- guage, Jiydrate of lime. The process of slaking is a simple one. The lime is spread out in a suitable bed and as much water as it will readily absorb is poured upon it. This moistening with water gives rise to various phenomena : the lime almost immediately cracks, swells, and falls into a bulky powder with a hissing, crackling sound, slight explo- sions, an 1 considerable evolution of heat and steam ; the volume is increased from two to three and a half times the original bulk, the variation depending both iipon the density of the original car- bonate and the manner of conducting the process The same process takes place slowly by absorption of moisture from the atmosphere ; the lime falls into powder with increase of volume, but without perceptible heating. Lime slaked in this way is said to be air-slaked. Some carbonic acid gas is also absorbed and a part of the lime returns to the state of a carbonate of lime. Air-slaked lime is deficient in setting properties and should not be used for building purposes. The common limes contain impurities which prevent a thor- ough, uniform, and prompt slaking of the entire, mass ; hence the necessity of slaking some days before the lime is required for use, to avoid all danger to the masonry by subsequent enlargement of volume and change of condition. The slaking of lime, although an exceedingly simple operation, is liable to be unskilfully performed by the workmen. They are apt either to use tr.o much water, which reduces the slaked lime to a semi-fluid condition and thereby injures its binding qualities ; or, not having used enough water in tlie first place, seek to remedy the error by adding more after the slaking has well progressed and a portion of the lime is already reduced to powder, thus suddenly depressing the temperature and chilling the lime, which renders it granular and lumpy. The lime should not be stirred while slaking. The essential point is to secure the reduction of all the lumps. The best mode of slaking, so far as regards the quality of the mortar, is by sprinkling the loose lump lime with about one fourth to one third by trial of its own bulk of water, and then covering LIME. 33 it with a layer of sand or with a tarpaulin ; this retains the heat and accelerates the slaking. All the lime necessary for any re- quired quantity of mortar should be slaked at least one day before it is incorporated with the sand. Memoranda and Definitions of Lime. Lime is shipped either in bulk or in barrels. If in bulk, it is impossible to preserve it for any considerable length of time. A barrel of lime usually weighs about 230 Ibs. net, and will make about three tenths of a cubic yard of stiff paste. A bushel weighs 75 Ibs. PURE LIME is a protoxide of calcium, or, in other words, a metallic oxide. It has a specific gravity of 2.3, is amorphous, somewhat spongy, highly caustic, quite infusible, possesses great affinity for water, and if brought in contact with it will rapidly absorb 22 to 23 per cent of its weight, passing into the condition of hydrate of lime. SLAKED LIME is hydrate of lime. QUICKLIME, or caustic lime, is the resulting lime left from the calcination of limestone it is chemically known as calcium oxide. LIMESTONE. Carbonate of lime. CRYSTALLIZED LIME. Marble. FOSSIL LIME. Chalk. SULPHATE OF LIME. Gypsum. CALCINATION is heating to redness in air. SLAKING is the process of chemical combination of quicklime with water. AIR-SLAKING. Hydra tion by the absorption of moisture from the atmosphere. 34 CEMENTS. Portland Cement. Portland cement is produced by burning, with a heat of suf- ficient intensity and duration to induce incipient vitrification, certain argillaceous limestones, or calcareous clays, or an artificial mixture of carbonate of lime and clay, and then reducing the burnt material to powder by grinding. Fully 95 per cent of the Portland cement produced is artificial. The name is derived from the resemblance which hardened mortar made of it bears to a stone found in the isle of Portland, off the south coast of England. The quality of Portland cement depends upon the quality of the raw materials, their proportion in the mixture, the degree to which the mixture is burnt, the fineness to which it is ground, and the constant and scientific supervision of all the details of manufacture. CHARACTERISTICS OF PORTLAND CEMENT. COLOR. The color should be a dull bluish or greenish gray, caused by the dark ferruginous lime and the intensely green man- ganese salts. Any variation from this color indicates the presence of some impurity : blue indicates an excess of lime ; dark green, a large percentage of iron ; brown, an excess of clay ; a yellowish shade indicates an underburned material. FINENESS. It should have a clear almost floury feel in the hand ; a gritty feel denotes coarse grinding. WEIGHT. It should weigh from 84 to 88 pounds per cubic foot. A cement weighing from 70 to 80 pounds per cubic foot is invari- ably a weak one, though it may be of the requisite fineness ; at the same time a heavy cement if coarsely ground is also weak and will have no carrying capacity for sand. Light weight may be caused by laudable fine grinding or by objectionable underburn- ing. In testing, weight and fineness must be taken in conjunction. SPECIFIC GRAVITY is between 3 and 3.05. As a rule the strength of Portland cement increases with its specific gravity. TENSILE STRENGTH. When moulded neat into a briquette and placed in water for seven days it should be capable of resisting a tensile strain of from 300 to 500 pounds per square inch. SETTING A pat made with the minimum amount of wa,ter should set in not less than three hours, nor take more than six hours. EXPANSION AND CONTRACTION. Pats left in the air or placed in water should during or after setting show neither expansion nor contraction, either by the appearance of cracks or change of form. CEMENTS. 35 A cement that possesses the foregoing properties may be con- sidered a fair sample of Portland cement and would be suitable for any class of work. OVERLIMED CEMENT is likely to gain strength, very rapidly in the beginning and later to lose its strength, or if the percentage of free lime be sufficient it will ultimately disintegrate. BLOWING or SWELLING of Portland cement is caused by too much lime or insufficient burning. It also takes place when the cement is very fresh and has not had time to cool. ADULTERATION. Portland cement is adulterated with slag cement and slaked lime. This adulteration may be distinguished by the light specific gravity of the cement, and by the color, which is of a mauve tint in powder, while the inside of a water-pat when broken is deep indigo. Gypsum or sulphate of lime is also used as an adulterant. Natural Cement. The Ro&endcde or natural cements are produced by burning in draw-kilns at a heat just sufficient in intensity and duration to expel the carbonic acid from argillaceous or silicious limestones containing less than 77 per cent of carbonate of lime, or argillo- magnesian limestone containing less than 77 per cent of both car- bonates, and then grinding the calcined product to a fine powder between millstones. The natural cements usually take the name of the place of manufacture. The name Rosendale is derived from the place (Ro- sendale, Ulster Co., N. Y.) where it was first made. CHARACTERISTICS OF ROSENDALE CEMENTS. The natural cements have a porous, globular texture. They do not heat up nor swell sensibly when mixed with water. They set quickly in air, but harden slowly under water, without shrinking, and attain great strength with well-developed adhesive force. COLOR. Usually brown, of greater or less intensity. The color gives no clue to the ce:i entitious value, since it is due chiefly to oxides of iron and manganese, which bear no direct relation to the cementing properties. A very light color generally indicates an inferior underburned cement A Rosendale cement made at Cop- lay, Pa , from the same stone as Portland is a light gray in color. SETTING. A pat made with the minimum amount of water should set in about 30 minutes. 36 CEMENTS. FINENESS. At least 93 per cent must pass through a No. 50 sieve. WEIGHT Varies from 49 to 56 pounds per cubic foot. SPECIFIC GRAVITY about 2.70. TENSILE STRENGTH. Neat cement one day, from 40 to 80 pounds. Seven days, from 60 to 100 pounds. One year, from 300 to 400 pounds. Inspection of Cement. The quality or constructive value of a cement is generally ascertained by submitting a sample of the particular cement to a series of tests. The properties usually examined are the color, weight, activity, soundness, fineness, and tensile strength. Chemical analysis is sometimes made, and specific gravity test is substituted for that of weight. Tests of compression and adhesion are also sometimes added. As these tests cannot be made upon the site of the work, it is usual to sample each lot of cement as it is delivered and send the samples to a testing laboratory. SAMPLING CEMENT. The cement is sampled by taking a small quantity (1 to 2 Ibs.) from the centre of the package. The num- ber of packages sampled in any given lot of cement will depend upon the character of the work, and varies from every package to 1 in 5 or 1 in 10. When the cement is brought in barrels the sample is obtained by boring with an auger either in the head or centre of the barrel, drawing out a sample, then closing the hole with a piece of tin firmly tacked over it. For drawing out the sample a brass tube sufficiently long to reach the bottom of the barrel is used. This is thrust into the barrel, turned around, pulled out, and the core of cement knocked out into the sample- can, which is usually a tin box with a tightly fitting cover. Each sample should be labelled, stating the number of the sam- ple, the number of bags or barrels it represents, the brand of the cement, the purpose for which it is to be used, the date of delivery, and date of sampling. FORM OF LABEL. Sample No , No. of Barrels Brand To be used Delivered 18. . Sampled 18. By CEMENTS. 37 The sample should be sent at once to the testing office, and none of the cement should be used until the report of the tests is received. The testing of cement ordinarily consumes 30 days. Therefore the supply must be so gauged that a sufficient quantity will be kept on hand to allow the tests to be made without delay to the work of construction. After the report of the tests is received the rejected packages should be conspicuously marked with a "C" and should be re- moved without delay ; otherwise it is liable to be used. Rough Tests for Cement. As one lot of cement is liable to differ very much from another lot of the same brand, it is very necessary that the inspector apply some rough tests to get an idea of how the cement is running. TEST FOR SETTING. Make a small pat of neat cement and note the interval of time that elapses until it resists penetration under alight pressure of the thumb-nail. TEST FOR EXPANSION. Make a small pat of neat cement and when set in air place it under water, where it should remain for a few days. If the cement be good the pat will show no altera- tion in form, but if any cracks show on the edges, or other devia- tions from the original shape of the pat, they indicate that the cement is of an expansive nature, and therefore not to be trusted. But because a cement will not stand this test it is not in all cases to be condemned as useless, as its expansive or blowing property may be attributable to its being used too soon after leaving the mill. A proper process of cooling placing it in a thin layer on a dry floor for a short time may correct the defect. TEST FOR SOUNDNESS. Place some mortar of neat cement in a glass tube (a milled lamp-chimney is excellent for this purpose) and pour water on top. If the tube breaks the cement is unfit for use in damp places. CONTRACTION due to the cement being overclayed may be de- tected by a similar test to that for expansion. BALL TEST. This test is extensively employed by masons. Take enough neat cement to make a ball an inch in diameter, mix. with just sufficient water to make it mould readily, and roll it into a ball. Allow it to set in air for about two hours, then place under water, and allow it to remain from 1 to 10 days. It should become gradually harder, and show no signs of cracking or crum- bling. Any cement that does not endure this test is not of suffi- ciently good quality to make satisfactory work.. 38 CEMENTS. Preservation of Cements. Cements require to be stored in a dry place protected from the weather ; the packages should not be placed directly on the ground, but on boards raised a few inches from it. If necessary to stack it out of doors a platform of planks should first be made and the pile covered with canvas, Portland cement exposed to the atmosphere will absorb moisture until it is practically ruined. The absorption of moisture by the natural cements will cause the development of carbonate of lime, which will interfere with the subsequent hydration. Cements Memoranda and Definitions. Cement is shipped in barrels or in cotton or paper bags. The usual dimensions of a barrel are : length 2 ft. 4 in. , middle diameter 1 ft. 4^ in., end diameter 1 ft. 3| in. The bags hold 50, 100, or 200 pounds. A barrel weighs about as follows : Rosendale, N. Y 300 Ibs. net " Western 265 Portland 375 A barrel of Rosendale cement contains about 3.40 cubic feet and will make from 3.70 to 3.75 cubic feet of stiff paste, or 79 to 83 pounds will make about one cubic foot of paste. A barrel of Rosendale cement (300 Ibs.) and two barrels of sand (7-j cubic feet) mixed with about half a barrel of water will make about 8 cubic feet of mortar, sufficient for 192 square feet of mortar-joint inch thick 288 " " " " | " 384 " " ' " " 768 " " " " A barrel of Portland cement contains about 3.25 to 3.35 cubic feet 100 pounds will make about one cubic foot of stiff paste. A barrel of cement measured loosely increases considerably in bulk. The following results were obtained by measuring in quan- tities of two cubic feet : 1 bbl. Norton's Rosendale gave .... 4.37 cu. ft. " Anchor Portland " 3.65 Sphinx " " 3.71 " Buckeye " " 4.25 " CEMENTS. 39 The weight of cement per cubic foot is as follows . Portland, English and German 77 to 90 Ibs. " fine-ground French 69 " " American 92 " 95 " Rosendale 49 " 56 " Roman 54 " A bushel contains 1.244 cubic feet. The weight of a bushel can be obtained sufficiently close by adding 25$ to the weight per cubic foot. ACTIVITY denotes the speed with which a cement begins to set. Cements differ w'dely in their rate and manner of setting. Some occupy but a few minutes in the operation, and others require several. Some begin setting immediately and take con- siderable time to complete the set, while others stand for a con- siderable time with no apparent action and then set very quickly. The point at which the set is supposed to begin is when tlie stiffening of the mass first becomes perceptible, and the end of the set is when cohesion extends through the mass sufficiently to offer such resistance to any change of form as to cause rupture before any deformation can take place. FINENESS. The cementing and economic value of a cement is affected by the degree of fineness to which it is ground. Coarse particles in a cement have no setting power and act as an adul- terant. In a mortar or concrete composed of a certain quantity of inert material bound together by a cementing material it is evident that to secure a strong mortar or concrete it is essential that each piece of aggregate shall be entirely surrounded by the cementing material, so that no two pieces are in actual contact. Obviously, then, the finer a cement the greater surface will a given weight cover, and the more economy will there be in its use. The proper degree of fineness is reached when it becomes cheaper to use more cement in proportion to the aggregate than to pay the extra cost of additional grinding. The fineness of a cement is determined by measuring the per- centage which will not pass through sieves of a certain number of meshes per square inch. Three sieves are generally used, viz. : No. 50, 2,500 meshes per square inch ' 74, 5,476 " " 100, 10,000 " * 40 CEMENTS. The usual degree of fineness required is that the residue left on a No. 50 sieve shall not be more than 10 per cent by weight. FREEZING OF CEMENT MORTARS. Portland cement mortar suffers no surface disintegration under any condition of freezing, but the strength is impaired, in a majority of cases, and some- times as much as 40 per cent. Rosendale cement is disintegrated upon the surface when exposed to frost while setting, the amount of injury depending to a certain extent upon the number of degrees of the exposure below the free zing-point. The cohesion of Rosendale cement mortar may be entirely destroyed by immersion in water, which becomes frozen around it. In some cases Rosendale cement shows an increase of strength acquired under the conditions which it passes through while frozen. Portland cement is injured relatively less by freezing as the ratio of cement to sand decreases. Salt used in the mixing water, in proportions varying around 1 to 15, assists Rosendale cement to resist the disintegrating action of frost, but appears to have an injurious effect on the strength. The injury to Portland cement is decreased with about the same proportion of salt. HYDRAULICITY. Lime or cement is said to be more or less hydraulic according to the extent to which paste or mortar made from it will set under water, or in positions where it is excluded from the action of the air. HYDRAULIC ACTIVITY is the term used to denote the quickness or time required for a mortar to attain a small degree of strength. HYDRAULIC ENERGY or STRENGTH is the term applied to the ultimate strength attained by a mortar. There is no necessary relation between time of setting and ultimate strength ; but, as a general rule, the slow-setting cements ultimately attain to a greater strength than quick- seting ones. QUICK AND SLOW SETTING. The aluminous natural cements are commonly " quick -setting, " though not always so, as those containing a considerable percentage of sulphuric acid may set quite slowly. The magnesian and Portland varieties may be either "quick" or "slow." Specimens of either variety may be had that will set at any rate, from the slowest to the most rapid, and no distinction can be drawn between the various classes in this regard. Water containing sulphate of lime in solution retards the set- CEMENTS. 4L ting. This fact has been made use of in the adulteration of cement, powdered gypsum being mixed with it to make it slow- setting, greatly to the injury of the material. The temperature of the water used affects the time required for setting : the higher the temperature, within certain limits, the more rapid the set. Many cements which require several hours to set when mixed with water at a temperature of 40 F. will set in a few minutes if the temperature of the water be increased to 80 F. Below a certain inferior limit, ordinarily from 30 to 40 F., the cement will not set, while at a certain upper limit, in many cements between 100 and 140 F., a change is suddenly made from a very rapid to a very slow rate, which then contin- ually decreases as the temperature increases, until practically the cement will not set. The quick- setting cements usually set so that experimental samples can be handled within 5 to 30 minutes after mixing. The slow-setting cements require from 1 to 8 hours. Freshly ground cements set quicker than older ones. STRENGTH. The strength of a cement mortar is usually deter- mined by submitting a specimen of known cross-section to a tensile strain. The reason for adopting tensile tests is that com- paratively light strains produce rupture ; and that, since mortar is less strong in tension than in compression, in most cases of failure of mortar it is broken by tensile stress, even though the masonry be under compression. Table 6 shows the average minimum and maximum tensile strength per square inch which some good cements have attained. SETTING denotes the process of combination amongst the par- ticles of the cement under the action of water. SOUNDNESS denotes the property of not expanding or contracting or cracking or checking in setting. These effects may be due to free lime, free magnesia, or to unknown causes. Testing sound- ness is, therefore, determining whether the cement contains any active impurity. An inert adulteration or impurity affects only its economic value; but an active impurity affects also its strength and durability. CEMENTS. TABLE 6. TENSILE STRENGTH OF CEMENT MORTAR. Age of Mortar when Tested. Average Tensile Strength in Pounds per Square Inch. Portland. Rosendale. CLEAR CEMENT. One hour, or until set, in air, the remain- der of the time in water: 1 iltty . . Min. 100 250 350 450 Max. 140 550 700 800 Min. 40 60 100 300 30 50 200 Max. 80 100 laO 400 50 80 300 One day in air, the remainder of the time in water : 1 week . . . 4 iveeJcs 1 year 1 PART CEMENT TO 1 PART SAND. One day in air, the remainder of the time in water : 1 PART CEMENT TO 3 PARTS SAND. One day in air, the remainder of the time in water : 1 ivttek .... 80 100 200 126 200 350 4 weeks 1 yeur. ... . Miscellaneous Cements. SLAG CEMENTS are those formed by an admixture of slaked lime with ground blast-furnace slag. The slag used has approximately the composition of an hydraulic cement, being composed mainly of silica and alumina, and lacking a proper proportion of lime to render it active as a cement. In preparing the cement the slag upon coming from the furnace is plunged into water and reduced to a spongy form from which it may be readily ground. This is dried and ground to a fine powder. The powdered slag and slaked lime are then mixed in proper proportions and ground together, so as to very thoroughly distribute them through the mixture. It is of the first importance in a slag cement that the slag be very finely ground, and that the ingredients be very uni- formly and intimately incorporated. Both the composition and methods of manufacture of slag cements vary considerably in different places. They usually con- tain a higher percentage of alumina than Portland cements, and CEMENTS. 43 the materials are in a different state of combination, as, being mixed after the burning, the silicates and aluminates of lime formed during the burning of Portland cement cannot exist in slag cement. The tests for slag cement are that briquettes made of one part of cement and three parts of sand by weight shall stand a tensile strain of 140 pounds per square inch (one day in air and six in water), and must show continually increasing strength after seven days, one month, etc. At least 90 per cent must pass a sieve con- taining 40,000 meshes to the square inch, and must stand the boiling test. POZZUOLANAS are cements made by a mixture of volcanic ashes with linie, although the name is sometimes applied to mixed cements in general. The use of pozzuolana in Europe dates back to the time of the Romans. ROMAN CEMENT is a natural cement manufactured from the sep- taria nodules of the London Clay formation; it is quick-setting, but deteriorates by age and exposure to the air. LAFARGE CEMENT. This is a patented cement similar to Port- land, but, unlike Portland or the natural cements, does not stain marble, limestone, or other porous stones when used in setting them. For this reason it is largely used in setting and backing up the stone-work in fine buildings. Asphalt uni. BITUMEN? ASPHALTUM, ASPHALT. Bitumen is the name used to denote a group of mineral substances, composed of different hydrocarbons, found widely diffused throughout the world in a variety of forms which grade from thin volatile liquids to thick semi-fluids and solids, sometimes in a free or pure state, but more frequently intermixed with or saturating different kinds of in- organic or organic matter. To designate the condition under which bitumen is found dif- ferent names are employed ; thus the liquid varieties are known as naphtha and petroleum, the semi-fluid or viscous as maltha or mineral tar, and the solid or compact as aspJialtum or asphalt. Three distinct varieties of asphaltum are recognized, namely, the earthy, the elastic, and the hard or compact. The earthy variety, represented by the chapopota of Mexico, Colombia, and other parts of South America, has a brownish- 44 CEMEKTS. black dull color, an earthy uneven fracture, when freshly exca- vated a strong though not unpleasant earthy odor, is soft enough to take an impression of the nail, hardens slightly on exposure to the atmosphere, and burns with a clear brisk flame, emitting a powerful odor, and depositing much soot. Elastic asphaltum is of various shades of brown; is soft, flexible, and elastic ; it has an odor strongly bituminous, and is of about the density of water ; it burns with a clear flame and much smoke. Like caoutchouc, it takes up pencil-marks, and on this account is called mineral caoutchouc ; it has been found only at three places : in the fissures of a slaty clay at Castleton, Eng- land ; at Montrelais, France ; and in Massachusetts. Hard or compact asphaltum is the most useful variety ; it forms large deposits in many parts of the world, and is of various de- grees of quality, according to its age and the impurities mixed with it ; when nearly pure its ordinary characteristics are as fol- lows : Color brownish black and black ; lustre resinous or coal-like ; opaque. At temperatures below 100 F. it is brittle and breaks with a conchoidal fracture. Melts ordinarily at 190 F. to 195 F., and is liquid at about 212 F. At 212 F. it has a peculiar but agreeable aromatic odor, somewhat resembling, but still very different from, that of coal-tar ; at ordinary temperatures the odor is scarcely perceptible, but when rubbed it is quite strong. It kindles readily and burns brightly with a thick smoke. Dis- tilled by itself it yields a bituminous oil of a yellow color (con- sisting of hydrocarbons mixed with oxidized matter), water, some combustible gases, and sometimes traces of ammonia. After combustion it leaves about one third of its weight of charcoal and ashes containing silica, alumina, oxide of iron, sometimes oxide of manganese, lime, and other inorganic and organic matter. Its composition and hardness are variable. Specific Gravity. Pure bitumen has a density less than water ; but in consequence of the impurities mixed with it the specific gravity of asphaltum varies from 1.0 to 1.7. Solubility: It is insoluble in water, partly or wholly soluble in chloroform and disulphide of carbon, partly or wholly in oil of turpentine and petroleum ether, and commonly partly in alcohol. By different solvents asphaltum may be decomposed into three distinct though complex substances which have been named by Boussingault and other chemists who have investigated it petro- lene, asphaltene, and retine. Nothing definite is known concern- ing these compounds or how their variable proportions and CEMENTS. 45 composition affect the quality of asphaltum. In the past they have received but little attention from chemists, due probably to the limited use of asphaltum ; but now, in view of its large and increasing employment for paving and other industrial purposes, their investigation offers a wide and undoubtedly profitable field for chemical research. The characteristics of these compounds, so far as known, are generally as follows : Petrolene is the compound which is considered to give the vis- cous or adhesive quality. It may be described as that portion of the bitumen which is soluble in petroleum ether. It is lighter than water, very combustible, and has a high boiling-point, pale- yellow color, and peculiar odor. On evaporating off the ether it remains as a resin with a brownish-black color, which dissolves readily in the volatile oils. Its composition is carbon, hydrogen; and sulphur. The amount present in an asphaltum is variable, ranging from 3 to 70 per cent of the weight of the asphaltum. Asphaltene is the compound which gives the hardness to as- phaltum. It contains the elements of petrolene, together with a quantity of oxygen, and probably arises from the oxidation of that compound. It is that portion of the bitumen which is insol- uble in ether. It is dissolved out by carbon disulphide, chloro- form, benzene, etc. Its color is a brilliant black ; density greater than water. It burns like resins in general, leaving a very abundant coke. Like petrolene, it is composed of carbon, hydro- gen, and oxygen, and the amount present in an asphaltum is as variable ranging from 1 to about 60 per cent. Retine is dissolved out by alcohol (anhydrous) from that por- tion of the asphaltum which is unaffected by the solvents above mentioned. It is a yellow resin composed of carbou, hydrogen, and sulphur. What effect this compound has upon asphaltum is unknown. Some authorities claim that its presence is injurious. ORIGIN OP BITUMEN. The origin of bitumen is unknown. It is supposed to be the ultimate product resulting from the de- struction under certain conditions of the organized remains of animals and vegetables, producing (1) naphtha, (2) petroleum, (3) maltha or mineral tar, (4) jisphaltum. The whole of these sub- stances merge into each other by insensible degrees, so it that is impossible to say at what point maltha ends and asphaltum begins. Naphtha, the first of the series, is in some localities found flow- ing out of the earth as a clear, limpid, and colorless liquid ; as such it is a mixture of hydrocarbons, some of which are very vol- 46 CEMENTS. atile aud evaporate on exposure. It takes up oxygen from the air, becomes brown and thick, and in this condition it is called petroleum. The hardening of the bituminous fluids which have oozed out or been exposed by other causes upon the surface of the earth seems, in most cases at least, to have resulted from the loss of the vaporizable portions, and also from a process of oxidation which consists, first, in a loss of hydrogen, and finally in the oxygenation or evaporation of the more volatile portions, which gradually transforms them into mineral tar or maltha, and, still later, into solid glossy asphaltum, of which gilsonite, wurtzilite, uintahite, etc., are examples. OCCURRENCE AND DISTRIBUTION OF ASPHALTUM. Deposits of asphaltum are found widely diffused throughout the world, and at various altitudes ranging from below sea-level to thou- sands of feet above. It is, however, seldom found among the primitive or older rock formations, but seems to belong exclu- sively to the secondary and tertiary formations. Intermixed with the argillaceous stratas it forms extensive beds or lake-like depos- its on both continents, the most remarkable of which are those situated in the West Indies and South America. The most nota- ble of these are the so-called pitch lakes on the island of Trim dad, and at Bermudez, Venezuela. Saturating the calcareous and sandstone formations, it forms large subterraneous deposits in Europe and the United States. The calcareous varieties occur more extensively in Europe than in America, and are the source of the material employ od there for street-paving under the name of asphalte. The sandstone class is found extensively in the Western and Southwestern States, especially in California, Texas, Kentucky, and the Indian Ter- ritory. In a free or nearly pure state it is found in veins and seams in the primitive rock and volcanic formations. This class of deposit is rare, and the amount of asphaltum is generally insignificant. A notable exception, however, are the deposits of Utah, etc The mines from which gilsonite, wurtzilite, uintahite are produced are said to be very extensive, and the material is very nearly pure Similar deposits are found in Mexico, Cuba, and various parts of South America. In many localities beds of shale, sand, and cretaceous limestone are found saturated with maltha, from which the bitumen is extracted by boiling or macerating with water. CEMENTS. 47 From the variety of the deposits and their manner of occurrence it seems that asphaltum belongs to no particular era or age. Moreover, the asphaltum obtained from these different sources is not uniform either in character, appearance, hardness, or chemical composition. The ultimate composition of specimens from several localities is given in the following table: COMPOSITION OF ASPHALTUM. Locality. Car- bon. Hydro- gen. Oxy- gen. Nitro- gen. Sul- phur. Ash. Trinidad, W. I (80.32 < to 6.30 to 0.56 to to 2.49 to Cuba " (85.89 82.34 11.06 9 10 1.40 6.25 0.50 1 91 11.48 40 *^ 0t Caxatambo, Peru .... N. S. (albertite) W. Va(grahamite)... Auvergne, France Oklahoma, I. T Mexico 88.66 86 04 76.45 77.64 -J55.00 80 34 9.69 8.96 7.83 7.86 10.21 10 09 I. 1.97 13.14 8.35 7.14 9 57 65 2.93 "i'.OiT 2.74 trace 0.10 2.26 5.13 24.91 and silicates Utah (gilsonite) 80.88 9.76 6.05 3.30 0.01 NOMENCLATURE. As indicated above, the varieties of bitumen and asphaltum are as numerous as the localities producing them ; hence there is a great variety of names used to designate the same substance, which is oftentimes misleading, if not con- fusing. As an illustration of this variety the following may be mentioned: native pitch, mineral pitch, glance pitch, grahamite, albertite, piauzite, elaterite, gilsonite, wurtzilite, uintahite, tur- rellite, etc. Sometimes the name of the locality where it is found is used as a prefix, and is thus useful to indicate the source. Such names are Dead Sea bitumen, Egyptian asphalt, Cuban, Trinidad, Ber- muda, Californian, Kentucky, etc. The name asphalle has been adopted by the French to designate the material obtained from their bituminous limestone deposits, and is now generally employed throughout Europe to denote both the carbonate of lime impregnated with asphaltum and the pave- in nt made from that material. The name litkocarbon has been adopted to designate a cretaceous limestone saturated with bitumen found in Texas. Some authorities apply the terms asphaltum, asphalt, and liquid asphalt to the semi-fluid and viscous bituminous substance, or maltha, which by heat may be transformed into asphaltum. This 48 CEMENTS. application seems to be erroneous, because asphaltum technically means bitumen in tbe solid form. Others use the same terms to designate the entire mixture of bitumen, mineral and organic matter, while others apply them to denote the purified material. The names which seem to be the most used in the United States, and which are at the same time descriptive of the various classes, are as follows: Crude asphaltum or crude asphalt is applied to all mixtures of bitumen, clay, sand, etc.; e. g., crude Trinidad asphalt. Refined asphaltum or asphalt is used to denote the asphaltum after it has been wholly or partly freed from the combined organic and inorganic matters. The limestone rocks impregnated with bitumen are called 'bituminous or asphaltic limestones. The term rock asphalt is also applied to the same material, the name of the source being also used, as "Italian rock asphalt," " Val de Travers rock asphalt," etc. The sandstones containing bitumen are known as bituminous or asphaltic sandstones, the name of the source being also mentioned. The semi-fluid bitumen is designated by the names maltha and mineral tar. The term aspJialt is also frequently but erroneously applied to various preparations in which the cementing material is coal-tar or the residue of oil-refineries, etc. substances which are entirely dissimilar to asphaltum, though apparently possessing some of its characteristics. The term bitumen is employed to designate the truly bituminous portion of the asphaltum and its compounds. Refined Asphaltum is asphaltum freed from the combined water and accompanying inorganic and organic matter. By com- paratively simple operations the several varieties of asphaltum may be reduced to an equal state of purity. The argillaceous varieties, such as Trinidad, Bermudez, etc., are purified in iron vessels by the application of heat either directly from fire or indirectly by steam; the temperature employed ranges from 212 F. to 350 F. During the application of the heat the as- phaltum is liquefied, the combined water is evaporated, the organic matters rise to the surface and are skimmed off, and the inorganic settle to the bottom of the vessel; when the liberation of the im- purities is completed the liquid asphaltum is drawn off into barrels, and constitutes the refined asphaltum of commerce. The calcareous and silicious varieties are purified by boiling or CEMENTS. 49 macerating them with hot water, according to the freedom with which they part with the intermixed impurities. Daring the action of the water the sand and other ingredients fall to the bottom of the vessel, and the bitumen rises to the surface or forms clots on the sides of the boiler, whence it is skimmed off and thrown into another boiler, where it is boiled for some time, during which the water and more volatile oils are evaporated, and the mineral matters still retained fall to the bottom, leaving the bitumen in the form of a thick viscid substance, in which state it is used in several of the arts. By continuing the boiling for a considerable time or by increasing the temperature to about 250 F. the volatile portions are driven off, and the viscid bitumen is brought to a condition which upon cooling causes it to become solid. The operation of refining or purifying, while exceedingly simple, requires to be performed with much care, for the reason that if the asphaltum is melted at too high a temperature it will be burned or coked, or if the heating is prolonged at a low tem- perature the result will be practically the same. In either case the petrolene is converted into asphaltene. Asphaltic Cement. Asphaltum in a refined or pure state is valueless as a cementing medium, owing to its hardness, brittle- ness, and lack of cementitious properties; therefore it is necessary to add some substance which will impart to it the required plastic, adhesive, and tenacious qualities. This substance must be one that will partially dissolve the asphaltene and form a chemical union by solution instead of a mechanical mixture. The duty which it has to perform is an important and peculiar one : if it is a perfect solvent of the constituents of the bitumen the adhesive qualities will be destroyed, if it is an imperfect one the asphaltum, will retain its brittleness. The requirements of a suitable flux are that it shall be a fluid containing no substances volatile under 300 F., and shall possess the power to dissolve the asphaltum without destroying or lessen- ing its adhesive properties. The materials employed to give the required qualities to the hard asphaltum are called the " flux," and those in general use are crude or specially prepared residuum oil obtained from the distillation of petroleum, and crude or refined maltha. The process of adding the flux is called " oiling "or " temper- ing," and is conducted as follows: The refined asphaltum is nielted and the temperature raised to about 300 F. ; the oil 50 CEMENTS. previously heated is then pumped or in other ways added to the asphaltum, in the proportion of 10 to 20 pounds of oil to 100 pounds of refined asphaltum; the proportion of the oil is varied between the limits stated according to its quality, the hardness of the asphaltum, and the purpose for which the cement is to be em- ployed. The mixture of residuum oil and asphaltum is agitated either by mechanical means or by a blast of air for several hours or until the material has acquired the desired properties. The agitation must be performed with great thoroughness to secure a uniform mixture, and must be continued whenever the material is in a melted condition, as a certain amount of separation takes place when the melted cement stands at rest. It is therefore customary to agitate it constantly when in use as well as during its preparation. The process of "tempering " when maltha is used as the flux is practically the same as outlined above, with the exception that the mixing is performed at a lower temperature and entirely by mechanical means, and a separation of the ingredients seldom occurs when the cement is standing at rest. The maltha from many localities is to be had in the market ; it is sold for fluxing purposes under various trade names, among which may be named " Alcatraz " liquid asphaltum, " Standard '" liquid asphalt, "Utah" liquid asphalt, etc.; also artificial flux- ing materials which are offered as substitutes for oil and maltha, such as the " Pittsburg," asphaltic flux etc. The analyses of some of these fluxing agents are as follows : *' ALCATRAZ " LIQUID ASPHALT. Specific gravity 1.05 Bitumen soluble in carbon disulphide 98.70 percent Bitumen soluble in petroleum naphtha. ... 89.17 " " Mineral matter 1.30 " " Organic non-bituminous matter trace " UTAH " LIQUID ASPHALT (CRUDE). Specific gravity 0.9068 Bitumen soluble in carbon disulphide.. ... 76 15 per cent Bitumen soluble in ether 64.90 " " Mineral matter. 3.40 " " Organic non-bituminous matter 20.45 " " Loss at 100 C.. . 24.72 " ' CEMENTS. 51 "PITTSBURGH" ASPHALTIC FLUX. Moisture 0.05 per cent Volatile oil 212 F. to 312 F 1.60 " " Volatile oil about 312 F 89.19 " " Fixed carbon 8.48 " " Ash 0.68 " " Bitumen soluble in carbon disulpbide 99.32 " " Bitumen soluble in etber 65.00 " " The enduring qualities of an asphaltic cement depend upon (1) the character of the fluxing agent, (2) the temperature at which the asphaltum has been refined, and the temperature at which the flux is added, (3j the degree of incorporation of the flux with the asphaltum, that is, whether the union is a chemical or mechanical one Residuum Oil is a thick heavy oil varying considerably in composition, according to the source of the petroleum and method of distillation ; its base is parqffine a substance so different from asphaltum that when the two are brought together the result is a mixture partly mechanical and partly chemical, and, being of different specific gravities, they partly separate when allowed to stand for any cansiderable period without stirring. In preparing the oil the object aimed at is (1) the removal of the hard paraffines, which are very susceptible to changes of tem- perature, becoming soft under the summer sun and brittle at or below the freezing-point; their presence imparts similar properties to the asphalt cement ; (2) to remove the lighter and more volatile oils ; care.in their removal must be exercised : if t^o large a per- .centage is removed the oil becomes heavy and thick, and too large a proportion is required to make a cement of suitable con- sistency therefore there is a limit to the amount that can be removed. The oil is carefully examined to a c certain ; 1. Specific gravity. 2. Flash-point. 3. Percentage volatile in a given time at 400 F. 4 Susceptibility to changes of temperature as revealed by changes in viscosity. 5. Presence of crystals of paraffine. The specifications of Washington, D. C., provide that the heavy petroleum oil used in the manufacture of asphalt cement shall have the following characteristics ; 52 CEMENTS. It shall be a petroleum from which the lighter oils have been removed by distillation without cracking. Specific gravity Baume 17 to 21. Flash-point not less than 300 F. Distillate at 400 F. for ten hours less than 10 per cent. Shall not cease to flow above 60 F. Shall not require more than 21 pounds of oil for each 100 pounds of refined asphalt to produce the specific quality of cement. The flash-point shall be taken in a New York State closed oil- tester. The distillate shall be made with about 90 grams of oil in a small glass retort provided with a thermometer and packed en- tirely in asbestos. The flowing-point shall be determined by cooling 100 cc. of oil in a small bottle and noting the temperature at which it flows readily from one end of the bottle to the other. Analysis and Tests of Asphaltum. The tests employed to determine the relative merits of asphaltum and asphaltic cements comprise both chemical and physical investigations. The chemical examination of the crude material involves the following determinations : Specific gravity. Percentage of moisture. ' ' " matter soluble in turpentine. " " " " " carbon bisulphide. " " " " " alcohol. " " " " " ether. " " " volatile in 10 hours at 400 F. " " sulphuretted hydrogen evolved at 400 F. " " non- bituminous organic matter. " " mineral constituents. Softening-point. Flowing-point. The examination of the physical properties (mechanical tests) involves the following determinations : 1. The refining of the crude material and making of an asphal- tic cement. 2. Determining the penetrability of the cement. 3 Making a paving mixture and testing it for tensile and crushing strength. The penetration tests are usually conducted in a machine in- vented by Prof. Bowen. This machine consists of a lever about 17 inches long, having the fulcrum at one end and a cambric CEMENTS. 53 needle inserted in the other end, above which is placed a weight of 100 grams. The end near the needle is connected by a steel rod and waxed cord with a spindle having a long hand which moves about a dial divided into 360 degrees. Another cord and weight upon an enlarged part of the spindle keeps the first- mentioned cord taut. By a suitably contrived spring clip the steel rod can be released for any length of time, and the needle, which has first been brought to coincide with the surface of the asphalt cement placed under it in a tin box, allowed to penetrate under the action of the weight into the cement. The number of degrees through which the hand moves on the dial records the penetration of the cement ; the length of time for which the needle is released is one second. Originally Prof. Bo wen selected 77 F. as the proper temperature at which the test should be made, and brought the cement and machine to this degree by keeping them in a room warmed to this point. But as it is some- times inconvenient or impossible to have a room temperature of 77, other temperatures may be made available by placing the tin sample-box of asphalt cement in water at 77 and allowing it to acquire that temperature, when the test can be made as before, certain allowance being made to reduce the result to the normal temperature of 77 F. The physical tests are performed in the usual machines em- ployed for testing other cements. :' s asphalt cement possesses the same qualities and can be used for th-j same purposes as hydraulic and other cements, its physi- cal qualities can be tested in a similar manner ; but the tests which have been made and published have been conducted without any regard to uniformity and under widely different conditions ; therefore they are of little or no value in determining the relative merits of the cements. TEST FOR BITUMINOUS ROCK. A specimen of the rock, freed from all extraneous matter, having been pulverized as finely as possible, should be dissolved in sulphurate of carbon, turpentine, ether, or benzine, placed in a glass vessel and stirred with a glass rod. A dark solution will result, from which will be precipitated the limestone. The solution of bitumen should then be poured off. The dissolvent speedily evaporates, leaving the constituent parts of the bitumen, each of which should be weighed so as to determine the exact proportion. The bitumen should be heated in a lead bath and tested with a porcelain or Baume thermometer to 428 degrees Fahr. There will be little loss by evaporation if 54 CEMEKTS. the bitumen is good, but if bituminous oil is present the loss will be considerable. Gritted mastic should be heated to 450 degrees Fahr. The limestone should be next examined. If the powder is white and soft to the touch it is a good component part of asphalt ; but if rough and dirty on being tested with reagents it will be found to contain iron pyrites, silicates, clay, etc. Some bituminous rocks are of a spongy or hygrometrical nature ; thus, as an analysis which merely gives so much bitumen and so much limestone may mislead, it is necessary to know the quality of the limestone and of the bitumen. The European bituminous limestone appears like a fine-grained rock, friable in summer, hard in winter. When heated to 50 or 60 degrees centigrade it can be crushed between the fingers, and if exposed for several hours to a fierce sun it crumbles into unctuous brown powder. Examined under the microscope it is found to consist of minute calcareous grains, each covered with a thin film of bitumen, which causes them to adhere together. If a small portion is heated the cementing bitumen is melted and releases the solid particles from a loose heap of a deep chocolate color. If this powder is raised to 175 or 212 degrees Fahr. and rapidly compressed in a mould it will regain, in cooling, its original consistency in the new form. And the process may be indefinitely repeated, no change being produced by melting, fol- lowed by compression and cooling. TIMBER. 55 V. TIMBER. Structure of Timber. Woods suitable for structural purposes are usually called tim- ber, and are almost exclusively obtained from trees that grow by the formation of layers of wood over the external surface, and therefore called exogenous. There are a few exceptions, as the trees of the palm family, the bamboo, etc., which belong to the endogenous class. When a tree is cut across it is seen that it is composed of three parts : 1st. The bark, having a thickness of from J to 1 inches or more. This has no value for structural purposes, though useful in other respects ; it hastens the decay of the tree after felling, and should always be removed. 3d. The sap-wood, which lies next the bark, having a thickness varying from to 4 inches ; it is indicated by a lighter color, by being softer and less com- pact than the inner portion. 3d. The central portion surrounded by the sap-wood and called the heart. The boundary between the sap-wood and the heart is in general distinctly marked. The heart- wood alone should be employed in those works in which strength and durability are required. Although the sap-wood is liable to rapid decay when exposed to unfavorable conditions, yet it can be safely used when entirely immersed in water, or when impregnated with certain preserving solutions, or when carefully seasoned and painted. Timber for building purposes may be divided into two classes : soft and hard. To the first class belong the pines and firs, to the second the oaks, chestnut, locust, hickory, etc. PROPERTIES OF TIMBER. Table 7 shows the weight and strength of timber collected from the experiments of different authorities. It will be seen that the figures vary throughout a very wide range, the difference being caused by the variations in the conditions of the growth of the timber, seasoning and pres- erveration, and upon the part of the tree from which the speci- men was cut, as well as upon the size and form of the piece tested and the method by which Ihe test was applied. In taking figures from the table the lowest recorded should be taken, applying a large factor of safety to cover defects in the pieces used, which defects may not have existed in the specimens experimented upon. 56 TIMBER. TABLE 7. DESCRIPTION AND PROPERTIES OF TIMBER. Description of Timber. Weight per Cubic Foot Dry. Lbs. Resistance to Shearing. Ten- sion. Crush- ing. Cross- break- ing. With the Grain. Aross the Grain. Pounds per Square Inch. ASH (White) 40.77 38.96 44.35 19.72 to 20.70 23.66 i-T s 1 o" 3' 3 3 rf o 3 3 450 to 700 1300 to 1519 6280 Color brown ; sap- wood much lighter, often nearly white. Wood heavy, hard, strong, ulti- mately brittle, coarse- grained, compact. Use : Interior and cabinet work. ASH (Red) Color rich brown ; sap- wood light brown streak- ed with yellow. Wood heavy, strong, brittle, coarse-grained, compact. Use : As a substitute for the more valuable white ash, with which it is often confounded Colorbrown; sap-wood lighter. Heavy, hard, strong, brittle, coarse- grained. Use : Substitute CEDAR (White) Color light brown, turn- ing darker with expo- sure; the thin sap-wood nearly white. Wood very light, soft, rather coarse- grained. Very durable in contact with the soil. Used for posts, fencing, railway ties, and shin- gles. CEDAR (Red) Color dull brown ting- ed with red ; the thin sap- wood nearly white. Wood very light, soft, brittle, rather coarse-grained, compact, easily worked. Very durable in contact with the soil. Used for interior finish, fencing, shingles. TIMBER. 57 DESCRIPTION AND PROPERTIES OF TIMBER. (Continued.) Resistance to Shearing. Description of Timber. Cubic Foot Dry. Ten- sion. Crush- ing. Cross- break- ing. With the Grain. Across the Grain. Lbs. Pounds per Square Inch. CEDAR (Central America).. JNJ 8 3 o CYPRESS (Yellow) Color bright, light 29.80 g clear yellow ; sap-wood nearly white. Wood light, hard, brittle, close-grain- 1 1 ed. Durable in contact Q with the soil. Easily ** +J +i worked. Satiny, polishes well. Has an agreeable 1 1 1 resinous odor. Use : Interior finish, cabinel work. ELM (White) 45.26 Color light clear o brown, often tinged with red ; sap-wood much lighter. Heavy, hard, 09 I strong, tough, very close- 4* grained. Susceptible of eo polish. Use : Bridge tim- bers, sills, ties. GUM 36.83 Color bright brown tinged with red. Heavy hard, tough, close-grain- ed, compact. Inclinec OD 1 ! to shrink and warp badly in seasoning. Suscepti ble of a beautiful polish O 3 i 1 Use : Boards and clap o" o boards, and as a substi 1-1 tute for black walnut. HICKORY 46.16 Color brown ; the thin to and more valuable sap 52.17 of _ S3 wood nearly white Q o c* Wood heavy, very hard and strong, tough, close a 3 3 3 grained, compact, flexi 731 O JO 3 ble. Use : Handles fo 1-1 t- implements, etc. H KM LOCK N. andS. Atlantic 26.42 * ' Pacific 32.29 Color light brown ting 8 3 3 g ed with red, or ofte 00 s nearly white. Sapwoo< g n somewhat darker. Woo "* light, soft, not strong 58 TIMBER. DESCRIPTION AND PROPERTIES OF TIMBER. (Continued.) Description of Timber. Weight pei- Cubic Foot Dry. Lbs. Resistance to Shearing. Ten- sion. Crush- ing. Cross- break- ing. With the Grain. Across the Grain. Pounds per Square Inch. brittle, coarse, crooked- grained. Difficult to work. Liable to wind- shake and splinter. Not durable. Use : Rough lumber for construction. Two varieties of the northern are recognized, red and white. LOCUST 45.70 71.24 to 83.00 43.08 32.84 35.00 8000 2300 to 17,900 to 8000 to 10,000 10,000 to 12,000 10,500 to 24,800 10,000 6000 6000 to 7000 to 9940 8000 to 9600 7000 to 11.700 7500 o i s 1 p Color brown, or more rarely light green; sap- wood yellow. Heavy, hard, strong, close-grain- ed, compact. Very dur- able in contact with the ground. Use: Posts, turning. LIGNUM VITJE Color rich yellow brown, varying to al- most black ; sap-wood light yellow. Heavy, hard, strong, brittle, close-grained, compact. Difficult to work, splits irregularly. Use: Sheaves of blocks. MAPLE (Hard) . . . Color light brown tinged with red ; sap- wood lighter. Heavy, hard , strong, tough , close- grained, compact. Sus ceptible of a good polish. Use : Flooring, interior finish. MAPLE (White) Light, hard, strong, brittle, close-g rained, compact. Easily worked Use: Flooring, furniture' MAHOGANY (Cent. America. Color red-brown of various shades and de- grees of brightness. Of- ten very much variedand mottled. Inferior quali- ties contain a large num- ber of gray specks. Wood strong, durable, flexible when green, brit- tle when dry, is very free TIMBER. 59 DESCRIPTION AND PROPERTIES OF TIMBER. (Continued.) Description of Timber. Weight Cubic Foot Dry. Lbs. Resistance to Shearing. Ten- sion. Crush- ing. Cross- break- ing. With the Grain. Across the Grain. Pounds per Square Inch. from shakes; is seldom attacked by dry rot or worms. Requires care in seasoning ; if seasoned too rapidly is liable to split into deep shakes. Use : Interior finish, handrails, patterns, etc. OAK (White) . .. 46.35 53.63 59.21 40.75 27.44 10,000 3000 to 11,000 10,000 to 10,250 to 19,500 16,380 8000 3000 to 6650 4000 to 8500 to 4684 to 9500 10,000 g 2 1 2 | 1 2 ?, 0* 2 e 2 8 1 i SI Color brown ; sap-wood light brown. Wood heavy, strong, hard, tough, close-g rained. Checks if not carefully seasoned. Use : Interior finish, cabinet-making. OAK (Chestnut) Color dark brown; sap- wood much lighter. Wood heavy,hard, strong, close- grained. Checks badly in drying. Durable in con- tact with the soil. Use : Railroad ties. OAK (Live) Color light brown 01 yellow: sap-wood nearly white. Wood very heavy hard, strong, tough, close- grained, compact. Diffi. cult to work. Polishes. OAK (Red and Black) Color light brown 01 red. Heavy, hard, coarse- grained . Checks in dry- ing. Use : Interior finish and furniture. PALMETTO (Florida). . Color light brown. Wood light, soft, fibres dark-colored. Hard and difficult to work. Use : Piles. Is impervious to the attacksof the Teredo, and very durable under water. PINE (White) Color lightbrown, often slightly tinged with red; sap-wood nearly white. Wood light, soft, very close, straight-grained. Easily worked. Polishes. 60 TIMBER. DESCRIPTION AND PROPERTIES OF TIMBER. (Continued.) Resistance to Shearing. Description of Timber. Cubic jFoot Dry. Ten- sion. Crush- ing. Cross- break- ing. With the Grain. Across the Grain. Lbs. Pounds per Square Inch. Use : Interior finish, win- dows, doors, etc Can., N. Atlantic States. 24.02 N Pacific coast 24 35 California 22.00 Colorado Arizona 30^39 PINE (Red), Norway Pine. 30.25 Color light red; sap- wood yellow or white. S Wood light, hard, coarse- 5? p o grained, compact. Res- o o c^ in-passages few, not js o conspicuous. Use : All 8 8 purposes of construction . PINE (Yellow), Long-leafed 43.62 Color light red or orange: sap-wood nearly white. Wood heavy, hard, 1 8 to strong, tough, coarse- grained; compact. Dur- able. Cells resinous and OT 3 I 1 g 1 1 dark-colored. Use : All o 8 eo c* purposesof construction. PINK (Yellow), Short-leafed Colororange ;sap-wood 38.40 white, Wocd vary ing greatly in quality and amount of sap. Heavy, ^ hard , coarse-g rained, compact.Cells broad, very o" 1 resinous ; resin-passages o o numerous, large. Medul- s -. i O lary rays numerous. Use: g All purposes of construc- tion. Frequently substi- s * tuted for long -leafed pine, which is superior. PINE (Oregon)(Z>ottgrZas Fir) 32.14 Color varying from light red to yellow; sap- wood nearly white. Wood hard, strong, varying greatly with age, condi- tions of growth, and 1 1 1 amount of sap. Difficult to work. Durable. Use : o 2 2 All kinds of construction. o SB Two varieties, red and 01 eg 00 yellow; red considered lessvaluable thanyellow. TIMBER. 61 DESCRIPTION AND PROPERTIES OF TIMBER. (Continued.) Description of Timber. Weight pei- Cubic Foot Dry. Lbs. Resistance to Shearing. Ten- sion. Crush- ing. Cross- break- ing. With the Grain. Across the Grain. Pounds per Square Inch. POPLAR (Whitewood). . 30 26.23 28.57 25.25 25.46 38.11 I i B to o o o o 1 2 1 1 1 8 253 to 374 00 5 i 1 Color light yellow or brown; sapwood nearly white. Soft, brittle, very close, straight-grained, compact. Easily worked. Use : interior finish, shin- gles. REDWOOD (Pacific coast)... Color clear, light red; Sap-wood nearly white. Wood tig I it, soft, very brittle, coarse-grained, compact. Easily worked. Polishes. Durable in con- tact with the soil. Use : Building material and general use SPRUCE (Black) Color light red or often nearly white; sap-wood lighter. Wood light, soft, not strong, close, straight-grained, com- pact, satiny. Use : Piles, lumber. SPRUCE (Whiter Color light yellow ; sap- wood hardly distinguish- able. Wood light, soft, not strong, close, straight-grained, com- pact, satiny. Use : Lum- ber for construction. WALNUT (White) (Butter" nut) Color light brown, turning dark on expo- sure. Light, soft, coarse- grained, compact. Easily worked. Satiny. Polishes well. Use: Interior finish. WALNUT (Black) Color rich dark brown; sap-wood lighter. Heavy, hard, strong, coarse- grained. Checks if not carefully seasoned. Easily worked. Polishes. Use: Interior finish, cabi- net-work. 62 TIMBER. Seasoning Timber. The seasoning of timber consists in expelling, as far as possible, the moisture which is contained in its pores. Two methods are practised, natural and artificial. NATURAL SEASONING is performed simply by exposing the tim- ber freely to the air in a dry place, piled under shelter. The bottom pieces should be placed upon skids (which should be free from decay), raised not less than two feet from the ground. It should be piled in horizontal layers with slats or piling- strips placed between each layer, one near the end of each pile and others at short distances, in order to keep the timber from winding: these strips should not be less than one inch thick. Each pile should contain but one description of timber and the piles should be placed at least 2| feet apart, so as to allow free circulation of the air. The timber should be replied at frequent intervals, and all pieces indicating decay should be removed, to prevent their affect- ing those which are still sound. The time required for natural seasoning varies according to the character of the wood and its dimensions. The following table shows the average time required for the woods named : White-pine board 1 year " plank 2 in. thick 1 " " " " 3" " 2 " Southern heart-pine 1 in. thick 1 " Black walnut 1 " " 1^-2 " 4 " " 4 " Hemlock will dry out sufficiently to be used as joists in from five to seven months ; oak and ash approximate walnut in the length of time required. WATER SEASONING is total immersion of timber in water for the purpose of dissolving the sap, and when thus seasoned it is less liable to warp and crack, but is rendered more brittle, and if kept too long immersed will upon being brought into the air be- come brashy and useless. Two weeks is about the usual time it is kept under water. After removal from the water it must be thor- oughly dried, with free access of air, and turned daily. ARTIFICIAL SEASONING. The best method consists in exposing the timber to a current of hot air in a drying-kiln. The best temperature for the hot air varies with the kind and dimensions TIMBER. 63 of the timber ; thus for oak the temperature required is about 105 F. and for pine 130 to 200 F. The time required for drying varies with the thickness. Too high temperatures evaporate the moisture too rapidly, and the timber cracks. Shrinkage and Expansion of Timber. During the drying or seasoning process timber shrinks consider- ably ; below about 30 per cent of moisture it shrinks nearly as much as it dries ; that is to say, when timber dries down from 30 per cent of moisture to 10 per cent moisture it dries out or loses in weight about 20 per cent of its dry weight. It also loses about 20 per cent of its dry volume. A board that is 1 foot wide at 30 per cent moisture is only llf inches wide at 10 per cent moisture, or a board 4 inches wide at 20 per cent moisture is only about 3f inches wide at 10 per cent moisture The shrinkage lengthwise is very slight. On account of the very large radial fibres (medullary rays) in oak wood this kind of timber shrinks mostly in a circumferential direction, and all timber shrinks more circumferentially than radially, since all woods have those medullary rays to a greater or less extent. It is for this reason that "quarter-sawed" (radial- sawed) lumber is more satisfactory than " flat-sawed " for all kinds of furniture and house trimmings. For flooring, quarter-sawed or "rift- sawed" boards, presenting an "edge-grain" surface, is far preferable to " flat-grain," because it wears evenly and does not sliver on the surface. The shrinkage of different woods is about as follows: Cedar Canada from 14 to 13.25 inches Elm " 11 " 10.75 " Oak " 12 " 11.625 " Pine (Northern pitch) " 10x10 " 9.75X9.75 " " (Southern pitch) " 18.375" 18.25 " " (white) " 12 " 11.875 " " (yellow Northern) " 18 " 17.875 " Spruce " 8.5 " 8.375 " EXPANSION OF TIMBER DUE TO THE ABSORPTION OF WATER. Pine. Oak. Chestnut. Elongation , per cent 0. 065 0. 085 0. 1 65 Lateral expansion, per cent 2.6 3.5 3.65 64 TIMBER. EXPANSION OP TIMBER BY HEAT. White pine for 1 degree F. 1 part in 440.530 or for 180 degrees 1 part in 2447, or about one third of the expansion of iron. Durability and Decay of Timber. The durability of wood is subject to too great variation to have any limits placed upon it, depending almost entirely upon the conditions to which it is exposed, as to heat and moisture, attacks of insects, etc. Well-seasoned wood in dry situations or in well- ventilated situations with uniform state of moisture or dryness (moisture preferred) should never decay. Timber kept constantly wet niay become softened and weakened, but it does not necessarily decay. Various kinds of timber, such as elm, alder, oak, and beech, possess great durability in this condition. The condition which is least favorable to durability is alternate wetness and dryness, or a slight degree of moisture, especially if accompanied by heat and confined air. The season and manner of felling and working are important in determining the life. Timber felled in winter is more durable than that felled in summer. Hewed wood is also more durable than sawed from the fact that the pores are closed and the fibre compacted by the blows, while the saw tears the fibre and opens it. Besides decomposition and decay, timber both in its growing and converted states is subject to the attacks of worms and insects ; these are often selective in their attacks ; the resinous woods, ironwood, and palmetto are not readily attacked. When the insects exist iii large numbers they remove so much of the wood as seriously to impair its strength. Dry Rot is the most formidable kind of decay to which timber is subject. It is caused by a fungus, whose spawn in the sap- wood, on the introduction of moisture, causes fermentation, and the decay of the tissues follows, and in a short time the wood will crumble beneath the touch. Dry rot occurs most frequently in ill-ventilated places. The ends of timbers built into walls, woodwork fixed to walls before they are dry, are quickly affected. Painting and tarring the surface of unseasoned timber has the same effect. An excess of moisture prevents the growth of the fungus, but a moderate warmth, com- bined with damp and want of air, accelerates it. The season of felling influences the resistance to dry rot, tim- ber felled in winter being less liable to attack, but the germs of TIMBER. 65 decay may remain inert in the wood for a long time, and finally become evident and active if the conditions be favorable. Once established in the wood it is very difficult to eradicate, the only remedy be'ng to remove all trace of the fungus and disinfect. Healthy wood is liable to receive germs from the air and water, and these sources are of more danger than the germs contained in the wood itself. The colors of the fungus are various: sometimes white, grayish white with violet, often of yellowish brown or a deep shade of fine rich brown. The softer and more porous woods are the more liable to decay by dry rot. Detection of Dry Rot. In the first stages of rottenness the timber swells and changes color, and is often covered with fungus or mouldiness, and emits a musty odor. In the absence of any outward fungus or other visible sign a hole may be bored into the wood : the appearance of the dust extracted and especially the odor will indicate the presence of dry rot. Sometimes the rot only appears in the form of reddish or yellow spots, which upon being scratched show that the fibres have been reduced to powder. Wet Rot is caused by the presence of moisture, which decom- poses the tissues of the wood, particularly those of the sap-wood. Wood felled between April and October is especially liable to wet rot. Common Rot is caused by the wood being piled to season in badly ventilated sheds. Outward indications are yellow spots upon the ends of the pieces, and a yellowish dust in the checks and cracks, particularly where the pieces rest upon the piling-strips. Worms. Of worms the two most active are the Teredo navalis and the Limnoria terebrans. The Teredo is most active in salt water. It is found in both warm and cold climates. It avoids fresh water and prefers clear water to that which is muddy. The Teredo is first deposited upon the timber in the shape of an egg, from which in time it emerges a small worm ; this worm soon becomes larger and commences its depredations. Furnished with a shelly substance in its head, shaped like an auger, it bores into the wood, in an upward course parallel to the grain ; at the same time it lines the hole it makes with a thin coating of carbonate of lime, and closes the opening with two small lids ; hence it prefers a calcareous seashore. 66 TIMBER. As the work of the Teredo advances its size increases. Worms two feet long and three fourths inch in diameter have been found The Limnoria tercbrans resembles in appearance a very small wood-louse and is most active in brackish water and prefers a silicious shore, formed by the decomposition of silicious rocks. As many as twenty thousand will appear on a surface only twelve inches square. The Limnoria prefers soft woods and avoids knots ; it does not bore, but destroys the wood by eating the surface at the rate of from one to three inches per annum. Both the Teredo and Limnoria confine their work to a space between high- and low- water marks, showing that they require both air and water. The Lycoris fucata is the enemy of the Teredo ; it is a little worm with legs, something like a centipede ; it lives in the mud, crawls up the pile inhabited by the Teredo, enters the tunnel in which it is ensconced, eats the Teredo, enlarges the entrance to the tunnel, and then lives in it. Many processes have been tried to protect timber from the ravages of those worms ; the most successful appears to be impegnation with creosote. Processes for Preserving' Timber. From the earliest times attempts have been made to preserve wood, and a vast number of processes and materials have been experimented with. A few of the successful methods are as fol- lows: BURNETT'S PROCESS, OR BURNETTIZING. Impregnation with chloride of zinc. The operation is performed in large metal cylinders called retorts, and is conducted about as follows: The load of timber, called a "charge," is placed in the retort and the heads or doors closed and bolted. A vacuum is then produced in the retort. When this has reached about twenty inches live steam at about 20 pounds' pressure is let in and continued for about four or five hours. It is then blown off and the retorts drained. A second vacuum is produced of from twenty -two to twenty -six inches. The zinc chloride solution is introduced under pressure; this pressure is raised to about 120 to 150 pounds per square inch and maintained until the required quantity of solution is injected into the timber; when this has been accomplished the surplus fluid is drawn off, the doors opened, and the charge pulled out. The solution of zinc chloride, called the "stock solution,," con- TIMBER. 67 sists of about 43 per cent pure zinc chlorine, 2 per cent of impu- rities (iron, aluminum, lead, etc.), and 55 per cent of water. The standard solution when ready for use should register 2^ Bauine at 60 F The solution is heated by steam passed through coils to about 150 F. before being pumped into the charge. To provide means for watching the effect of the various steps in the process the retorts are provided with thermometers and vacuum-gauges, the steam-pipes with pyrometers, the tanks with gauges, the condenser with a measuring- well, and the solution is taken from a gauged measuring-tank. The quantity of zinc injected per cubic foot of timber is about T 2 D ^y of a pound. The time required for treatment ranges from 8 to 12 hours, depending upon the condition of the timber ; the greener the wood the more easily it is impregnated. Burnettizing has not been so successful in the United States as in Europe. WELLSHOUSE'S PROCESS is a modification of Burnett's. The timber is steamed in a cylinder one to three hours (according to size); zinc chloride and glue solution is then forced in, after which tannin is injected, the purpose of the glue being to combine with the tannic acid in the wood, precipitating the glue as an insoluble compound and retaining the zinc. The tannic acid is added to precipitate the excess of glue. THILMANY'S PROCESS. Impregnation with zinc or copper sul- phate. For this process green wood is preferred, the dry requiring to be longer steamed. The timber is run on flat cars into a cylinder, steam is applied to drive out the sap, and an air-pump is connected to draw air and condensed moisture and form a vacuum. The cylinder is then filled with a 1^ per cent solution of zinc or copper sulphate and a pressure of 80 to 100 pounds applied until charged. The sulphate solution is then drawn off and a 1 per cent solution of barium chloride similarly charged. The strength of the solu- tion is varied according to the class of timber to be impregnated. KYAN'S PROCESS. Saturating with corrosive sublimate. BURCHERI'S PROCESS. Impregnation with sulphate of copper under a pressure of about 15 Ibs. per sq. in. CREOSOTINU (BETIIKLL'S PROCESS). Impregnating with dead oil of coal tar or distillates from wood-tars. The timber is placed in cylinders, steam turned on and continued until the mass is thoroughly heated and the sap va orizod. The steam and sap are drawn off by a pump, a partial vacuum formed, and the cylinder filled with the oil, which is usually heated to a 68 TIMBER. temperature of about 160. A pressure varying from 150 to 200 Ibs. is applied and continued until the gauge stands constant, showing that no more oil is being absorbed. The oil is then drawn off and the charge removed. The details of the operation vary in different establishments. The time required for steaming varies from 30 minutes to several hours according to the variety of wood under treatment, green and hard timber requiring more than seasoned or soft timber. The amount of oil absorbed by the timber also varies according to its variety ; from 12 to 18 pounds per cubic foot appears to be the usual amount. The treatment of a charge requires on an average 24 hours. PAYNE'S PROCESS. Impregnating the wood while in a vacuum with sulphate of iron, followed by a solution of sulphate of lime or soda. This process is also said to render the wood incom- bustible. SEELEY'S PROCESS is a modification of Bethell's. The timber is immersed in creosote at a temperature of 212 to 300 F. for a time sufficient to expel the moisture, the hot oil is drawn off and replaced by cold oil. About 4 Ibs. per cubic foot is said to be absorbed by this process. VULCANIZING is the process of rendering the sap insoluble and undecomposable within the cells by means of heat. To do this the wood- is subjected to such pressure of air, in a closed vessel, that the sap will not vaporize on the application of heat. Heat is then applied gradually, the pressure being maintained or increased as the temperature rises. About 400 F. is generally sufficient to vulcanize ordinary woods. The time required is about 8 hours for soft and from 10 to 20 hours for hard woods. TIMBER. 69 Inspection of Treated Timber. Inspect for penetration by boring two ^-inch holes at a distance of from 3 to 15 feet from each end, according to the length of the stick ; the two holes near each end to be diametrically oppo- site, and the pair on one end to be at right angles to that on the other. In special cases other holes may be bored. Care must be taken not to bore into a check. After inspection the holes are to be plugged with preserved plugs turned to a driving fit. TESTING TIMBER TREATED WITH ZINC CHLORIDE. At inter- vals during the progress of the impregnation and whenever any charge shows some change in the treatment as to vacuum, time or amount of pressure, and after each change in kind, quality, or dryuess of timber four samples are taken from a charge consist- ing of pieces of average grain one heaviest, one lightest, and two average weight, Each piece is bored in the middle of its width and length with a one-inch auger. The first half inch of the borings is thrown away, after which each inch of borings is pre- served separately and designated as 1-inch, 2-inch, 3-inch, etc., specimens. Each specimen is burned to an ash, over a gasoline jet, in a porcelain roastiug-dish, in contact with the air. The ashes are carefully collected in a platinum cup, distilled water added, with a slight excess of hydrochloric acid, converting the zinc oxide into zinc chloride. It is then filtered into a test-tube and the zinc hydrate thrown down with sodium carbonate, mak- ing a white flocculeut precipitate. The liquid is then made up with distilled water to three drachms. The resulting milky liquid is compared with standard liquids in tubes of the same size as the test-tubes, each tube containing three drachms*. The standard liquids are graded to represent 6, 9, 12, 15, 18, 21, and 24 oue- hundiedths of u pound of zinc chloride per cubic foot of timber. The maximum of zinc chloride per cubic foot of timber is 24 oue-huudredths of a pound. 70 TIMBER. FORM OF REPORT. WOOD-PRESERVING. Report of Creosotedat. 189. Retort No Kind of timber Charge number. . . . Date going in Date coming out TIME : Load in at Pressure began at Pressure left off at Load out at , Total time TEMPERATURE : When filled At end of pressure when oil is let out of steam PRESSURE : At beginning At end CONDENSATION ; Quantity of oil pumped Number of pieces in charge Number of cubic feet in charge Length, breadth, and thickness of pieces. . , Maximum penetration: Ends. .. .Centre. Minimum penetration: Ends Centre. Amount of creosote per cubic foot FORM OF REPORT. WOOD-PRESERVING. Report of. Burnettized at 189. Retort No Charge number. . . . Date going in Date going out Number of pieces in charge. . . . Length, breadth, thickness Number of cubic feet in charge TIMBER. 71 TIME: Charge'in at Vacuum begun at Inches of vacuum. . . . Steam turned in at Steam-pressure Vacuum begun at Injection begun at Pressure begun at Pressure left off at Charge out at Total time TEMPERATURE : At end of live steam. . . . When injection began. . . . At end of pressure. . . . When solution is let off. . . . PRESSURE : At beginning At end Quantity of solution pumped in. Quantity drawn off REPORT OP TESTS. PILES : Number of specimens tested. . . . Length of piles Diameter of piles Maximum penetration : Butt Tip Minimum penetration : Butt Tip TIMBER : Number of pieces tested. . . . Length Breadth Thickness Weight Solution, and penetration per cubic foot REMARKS: Penetration uniform or irregular. Depth of penetration Effect on timber splitting, checking, or cracking. TIMBER. 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