None
INDEX jrl^brasion tests of stone, results of, 645 Absorption test of stone, 636 Acid and basic open-hearth processes com- pared, 142 Added material on one side of member, effects of, 86 Adhesion of natural to Portland cement, 598 Adhesion tests of cement, 449 Adhesive force of nails in oak wood, 689 Adhesive strength of cement-mortars to various substances, 597 Age (in storage), effect of, on the strength of cement, 593 Albert-lay of wire rope, 701 Alloys, the manufacture of the more use- ful : nature of metallic alloys, 173 the copper-zinc-tin alloys, 174, 550, 552 the brasses — copper and zinc, 176, 550 Delta-metal, 177, 56" Tobin bronze, 178, 554, 556 the bronzes— copper and tin, 178, 550, 565 phosphor bronze, 178, 554, 556 silicon bronze, 179 aluminum bronze, 179, 555, 556 hardened aluminum, 180 fusible alloys, 180 Aluminum : general properties of, 173 how hardened, 180 in steel, 180 Aluminum bronze : how made, 179 strength of, 555 Angular deformation under direct stress, 6 Annealing copper wire and plate, 550 Annealing steel, 146, 153, 168, 170, 731 effect of, on strength qualities, 498, 501 Annual rings in wood, 207 Apparent elastic limit, 12, 18, 309 Areas of contact between car- wheels and rails, 506 Ash (species of) in the U. 8., 279 Aspen in the U. S., 281 Autographic stress-diagram apparatus, 844 Axles: steel, tested by cold bending, 517 wrought iron and steel, temperature tests on, 568 Ba ►ftch's compressometer, 355 Bach's tests on concrete columns or prisms, 601 Baclg's comparative analysis of recommen- dations of the Conventions and of the French Commission, 737 Basic and acid open-hearth processes com- pared, 142 Basswood in the U. S., 281 Bauschinger, Prof. Johann, biographical sketch of, 728 Bauschinger's mirror extensometer, 842 Beams — see Cross-bending stress. Beams, wooden : tables of strength of, 681, 682 effect of size on strength of, 672 Bearing resistance of irou and steel plates, 529 Beech in the U. S., 282 Bending, cold — see Cold bending. Bessemer and open-hearth steel compared, 142 Bessemer process of making steel, 188 778 774 INDEX. Billet tests of steel, valuable, 502 Birch in the U. S., 282 Bleeding Southern pine, effects of, 672 Boiling test of cement, 417 Brard's process — see Sulphate-of-soda test. Brass, strength of, 550 Brasses, the manufacture of, 176 Brick, building : strength and elastic properties of, 651, 662 strength of brick piers, with stress-dia- grams, 651-659 Brick, " vitrified," (for street-paving:) definition of, 196 clays employed in manufacture of, 197 physical properties of clays for, 198 preparation of the clays, 200 moulding the brick, 201 drying and burning, 202 aunealing after burning, 208 -sorting the brick, 204 kinds of tests required, 456 the cross-breaking test, 457 the crushing test, 457 the rattler test, 457, 460 standard tests of the Nat'l Brick Mfg. Assoc, 460 results of tests, 660 Brick piers, strength of, 651-659 Briquettes, cement : forms of, 432 form proposed by author, 434 distribution of stress in, 435 Brittle and plastic materials, 24 Brittle materials in compression, 24 Bronzes, strength of, 550-556 Buckeye (horse-chestnut) in the U. 8., 283 Building-brick, results of tests of, 660, 662 Burning of cement9, 187, 194 tests for thoroughness of, 413 Butternut-trees in the U. S., 284 Ca Calcining of Portland cement, 187, 194 Callipers, micrometer, 350 Car-axles, strength of, affected by temper- ature, 564 Carbon : in cast iron, 91 in iron and steel, 151 change in, at a low yellow heat, 158 effect of, on the teusile strength of steel, 156, 491-495 Carbon, effect of, on ductility, 158, 491- 495 Carbonic-acid gas, effects of, on the hard- ening of natural and slag cements, 597 Cast iron : historical account of, 87 general properties of, 90 carbon in, 91 silicon in, 92 influence of, on mechanical prop- erties, 94 influence of, on shrinkage, 95 sulphur in, 97 phosphorus in, 97 manganese in, 98 pig-iron, grading of, 99 foundry practice, 100 the cupola, 100 effect of re melting, 101 the moulds, 102 moulding sand, 104 effect of size and shape, 105 pipes and columns, 480 shrinkage, 105 shrinkage stresses, 477 the mechanical properties of, 106 harduess, 106 hardness and strength, 107 crushing strength, 77, 473 transverse strength, 109, 475 transverse deflection, 373 modulus of elasticity of, 476 tensile streuglh, 110, 469 Kirkaldy's results, 477 strength measured by shocks, 480 malleable cast iron, 112 defined, 112 method of manufacture, 113 mechanical properties of, 114 magnetic testing of, 701 Catalpa- trees in the U. S., 284 Cedars of the U. 775 Cement, natural : mortar of : hardening in air and in water, 576-7 effect of regauging after set begins, 593 effect of carbonic-acid gas on the hardening of, 597 effect of freezing on, 613 effect of salt on, 617-621 adhesive strength of, 597 effects of long storage on the strength of, 593 Cement, Portland : historical account of, 188 iugredients of, 185 % clays for, 185 silica and its compounds, 186 alumina for, 186 sulphur compounds in, 187 chemical reactions in calcining, 187 explanation of the setting and harden- ing, 189 sources of the raw materials for, 191 pulverizing and mixing the raw ma- terials, 192 processes used in burning, 194 grinding the clinker, 195 strength of, 572 modulus of elasticity of mortars, 575, 601 hardening in air and in water, 576-7 mortar of : with different proportions of sand, 579 with different sizes of sand-grains, 582 economy of coarse and fine sands, 587 relations between strength and cost, 606 porosity of, for different sands, 591 strength of, at various periods, in terms of its strength at 28 days, 573 compressive strength and elas- ticity of, 603 economy of, 605 effects of freezing on, 612 effects of salt on, 617-621 long storage, effect of, 593 regauging, effect of, on strength, 593 Cement, Portland : adhesive strength of, 597 concretes, 8 strength and elasticity of, 601 economy of, 605 Wheeler's tests of concrete beams, 608 filtration through, 612 mixtures, volumes of, 608, 628 in sea-water, 628 fire-resisting properties of various { mixtures, 626 cinder-concretes, cost and proper- ties of, 627 Cement, slag— see Slag-cement. Cement-testing : standard tests, 407 fineness of grinding, 409 thoroughness of burniug, 413 rate of setting, 415 tests for soundness, 417 the boiling test, 417 tensile-strength tests, 419 fixed relation between tensile and compressive strength, 419 standard consistency of briquettes, 420 standard sand to be used, 424 standard consistency of cement-mor- tars, 429 formation of the briquettes, 430 Btthme's hammer, 432 Tetmajer's apparatus, 433 form of the briquette, 432 staudard American and English form, 433 standard German form, 434 form proposed by the author, 484 distribution of stress over mini- mum section, 435 moulds for briquettes, 488 clips, their bearings and mountings, 438 the1 author's design, 440 tension-test machines, 440 standard German form, 441 Fairbanks' machine, 441 Riehle's machine, 448 Olsen's machine, 444 Porter's machine, 445 rate of applying the load, effect of, 442 eccentric position in the clips. 446 776 INDEX. Cement-testing : compression tests of cement, 446 Swiss machine for making, 448 cross-bending tests, 448 adhesion tests of cement, 449 form of adhesion briquette, 450 variations (normal) of volume in air and in water, 451 French Commission recommenda- tion, 452 permeability test, 452 decomposing action of sea- water, test for, 454 Cement-testing machines, 440 Centre-punch, double-pointed, 352 Chains, strength of wrought-iron, 489 Changes in the elastic limits by stressing beyond these limits, 522 Charcoal, 248 Chemical aualysis not adequate to explain mechanical qualities of steel, 150-154 Chemical composition of wood, 246 Chemical constituents, limiting values al- lowable in steel, 167 Chemical tests of stone, 635 CHerry-trees of the U. 8., 285 Chestnut-trees of the U. S., 285 Cinder-concrete mixtures, strength and economy of, 627 Cinder-concrete with metal base, strength of, 629 Clays : for Portland cement, 185 for paving- brick, 197 Cleavability of wood, 243 Clinker-cement, 187, 195 Clips for cement briquettes, 488 the author's design, 440 Coarse particles in cement have no cement- ing quality, 409 Coffee-trees of the U. S., 286 Cold-bending tests : character and significance of, 394 methods of making, 395 preparation of the specimen, 397 comparison of results from, with those from tension tests, 399 combined specified requirements in tension and cold bending, 402 comparison of results from tension, impact, and cold bending, 403 Cold-bending tests : of steel axles, 518 of steel wire, 697 Columns : cast-iron, defects in, 481 effect of the addition of material to one aide of, 86 eccentric loading on, 86 tests of, 359 strength of, 360 Considered results, 861 Tetmajer's results, 364 formulae for, 866 Columns, wooden : tests of, 682-689 formulae for, 683-4 Composite (concrete and steel) beams com- puted, 72 Compression -members — see Columns. Compression tests, 24 two classes of materials, 24 on plastic materials, 24 on brittle materials, the laws of, 24 angle of rupture found, 25 relation of crushing strength, to shearing strength, 28 relation of strength to form of specimen, 29 relative strength of prisms and cubes, 81 effect of loading a portion of the surface, 82 test-specimens for, 853 bedding of specimens in the test- ing-machine, 354 eccentric loading, 36 effect of material added to one side of column, 36 compression testing-machines, 355 compressometers, 355 Olsen's, 355. Bach's, 855 the author's, 357 Tetmajer's, 359 tests of columns, 859 compressive strength of columns the same as the ''apparent elastic limit." 860 Considdre's mounting for column tests. 361 Considered results of column tests, 362 Tetmajer's " " " «• 864-5 INDEX. 777 Compression tests : ultimate strength formulas for col- umns, 366 spring testing-machines, 867 compression tests of cement, 446 Swiss machine for making, 448 on cast iron, 77, 473 on steel, 503-509 Compressive strength of cement-mortar as related to its tensile strength, 419 Compressometere, 355 Concrete (see also Portland cement and Natural cement) : compressive strength and elasticity of, 603 economy of various mixtures, 605 volumes " 608 Concrete and steel in combination, strength computed, 72 Concrete beams, mixtures and strength of, 608 Concrete mixture, absolute volumes in, 623 Concrete structures in sea-water, 623 Conductivity, electrical, table of, 721 Consistency of cement mortars in test bri- quettes, 420, 429 Conventions, comparative analysis of recommendations of, 787 Copper : general properties of, 172 strength of, 548, 566 annealing of, 550 CoFrosion of iron and steel, 171 Cotton woods of the U. 8., 298 Cross-bending strength of timber ex- plained, 236 Cross- ben ding stress : historical sketch of theories, 42 fundamental equations of equilibrium, 44 relation between moment of resistance and stress on extreme fibre, 46 noment of resistance of various forms, 48 moment of resistance beyond the elas- tic limit, 49 distribution of stress and position of neutral axis at rupture, 50 moduli of rupture in cross-breaking, 51 distribution of shearing stress in a beam, 52 Cross-bending stress : beams proportioned for shearing stress, 56 deflection of beams— general formu- la?, 57 beam fixed at one end and loaded at the other, 59 beam supported at the ends and loaded at the centre, 60 beam supported at the ends and uni- formly loaded, 61 table of moments, stresses, and deflec- tions, 61 deflection from shearing forces, 66 determination of Young's modulus of elasticity, 67 the rational designing of flitched beams, 68 composite concrete and steel beam, 72 flat plates uuiformly loaded, 73 v resilience of beams, 83 Cross-bending tests objects of, 869 essential conditions of, 869 machines for, 370 deflection essential when testing cast iron, 872 computed strength' in pounds per square inch, 373 modulus of elasticity (stiffness), 874 of cast iron, 109, 475 of cement, 448 Crucible process of making steel, 133 Crushing — see Compression. Crushing strength a function of shearing strength, 28 Crystalline fractures in wrought iron, the causes of, 120 Cubes and prisms, relative strength of, 81 Cucumber- tree, 301 Cutting up logs in the U. S. timber tests, 464^ Cylinders on planes, elastic-limit loads of, 508 Cypress of the U. S., 269 De 'ecay of wood : produced by fungus-growth, 250 prevention of, 252 Decomposing action of sea- water on cement* mortar, test of, 454 Defects, microscopic, in steel, 537 778 INDEX. Deflection of beams, 57 table of, 61 from shearing forces, 66 Deformation : defined, 2 various kinds of, 4 longitudinal and lateral, under direct stress, 5 of volume, 5 significant limits of, 306 Deformation, angular, uuder direct stress, 6 Delia-metal : strength of, at various temperatures, 566 bow made, 177 Distillation products of wood, 248 Distribution, geographical, of the Southern piues, 684 Drifting tests : their character and significance, 406 specification for, 406 Drying timber, 224, 676 Durability of wood, relative, of different species, 250, 258 Ec iccentric loading, effects of, 36 Eccentric position of briquette in clips, effects of, 446 Economy of cement-concrete mixtures, 605, 627 Elastic and plastic bodies defined, 1 Elastic field destroyed by overstraining, 522 Elastic limit : defined, 18, 806 absolute limits unsatisfactory, 308 the "apparent elastic limit," 12, 18, 309 of wrought iron in tension, 486 of wrought iron after stressing beyond the elastic limit, 486-488 of steel in tension, 491^496 of steel in compression, 504 of steel cylinders on planes, 508 of steel as affected by loading beyond the elastic limits, 512, 522 of nickel -steel, 516 of timber, 670 Elastic limits changed by overstraining, 486, 522 Electrical conductivity of metals, 721 Elms of the U. S., 286 Elongation : how distributed in a steel test-speci- men, 502 of tension test-specimens, Tetmajer's analysis of, 317 percentage of, 21 Emery testing-machines, 828 Extensometers, 340 r actors of safety with timber, 680 Fatigue of metals : fatigue defined, a new definition of- fered, 537 micro-flaws in steel, 537 WOhler's tests and appliances, 539 results of fatigue tests, 541 limits of max. and min. stresses for an indefinite number of repetitions, 541 a new formula for dimensioning, 545 Filtration through concrete, 612 Fineness of grinding of cements, signifi- cance and tests, 409 Fir of the U. S., 269 Fire-resisting qualities of different kinds of concrete, 625 Flat plates uniformly loaded approxi- mately computed, 73 Flaws, microscopic, in steel, 537 Flexibility of wood, 244 Flitched beams, the design of, 68 Forging under a light hammer, effects of, 517 Form of specimen a function of crushing strength, 29 Formulae : for the ultimate strength of columns, 366, 683 for dimensioning for repeated loads, 545 Foundry practice — ses Cast iron. Fractured specimens : of timber, 241 of car axles, 563 of wrought-iron and steel, 398 Freezing, effects of, on cement-mortars, 613 Freezing tests of stone, 633 French Commission, report of, compared with resolutions of the Conventions, 737 Frictional resistance : of riveted joints, 525 per square inch of rivet area, 527 INDEX. 779 Fuel value of wood, 247 Fusible alloys, 180 vJTauging implements, 852 Geographical distribution of Southern pines, 684 Gneiss— see Granite. Grains of wood, 215 Granites and gneisses: structure of, '630, 681. strength of. 640, 643. 645 resistance to abnision, 650 Gray's autographic stress-diagram appara- tus, 346 Grinding of cement-clinker, 195 Gripping devices, 324 Grooved sections, tensile strength of, 514, 530 Gum-trees of the U. S. , 288 H. Lackberry-trees of the U. S., 289 Hardening of cement-mortars in air and in water, 576-577 Hardening, tempering, and annealing of steel, 168, 170, 731, 734 Hardness tests: hardness defined, 381 test for resistance to indentation, 381 test for resistance to abrasion, 383 Hardness of timber, 243 Heart-wood, 207, 255 Hemlock of the U. S., 271 * Hickory-trees of the U. S., 289 Holly-trees of the U. S., 291 Hysteresis, magnetic, of iron and steel, 101 X beams and plate girders tested and com- pared with specimeu tests, 518 Immersion, long, effects of, on the strength of timber, 677 Impact stresses for given deformations, 79 Impact tests: give no absolute results, 80 objects of, 875 essential conditions of, 876 the energy* of the blow, 876 the pendulum test standardized, 877 impact testing-machines, 379 compared with cold-bending tests, 403 Impact tests on car-axles, 564 Impact testing machines, 879 Iron (see also Cast iron, Wrought iron, and Steel): historical account of its manufacture, 87 classification of iron aod steel, 88 magnetic testing of. 708 micrographic analysis of, 725 structural constituents of, 734 Iron wood-trees of the U. 8., 283 Ke .eep's testing-machine, 380 Keep's diagrams of the strength of cast iron, 95. 96 Kenuedy's sheariug-test apparatus, 386 Key to wood species based on wood struc- ture, 254, 258 J^/an impblack from wood, 249 Larch (tamarack) of the U. S., 272 Launhardl's and Weyrauch's formulae re- placed by one new formula, 545 Lateral deformation under direct stress, 5 Length of reduced section, effect of, 514 Lime, hydraulic, 182 Lime, manufacture of, 181 Lime-mortar, hnrdening of, 181 Limestone and marble: structure of, 630, 631 strength of, 640, 643, 645 resistance to abrasion, 650 Limit of elasticity— see Elastic limit. Limits of stress for indefinite number of repetitions, 541 Loading, effects of rate of, 305 Loads suddenly imposed, 81 Locust-trees of the U. S., 291 Long storage, effect of, on the strength of cement, 593 Louisville cement, strength of, 569, 570 Low red heat, effects of finishing steel at, 499 M. achines, testing, general requirements for, 804 ' " Magnetic testing of iron and steel: magnetic properties defined, 703 permeability, 703 unit of man eti zing force. 708 unit of magnetization, 708 hysteresis, 708 Steinmetz law on hysteresis, 705 780 INDEX. Magnetic testing of iron and steel: methods of testing, 705 measurement of permeability, 705 ring method. 706 dividedbar method, 708 double-bar method, 709 magnetic -bridge method, 710 voltmeter method, 711 permeameter method, 712 magnetic balance, 712 measurement of hysteresis, 718 miscellaneous methods, 718 ring method, 713 E wing's hysteresis-tester, 714 - results of tests, 716 development due to testing, 716 conditions affecting magnetic quality, 718 conductivity data, 721 importance of testing, 722 Magnetization, unit of, 703 Magnetizing force, unit of, 703 Magnolia-trees of the U. S., 300 Manganese: in cast iron, 98 in steel, 161, 162 Mauganese bronze, strength of, at various temperatures, 566 Malleable iron — see Cast iron, 112 Maple-trees of the U. S., 291 Marshall's extensometer, 840 Martel'8 law of indentations, 882 Mechanical properties of timber, 183 to 245 Mechanical tests in general, 802 classification of, 303 Micro-flaws in steel, 537 Micrograph ic analysis of iron and steel, 725 Micrometer-callipers, 350 Microscopic tests of stone, 635 Milwaukee cement, strength of, 569 Modulus of elasticity (Youdg's): defined, 3 of volume under direct stress, 6 for shearing stress, 8 determination of, from beam deflec- tions, 67, 374 of cast iron, 476 of wrought iron (Pig. 392), 483 of steel, 509 independent of other qualities in steel, 510 Modulus of elasticity (Young's) : of cement-mortars and concretes, 575, 601, 602, 603 of timber, 670 Moisture in timber, 676 distribution of, 223 test for, 667 reabsorbed, 668 effects of, on strength, 242, 667 Molecular structure of wrought iron and steel, 144 Moments of inertia of various forms, 48 Moments of resistance of various forms of beams, 48 Mortar, cement : hardening in air and in water, 576-7 strength of, for different proportions of sand, 579 strength of, for different sizes of sand- grains, 582 strength of, at various periods as com- pared with the strength at 28 days, 573 economy of coarse and fine sands, 587 with artificial compositions of sand 589 porosity of, as dependent on the sand used, 591 adhesive strength of, 597 compressive strength and elasticity of, 603 economy of, 605 effects of freezing on, 613 auti-freezing mixtures, 615 rates of setting at different tempera* tures, 616 effects of salt on, 617-621 fire-resisting properties of various mix- tures, 626 Mortar, lime : hardening of, 181 Moulds for cemeut briquettes, 438 Muck bars, 122 Mulberry-trees of the U. Nickel-steel, 515 Oa Fak-trees of the U. 8., 298 01 sen's testing-pppliances: testing-machines, 320 INDEX. 781 Olsen's testing-appliances : stress-diagram apparatus, 349 compressometers, 355 Open -b ear tn and Bessemer steel, com- pared, 142 Open -hearth process of making steel, 138 O sage-orange trees of the U. S., 298 Outerbridge's experiments on increasing the strength of cast iron, 480 Overstraining destroys the elastic field, 522 Overstrained metal restored by annealing, 513 JL aving-brick— see Brick, vitrified. Paving- brick tests, 456 cross-breaking, 457 crushing, 457 rattler test, 457, 460 general table of results, 660 Pendulum impact testing- machines, 377 Permeability, magnetic, of iron and steel, 703 Permeability (to water), test of cement- mortars for, 452 Persimmon-trees of the U. S. , 298 Phosphor-bronze : how made, 178 strength of, 554, 556 Phosphorus: in cast iron, 97 in wrought iron and steel, 165-7 in bronze, 178, 554, 556 Photomicrographs of steel, 736 Pig iron, grading of, 99 Pillars — tee Columns. Pines of the United States : soft, 274 hard, 275 Pine, short-leaf and long-leaf, identified by geographical distribution, 684 Pipes, cast iron, with uusymmetrlcal thick- ness, 481 Plastic and elastic bodies defined, 1 Plastic and viscous materials, 24 Plastic materials in compression, 24 Plate girders, tests on, 518 Poissou's ratio defined and values given, 5 Poplar-trees of the U. S. (see also Tulip), 298. Porosity of mortars as dependent on the quality of the sand used, 591 Portland cement— see Cement, Portland. Posts — see Columns. Prisms and cubes, relative crushing strength of, 31 Puddling process, 117 Punching and shearing, injurious effects of, 532 Punching tests of steel not valuable, 500 Puzzolana cement— wd Slag-cements. V^uenchiug and annealing, effects of, on low-carbou steel, 500 Ra mils, car-wheels on, 506 Kate of applying load : effects of, in general, 305 effect in cement-testing, 442 Rattler test of paving brick, 457, 460 Reduction in the rolls, effect of : on strength of wrought-iron, 181, 483 ou strength of steel, 496-498 Reduction of area in tensile tests, 23 Reduction of area on steel test-specimens, 502 Regaugings after set has begun, effect of, on strength, 593 Resilience : defined, 75 stored in elastic bodies, 76 a measure of the body to resist shock, 76 areas of stress-diagrams, 82 of bodies under direct stress, 83 . in cross-bending, 83, 372 in torsion , 85 comparative, for different kinds of stress, 86 of cast iron, 478 Resin from wood, 249 Resonance of wood, 218 Riehle's testing-machines, 320, 327 Rivet-steel, stress-diagram of, 496 Rodman's apparatus for testing hardness standardized, 296 Rope, wire — see Wire rope. Rosen dale cement, strength of, 568 Rusting — see Corrosion. s. rait, effect of, on cement-mortars, 617-621 Sand in cement-mortars. standard to be used in cement tests, 424 effect of different sands on the strength of cement- mortar, 424 782 INDEX. Sand in cement-mortars: effect of increasing proportions, 579 " " varying sizes, 582 " " composition, 587, 589 Sand-cement, strength of mortar of, 576 Sandstones : structure of, 631, 632 strength of, 639, 640, 643, 645 resistance to abrasion, 650 Sap-wood, 207. 255 Sassafras-trees of the U. 8., 300 Scarfed joints, how to avoid, in riveted work, 533 Sea-water, effect of, on cement-concretes, 623 Setting of cement, 189 rate of, 415 automatically recorded, 415 retardation of, at low temperatures, 616 Shaft 16 in. diam. forged under a light hammer, 517 Shafts, steel, drawn through dies, 518 Shearing modulus of elasticity, 8 Shearing and direct stresses, 7 ' Shearing and punching, injurious effects of, 633 Shearing strength : governs crushing strength, 28 of wrought iron, 485 of steel, 525 of timber, 240 Shearing stresses : cases of, 38, 385 in beams, 52 Shearing tests. essential conditions of, 385 appliances for making, 386 of wrought iron, 485 of steel, 525 Shock- resistance measured by resilience, 76 Shrinkage of timber * explained, 227 effects of, 229 amount of, 232 Sifting cement, 410 Silicon : in cast iron, 92 influence of, on mechanical properties, 74 „ influence of. on shrinkage, 95 on iron and steel, 160 Silicon bronze, how made, 179 Size of wooden beams — effects of, on strength, 672 Slag-cements : described, 190 long storage, effect of, on strength, 594 effect of carbonic- acid gas on, 596 Slipping of riveted joints, 527 Soundness test of cements, 417 Specifications for iron and steel : of American Society of Civil Engi- neers, 756 of Mr. H. H. Campbell, 756 of American steel manufacturers, 767 Specific gravity: of cements, 418 of wood, 219 of different species of timber, 222 of stone, 637 Spring and summer wood, 208 Spring testing machines. 867 Spruces of the U. S r277 Standard tests of paving-brick, 460 Steel: methods cf manufacture, 133 the crucible process, 133 the Bessemer process, 133 the open- hearth process, 138 comparison of basic and acid open- hearth processes, 142 comparison of Bessemer and open- hearth steel, 142 molecular structure of wrought iron and steel, 144 fracture showing structure, 145 as affected by heat treatment, 146 mechanical qualities of steel of various grades, 147 not fully explained by its chemi- cal composition, 150 influence of carbon on iron, 151 combination of carbon with iron, i51 fouud in three forms, 151 change in the carbon at a low yel- low heat, 153 hardening and tempering steel, 153 chemical analyses cannot explain mechanical effects, 154 the hardening of steel, 155 effect on the tensile strength, 156 Eng 318.97 The materials of construction. Cabot SctofKW 0054*] I 3 2044 091 857 52 m w I ll * *t ■ ■ m n ilLVFl Hi W LXI. 