Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

jy OF ENGINEERING fobmulæ. Strength and Weight of Materials—continued. ..................Stones, &c. Specific Gravity. Weight of a cubic foot. Weight of a cubic inch. Tensile ' Strength per sq. in. Crushing Strain per sq. in. 1 Transverse | Strength. lbs. lbs. Ibs. lbs. 1b«. Basalt, Scotch 2-95 184 •106 1,469 8,300 —— „ Greenstone .. .. 2-9 181 •104 17,200 ■—- „ Welsh 2-75 172 •099 16,800 Chalk 2'33 145 •084 —- 501 Firestone ... 2-62 162 •094 —— — 1-8 112 •065 — Granite, Aberdeen grey .. 2-62 163 •094 — 10,900 —— „ „ red .. 2-62 165 •095 —- „ Cornish .. .. 2-66 166 •096 —-. 6,300 „ Mount Sorrel .. 2-67 167 •096 ■1 » ■ 12,800 — Limestone, Compact .. 2-58 161 •093 —— 1,100 „ Purbeck .. .. 2-6 162 •093 — 9,160 4"*«» „ Anglesea ,. —. —• — 7,579 —— „ Bina Lias ,. 2-467 154 •089 «— —• „ Lithographic.. Marble, Statuary .. .. 2-6 162 •093 —■ — — 2'718 170 •098 722 3,216 —■ „ Italian 2-726 170 •098 —. 9,681 — „ Brabant block .. 2'697 168 •097 —— 9,219 „ Devonshire .. .. Oolite, Portland stone .. — — — — 7,428 2-423 151 ■087 —— 4,100 „ Bath stone .. .. 1-978 123 •072 - - — Sandstone, Arbroath pave-) ment .. .. 5 2-477 155 •089 1,261 7,884 4- „ Brainley-Kall .. 2-5 156 •09 6,(150 — „ Caithness .. .. 2-638 165 •095 1,054 6,490 857 „ Craglieth .. .. 2-45 153 •088 453 5,287 „ Derby grit .. 2-4 150 •086 — 3,100 —— „ Red (Cheshire) 2-15 133 •077 2,185^ „ Y orkshire paving Slate, Anglesea 2-51 157 •09 — 5,714 — 2-8? 1T9 •103 ) 9,600 10,000 „ Cornwall 2-51 157 •09 > to to „ Welsh 2-88 180 •104 512,800 21,000:196]' Trap 2-72 170 •098 - — 1 c 2