Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

288 Molesworth’s pocket-book Low Masonry Dams. Width, at bottom = height x 0’7. Width at middle e= height x 0’5. Width, at top .. = height x 0'3. Eabthen Reservoir Dams. Width at top in high dams from 7 to 20 feet. Width at top in low dams.. = height. Breast slopes ................= 3 to 1. Back slopes...................= 2 to 1. Height above surface of water not less than 3 feet 6 inches. Table of Rainfall, showing the Quantity of Wateu Due io a given Rainfall oveb a given Area. Area of Catchment in Acres. One Square Mile. Cube feet. Thousand cube feet Million cube ft. 2 3 4 5 6 8 9 10 12 15 20 I 3,630 I 7,260 10,890 14,520 18,150 21,780 25,410 29,040 32,670 36,300 43,560 54,450 72,600 90,750 108,900 30 . 40 ;145,200 50 181,500 i 60 '217,800 7 14 22 29 36 44 51 58 65 13 81 109 145 181 218 290 363 436 11 I 22 j 33; 44 I 54 i 65 I 14 29 I 44 58 I 13 Si I 18l 36; 54. 73[ 91 109 109 131{ 22 44 65 81 bo I o7 109 13. 76 m 127 15: H1? I lift UK I1?, 81 I 116 98 i 131 109 1145 131 j 174 163 j 21« 218 272 436 544 653 290 363 436 581 726 871 145 174 163 19« 1811 218! 218 21'2 363 454 544 726 907 1 1089 ; 261 327 436 5441 653) 25 511 76 102 127 j 152! 178 203 229| 2541 305 381 508 635 762 871 1016 1089 1270 13071525 29 58; 871 1161 145 2031 232J 261 i 290’ 348 i 4361 681' 726! 871! 1162 1307 1452,1633; i742|iaeo 33 65 98 131 163 196 229 261 294 327 392 490 653 817 980 7 9i Hi 14 16| 181 21 23i 27f 34f 46* 68 69i 93 116i I39i