Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

243 OF EXGINEERIXO FORMULAS. Useful Memoranda for Hydraulic Calculations. “1 cubic foot of water .. = 62-425 lbs. = ’557 cwt. = • 028 ton. 1 cubic inch .. .. = *03612 lb. 1 gallon __________= 10 lbs. = *16 cube ft. 1 cube foot of water .. = 6 ’ 24 gallons = say 6| gallons. 1 cwt. of water .. .. = 1 ‘8 cube foot = 11'2 gallons. 1 ton of water .. .. =35-9 cube feet = 224 gallons. P = Pressure in lbs. per square inch. H = Head of water in feet. V — Theoretical velocity in feet per second. g = Force of gravity. P = H X -4335. H = P x 2-307. Pressure per square foot = H 62 • 4. # = 32-2. 2^ = 61-4. = 8-025. V = V 2 </Ö = 8-025 V H. V2 1 H = = -0155 V2. -^=-0155. 2<7 2g SEA WATER, 1 cube foot of sea water = 64'11 lbs. Wt. of sea water = 1 • 027 weight of fresh water. % RAINFALL. Inches of rainfall x 2,323,200 = cube feet per square mile. Inches of rainfall X 144 = millions of gallons * By sale of Gas Act of 1859 the weight of water was fixed at 62'321 lbs, per cubic foot. R 2