Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

273 OF ENQIJTEEBINl} FOBMULÆ. SEWERS. Flow of Wateb in Seweb. x - Area of sewer 4- the wetted perimeter in ft. f = Fall in feet per mile. V = Velocity in feet per minute. A = Area in square feet. C — Cubic feet of water delivered per minute. V = 55 J x x 2/. C = V x A. Egg-shaped Sewer. R = D. Internal Dimensions. Let B — Diameter of bottom of sewer. 0 = „ top „ K = Radius of sides „ D = Depth of sewer B = |- C=^, When D is less than 6 feet the brickwork is generally 9 inches thick. Above 6 feet, and under 9 feet, brickwork 14 inches thick. T