Pocketbook of Useful Formulæ and Memoranda
for Civil and Mechanical Engineers

 551 Molesworth’s pocket-book Simpson’s Method of Calculating Areas (for displacement). Divide the base into any number of equal parts, taking care that the number of ordinates are odd, viz. 1, 9, or 11, &c. Let y = Distance of the ordinates apart. S — The sum of the lengths of the even ordinates, 2, 4, 6, &c. 2 = The sum of the lengths of the odd ordinates, 1, 3, 5,1, &c. E =s The sum of the lengths of the end ordinates C and B. A = Area of the figure. A = y- (E + 4S+ 2S). Thickness of Plates in Iron Ships. T = Thickness of plate in inches. S = Span unsupported by ribs in feet. D = Depth of submergence in feet. T = -05S Salinometer. The temperature of water drawn from marine boilers when boiled in the open air should not exceed 215|° Fahr., or 3 1 • 99 specific gravity, or — degrees of saltness, as deposit turnmerices a little beyond that point.