Professor at the Univcrsity of Li6ge. THE Author has adopted a title that Messrs. Donkin and Salter gave to a paper, published by the Institution, in 1885,' because his investigations have the same object, namely, to determine the coefficients of discharge of a rectangular weir, 2 9528 inches in width (75 mm.), formed in a sheet of copper bevelled throughout the perimeter, and over which was passed the whole of the circulating-water of a condenser for the purpose of gauging it. This condenser

more »

... longs to the mechanical laboratory of the School of Mines of LiBge. The weight of circulating water is one of t h e experimental data necessary for applying Hirn's method. The formula employed to calculate the Bow, Q cubic metres per hour, over a weir o f width L metres, the height of water oTer the weir being h metres, is, as is well known : Q = 3600 X $ L J~x h3 X C ; which reduces to-L-Q = C X 'i97.22h; when L = 0.075 ; or Q = C X 118.3541~3 when L = 2-9528 inches, and h is in inches and Q in lbs. per minute.