Floatin' Down The River
Wishing to ascertain the amount of water discharged by a certain river, a place was selected where the banks were nearly regular slopes and the bottom level, making the river of uniform depth. Measurements were then taken which showed that the stream was 351 ft. wide on the bottom, 359 ft. on the surface, and 5 1/2 ft. deep. A float on the stream showed that the current flowed 2 mi. per hour. How many barrels would such a river discharge in 24 hours?
Source: E. Olney’s The Science of Arithmetic, 1876