— The water in a pit is hauled up the shaft 350 yards deep in two tanks each holding 350 gallons, one ascending the other descending ; what horse-power is the engine which delivers a tank of water every three minutes at the surface, not including the time of stoppage ?
Question 79.  — The water in a pit is hauled up the shaft 350 yards deep in two tanks each holding 350 gallons, one ascending the other descending ; what horse-power is the engine which delivers a tank of water every three minutes at the surface, not including the time of stoppage ?  The speed of the load is 350 feet per minute and its weight 350 x 10 = •j, Soo lbs.