August 23, 1918. THE COLLIERY GUARDIAN. 403 It speaks for itself 1050 1000 ■troll SO- 70- 60 1100 > Q Z UJ g u u. u f- Id Id U. Z o fl I _l fl 2 500 400 I •300 co 600 700 800 900 1000 1100 GALLONS PER MINUTE. Pumping Plant in a Colliery Pumproom 1,050 feet below surface. Three units each delivering 50,000 gallons per hour to the surface. Efficiency of Pumps, 79 per cent. Speed, 1,485 revs, per minute. Motors work at 5,500 volts. Write for List No. 736 Pulsometer engineering C°. IL OFFICES : WORKS: 11, Tothill Street, LONDON, S.W. 1 Nine Elms Iron Works READING