All About Engines

The Gas Engine 205 long as the supply of gas does not fail and the igni- tion device is in order the pump will go on working week after week, month after month, year after year, delivering with unfailing regularity from 12 to 14 tons of water per stroke. Four of the Chingford pumps are capable of lifting 40,000,000 gallons through a height of from 20 to 25 feet every twenty-four hours. Sidney Smith describes an old woman who took a cottage on the west coast that was liable to be invaded by the sea; and when the waves came rolling in she stood at the door, broom in hand, reso- lutely prepared to sweep back the Atlantic Ocean ! She would have been safer had she lived to-day, for she might have dug a deep ditch and emptied it between tides by the aid of an explosion pump. But there is a more important role for this pump if tradition and vested interests do not stand in the way. Suppose a town with a hill close at hand and a lake or river curling round the lower slopes. With a Humphrey pump, working under more ideal condi- tions of constant load than is possible with any other form of prime mover, the water could be pumped up into a reservoir on the top of the hill, and thence it could flow down, through pipes, to drive water turbines. And these turbines, constituting the most perfect form of drive for generating electricity, would be coupled to dynamos, providing all the light and heat and power that the town required. Such is an ideal arrangement which the Humphrey pump has brought within the range of practicability.