IMPROVED DEW PONDS.

Thames Star, Volume LVII, Issue 15308, 5 June 1922, Page 6

IMPROVED DEW PONDS.

In many countries where rainfall is comparatively slight there are frequent heavy dews, which are partly i absorbed in the soil and partly lost by evaporation when the sun rises. A British man of science has suggested a means by which the dev/ can be collected 'in a reservoir. His plan is to arrange a radiating surface over a tank or cistern and to interpose a heat insulator between the two. The cistern is sunk slightly into the ground on a somewhat elevated site and it is surmounted by heat insulating material. When water condenses on the radiating surfaces it drains into the reservoir, where it is protected from evaporation by the heat insulator. The inventor calculates' that in the eastern counties of England, where the rainfall is often inadequate, a reservoir with a cover of 100 square yards and a storage capacity of 12,000 gallons would furnish an average daily supply of 120 gallons during the hot summer months and 50 gallons for the rest of the year.

STILL IMPROVING THE LOCOMOTIVE. The locomotive, now about a hundred' years old, was a British invention; and to-day British engineers continue to introduce improvements in its design. Over forty years ago a device known as the “exhaust steam injector" was brought out. Its purpose is to use the power in the exhaust steam from the cylinders to force water into the boiler. The first injector of this kind was able to do its work against a pressure in the boiler of 701bs. per square inch. Later it was improved so as to feed at 120'lbs., and for higher pressures it was necessary to call in the aid of live steam from the boiler itself. Lately, however, a British firm invented a modification by means of which the injector can work against a pressure of 150 lbs. per square inch with one pound of exhaust presure, thus 'effecting a great economy in live steam. This improvement is due to the use of an additional nozzle which brings the steam into more effective contact with the stream of water. In practice the amount of live steam required when this new device is fitted is nearly half what it was formerly and amounts to only per cent, of the total steam produced by v the boiler.