SCIENCE and INVENTIONS.

New Zealand Herald, Volume LV, Issue 16823, 13 April 1918, Page 3 (Supplement)

SCIENCE and INVENTIONS.

PROTECTION FOR FRUIT TREES. For protecting fruit trees from frost a foreign inventor has patented a tent to be placed under them and diffuse through them the heat from a lamp beside the tent. NEW BUILDING SCHEME. A new fireproof material used in the Philippines for experimental homes for the poor contains equal parts of cement, sand, and rice husks. Half-inch slabs four to six feet long and two feet wide, weighing six pounds per square foot, are mado for the walls; and suitable tiles for tho roof are moulded from the same material. SULPHUR TO NOURISH SOIL. Tho tests of sulphur as a fertiliser are reported to have greatly added to leguminous and cereal crops, and an increase in the yield of peas of more than 300 per cent, is claimed. While the use of this new soil stimulant is not yet well understood, certain conditions have been found necessary to success. It appears that the soil must have an abundance of humus, with a slight excess of lime, or lime must bo applied with tho sulphur, and tho moisture must be not more than 18 nor less than 5 per cent. ROMANCE IN MAKING ELECTRIC A certain element of romance in steelmaking is suggested in an account received from England of the operation of a two-ton electric-steel furnace at Sheffield. The furnace is entirely hand-operated through a control worked in conjunction with recording ammeters; but the chief point is the size of the operator. A boy of 14 or 15 runs the furnace constantly and other furnaces of this particular type are now operated in the same manner by

girls, owing to the scarcity of male labour. The whole is an object lesson in tlio I steadiness and simplicity of the new type of ateol-making furnace. Such results i would havo been ridiculed only a few years ago.

A QUICK-ACTING JACK. An operation that every car operator detests is the placing and manipulation of the jack, when a tire change is necessary on tho road. To dispose of this objectionable features of this tool an English inventor has devised a mechanism that provides for two jacks under each axle, permanently attached, and all connected so as to be operated by a single shank, placed at the side of the car. The gearing is so designed that the car can, in a few seconds, he raised sufficiently to enable a wheel to bo removed. A serious objestion to the device is its very considerable weight.

USE FOB SHARKS' HIDES. As a result of the policy adopted by the United States Bureau of Fisheries of furnishing the skins of sharks and other fishes to persons who wish to experiment with these products, more than forty tanners have had an opportunity to give them a trial, and several companies are now in the market for the hides of sharks and porpoises. Some cabinetmakers in the United States of America still use the skins of certain sharks for polishing purposes. The skins that heretofore have been used are those of one of the European sharks. The Bureau of Fisheries is now determining whether the skins of some of the sharks on American coasts are not equally suited for this purpose. SUPERFLUOUS ELECTRIC ENERGY.

In Alpine regions of Europe where hydro-electric power is abundant, efforts have been made to store the superfluous elcctrio energy of power plants. Boilers arranged to use electric neat have been employed in Switzerland and in Italy. In the latter country, the ohmic resistance of the water to the passage of electric current has been utilised. In a boiler of this type (invented, by Colonel Revel, of the Italian army, alternating current of from 200 to 3600 volts is turned into the boiler. Tho production of steam is regulated automatically and continuously, so that it requires no attention. The steam generator works at any pressure up to 14 atmospheres, and may be connected to the ordinary steam boilers at any time.

HOW TORPEDOES ARE EXPLODED. The early torpedoes were detonated by means of a striker pin, which projected axially from the warhead, and, upon contact with a ship, was driven in. This had the objection that, if tho torpedo struck a glancing blow, the pin might not be operated, and there would he no explosion. In the present type, the firing of the change is dono by the inertia of a small steel hammer or striker, which, when the torpedo is not in use, is held in place by a catch at the inner head of tho safety pin. When the torpedo is fired, its progress through the water' causes a little propellor on the safety pin to rotate a nut, wliich draws the pin forward, releasing the hammer and leaving it free to move. The least shock, ahead or lateral, causes the hammer to move and fire the charge.