Science.

Waikato Times, Volume XIX, Issue 1639, 6 January 1883, Page 6

Science.

ELECTRICITY, ETC. Gas is far preferable to coal for iron puddling. Dr. Siemens has done a great deal in the production of steel by his gas furnaces, which can produce as much as 5 tons at a charge. The electric light may not only extinguish the gas lamps, but electricity, it is evident, will be in increasing request for many other purposes connected- with our leading industries, especially in the making of iron and steel. The ultimate result of the substitution of gas for coal will be the saving of millions of tons of coal per annum. But electricity still will be the enemy of gas in metallurgical operations owing to its intense heat. Electricity can fuse metal with the greatest ease and rapidity. In experiments made by Dr. Siemens a crucible was charged with a pound weight of old iron broken up, and the dynamo-electric current being sent through it, the mass was completely melted in about twelve minutes, being poured out in a highly fluid state, whilst a second charge was reduced in about eight minutes. According to this eminent electrician, lib of coal will melt a similar weight of mild steel, the coal being burnt in the engine driving the dynamo-electric machine. By the ordinary system carried out in Sheffield and elsewhere, a ton of steel in crucibles requires to melt it from 2£ to 3 tons of coke, the same work being done with 1 ton of coal when the crucibles are heated in the regenerative gas furnace ; but in the furnace to which the dynamo-electric current is applied, a ton of steel can be made with 12 cwt. of coal. The temperature obtained by electricity is something enormous ; one scientist has estimated it at 3,500 deg. Centigrade, whilst Dr. Siemens considers it practically unlimited.

Mr. Willoughby Smith has been experimenting in a direction full of promise of valuable results. Using a tuning-fork as a make and break in circuit with cv large fiat disc of insulated wire, he finds that a telephone (or a 13ell telephone without the coil, or a magnet, or a piece of iron) altogether unconnected with the circuit, will reproduce the musical sound of the tuning-fork. By means of a diaphragm, he has investigated the lines of force from the coil, and has obtained some interesting results. The sounds are reproduced if the receiving diaphragm is in another room, or if there are two roeins with their walls and air between. In fact, the lines of force seem to extend a long way. If the diaphragm is placed parallel to the lines of force, no result is obtained ; but, of course, this may be obviated by using a hollow cylindrical or polythedral diaphragm with a suitable magnet.

If two metallic surfaces be placed for a few moments opposite each other, at a short distance fa small fraction of an inch) it is found that each metal has undergone a slight superficial alteration. The change increases with time, then tends to a limit. When the influencing metal is withdrawn, the metal affected reverts gradually to its previous state. These observations have been made by M. Pellat, who detected and estimated the alteration by measuring the difference of potential. He shows reason for believing that the action is not electrical, but purely material. It depends essentially on the nature of the influencing metal, being great with lead, less with copper, and nil with zinc.

When Faure's discovery of the storage of electricity was made known, many novel uses were claimed for the new discovery, but no one ventured to think it would be likely to increase our fish supply. Yet this it may do. The French Government have just sanctioned the experiment of fishing by electricity. It is well known that light at night exercises an irresistible influence over fish. — (S. F. Netvs Letter.