Science Siftings

New Zealand Tablet, 10 April 1913, Page 51

Science Siftings

By Volt.' Protecting Iron Works. Two German chemists, Liebreich. and Spitzer, have found from tests that a single application of paint is more efficient for the protection of iron against rust than are several coats. The explanation they offer for this somewhat surprising observation, is that a single coat is more elastic and less liable to scaling or cracking than a double coat, and thus affords more satisfactory protection from atmospheric influences. Loss of Life in Mines. In a report, Dr. Joseph A. Holmes, director of the United States Bureau of Mines, fixes the toll of one miner's life on each 183,000 tons of coal unearthed. These figures are for the year 1911. As compared with those of the preceding years a marked decrease is noted and this is attributed to the federal government's work in the mining field. It is also stated that the death rate in metal mines of the country is nearly as high as the above, averaging more than three men per thousand employed. The report strongly advises that the health conditions in and about mines be investigated, as preliminary inquiries have shown the prevalence of tuberculosis and the present of the hookworm disease in several different localities of the States. .Vertebrate Animals. The contrast between the first two great divisions of the vertebrate animalsmammals and birds almost startling from its suddenness. There are no connecting links between them, and it is utterly impossible to mistake the one for the other. Yet, the same materials are employed in the structure of both. The skeleton of birds is made of hard bone, as in the mammalia; the respiration is carried on by means of lungs the heart is divided into four parts, each with its set of valves; and the exterior of .the body is covered with horny matter that is secreted from the skin. But the skeleton, lungs, and clothing of the birds are utterly distinct from those of the mammalia; and the outward and visible differences are so boldly marked that even a baby can discern them. Send Messages Fifty Miles. Mr. Eugene Reinhard, of the Australasian Wireless Company, has just completed the erection of the highpower station at Awanui, near the North Cape, a station which will be able to communicate with Sydney during the daytime and a much longer distance at night-time. Mr. Reinhard, while on a visit to Wellington, will give demonstrations to the officials of the Postal and Defence Departments of the portable field" wireless set, which is capable of sending messages for a distance of 50 miles. The power for driving the dynamo is obtained with a bicycle attachment, worked by a man precisely as if he were riding a cycle. The whole outfit can be carried by three pack horses. The set includes small telescoped steel pipe masts, which support the aerials. Wireless Telegraphy. Some remarkable long-distance wireless telegraphy was accomplished by the Marconi operator on the Shaw, Savill and Albion steamer Pakeha on the voyage from Liverpool to Sydney and Auckland. The vessel was only out of communication with the outside world for two days during the whole voyage, and as she was carrying over 1090 immigrants to Sydney they were kept posted with news almost daily. Crossing the Southern Ocean the Pakeha operator was in constant touch with the steamers Persic, Stobburg, and the Rangatire, while off Cape Maria van Diemen, messages were received from the New Zealand Shipping Company's liner Tongariro off the Bluff, and then distant over 1200 miles from the Pakeha. The steamer Fiona, bound from Sydney to Suva, was easily picked up at a distance of 330 miles in the daytime. Before reaching Capetown the Pakeha's operator dispatched and received messages with the land station there, at a distance of over 400 miles in daylight. ; - ' ■ J