SCIENCE SIFTINGS

New Zealand Tablet, 11 July 1918, Page 46

SCIENCE SIFTINGS

By "Volt.'i

Fruit Pits Made into Oil. Fruit pits, systematically gathered by Germany's school children, are turned over to chemists, who are converting them into rich lubricating oils. Cherry and plum stones are said to be the best for this purpose. Longest Days. The longest day of the year at Spitzbergen is three and one-half months. At Wardbury, Norway, the longest day lasts from May 21 to July 22 without intermission. AtTornea, Finland, June 21 is twentytwo hours long, and Christmas has less than three hours of daylight. At Petrograd the longest day is nineteen hours, at Montreal it is sixteen hours, and at Philadelphia about fifteen hours. Sailors-' Finger-prints. Every officer and man in the United States navy is to have his finger-print on his identification disc. The disc has the man's name, date of birth, and of joining up on one side, and on the other the finger-print impression. The latter is engraved on the metal from the original impression of the index finger of the right hand. The risk in making a wrong identification is estimated at only 1 in 65,000,000. Growth of New Zealand Trees. Addressing the members of the Wellington Philosophical Society at one of its recent meetings, Mr. E. Phillips Turner, F.R.G.S., referring to the growth of New Zealand native trees said that the age of trees was a matter about which there had been considerable uncertainty. During the last two years a great deal of interest had been shown in the rate of growth of our native trees, aroused mainly because of the statements of Mr. D. E. Hutchins, formerly of the Indian Forest Service, who said that the chief New Zealand timber-yielding trees were as quick in growth as the chief timber trees of European forests, and on that account our milling forests should be subjected to regenerative treatment. In the exploitation of a forest, said Mr. Turner, one of the first duties was to ascertain the annual increment in the volume of the timber. After the permanent forests had been got into order the annual cut should not exceed the annual volume of increment, otherwise it. was not possible, except by replanting, to have a continuous timber supply. In 1913, Mr. T. F. Cheeseman, F.L.S., in the course of a paper on forestry, said that the average increment was one inch in 4.85 years. In nearly every instance the kauri occupied land of very low farming value, so that there was not the same excuse for clearing it as there was for clearing white pine, which, as a rule, occupied more valuable land. The conservation of kauri forests had never been properly tested. The lecturer then went into great detail regarding the characteristics of the growth of various New Zealand trees, pointing out, as in the case of the kauri, that conservation was becoming more and more necessary .