MARCH OF SCIENCE

Otago Daily Times, Issue 22246, 26 April 1934, Page 11

MARCH OF SCIENCE

SOME RECENT RESEARCH IN VARIOUS FIELDS. Mach research has followed H. J. Muller’s discovery that new varieties of insects and plants could be produced by treatment with X-rays (writes the scientific correspondent of the Manchester Guardian). The subject has been vigorously investigated by the General Electric Company of America, which no doubt considers that it may contain the clue to the discovery of the new flowers and vegetables and domesticated animals of the future. Its experiments on the influence of X-rays on the heredity of petunias have been particularly striking. The petunia buds are exposed to the X-rays from a 200,000-volt tube. It ,is found that a certain quantity of X-ray energy changes the hereditary constitution of the buds so that the flowers from them have new colours, flecks, or streaks. In one experiment the buds on a single petunia stalk were irradiated. When they flowered the eldest was normal, while the second and third were spotted with white. The fourth, fifth and sixth were streaked, and the seventh and eighth were striped, and the ninth- and tenth were nearly white. The succeeding buds which had not been-irradiated, produced normal flowers. _ The twisting habit of many plants and tendrils lias been shown by similar X-ray experiments to be due to hereditary constitution rather than environment. Plants do not twist because it is convenient but because they must. The way in which they are built imposes twisting on them. They therefore grow in places where twisting is advantageous, and do not try to twist in order to conquer their environment. In the opinion of the leather trade and technical experts the use of reptile skins for making women’s shoes will be permanent and will increase. Leather made from the skins of reptiles is stronger than leather made from the skins of sheep, goats, or calves. It is easily dyed and obtainable in a large variety of designs. The mass production of reptile shoes and bags started after 1920. The demand for skins is now noticeably depleting the world’s reptile population, especially of North American alligators, edible terrapins, and green turtles. In 1932, 2,500,000 reptile skins were exported from India, and more than 2,000,000 were exported from the Dutch East Indies in 1931. This consumption of reptiles may produce a new animal industry—reptile breeding and farming. From time to time the erection of the great Boulder Dam hydro-electric power station is mentioned. This vast construction in the Boulder Canyon of the Colorado River has several recordbreaking features. On one side of the river the cliffs of Nevada rise almost vertically to a height of 1200, feet, and are faced by the equally precipitous cliffs of Arizona. The world’s strongest cableway has been slung across the chasm. There are six bearing cables each 3} inches thick. These carry a truck with 48 running -wheels which will take loads up to 200 tons. This is four times greater than the load of any comparable cableway previously constructed.

The span is 1226 ft, and the hauling motor will develop from 250 h.p. to 1000 h.p. under exceptional loads. The cableway has been strncted to carry largo metal castings and parts for the turbine generators. Some of these will 1)0 the largest in the world. Two will develop 110,000 h.p. each, as compared with the 300,000 h.p. of the turbines at Dnieprostroi, now the world’s largest; these are also constructed by the General Electric Company of America. Each of the Boulder Dam machines weighs over 1000 tons, and the installation will deliver electricity to Los Angeles, 265 miles distant.