Science Siftings

New Zealand Tablet, 28 December 1911, Page 2670

Science Siftings

By ‘ Volt.’

A Sky Scraper. . The new Woolworth building to be erected in New York will be the highest business structure in the world. It will be fifty-five stories, measuring 750 feet, containing 20,000 tons of iron girders, and will cost £7,500,000. .-■■■•.

The Light of the Glow-Worm.

_ The most economical artificial illuminant only gives us in light some 4 per cent, of the energy necessary to generate it, whereas between 96 and 100 per cent, of the energy raidiated by the glow-worm reaches our eyes as light. The glow-worm is the most efficient of all light engineers; and when its secret is discovered, and artificial light can be produced as economically, our quarterly lighting accounts will scarcely be worth the cost of collecting.

Best Light for the Eyes.

According to scientists, the least injurious of present day illuminants is the acetylene flame, for the •reason that it is the nearest approach to the character of daylight. For reading or writing purposes the oil lamp or candle is the best, because of its soft, yellow light. Daylight, of course, is the ideal. It is a mixture of all colors, and, as far as the eyes are concerned, the green, yellowish rays predominate. It is the invisible and ultra-violet rays that are so harmful, and in daylight there are not enough of these to hurt. Of the various forms of electric light, the violet* is the most harmful.

The Rubber Tree.

It was a Jesuit missionary, Father Marcel de Esperance, who discovered the rubber tree. He found it while on one of his apostolic journeys among the Cambeba Indians of South America, and gave it the singular name of the seringuera, because he remarked that the savages used the sap of this tree, which hardens quickly, to make rude bottles that were shaped like a syringe. A rubber-seeker's camp is still called a seringa!, and the workers are known as seringueiros. The name caoutchouc was given to this product by La Condamme, a French astronomer, who visited South America. In an account of his travels before the Paris Academy of Science, he said: The Indians of the Amazon give the name of cahutchu to a white sap drawn from the hyeve tree.' The best caoutchouc (rubber) is obtained in the vicinity of Para, Brazil

The Formation of Deserts.

lliere is a popular idea that deserts like the Sahara are the bottoms of ancient seas which have been lifted above the original elevation by geological forces This notion is an erroneous one. It is absolutely certain, high authorities contend, that the sands of all the great deserts have been formed on the spot by the disintegration of the solid rocks on which they rest Desert sands correspond in all respects, so far as their mode or origin is concerned, to the dust and sand that accumulates on our high roads in summer. All deserts are situated where the winds from the ocean, before reaching them, are exhausted of their moisture by passing over mountains or across extensive tracts of land '

The Cedars of Lebanon.

Very carefully enclosed and guarded are the two hundred remaining cedars of Lebanon, those famous trees that once clothed all the side of the Syrian mountains. So tall and beautiful were they in comparison with the trees of Palestine that the Hebrew writers celebrate them with extraordinary praise, and from the earliest times their soft, white wood was the glory of Jewish architecture. They were used in Solomon' Si«? \ n -u SI i CC ? SSOr ' and also in the church that Constantine built at, Jerusalem. Several of the trees in the grove are over fifteen hundred years old and have a height of one hundred feet and a circumference