SCIENCE OF THE DAY.

New Zealand Herald, Volume LXVI, Issue 20176, 9 February 1929, Page 6 (Supplement)

SCIENCE OF THE DAY.

VISIONS OF NEW CONTINENTS.

"Is the earth dead ? Are It o ocean basins and continents made and finished 1 Aro thero no activo asthenoliths 1" These questions wero discussed recently before tho American Association for tlio Advancement of Scienco by Dr Bailey Willis, of Loland Stanford University, who named certain sectors of tho univorso where land shifts vvould, in slow time, cause tho upbuilding of new continents. Tlio asthenoliths, Dr. Willis asked about aro popularly —among his craft, that is—known as blisters, caused bv heat. " Compression of gravity," sum Dr. Willis, " is capable of producing all tho heat of which wo have evidence. As rocks heat, tho melting tends to extend laterally faster than upward, thus forming asthenoliths." The formation of asthenoliths appears to develop SO to 600 miles below the earth's surface, and probably only those within 100 miles of tho surface directly affect it. A blister requires several million years to grow. " There is a great deep tff Japan and tho chain of volcanoes dominated by Fujisan," Dr. Willis said " There is tho deep of the Aleutian with Katmal and many othei volcanoes. There is Atacanadeep off Central Chile and the volcanoes that rise in the Andes. Ihere aro many others in tho Pacific and the West Inches. Onlj the Atlantic naw appears relatively cold, although perhaps warmin-T up to becomo active 6ome millions of years hence."

BURGLAR'S INVISIBLE FOE. Tho successful burglar of tho future, it seems, will havo (o protect himself with some kind of armour against tho rays, which are likely to bo used to bring about his capturo. An invisible beam device has been demonstrated in London, and tho invention shows remarkable possibilities Infra-red rays, which are invisible, can bo thrown across doorways or right across a department. They act on selenium cells, which are susceptible to their effect instantaneously. When a burglar steps into the ray, or intercepts it with any part of his body, an electric circuit will be broken, causing an alarm bell to ring outsido tho premises. A scientist says tho schemo is eminently practical, and that ultra-violet or infra-

rcfl rays conk] lie used. Every bell in a building could I'D set ringing directly a he,"in was broken. '"Then tlio burglar might be conlrontrd villi tho howling showcase or safe," ho continues. " These objects cc.ild be protected—as, indeed, could a house-—bv (lie application of a perfectly simple property of a wireless set. Suppose, for example, you have a safe in the wall of a room. On top of it you put a wireless set so prepared that it is very near oscillating point. If you put your hand near it. it will start oscillating or howling, "it is an easy matter to cause 11 is reception of the oscillations to start, an alarm outside tho building. 'J hoy could be picked up hundreds of yards away." Another remarkable invisible ray adaption throws a beam of light across a railway track, works tho signal, and, it is claimed, applies the brakes, thus avoiding all possibility of collision.

AN INTERESTING MINERAL. Gilsonite, a brilliant black asphaltic substance found only in Utah, is one of tlio oddest minerals in tho world. Although discovered in 1862, it was not successfully* markoted until 1904, when a railway track was laid to tho rich Black Dragon vein in tho Utah Basin. To-day it is in great demand all over tho world for uso in manufacturing paint, varnish, ink, and telephone mouthpieces. Early soUlers thought gilsonito was a new variety of coal, but when thoy tried to burn it, it gave off a dense black smoke with a peculiar odour. Instead of being reduced to ashes, the material molted and drew out inlo tar-liko threads. The mineral is exceedingly brittle and difficult to miuc, as clouds of chocolate-col-oured dust rise when operations begin. This dust softens under tho heat of tho body and penetrates tho skin. Water will not removo it and relief has to bo obtained from heavy oils, alcohol, or turpentine.