MODERN SCIENCE.

New Zealand Herald, Volume LXI, Issue 18861, 8 November 1924, Page 7 (Supplement)

MODERN SCIENCE.

ITEMS OF INTEREST.

marvels of lightning.

ENERGY of a single flash.

Science recognises several kinds of lightning, although authorities differ as to whether some types are not identical and merely appear different because of the peculiarities of human vision. „ Forked lightning is the most common typo. The irregular path of the discharge is believed to be duo to the presence of solid particles and electrical charges that make a iaeged course along the path of least resistance. Sheet ligntning, which illuminates large areas of the sky, is believed to be merely the reflection oi _ forked lightning from a distance. The majority of victims of lightning are not killed instantly. They are merely stunned, and can be revived by the application of artificial respiration and the other first-aid measures commonly employed in cases" of drowning and asphyxia^ tion. . 11 Most of the exceptionally tall structures of the world have been struck by lightning more than once, but have escaped damage because the lightning has • been carried harmlessly to the ground by lightning rods. The Eiffel lower in Paris has been struck many times without damage, despito the belief that lightning never strikes twice in the same place. A single flash of lightning concentrates many times more energy than could be produced at one instant by all the power plants in the world. the electric rickshaw. The new jinriksha, designed in China lo replace the coolie-drawn two-wheeled vehicle, ha 3 four wheels, and is driven by an electric motor. There are two seats instead of one, the driver being perched on the front seat over the storage battery. The new "rickshaw" has four times the speed of the old, and seems to offer a real contribution to the awakening of the Orient. Shanghai is said to have 15,000 of the man-drawn jinrikshas, and Peking as many as 25,000, ■while Japan has more than 100,000.

A STUDY OP PLEAS. Dogs do not carry fleas which transmit bubonic plague, according to the results of experiments conducted by Mr. C.__E. Pemberton, entomologist of the Hawaiian Sugar Planters' Association. During the past year or so Mr. Pemberton has caught nearly 3000 fleas from Hawaiian dogs. In not a single instance has he found a rat flea, and, as is well known, it is tho rat fleas \vhich carry bubonic plague. Only fleas from infected rats can transmit the disease. The flea found on dogs and cats, ho says, is a quite distinct species from tho rat, chicken, or human flea. The families do not mix well. Mr. Pemberton believes that the dog has been given an undeserved reputation as a disease carrier. which has resulted in stringent laws against stray canines in some localities.

' TOETOISESHELL OATS. It has been known for some tim« that tortoiseshell cats are almost always females, but the peculiar behaviour of the tortoiseshell character in breeding has only recently been, explained as a Mendelian phenomenon. Mr. F. A. Hays points out m the Journal of Heredity that the genetics of tortoiseshell cats present the following points:—Black males mated to yellow females give tortoiseshell females and yellow males, although an occasional black female has been known to arise. Black males mated with tortoiseshell females give both tortoiseshell and black females and both yellow aud black males. Yellow, males mated to ,v tortoiseshell females, give both tortoiseshell and yellow females, and both yellow and black males. Tortoiseshell males have been known to arise as a sort of rare freak. BREAKING OF THE ATOM. Dr. ; T. F. Wall, of Sheffield University, States that he believes ho will be able to break' up the atom and control its energy. Ho lias been experimenting with a "death-ray* machine, and it is suggested that the electrical energy produced by this machine can bo so concentrated and directed that tho atom ran

be broken up. Dr. Wall explained that the power ho could project by means of bis machine 011 to a very small object ■was equal to one-third of that generated by tho entire Sheffield power station. When modifications and different arrangements of tho coils in tho machine had been completed, said Dr. Wall, tho power vrould then be so great that it might wreck the whole university. The experiments were dangerous, but the next few would see tho completion of his labours, and perhaps tho atom would be broken.

ANCIENT MID-PACIFIC RUINS. New light on the old mystery of the origin of tho Pacific island races may be shed by recent discoveries on two tiny islands belonging to the United States — islands whose very existence, let alone their ownership, was unsuspected by most Americans. The Bernice P. Bishop Museum expedition, working in cooperation with the United States Navy, has spent many months in a scientific reconnaissance of the chain of small islands extending * thousand miles north-westward from Hawaii, and discovered on tho islands of Nihoa' and Necker tho remains of ancient dwellings. Theso two islands are eroded remnants of volcanic masses, cliff-bound, and without water. The settlements must have been made when life was possible there, and have been abandoned when conditions became unfavourable, no one knows bow long ago. Preliminary cleartog has brought to light old walls, house platforms, burial grounds, and terraced •\'

A MAN-EATING TREE. "If you can imagine a pineapple Bft. high and thick in proportion at its base," said Mr. Salmon S. Chase, the explorer, when talking about a man-eat-ing tree encountered on his travels in Madagascar, "yon will have a good idea of the trunk—with a series of long hairy green tendrils (palpi) stretched out in «very direction. My observations were interrupted by the natives, who had been shrieking around the tree with their shrill .voices, and chanting what I was told ■were propitiatory hymns to the great tree devil. With still wilder shrieks and chants they now surrounded one of the women, and urged her with the points of their javelins, until slowly and despairingly she climbed up the stalk and stood on the summit of the cone, the palpi swirling about her. The slender palpi quivered a moment over her head, and then fastened upon her in sudden coils round her neck and arms."

NATURE'S LIVING LAMPS.

What is the most efficient lifrht in the World ? Some people might vote at once ..for the "last word" of science in artificial illumination, but tbev would t<e yrong. The most efficient light known to ♦ha human race was known in the days of pine torches and rush-lights. It is "that with which Nature has endowed the glowWorm and the firefly. Science has so far failed to solve the problem of the production of light without heat—a problem which seems to have given Dame Nature no difficulty. In all artificial light production an enormous amount of energy is lost in the form of heat rays and chemical rays. Thus a four-watt carbon glow lamp has a luminous efficiency of less;than a half per cent., and the most perfect artificial luminant has an efficiency of only 4 per cent. Science here compares Ladly with Nature, for the luminous efficiency of the firefly is no less than 99.5 per cent., while the glow-worm's light ifj eighty timQS more efficient than a fcxngsten lamp..