SCIENCE OF THE BAY.

New Zealand Herald, Volume LXVII, Issue 20620, 19 July 1930, Page 5 (Supplement)

SCIENCE OF THE BAY.

VALUE OF VIOLET RAYS. At a farm in Micklcficld Green, a Hertfordshire village, experiments with ultraviolet rays in farming, have been earned on by Mr. J. 0. Hickman, a practical gentleman farmer. Litters of pigs, immediately aftei weaning, have been subjected to tho rays of a tungsten arc lamp, and have grown so rapidly that :t was possible to market them four weeks earlier than pigs, reared in the normal way. Mr. Hickman has also found that ultraviolet rays, applied for a few seconds beforo milking to tho udders of his cows, havo greatly reduced tbe bacteria in the milk. Tho subsequent irradiation of the milk still further reduced the bacteria content, enabling it to bo kept fresh for a much longer period. At the same time it is stated, it added to it the valuable vitamin D, the anti-rickets vitamin, without destroyng tho equally valuable vitamin A. Mr. Hickman's two youngest children, a boy aged seven and a girl aged six, had their ordinary milk replaced by irradiaLed milk in 1928; in tho first year each increased in height by and 4in. respectively, as against ljjin. and 2iin. the previous year; and in weight hy 51b. 2oand 41b. loz., against 31b soz. and 21b. 9oz. Meanwhile the whole district is laughing over tho eflect it has had upon an old man, aged 85 years, says the Morning Post, which has been investigating the new process. During the winter he suffered from bronchitis, and was thin and ailing. He was put on irradiated milk for a month, and is now tho picture of health, but he refuses to take it any longer, as he- is growing out of his clothes, and ho states that ho cannot afford a new suit. CRIME CONFESSION MACHINE. Details have been deposited at the London Patent Offico of an invention for extorting confessions from criminals. The inventor, Mrs. Helen Adelaide Shelby, of Oakland, California, claims that it is impossible for criminals questioned by her invention to adopt the common practice of denying things they have said during a police examination. The apparatus consists of a structure divided into two chambers, in ono of which tho suspect is confined in total darkness, while the person who is to question him is in the other. In tho partition separating tho two is a panel with a figure like a skeleton mounted on tho side facing the prisoner. The

J examiner speaks into a megaphone conI ncct-ed with tho skeleton's mouthpiece, and ' fhn prisoner's answers and confessions arc j recorded by a form of talking film camera, room for which is found by removing too hack of the skeleton's skull. The skull's eye-sockets contain electric bulbs, glow in a variety <>f colours, and are made to | blink with' the sound-wave variations. i GLASS CAGES FOE BILLIARDS. j Import ant, match games at thrcc-cuslnon | and balk-lino billiards, which arc the ! favourite American games, will bo played I in glass cages in the future in older Ito control air currents and changes jin temperature to which the ivory ! balls arc sensitive, securing t ho uniI fortuity of piaying conditions which the | feinperainental title performers demand. | Tests arc being made in America with | enclosures 25ft. long, 20ft. wide, ami lOtt. | high, with ventilators at the top. in order I not to destroy an important part of any j billiards game, the clicking of the ivory, i loud speakers will be used, lor they must j bo installed if the referee's voice is to bo 1 heard. If the ivory is cold it, contracts j and loses much of its resiliency, or even become.; " egg " shaped and " rolls nit. I In the past electric heaters sometimes ! have been placed beneath the tables in | order to take the chill out. of the slate bed. | MINING BY HOSE-PIPE. i One. of the most extraordinary ways of | extracting metals from the earth, is that ; to be seen in the tin mines of the Malay 1 States -With the exception ol precious 1 metals, such as gold, silver, platinum. | and radium, tin is now the most valuable | in the world Often the tin-bearing j ground rises cliff-like from the plain. I Minii'u' is then carried out not by orthoI (lon methods, but with the help of a super ! hose-pipe. This hose throws a thin jet ' of water at it pressure of more than 2COlb. to the f.i|t<are inch. Until r.tio has seen fiiiih a jet it. i* almost impossible to realise what it, is like. Ihe strongest man, for instance, could not, cut through the jet near the noz/.10 of a hose with j a heavy sword ll la* tried, ;i broken ! blade, and probably a broken arm. would result. The jet is directed against the face of the cliff, which crumbles away almost, as i? it has been blown up by dynamite. ELECTRICITY PRODUCTION. Returns have been published showing ' Unit while in 1920 the British produc ion of electricity increased to mi ton units As compared with 14.900 million units in 1928. This is altogether out distanced by both America and Germany. •I'lie American production rose from 114,000 million fo 126,700 million units while that in Germany rose, from 28..000 ' million to 53,000 million units.