PROGRESS OF SCIENCE

Evening Post, Volume CXXI, Issue 36, 12 February 1936, Page 18

PROGRESS OF SCIENCE

DECENT RESEARCHES

NEW EXPLOSIVE

i ■j In' the "General Electric Review j two writers have described the usi 'of compressed air, instead of dynamite for blasting coal seams in mines, state the "Manchester Guardian." A meta case containing air at a pressure o. 15,0001b, or about seven tons, to tin square inch is put into the hole borec ,in the coal seam. The air is releasec by a valve operated at a distance. As 1 the "air: expands less violently than the 'gases from exploding dynamite, it doe: not break the coal into such smai pieces. It pushes the pieces of coa: out relatively gently, and their excep tional size has an extra commercia: value. The metal cases may be usec repeatedly. This method of blasting saves the miners from exposure to the fumes, which may be dangerous, from detonated explosives. The metal cases are •filled by an air compressor working at the coal face. The air explosion is made at a distance of 100 to 150 feet from the miners and the equipment, and the entire operation of charging with air and releasing takes about ninety seconds of time. A PATENT LILY. Since Professor H. J. Muller, of Texas, now working at Moscow, demonstrated the power of X-rays to change the hereditary constitution of living organisms, much research on this phenomenon has been made. The great electrical companies, such as the General Electric Company of America, have been vigorously exploring the effects of electric-ally-produced X-rays on plants and animals, in order, no doubt, to discover new uses for electrical equipment in agriculture and medicine. Mr. C. N. Moore, of its laboratories, has been studying the effects of X-rays on the bulbs of regal lilies. He obtained a number of monstrosities of no obvious practical value, but two of the bulbs gave flowers with an interesting peculiarity. The pollen-laden anthers of the ordinary regal lily swell and burst soon after the flowers open. The pollen is bright yellow, and sticks to the white petals if it falls on them.; This spoils the appearance of the flowers and their commercial value. The anthers of the flowers of the peculiar X-rayed bulbs do not burst at all, but wither unopened as the flowers age. Thus the petals are saved from spotting by the pollen, -which is never liberated. These lilies with non-open-ing anthers appear to be a permanent strain, as plants have been bred from them through several generations whicn steadily retain the peculiar character. The company has applied for a patenL for the cultivation of this lily. VIOLIN TONE. The Proceedings of the Royal Institution contain a paper by Major C. E. S. Phillips on the problems of the tone of violins. He has found a violin made of copper which emits sounds of pleasant woody quality. In spite of much research the secrets of Stradivari remain undiscovered. It is thought that the size of the molecules in the varnish may be of importance. It is particularly difficult to get any varnish to enter the surface of the wood, and this properly was possessed by the early Cremona varnish. Modern research on the physics of solutions has strengthened the opinion that the mode of application is of great importance and that the atmosphere of Italy helps to give the best results. The ■ penetration of the varnish binds the top cells of the wood together. This provides a plate that vibrates as a whole. There is a possibility that investigation by ultraviolet rays may settle whether Stradivari used an oil or a spirit varnish. The sounds of Stradivari violins are being analysed with cathode-ray oscillographs, and it is hoped that the comparison of the structure of their sounds with those of other violins may provide instructive information. The excellence of Italian violins is due to more than one circumstance. In 1820 it was noted that guts from thin sheep were tougher than those from fat sheep and that Italian sheep-gut was particularly good because of the condition of the sheep in that country. DRIED COCKROACHES. The influence of humidity iand wind m animals and insects is probably of arofound importance, but little is tnown about it. Everyone is aware of he alleged connection between comnon colds and draughts, but it has not Deen adequately investigated. In the toological department at Cambridge University a wind-tunnel has been constructed for the study of the effect of .vind on animals. It is about twenty !eet over all, and of the sort introduced 3y physicists for the investigation of he properties of aeroplane models. Chis application of the products of the echnique of modern aviation to zooogical problems is interesting. The unnel has been constructed and operated by J; A. Ramsay. The wind is made )y a propeller driven by a half-horse-sower motor. Experiments are made vith animals and insects in a constricion in the wind channel about 15in ong. Hitherto, in experiments on aninals, the movements of the air around hem have not been accurately known. Jut in the tunnel the movements of he air are accurately known. Some ixperiments on the rate of evaporation -f water from cockroaches have aleady been made. It has been found hat the evaporation from the tracheal which corresponds to the breathing) ystem of a cockroach was increased even times when the speed of the wind ;as increased from four to twenty netres per second, and from the body >y 30 per cent. The evaporation when he insect is placed across the wind is ibout twice" the evaporation when )laced head on. > Ramsay has discovered that the cock•oach's body is covered with a fat that ippears to melt at 86deg F. Above that emperature evaporation is much ;reater. At lower temperatures the-fat orms a film over water and hinders its vaporation. Further discoveries in his direction may lead to new methods f controlling insects and vermin.