Science of the Day

New Zealand Herald, Volume LXIX, Issue 21332, 5 November 1932, Page 7 (Supplement)

Science of the Day

PREDICTING EARTHQUAKES MACHINE IN AMERICA A machine which may solve tho problem of predicting earthquakes in time to warn persons in affected areas of their peril has been invented by George E. Merritt, of the United Stales Bureau of Standards, in Washington. It is known as a tilt meter, and it resulted from a discovery made several years ago by Japanese scientists. A short time before tho earthquake occurs, it Was announced, a tilt takes place in the earth's crust. This suggested to Merritt the possibility of developing a machino which would record slight tilting of the earth's crust says Popular Science. Ho devised his tiltmeler. Embedded in the earth at the bottom of a pit or well are two parallel reflecting surfaces, a quartz plato, and a tray of oil resting upon it. They reflect a ray of light to an operator above who watches through a special device. Any tilting of the earth's crust throws the two reflected beams out of alignment and produces an effect known as " interference fringes" by which tho angle of tilt can be measured with the optical instrument through which tho operator is looking. Tho new apparatus is said to be so sensitive that it will measure any change that takes place in tho earth's crust within the space of one-tenth of a second. SCIENCE IN TRAFFIC CONTROL Traffic control by invisible rays may one day be adopted in Paris in order to render driving by night less dangerous. The idea is being considorod by M. Berthier, tho traffic director. He says 110 believes that practical use might be made of the varying elcctical resistance of selenium in light and in darkness. This would bo done by placing a lamp giving forth infra-red rays—which art now visible to tho naked eyo—oll ono pavement, while 011 tlie opposite sido of the road near a corner would bo fixed a selenium cell controlling red and green lamps. Normally the green lamp would bo alight. But when a motorist approached tho crossj roads his car would momentarily block out the infra-red iays focussed 011 the selenium cell, and tho red lamp would be lighted for a few seconds. If another motorist were approaching along one of the sido roads, lie would see that the signal was against him, and slow down. It is pointed out that this method, if it proved practicable, would b<? simpler and less costly than the method of sinking a bar controlling the signal lamps in the roadway near cross-roads. SOUNDS PRODUCED BY ICE A woman bought an ice-cream block from a street vendor. She noticed that when he placed ice against his bicycle bell, the bell rang. In such a way are scientific discoveries made. Tho woman w - as Miss Mary D. Waller, lecturer in physics at tho London School of Medicine for Women. Before the British Association at York, Miss Waller demonstrated that a solid block of carbon dioxide, which had a temperature of 0.8 centigrade, when placed against metal instruments could pioduce a number of musical and, in some cases, unmusical sounds. Carbon dioxide is used in the artificial prepare tion of ice. The explanation of the phenr rnenon, Miss Waller said, appeared to be that the forces of energy causing the vibrations were produced by tho heat of the metal coming into contact with tho carbon dioxide. Steel, brass and silver were tho most satisfactory for producing musical sounds. ELECTRIC EYE WITH MEMORY An electric eyo which not only sees but remembers lias been invented by Dr. i'. Dussatid, a French scientist, accorda re P°rt submitted to the Academy of science, in Paris. Tho apparatus, it is claimed, combines tho actions of a camera with those of a kinematographic projector but without the use of plates or films. Scenes, either moving or still, are recorded by a televisual camera as electric waves of varying intensity. When the process is reversed the waves become a picture which can be thrown upon a television screen. According to Professor Alfred Lacroix, Permanent Secretary of the Academy of Science, the sights ''seen" by the machine are stored inside in the form of elect r'c currents for any length of time, and only become pictures again when the waves are communicated to a screen.