SCIENCE MARVELS

Evening Post, Volume CVIII, Issue 120, 16 November 1929, Page 20

SCIENCE MARVELS

I,OQO,OOOTH OF AN INCH

One of the most interesting of the exhibits arranged by the Eoyal Society for its conversazione in London recently was the Fabry-Perot interferometer, lent by the National Physical Laboratory. By means of this apparatus measurements up to a millionth part of an inch can bo obtained with accuracy says an oversea paper. Another instrument shown was the Brown artificial, horizon, named after ,its' inventor, Mr. S. G. Brown. The principal feature of this invention is a .gyrot/pc fitted with a mirror, which, turning at the rate of 6000 revolutions a minute, remains in a horizontal position irrespective of any external movement. The instrument is specially intended for taking altitudes of. the sun at sea by sextants, or for. obtaining the true horizontal when the weather conditions- prevent the natural horizon "from being seen. ■ ■ '. Another invention which attracted much attention was the mu'tochrome, aii instrument with a wide range of uses in .decorative trades. A design, in outline, is first projected on to a screen, and then, fey means of coloured lenses in the-apparatus, each separate element in tlie pattern can' be coloured, and the colours changed at will until the desired effect is obtained,1. A modification of this instrument is contemplated for application to theatrical stage scenery! Of special interest to women was a specimen of cosmetic from a sealed jar discovered in the tomb of Tutank-1 hamen; The experts at the British Museum Laboratory have discovered the secret of the' Egyptian chemist who compounded the substance 3300 years ago. The cosmetic probably consisted of 90 per cent, natural animal fat and 10 per cent, resin or balsam.