NEW TEST FOR OILS

Evening Post, Volume CXXI, Issue 115, 16 May 1936, Page 30

NEW TEST FOR OILS

A STREAM OP ELECTRONS

One of the hardest questions to answer has been why two oils almost identical in density, viscosity, and other common physical properties, may differ widely in their lubricating qualities. One cannot tell by any simple, physical test, in advance, of actual use of the oils, which one will be the better lubricant. t Chemists 'have discovered that the molecule of a good lubricant' consists of a long chain of atoms, so that "the molecule has the form of a long, slender filament, states "Science Service." -These molecules stand on end

on . a metallic surface, one end adher-1 ing firmly to the surface. 'In this way they, pack, very closely together, and pressure between two surfaces' cannot squeeze thenvout. V A second layer of oil molecules stands on top-of the*first.;layer,:.anotheron that, and so on; Two- metallic surfaces thus , r ride on ,velvety cushions and- slide easily on each other. The longer the filaments, and the .more regularly and closely packed they are, the better is the lubricant., These facts have been disclosed by the use of X-rays. , A new mode of testing has been applied by Dr. C. A. ; Murison and is reported in the "London. Philosophical Magazine." Dr. Murison directs. a stream of electrons at a glancing angle at a film of oil and studies the diffraction pattern produced by the reflected electrons.- 'From this he can tell at once • the lubricating qualities of the oil. He found for one thing that oils of high molecular weight are. superior. Electron diffraction was discovered by'Drs. C. J. Davison and L. H. Germer, of the Bell Telephone Laboratories in 1927 .and demonstrated the wave properties of electrons predicted by Due Louis Be Brbglie and Professor E. Schrodinger. ■■.'.- . An answer is thus given to ■ those who w,ant to,- knov^ what is- the use of all- these rec6hdite:"researches. into atoms and electrons,; for <here is ■an application .of great-practical value. Doubtless many important applications will be found, as time goes-on, for the scientific knowledge now piling up rapidly. '"•• ■-•-. ■ . ■ .• Sudden stops and' the, accidents which they, of ten cause can generally be avoided by keeping a safe distance from the car'ahead. It is also wise to avoid speeds which may require a sudden application of the brakes.