3S6 SECTIONAL TRANSACTIONS.— F*, G. 



Tuesday, September 6. 



Afternoon. 

 Discussion on Fashion cycles (Chairman : Mr. Edward A. Filene) : — 



Mr. R. F. Wilson. — Colour and colour cycles. 



Historical considerations. Colour as a factor in interpretation of national 

 group-psychology. The part played by colour in religion, war, commerce, 

 etc. Similarity of human emotional responses (individual and collective) 

 to certain colours throughout the ages. Relation of cycles of colour in- 

 fluence to changes in national outlook. International reactions in uses of 

 colour. Effects of improved international communication on extent of areas 

 affected by colour cycles. Influence of aesthetic appreciation upon national 

 commerce. Influence of recent industrial-economic changes and techno- 

 logical progress upon colour cycles. Influence of personal prestige and 

 publicity upon new cycles. Effects of modern living and trading conditions 

 upon the nature of ' cycles of colour.' 



SECTION G.— ENGINEERING. 



Thursday, September 1. 



Dr. G. W. C. Kaye, O.B.E. — The suppression of noise. 



Noise is generally regarded as an attendant evil of present-day civilisation, 

 though the problem is really one of long standing. There is, however, a 

 steadily increasing volume of public opinion which is making its influence 

 felt beneficially in many directions. 



The problem of noise suppression is largely bound up with that of noise 

 measurement, and although the latter is one of some complexity, bound up 

 as it is with physiology and psychology, the physics of acoustical measure- 

 ment has made great strides in recent years owing to the exactitude and 

 facility of electrical methods. By such means, noises can be analysed into 

 spectra, and their loudness can be measured by the microphone. Alterna- 

 tively, noises can be matched aurally against some calibrated standard of 

 loudness. 



The unit of intensity now generally adopted in noise measurement is the 

 decibel, which corresponds approximately to a 25 per cent, increase in 

 energy. Such a scale of geometrical progression is a rough fit with the 

 sensation scale of loudness. The decibel has the further advantage of 

 corresponding approximately to the least change of loudness which can 

 be detected under ordinary conditions. The auditory range of loudness 

 embraces about 120 decibels. 



The best way of suppressing noise is to silence it at its source, failing 

 which a policy of isolation is likely to be more effective than one of 

 absorption. All three expedients have been resorted to, each with partial 

 success, in the modern aeroplane liner, so that in the aggregate the noise 

 heard by the passenger, which was formerly intolerable, is now but little 

 louder than he would experience in a train. 



For the study of noise and associated problems new acoustic laboratories 

 are being erected at the National Physical Laboratory. Each of the experi- 

 mental rooms is as completely isolated as possible, the massive double walls 



