DISCOVERY 



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done at the universities in Great Britain and through- 

 out the Empire. Pleas for a wider study of geography 

 and physiology and for bringing these sciences more 

 into touch with national life were made by Dr. D. G. 

 Hogarth and Sir Walter Fletcher respectively. 



Below are given resumes of some of the sectional 

 addresses and discussions likely to be of interest to 

 readers. 



THE AGE OF THE E.\RTH 



There are three main points of view : the physical, the 

 astronomical, and the geological. In Victorian days Lord 

 Kelvin startled the world by calculating that the greatest 

 time for which the earth could have been habitable was 

 twenty million years. He based this theory on two ideas : 

 (i) that the earth was losing its primitive heat, like a 

 hot loaf taken from the oven, at a rate which could be 

 calculated, and (2) that the heat radiated by the sun was 

 due to energy produced by its contraction. 



Lord Rayleigh, who opened the discussion, pointed out 

 that present-day knowledge of physics extended the period 

 of life on the globe to 1,000 million years, and that the 

 total age of the earth was probably a few times this 

 amoimt. The earth was not cooling like a hot loaf. It 

 had a supply of heat of its own within it, namely that 

 emitted continuously, spontaneously, and apparently 

 always at the same rate, by the radio-active elements 

 (uranium, thorium, radium, etc.). It was fortunately 

 possible to calculate the age of the rocks which contained 

 these elements, and the Eocene rocks were estimated to 

 be about 30 milUon years old, and the oldest known 

 rocks 952 million years ! 



Professor Sollas put forward the geological view. Geolo- 

 gists considered Lord Kelvin's estimate much too low, 

 Lord Rayleigh's much too high. He pointed out that if 

 radio-active bodies originaUj- emitted energy more rapidly 

 than they now do — and there is some evidence of this — 

 Lord Rayleigh's might be reduced. Professor Gregory 

 pointed out that the geological estimate was based on the 

 time required for the deposition of geological formations. 

 The rate at which this went on was assumed to be uniform, 

 but probably periods of slow and quick denudation had 

 occurred in consequence of deformations of the earth, and 

 allowance for these would bring the geological estimate 

 nearer Lord Rayleigh's. Professor Eddington said that 

 present-day astronomy was against Kelvin's time-limit, 

 also against his attributing the sun's heat to its con- 

 traction. 



PROBLEMS OF PHYSICS 



Prof. O. \V. Richardson's address considered the present 

 state of some of the important problems of physics : the 

 theory of Relativity, the quantum theory, the structure 

 of the atoin, the emission of ions from incandescent 

 bodies, the close connection between the phenomena of 

 light and of X-rays. It was, for the most part, extremely 

 technical. Artificial transformation was now an accom- 

 pUshed fact, though it had been effected so far only on an 

 extremely small scale. The transformed element was not 

 merely changed into others, but the energj' liberated when 

 this occurred was greater than that necessary to initiate the 



process. This energy was very small, but it was enormous 

 in comparison with the quantity of matter involved. 

 A start had been made ; if these effects could be intensified 

 and yet be kept under control, an almost illimitable 

 supply of energy was at man's disposal. It was yet too 

 early to say whether or not the conditions for producing 

 this energy on a large scale under control could be realised 

 in practice. Time would tell. We might be at the 

 beginning of a new age which would be referred to as 

 the age of sub-atomic power. 



Professor A. S. Eddington gave an illuminating account 

 of Relativity, mentioning that the theory made the ether 

 an idle hypothesis unsupported by experiment and giving 

 explanations of nothing. Sir Oliver Lodge said that 

 an exponent of relativity was so immersed in this subject 

 that he thought it self-evident. He was like the cricketer 

 who, being asked to explain a yorker, replied that it was 

 just a " yorker." Sir Oliver was not prepared to abandon 

 the ether. 



VOCATIONAL TRAINING AND TESTS 

 Members of the Sections for Psychology, Education, and 

 Economics took part. Dr. C. W. Kimmins opened the 

 discussion. Psychology was permeating everything and 

 becoming embarrassingly popular. Intelligence tests 

 were being used in connection with the admission of 

 defective children into special schools. London, \vith 

 800.000 children and 20,000 teachers under one authority, 

 was the finest field in the world for research on this subject. 

 In the old days backward children were sent to special 

 schools without the cause of their back\vardness being 

 considered. Now they could tell by intelligence tests 

 whether or not a child had abiUty apart from the knowledge 

 he had gained. These tests had also been of assistance in 

 transferring pupils to the classes in schools which really 

 suited their abiUties. In some cases unlikely pupils in the 

 wrong classes had on transference blossomed into scholar- 

 ship winners. As regards vocational tests, a recent investi- 

 gation of his into the after-employment of children in the 

 London area had revealed a tragic state of things. Large 

 numbers of children started work in jobs that were unsuit- 

 able to them, and later drifted from one position to another. 

 There were too many misfits ; boys of promise became 

 van-boys ! The money that we were spending on educa- 

 tion would be thrown away unless greater attention were 

 paid to fitting the right boy, as far as it was possible, into 

 the right job. 



Dr. C. S. Myers said that a child was badly educated 

 unless he showed special interests or abiUties of some kind. 

 A choice of occupation must be made by the boy himself, 

 and he should not be bullied out of it. But naturally 

 information about different occupations must be given him. 

 There should be cinematograph films showing the responsi- 

 bilities, prospects, advantages, and dangers of various 

 occupations. Neither parent nor teacher could give 

 adequate advice on occupations, because they knew Uttle 

 of industrial requirements. Expert advice and the 

 teacher's co-operation were necessary. 



Subsequent speakers talked much of the misery and 

 unhappiness arising from mistaken choice of occupation — 



