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after he had collected his facts, which spoke for themselves so far as to reveal 

 plainly the essential features of the phenomenon in question. 



Modern discoveries (on the preceding page of the ' B. of P.') have not 

 been made by large collections of facts, with subsequent discussion, separa- 

 tion, and resulting deduction of a truth thus rendered perceptible. 



To this I venture to oppose not only such work as that of Bradley, but much 

 in the recent history of astronomy; the discoveries about systematic proper 

 motions, about moving clusters, about the growth of velocity with life history, 

 and so forth. 



There is an attempt at induction going on, which has yielded little or no 

 fruit, the observations made in the meteorological observatories. The 

 attempt is carried on in a manner which would have caused Bacon to dance 

 for joy. . . . And what has come of it? Nothing, says M. Biot, and 

 nothing will ever come of it : the veteran mathematician and experimental 

 philosopher declares, as does Mr. Ellis, that no single branch of science has 

 ever been fruitfully explored in this way. 



De Morgan was a mathematician, and I have noticed that mathematicians are 

 apt to be crisp in their statements : but he is a bold man who says ' nothing 

 will ever come of it.' Perhaps an equally crisp statement on the other side may 

 be pardoned. I adventure the remark that if nothing has hitherto come of such 

 observations, it is because observers have been misled by the very teaching of 

 De Morgan and others who share his views : they have been told that they will 

 do no good without a theory until they have come to believe it; whereas the 

 truth probably lies in a quite different direction. To present my reasons for 

 this proposition I must ask you first to consider in some detail the method of 

 discussing meteorological observations suggested some years ago by Professor 

 Schuster. He gave an account of it to the Department of Cosmical Physics over 

 which he presided in 1902, so that I must face some repetition of what he said ; 

 but the matter is so important that I trust this may be pardoned. 



Let us compare the records produced on a gramophone disc by the playing 

 of a single instrument and by that of an orchestra. The first will be compara- 

 tively simple, and when suitably magnified will show a series of waves which in 

 certain parts of the record form sequences of great regularity. These represent 

 occasions when the single instrument played a long sustained note, the pitch of 

 which is indicated by the frequency of the wave. If the instrument plays more 

 loudly, while still keeping to the same note, the heights of the waves will 

 increase, though their frequency will not be altered. The exact shape of each 

 wave will represent the quality of tone which characterises the instrument : 

 and if another instrument were to play the same note it would be different. But 

 so long as we keep to the same instrument, whenever the same note recurred 

 we should find, generally speaking, the same shape of wave : and we could resolve 

 it into its constituents, one being the main wave and others harmonics of dif- 

 ferent intensities. The analysis of such a record would thus be a comparatively 

 simple matter, on which we need scarcely dwell further. Very different is the 

 case of the orchestral record. There are numerous instruments, playing notes 

 of different pitch, intensity, and character, each of which, if playing alone, 

 would produce its own peculiar record. But when they play together the re- 

 cords are all combined into one. The needle can only make one record, but it 

 is a true sum of all the individuals; for when the instrument is set to reproduce 

 the playing of the orchestra, a trained ear can perceive the playing of the 

 separate instruments — when the strings are playing alone, and when the wind 

 joins them : when the horn comes in and whether there are two players or only 

 one : nay, even that one of the eecond violins is playing somewhat flat ! This 

 could not happen unless the individual performances were essentially and truly 

 existent in the combined record ; and yet this consists of only one single wavy 

 line. The waves are, however, now of great complexity, and it seems at first 

 sight hopeless to analyse them. The mathematician knows, however, that such 

 analysis is possible, and is quite simple in conception, though it may be laborious 

 in execution. Selecting a note of any given pitch, a simple calculation devised 

 by Fourier will reveal when and how loudly that particular note was being 



