Sir Francis Galton. 



xv 



alike, and that the patterns are susceptible of arrangement according to types 

 and classes in such a way as to render it possible to construct a dictionary of 

 finger-prints, whence an individual who has left a mark may be surely 

 identified. All this he did, and the method is now in successful use in the 

 criminal departments of every civilised country. 



It is due to Galton, far more than to any other man, that many attributes 

 of man, which at first sight appear only susceptible of qualitative estima- 

 tion, have been made reducible to exact measurement. Some people have 

 thought that some of his ideas were elaborate jokes, and, indeed, he himself 

 enjoyed the humorous side of his attempts as much as anyone. But such 

 a view would be quite erroneous, for it will be perceived on closer scrutiny 

 that he was always trying — and generally successfully — to measure some- 

 thing which might, perhaps, be regarded as beyond the scope of an 

 exact estimate. Measurement is the soul of science, and he was thus 

 carrying the accuracy of scientific investigation into new fields. Thus he 

 made a beauty-map of England and Scotland, showing the geographical 

 distribution of good looks in the population, and he devised the method of 

 composite photographs, in which each member of a group of persons made an 

 equal impress on the resulting portrait. In this way family or other 

 resemblances were given concrete shapes. He tried also to register the 

 individualities of faces, while annulling their common features, but the 

 attempt did not lead to any intelligible conclusions and was a failure. 



Galton also made important and very original contributions to Psychology. 

 It was thought by earlier investigators that if they could discover by 

 introspection how their own minds worked, they would have solved the 

 general problem of the working of the human intellect. But Galton 

 showed that different minds work in different ways, and, for example, 

 that visual images play a large part with many people, but not so with 

 others. In this connection he investigated the pictures of scenes recalled in 

 memory, as to illumination, definition, colouring, and as to other peculiarities. 

 Akin to this was an inquiry into visions seen by the sane, which he found 

 to be much more frequent and realistic than is generally supposed to be the 

 case. A curious example, of a somewhat analogous character, is afforded by 

 the visual patterns or pictures associated in many minds with numbers. He 

 also experimented on the senses of taste and smell, on the power of accurately 

 estimating weight by the muscular sense, on the judgment of experts in 

 guessing the weights of cattle, and on other such matters too numerous to 

 mention. This mere catalogue of highly original investigations, and the fact 

 that he was the first man in England to make psychometric experiments 

 and to publish the results, show that Galton deserves a high rank amongst 

 experimental psychologists, and yet his investigations were merely collateral 

 to the main line of his work. 



When in 1859 the ' Origin of Species ' was published by his cousin, 

 Charles Darwin, Galton became at once a convert, and began to reflect 

 deeply on the problems of inheritance, especially as applicable to the human 



VOL. LXXXIV. — B. b 



