PHOTOGRAPHIC RESEARCHES AND PORTRAITURE
"Whatever he touched he was sure to draw from it something that it had never before yielded, and he was wholly free from that familiarity which comes to the professed student in every branch of science, and blinds the mental eye to the significance of things which are overlooked because always in view." Nature on CHARLES DARWIN, Vol. xxvi, p. 147.
WE have seen in the preceding chapter how Galton supposed composite portraiture to be connected fundamentally with psychological inquiry. Galton developed composite photography in his search for a method of ascertaining whether physiognomy is an index to mind, i.e. whether facial characteristics are correlated with mental traits. The actual method he employed, however, was curiously enough suggested to him as a result of his attempts to illustrate the multiple geographical features of a country, where he wanted more than could be readily exhibited on the usual type of maps. Galton's own idea of composite portraiture would fully justify our discussing it under the beading _of "Psychometric Investigations." But as Galton's contributions to scientific photography are numerous and important, it has seemed to me desirable to devote an entire chapter to the subject, although much that will be contained in this chapter has great psychometric interest.
Galton's contributions to photographic science break up into six sections, namely
(A) Composite Photography. .
(B) Bi-projections by Photography.
(C) Analytical Photography.
(D) Measurements by Photography.
(E) Indexing and Numeralisation of Portraits.
(F) Measurements of Resemblance, chiefly by photographs.
We shall also include in this chapter, as closely related to our present topics, the subjects of the indexing of portraits and the telegraphy of portraits. The matters to be discussed occupied Galton's mind almost continuously from 1878 to 1911, i.e. more than thirty years. They had singular fascination far him not only because they combined fairly simple mathematical investigation with mechanical invention( and experiment, but also because they were closely associated with psychological and hereditary inquiries.
(A) Composite Photography.
There is a paper on combining various data in maps which explains the origin of Galton's inquiries into composite photography. As he himself says in a paper of 1878
" It was while endeavouring to elicit the principal criminal types by methods of optical 36-2