Plintoiiraplilf Hesearchen ami Port rait nrr 311 



is a very important point in the case of" reduction to an exact size. Oalton's 

 papers sliow a lartfe numhei- ot" attempts at its solution. He ultimately 

 sonjfht the aid of Mr (now Sir) Iloi-aco Darwin, who in 1878 puhlished in 

 Nature' a sati.sfiictory theoretical H<)lution i)y aid of a douhle Peauceilier's 

 'Cell. Galton found, however, that the cells would have to be of unwieldy 

 size, if th(vso arruiiu[«'nK>ntH were used. I am not aware that the problem 

 has even yet been Holved practicallv, altliough for scientific photo<;ra|>hy its 

 solution is very important. 



(C) Analylicdl J'/ioliMfniphi/. 



At the .stmie time that fialton was working out his idea of composite 

 portraiture a new problem occurred to him, that of creating what he termed 

 a "transformer" which would transform the type into any individual com- 

 ponent. The transformer would thus be a measure of the difference I)etweea 

 individual and type, or indeed between any two individual.s. He projx)sed 

 by this method to analyse the differences between type.s (or races), between 

 individualH (or l)etween an individual and his family type), or l)etween an 

 l^_ individual on different occa.sions. (lalton termed the production and study 

 l^p of transformers Anali/tical Phntocjraphy. The idea appears first to have 

 occurred to him in 1881; but not till 1900 did he write a letter, which ap- 

 peared in Ntiturc'-, August 2, on the subject, stating the outlines of the 

 process, and speaking somewhat doubtfully of his own power of carrying it 

 out. In this letter, after describing the theory' and something of the 

 technique, he writes: 



" I photographwl two faces, each in two expressions, the one glum antl the other smiling 

 broadly. 1 could turn the glum face into the? smiling one, or vice versd, by means of the 

 suitable transformer; but tiie transformers were ghastly to look at, and did not at all give the 

 impre.ssion of a detached smile or of a detached glumness." 



Later Galton realised that transformers were hieroglyphicswhich required 

 a key to their interpretiition; the photograph of a "smile" is really the 

 photograph of facial modifications which failing the stable basis of the face 

 we do not recognise as a smile at all. I owe to Mr Egon S. Peai-son the 

 photogruplis on p. '?>V1. A is the normal, B the smiling suoject. C and D are 

 the transformers. D is the "glumness" and C the "photograph of a smile." 

 All that can be said of the latter is that it does not closely correspond with 

 John Tenniel's conception of the grin which remained some time afler the 

 rest of the t'heshire cat had vanished\ 



' Vol. xvni, p. 383. « Vol. Lxn, p. 320. 



 If a; be the transformer, Galton lays down two equations 



(i) pos. a + neg. a = grey, and (ii) pos. a ■*■ x = pos. 6, 

 whence he deduces 



(iii) jH)8. a + [pos. b + iieg, a\ = pos. b + grey, (iv) pos. b + \po». a + neg. b\ = pos. a + grey. 



Thus the quantities in curled brackets are the transfomiers, one the negative of the other 

 (the "sn\ile" and the "glumness"). 



* Alice's Adventures in Wonderland, Edn. 1872, p. 93. 



