SCIENCE. 



FRIDAY, MAY 8, 1885. 



COMMENT AND CRITICISM. 

 In all branches of science where the ob- 

 server deals with the forms of objects, it is 

 more or less desirable that an average of the 

 shapes of the objects should be attained. This 

 end has hitherto been sought through a system 

 of measurements, which is at best a clumsy 

 method, suited only to determine the average 

 of some single dimension ; for, where it is the 

 aim to present to the eye a normal or typical 

 form, it is quite incompetent to serve the desired 

 end. So far the beautiful method of composite 

 photography devised by Francis Galton has 

 only been applied to the human face, with the 

 single exception of Dr. Billings's experiments 

 in craniology : if it can be carried into no other 

 fields, it will still remain one of the most im- 

 portant contributions to the graphic resources 

 of science. But the naturalist who has felt 

 the need of this resource in various directions 

 is drawn to consider how far its use may be 

 extended to other branches of inquiry. It 

 seems at first sight that there may be use for 

 it in obtaining the normal or average form of 

 all objects which do not depart too far from a 

 mean shape. It may be that the zoologist or 

 botanist who wishes to present a picture giving 

 the normal aspect of a variable species, can, 

 by selecting for delineation individuals of the 

 same size, present to the eye a composite 

 combining the general features, and neglecting 

 the individual variations. In this wa} T we shall 

 be able to give to the term ' normal form ' a 

 definite and valuable meaning which has 

 hitherto been wanting. It will also be re- 

 membered that the late Professor Agassiz 

 laid particular stress on form as the under- 

 lying element of ' family ' structure among 

 animals ; and this would seem to offer an 

 opportunity to test experimentally the view 

 held by the great naturalist. 



No. 118 — 1885. 



It may also be hoped, that, in certain lines 

 of inquiry in the inorganic world, this method 

 of graphic averaging, this Galtonizing process, 

 if we ma} T so term it, will be of great use. 

 Yet, important as are the prospects for the 

 extension of this method of delineation to other 

 fields of inquiry, its greatest use must be in 

 the study of the human bod}-. There this 

 admirable process is full of promise. It ma}', 

 for instance, be possible to secure an average 

 picture of our school-children at different ages, 

 which will give us a new measure of Iheir con- 

 dition, and so help us in what is perhaps the 

 most important branch of social inquiiy. The 

 effect of occupations, and the results of dif- 

 ferent methods of physical culture, can also be 

 accurately compared. It may be serviceable 

 in testing the action of different sj'stems of 

 training on young soldiers, as also the influence 

 of their accoutrements on the form of the bod}\ 

 So, too, the effects of certain diseases on the 

 bodily form may be ascertained, to the great 

 gain of medical science. Indeed, the possi- 

 bilities of this method crowd on the mind. 

 Practice ma} T show limits to its use, and will 

 doubtless do much to overcome certain diffi- 

 culties evident at the outset of the work. 



The charming composite photographs for 

 which we are to-day indebted to Professor 

 Pumpelfy show the admirable results which 

 may be obtained, and at the same time some 

 of the critical difficulties of the process. Xo 

 one can look upon them without a new respect 

 for that shadow}' thing called the normal man. 

 There is a singular dignity in these combined 

 shadows : they are strong faces, those of high- 

 browed, deep-eyed, earnest-looking men, fit 

 for all sorts of trials. But most of those who 

 review the faces of American men of science 

 will recognize that in figs. 2 and 3 one face 

 appears, curiously, to dominate all the others, 

 yet which, taken by itself, is perhaps the most 



