380 Life and Letters of Francis Galton 



Vacations to special "ethuical islands" in Ireland in the hope of unravelling 

 "the tangled skein of the so-called ' Irish Ilace.' " The peripatetic princijile 

 of Galton was again adopted by Gray and Tocher in their Scottish surveys. 

 If the people wul not come to you, you must go to the people, and stand 

 beside the itinerant dentist and the cheapjacK in the market-|)lace and 

 measure their crowds. 



Looking back on those yeam dining which the Antliropometric Laboratory 

 existed we ask what definitely was achieved? Well, (i) An immense amount 

 of material wjis collected, which only forty years later is being ade<juately 

 reduced, (ii) From small portions of it Gralton deduced the foundations of 

 the correlational calculus. Here Galton evolved an entirely new princi])le 

 described in his paper of 1889, yet to be placed before the rejuler. This was 

 in itself a very big achievement, much bigger in the light of what has 

 followed than it might have appeared to casual observers of that day. It 

 reduced 



"all furms of correlation, including herwlitary qimlitica, to one simple law, namely that of the 

 relation between two variables partly dependent on a common set of influences." 



(iii) It led to laws of growth and development whose study had hitherto 

 been impossible, and it enabled investigators to take account of social status 

 and of occupations, (iv) The limitations of such systems of pereonal identi- 

 Hcation as that of Bertillon became apparent and this prepared the way for 

 Galton's finger-print system combining indexing with identification, (v) It 

 provided material by which many interesting problems could be solved, such 

 as diunial changes in measurement, fallibility of the measurer, and the limits 

 of change after adult age in various anthropometric " constants." 



Lastly the Laboratory gave a most vigorous push to anthropology; it 

 indicated what might be achieved by anthropometry taken seriously and 

 the impetus is yet far from exhausted. There are still anthropologists who 

 believe that great racial problems can be solved by juggling with a few 

 cephalic indices. They do not recognise that a human being is a vast con- 

 geries of faculties, and that only certain of these are highly correlated. Others 

 are practically independent and are largely modified by intermixture in each 

 new generation. It is wholly impossible to define an individual, still less a 

 race or associated group of individuals, on the basis of a single character. It 

 requires a great many measurements to describe with moderate accuracy an 

 individual, and quite as many to characterise, or provide the type of, a local 

 group of men. Anthropometry whether physical, psychical or medical has 

 this end in view : the definition of Type — in particular racial type — by the 

 measurement of a fairly representative system of characters. Anthropologists 

 learnt from Galton's Anthropometric Laooratories not only the importance of 

 their task, but how to set about it. They learnt for the first time to what 

 extent characters are correlated and how to measure the degree of their asso- 

 ciation. That could only result, when the investigator learnt to deal with the 

 whole system of variations and did not occupy himself simply with the averages 

 of characters. The last quarter of the nineteenth century revolutionised 

 anthropology, and Galton was the main mover in those momentous changes. 



