164 Life and Letters of Francis Galton 



These are represented in the following diagram: 



wsv 



Bw 



WBV 



Fig. 22. Classifying by nature of Ridges from Deltas. 



We can, perhaps, improve somewhat Galton's indexing in the following 

 manner*. Consider the digits taken in order from little finger of left hand to 

 little finger of right (as the hands are placed palms downward on the knees) 

 to occupy the places from first to last of a ten-figure number, e.g. 32881,56490, 

 then this would be interpreted as me/ming that the little finger of the left 

 hand was SV— BW, the ring finger SW— BV, the pointer and the forefinger 

 WSV-BW and the thumb WSV- WBV; the thumb of the right hand 

 would be WSV — BV, and so on down to the little finger of the right which 

 would be an arch. Thus a thousand million variations would be possible, and 

 every individual would have his own ten-figure index number, which could be 



Fig. 23. " Outlining" a rolled pattern. 



recorded in numerical order in the index. The question, however, of how 

 many of these would be "repeats" remains to be considered. Galton shows 

 how, after outlining the pattern, it is fairly easy to classify a great variety of 

 patterns according to his scheme (see his Fig. 9, p. 7, which contains forty 



* Galton later drops without comment his classification of prints from the contours of the 

 cores. He nowhere states why. Probably he found it not adequately discriminative for large 

 numbers, or perhaps he discovered the personal equation involved in drawing contours. 



