Finger Prints by Francis Galton : image 0172

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FINGER PRINTS CHAP.

It may be that every one of the 42 x 38, or one hundred and five thousand possible varieties of index-headings, according to the " i-o fore-finger method, may occur in Nature, but there is much probability that some of them may be so rare that instances of no entry under certain heads would appear in the register, even of an enormous number of persons.

Hitherto we have supposed that prints of the ten fingers have in each case been indexed. The question now to be considered is the gain through dealing in each case with all ten digits, instead of following the easier practice of regarding only a few of them. The following table, drawn up from the hundred cases by the " all slopes " method, "will show its amount.

TABLE XIV. From 100 Sets.

		No. of different index-headings.
Digits.	No. of digits.	All slopes.	i and o fore-finger.	No slope.
Fore and middle of right hand	2	11	8	7
Fore, middle and ring of right hand	3	23	16	14
Fore, middle and ring of both hands	6	65	50	45
All ten digits	10	83	76	73

The trouble of printing, reading off, and indexing the ten digits, is practically twice that of dealing with the six fingers ; namely, three on each of the

OCR Rendition - approximate