1891.] Method of indexing Finger-Marks. 541 



mitting them to be taken, which can be founded either upon personal 

 vanity or upon an unwillingness to communicate undesirable family 

 peculiarities. 



Without caring to dwell on many of my earlier failures to index 

 the finger prints in a satisfactory way, my description shall be con- 

 fined to that which has proved to be a success. It is based on a 

 small variety of conspicuous differences of pattern in each of many 

 digits, and not upon the numerous minute peculiarities of a single 

 digit. My conclusions are principally based on a study of the im- 

 pressions of all ten digits of 289 different persons, but the tables 

 about to be given refer only to the first 100 on my list. These 

 are sufficiently numerous to serve as a fair sample of what we might 

 always expect to find, while they are not too cumbrous to print and 

 to discuss in full detail. 



I described in my previous memoir the way in which the impres- 

 sions had been made that were then shown. A plate of copper was 

 blackened with printer's ink, the ink being of a rather fluid cha- 

 racter, and spread very thinly and evenly over its surface by a 

 printer's roller. The thumb, which was then the subject of discussion, 

 was pressed and slightly rolled on the inked plate, and afterwards on 

 the paper. In the present collection of all ten digits, four operations 

 were used in each case. First the four fingers of one hand were 

 simultaneously printed from, and then its thumb in the way above 

 described ; afterwards, the other hand was treated in the same way. 



Though I have spoken and shall speak only of impressions, it is 

 not really necessary for the purpose of compiling an index to make 

 any impression at all. The entries that are wanted for the index can 

 be derived directly from the fingers themselves. 



I rely, for the purpose of indexing, on the three elementary divi- 

 sions of primaries, whorls, and loops. They are severally expressed 

 by the numerals 1 and 2, 3 and 4, 5 and 6. The reason of this 

 double numeration is that most of the patterns have a definite axis. 

 Those that are formed by ridges which proceed from only one side 

 of the finger, will necessarily lie in a sloping direction across its 

 axis pointing to the one side or the other according to that from 

 which the supply of ridges proceeds. The only patterns that are 

 symmetrically disposed about a vertical axis are 6 and to a lesser 

 degree a, c, h, and i in fig. 1. Usually, and, as we may say, normally, 

 the slope of the axis of the pattern is (roughly) parallel to a line 

 drawn from a tip of the forefinger to the base of the little finger. 

 All normal slopes, as well as all the patterns that have no definite 

 axis, are expressed by the odd numerals 1, 3, or 5. All abnormal 

 slopes are expressed by the even numerals 2, 4, or 6. It cannot be 

 too strongly insisted that the words right and left are ambiguous and 

 should not be used here. 



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