68 



KNOWLEDGE. 



[Mabch 1, 1901. 



right hand being on a table, the downward slope of the 

 ridges forming the looj) is from the thumb towards the 

 little finger, the slope is said to be ulnar, on account of 

 running towards the ulna, or larger bone of the fore-arm. 

 In the right hand of individual A (see figures) all 

 the slopes are ulnar. When the loops in the right hand 

 take the opposite direction, that is to say when they 

 incline from the little finger towards the thumb, they 

 arc said to be radial, on account of pointing towards the 

 radius, or smaller bone of the fore-arm. It will be obvious 

 that the direction of ulnar and radial slopes will be the 

 reverse in the left hand of what it is in the right ; 

 consequently all the loops in the left hand of individual 

 A will likewise be ulnar. Hence the individual in 

 question shows no radial loop at all. 



In the formula adopted for the division of finger-prints 

 into primary groups, all loops, whatever their direction 

 (as well as arches), are indicated by the letter L. The 

 digits are then taken in pairs as follows, viz. ; — 



Right, tluimb. 



Eiglit middle. 



Right littk'. 



Kight index. Hight ring. Left thumb. 



Left iudex. Left riug. 



Lrft middle. ~ T:.eft little. 

 And the letter L or W substituted for the names of the 

 fingers themselves, according as their respective impres- 

 sions show loops or whorls. Following this arrange- 

 ment, the formula of the finger-prints made by individual 

 A will be 



L L L W L, 



L 1, h h ~ V 



In individual B, on the contrary, the formula will be 

 AV WW \V W 



W W w ■ W W 



Tlii.s, however, does not help much in making a workable 

 scheme of classification, and the following plan has con- 

 sequently been proposed. Whenever a whorl (W) occurs 

 in the first of the five pairs, it is allowed to cx)unt as 

 16; if it occurs in the second pair its value is 8 ; if 

 in the third pair 4, if in the fourth 2, and if in the 

 fifth 1. Consequently the numerical value of individual 

 A will be 



£_ — __£ -—"-.^ 



U ' ~ 0' 



while that of individual B will work out as 



10 8__4_£_1. 31 



Itj " 8 ~" 4 ~ 2" "■ 1 " 31' 



To each value thus attaiued - is added, and the fraction* 

 being inverted, what is known as the primary classification 

 number is obtained. Accordingly, in individual A we have 

 ^ -I- ^ = ^, and by inversion — - ; while in B we have 

 31 i _ ^ 



31 + 1 ~ 32' 



It will be obvious that individual B presents the 

 highest possible formula, every one of the digits exhibit- 

 ing a whorl. Individual A, on the contrary, displays 

 very nearly the lowest possible formiila, which would 

 occur when there were loops in every digit, in which case 



.IX- 1 111" 1 1 



the tormula would he -|- . = ,-• 



Consequently all possible combinations of loops and 

 whorls may be indicated by formulse varying in value 



i 32 



between a minimum of and a inaximum of ^■ 



1 32 



* Although, of course, not really a fraction, it; is sometimes con- 

 venient to Kpeali of tlip value as sueli. 



But in the first pair of digits the number of combina- 

 tions of loops and whorls that it is possible to have 

 are four, that is to say we may have any one of the 



following four values, viz : ^, "7^, ^, or -— • And 



L \\ L W 



since (to paraphrase from Mr. Henry's book on finger- 

 ]3rints) the same numLer of combinations occur in 

 the second pair of digits, and as each of these may be 

 combined with each and every arrangement obtain- 

 ing in the first pair, the total number of possible com- 

 binations in these two is sixteen. But the third pair of 

 digits has likewise four possible arrangements, which, 

 taken with those of the first and second pairs, raise the 

 number to 64. By adding the combinations to tiie 

 fourth pair, the number rises to 2256, and with the 

 inclusion of the fifth pair to 1024, which is the square of 

 32. Consequently a square cabinet containing 32 tiers 

 of 32 compartments each will suflice for the accommo- 

 dation of all the groups into which finger-prints are 

 divisible according to the primary classification. 



But it is obvious that there may be a very large 

 number of individuals in whom the patterns on the 



1 32 



fingers are expressed by the formula -, or 7^-, ; and as a 



matter of fact the largest accumulations do occur in the 



case where there are either all loops (r) or all whorls (.-,^)- 



Consequently sub-divisions of these great groups are 

 essential. And a secondary classification has been in- 

 vented, depending, in the case of the lower values, on 

 the occurrence of arches or in the direction of the loops 

 in certain digits, or, in the case of the higher values, 

 on the manner in which the individual lines are arranged 

 in the whorls or composites. To enter in detail into 

 this secondary classification would be quite out of place, 

 and those who would study the subject seriously must 

 consult Mr. Heruy's book. 



In the lower values attention is paid to the circum- 

 stance whether the index fingers show an arch, a radial, 

 or an ulnar loop, or, when they have a whorl, as to the 

 arrangement of the central lines. In cases where whorls 



are absent, and the formula is consequently -, both index 



. 1 A 



fingers may show an arch, when the formula wiU be - , -, 



or a radial loop, when it will be -, :^, or an ulnar loop, 



1 Ti, 



when it will be expressed as -, =. And there may, of 



1 A 

 course, be any combinations of these, such as j, ^. In 



the individual indicated as A, in the figure, whose primary 



formula is 7,, it will be seen that the right index has an 



o 



ulnar slope ; while in what are known as the deltas of the 

 whorl in the left index, a certain line takes a course 

 external to another, and is consequently_classed as outer, 

 with the symbol 0. The full classification formula of 



individual A will therefore be -^ — ^, 



Turning to individual B, the characteristic delta-line in 

 the right index is internal, while in the left index it is 



external or outer, this being indicated by tlie symbol ^. 



Again, in the right middle finger the distinctive delta-line 

 is internal, while in the corresponding digit of the left 



hand it is median in position, this being expressed as =r^. 

 Consequently the coiniilete classification number for in- 

 dividual B will be g| - q',^-' 



It will thus be seen that by paying attention to minute 

 liolnts, the larger aocnnuilations of sheets may bo broken 



