In a possible collection of half-a-million or a million complete sets of finger-prints, can the one before me, of one Thomas Atkins, John Doe, or Richard Roe—under whatever alias—be promptly found if it is there, or, if not there, can its absence be conclusively determined? We have seen, I think, that if two such patterns are confronted, common-sense, and the use of fine measurements, will soon determine whether they be of the same original, or different. The problem, then, is to get this swift and sure confrontation effected.
This problem engaged my attention from the first, or at least not many months after I first began to attend to finger-patterns, and in 1880, when I proposed the printing and recording of the ten fingers of old criminals, I had thought out the same method now outlined in this chapter. It would be impossible to compress all the details necessary to work out the matter officially, without producing a work as large, and perhaps as expensive, as a Chinese dictionary, of which the probabilities are that one or perhaps two copies might be sold.
I laid this matter in outline before Inspector Tunbridge, in his official capacity, in 1888, and again before the War Office Committee, at which an Under-Secretary of the Home Office was present, taking diligent notes. The system now in official use—an improvement made by Sir Edward R. Henry upon Sir F. Galton’s very premature attempt (after a few years’ study in old age) seems to work practically, and therefore I have no criticism to offer, further than to suggest, that if in our system of mercantile book-keeping we had retained the use of Roman numerals, fortunes might continue to be made or lost. I cannot think, however, that our merchants would now give up the Arabic notation for the more complex and clumsy one of ancient Italy. Nor is nature likely to resume her interest in the kangaroo and its future.
Science seeks simplicity, and the Syllabic system, now familiar to every one who uses a telegraphic code, is what I proposed for finger-print registers. In this I simply followed the method of transliterating Japanese and Chinese words into syllables of the Roman alphabet, a condition originally imposed by the old Japanese language itself, in which consonants do not occur singly, but are followed by vowels. Purkinje’s first analysis of the finger-print patterns was not known to me, nor, I believe, to anyone in Europe or America, when I first wrote, although I often in those years suggested that he had probably written something on the subject. My first article in Nature, as sent up, contained a kind of analysis of patterns, with many types, named as whorls, ovals, deltas, loops, junctions, and the like. Some are referred to in the text, but the editor expressed his regret that he had not been able to insert the figures, and their lack made the references in my article obscure. We shall deal with a few of these elementary or typical figures presently. But, let us now come to the main aspect of the syllabic system, in contrast with that devised by Sir F. Galton, who looked upon it as merely ancillary to the anthropometric system of Mons. A. Bertillon, of the French police. Galton was supremely anxious to have his natural facts, his finger-print records, arranged precisely in similar parcels, so that one would not be excessively rich in records compared with its neighbour. Now, what does it matter to the keeper of records, or even to the tax-payer, whether one class of patterns is big or little? The whole absurd complexity arising now, and increasing from year to year, grows out of this essential misapprehension from the first of the vital problems of finger-print classification. Advancing a stage for the moment, let us suppose that a rich register exists, arranged on the syllabic system. A type-writer, not necessarily a very intellectual creature, or a boy-clerk, is in the room, and has the call to find A-bra-ca-da-bra. I use here for convenience only five syllables, representing one hand. The sheets or cards (sheets have been found best by experience) are not separated in bundles except as to a convenient size. It does not take long to look along the shelves till A-bra- etc., is reached, and then the cabalistic word itself. It may prove that there are some ten sheets on the register under this syllabic title. These are transmitted, all in a few moments, to the expert keeper of the records. At a glance an expert eye like his perceives that, perhaps, seven out of the ten can have no possible relation to the case now being enquired into. Of the three, one is perhaps now in prison and cannot be the suspect. Of the two remaining forms, the details of the first two fingers compared may diverge completely in many ways, as determined by counting lines, measuring curves, and so on. I am sure this would be no fancy description, from the many tests I have applied. The whole strain of the recognition lies on the expert, as the strain of the primary classification of records had lain upon him at the time they were being made. Of course, more than one expert might be needed.
It will be noticed, perhaps, that the syllable bra occurs twice on the same hand register. It by no means follows that the finger-print represented by the second bra is very like that of the first one. In the same way, none of the patterns indicated by bra in the cards of similar syllabic index may much resemble the others, even broadly. The pattern simply is of a certain typical form with which bra is to be linked for registration purposes. The same word, so to speak, might be divided in a different syllabic way, thus:—
Ab-ra-cad-ab-ra;
Ab-rac-ad-ab-ra; and so on.
Hence the necessity of separating the syllables by hyphens.
The divergence of cards will be greater, of course, in the case of a two-hand register, and even in one which comprehended, say, one million of complete sets there would be very few repetitions of the same arrangement of syllables.
One great advantage of the syllabic form is the help given to the memory in transferring the eye from one sheet to others which may be wanted. In the system now in use the symbols do not rivet themselves in the same way, and have a monotony that becomes very tiring.
A general view of the precise intention aimed at in the particular register must determine the extensiveness of the form the register is to compass. Are the numbers likely to be large? Must the registers extend over long periods? Are infants to be kept in view over adult life, if that is reached? Many enquiries of this kind may have to be met before the exact form of the cards or sheets is determined. For such civil and social purposes as life insurances, signatures of deeds, benefit of friendly societies, and the like, a comparatively simple form of register and limited number of finger imprints might be all that would be required for an effective service. The number of cards would not be very great, and the probabilities of personation would likely be restricted to a few local residents whose finger-prints would not often be found even to approach coincidence in a slight degree. To serve such needs, an elementary form of classification would go a long way to overtake ordinary requirements, and would be easy of reference. Few of the difficulties involved in graver conditions of legal identification need be raised as an objection to the general use in banking and ordinary business of this new mode of identification. In forming a system, even with a very wide range, the whole amount of possible complexity in finger-patterns need rarely be called upon, and could not conceivably be exhausted. I speak confidently on this point. The central part of the pattern used is generally very limited, and its area may be widened whenever an enlargement of the primary requirements may demand more complexity in the factors of identification. The ramifications will usually provide variety enough to satisfy the most avaricious register.