(School for Scandal.)
From a Photo by Barraud, London.
[Martin Hewitt, Investigator.]
By Arthur Morrison.
III.—THE CASE OF MR. FOGGATT.
Almost the only dogmatism that Martin Hewitt permitted himself in regard to his professional methods was one on the matter of accumulative probabilities. Often when I have remarked upon the apparently trivial nature of the clues by which he allowed himself to be guided—sometimes, to all seeming, in the very face of all likelihood—he has replied that two trivialities, pointing in the same direction, became at once, by their mere agreement, no trivialities at all, but enormously important considerations. "If I were in search of a man," he would say, "of whom I knew nothing but that he squinted, bore a birthmark on his right hand, and limped, and I observed a man who answered to the first peculiarity, so far the clue would be trivial, because thousands of men squint. Now, if that man presently moved and exhibited a birthmark on his right hand, the value of that squint and that mark would increase at once a hundred or a thousand fold. Apart they are little; together much. The weight of evidence is not doubled merely; it would be only doubled if half the men who squinted had right-hand birthmarks; whereas, the proportion, if it could be ascertained, would be perhaps more like one in ten thousand. The two trivialities, pointing in the same direction, become very strong evidence. And when the man is seen to walk with a limp, that limp (another triviality), reinforcing the others, brings the matter to the rank of a practical certainty. The Bertillon system of identification—what is it but a summary of trivialities? Thousands of men are of the same height, thousands of the same length of foot, thousands of the same girth of head—thousands correspond in any separate measurement you may name. It is when the measurements are taken together that you have your man identified for ever. Just consider how few, if any, of your friends correspond exactly in any two personal peculiarities." Hewitt's dogma received its illustration unexpectedly close at home.
