Statistical Investigations 341
recorder consists of a brass disk sliding with a range of about 3" vertically, and rather more than gl" horizontally, so that a needle which projects from the disk on pressing a spring is capable of holing about one square inch of visiting card supported on chamois leather. 'The range is adequate for the record of two, possibly three characters.
The most complete registrator was one made for Galton by Hawksley; the needle point is doneaway with, and the instrument records on five dials the number of separate pressures on five pins. These pins or stops communicate by a ratchet with a separate index-arm that moves round its own dial. The dials are covered by a plate which can be removed to read off the results. The instrument is _I" thick, 4" long and 14" wide and it can be held unseen in either hand with a separate finger and thumb on each stop. When any finger is pressed on the stop below it the corresponding index-arm records a unit. Guides are placed to keep the fingers in their proper positions. The instrument may be used in the pocket or under a loose glove or other cover. "It is possible by its means to take anthropological statistics of any kind among crowds of people without exciting observation, which it is otherwise exceedingly difficult to do'." I may remark that it requires some little training to press with the correct finger. With an instrument Qf this kind Galton recorded the percentage of attractive, indifferent and repellent looking women he met in his walks through the streets of various towns with the object of forming a "Beauty-map" of the British Isles-a project he never completed, although he held London-to have most and Aberdeen fewest beautiful women of the' towns he had observed. He once also remarked to me that he had found Salonika to be the centre of gravity of lying, though I have no direct evidence that he used a registrator to tick off liars and truthspeakers in his travels in Greece.
While busy with his Hereditary Genius, 1869, Galton had noticed how apt are the families of great men to die out and that genius has been asserted to be related to sterility. He endeavoured to explain the matter in the case of the judges and in the case of peers by special causes (see our pp. 93-96). De Candolle also referred to this topic in his Histoire des Sciences, four years later, and suggested without mathematical investigation that families in the male line must always tend to die out, the name becoming extinguished when a son failed to be born. He suggested that a mathematician ought to be able to solve this problem of the extinction of surnames. Galton saw the importance of the determination of the rate of extermination of surnames as a preliminary investigation to the inquiry as to the dying out of the families of men of ability, in whose cases heredity had been too often traced in the male line only-e.g. the extinction of peerages granted for great achievements-and this extinction of the line attributed to some unexplained sterility in able men. Galton accordingly propounded the problem in the Educational Times, and there it met with poor success at first-one erroneous solution. Ultimately the late H. W. Watson, a personal friend of Galton's,
' See the paper: "Pocket Registrator for Anthropological Purposes," British Association Report, Swansea, 1880, p. 625.