310   Life and Letters of Francis Galton

was black on one side, and the silhouette that had been cut out was pasted then and there, with the black side upwards, upon a white card, and framed. A perfectly durable and often a good likeness was thereby produced in a very short time. This art was superseded by photography, and is now temporarily extinct ; but I want to show that it might with great facilityand I think with some profit in a humble way-be advantageously re-introduced by the help of the very agency that extinguished it."

Galton next suggests photographing the profile of a sitter, either in a strong light against a dark background, or vice versa, and then taking a print of this result, cutting out the profile and blackening it'. In his second letter Galton gives an example of a silhouette prepared in this way. Such silhouettes are, he says,

`.`particularly useful in studying family characteristics which, I think, are on the average far better observed in profiles than in any other single view of the features. The truth of this statement may be verified in church, where whole families, each occupying a pew, can often be seen sideways, and each family can be taken in and its members compared at a single glance.

Galton's photographic silhouettes of himself, aged 65.

The instances will be found numerous in which the profiles of a family are curiously similar, especially those of the mother and her daughters. This is most noticeable where their ages and bodily shapes differ greatly, as when the daughters are partly children and partly slim girls, and the mother is not slim at all."

It must be admitted that Galton went to church rather for scientific than religious purposes; but the reader of this passage will hardly be inclined to acce~t_ Dr Beddoes' statement that Galton was wanting in a sense of humour See Vol. I, p. 59.

Another photographic problem which occupied a good deal of Galton's thoughts at one time was the problem of keeping the object and the focal plane at the conjugate foci of the optical centre of the object-glass. This

1 If the sitter be placed in front of a window, a half plate will give a silhouette of about four inches high, which is often a very characteristic portrait. The chief need is the 'deft hand' in cutting out the print and avoiding angles. In the Galton Laboratory we have a silhouetting arrangement in which the sitter's head is adjusted to the `Frankfurt horizontal plane,' and the shadow is cast by an arc light some fifty yards away. The shadow is traced by an artist's hand and the resulting silhouette preserved. with the anthropometric records of the subject. It is used for measurements and by compounding series of subjects to obtain type profiles.