364 REPORTS ON THE STATE OF SCIENCE. 
full-length portraits on the French ‘13 x 18cm.’ plate (approximately 
the English 5x7” size). See Rev. He. Anthr. viii. (1898), p. 109. 
HEAD-AND-SHOULDERS PoRrRAIts. 
The ‘half-plate’ and ‘quarter-plate’ are just too small to admit with 
security a head-and-shoulders portrait on the scale of 4 and 2 respec- 
tively. 
The French scale for these portraits, and for other parts of the body in 
detail, is $ (=~=2), which permits a head-and-shoulders portrait to be 
taken easily on a ‘13 x 18cm,’ plate, and with ample margin on a ‘half- 
plate.’ Similarly on the scale of } a ‘ head-and-shoulders’ portrait can be 
taken easily on a ‘ quarter-plate.’ 
A board, on which is marked very legibly a scale of feet and inches 
and also a ‘metric’ scale, should be suspended over the head of the sub- 
ject in the plane of his profile, and so as just to fall within the photographic 
picture. This is the only certain method of preserving a record of the 
scale, and also makes it easy to secure whatever scale of reduction may 
be adopted, by comparison of the image of this board with a line or rect- 
angle of proportional size drawn on the focussing screen of the camera. 
The name of the district and of the sitter (or at all events a distinctive 
letter or number) may be written with chalk or charcoal on this same 
board, thus securing the identification of each subject. 
Background.—The background should be at a considerable distance 
from the subject. It should be of a medium tint (say a deep shadow, or 
a sheet of light brown or French grey paper pinned against the wall 
beyond), very dark and very light tints being both unsuitable. Some, 
however, use dead black ; others, red baize. A soft material which does 
not readily crease obviates trouble from accidental shadows. In any case 
due allowance must be made for the complexion or skin colour of the 
persons to be photographed ; and preliminary experiment is advisable. 
A note should be made of the colour of the background, and also of the 
complexion or skin colour of the subject. 
The essential condition is that the*outlines of the figure shall be clearly 
defined against the background. 
Illumination.—The incidence of the light should be the same in all 
cases, otherwise the photographs are difficult to compare, and cannot be 
used to make composite portraits. 
The source of light should be single, definite, and placed behind the 
camera and above it, so that the shadows may be equally distributed 
on either side of the face. This is especially important for composite 
work. 
The light, however, must not be so strong or concentrated as to 
distress the subject or cause him to close or strain his eyes. But note 
that subdued light involves longer exposure. A dark background behind 
the camera relieves eye-strain, without cutting off top-light. When the 
top-light is strong, a white sheet on the ground lightens the shadows, and 
helps to prevent the subject from looking down. 
Mounting.—The photographs should be mownted on cards, each card 
bearing the name of the district, and a letter or number to distinguish 
the individual portraits ; the cards of each series may be secured together 
by a thread passing loosely through a hole in their upper left-hand 
corners. 
For convenience of comparison and interchange, attention is called to 
