23 AUGUST 1940, Page 15

CAMOUFLAGE

SIR,—The type of camouflage which is now used on many buildings and vehicles betrays a lack of appreciation of the basis of this science which should not exist when advice could so easily be obtained from experts in the physiology of vision.

The aim of " dazzle " or disruptive camouflage is to cover an object with patches of colour the outlines of which are more conspicuous than the general outline of the object against its background. The eye is then presented with a medley of meaningless shapes rather than with the outline of a familiar object, and, as an observer notoriously sees mainly what he expects to see, the object may either be overlooked or, if noticed, be very difficult to identify. To produce this result it is essential that the adjacent patches of colour should differ considerably in brightness or tone value. Differences in hue or tint unaccompanied by difference in brightness are ineffective, as such differences disappear when viewed at quite short distances. The prevailing. habit of painting vehicles in stripes or blotches of colours of nearly equal brightness defeats the ends of camouflage. At a short distance the differences of tint are not apparent and the outline of a vehicle of a uniform drab colour is - plainly evident.—Yours faithfully, W. T. AGAR. University Laboratory of Physiology, Oxford.