PHOTOGRAPHY BY INVISIBLE RAYS.

Northern Advocate, 26 November 1910, Page 2

PHOTOGRAPHY BY INVISIBLE RAYS.

Professor R. W. Wood, of Baltimore, U.S.A., recently described some experiments he has lately been making in photography by invisible rays. He said that although the eye was insensitive to the ultra-wolet light and in-fra-red regions of the spectrum, the photographic plate w- iS poi, and by means of suitable screens which cut out all visible light and only allowed ultra-violet or infra r.-d rays to penetrate, some most curious affects were to be observed. In landscape pictures taken by means of the inf i a-red rays the foliage of trees was rendered as white as snow and the blue sky as black as ink. In pictures taken with ultra-violet light there were no shadows, and the general.appearance of the landscape was similar to that which would be visible in the atmosphereless moon. Chinese white and white flowers were rendered black. Professor Wood thought that the photography of the moon and possibly of the planets by this means would be of great, service in adding co our knowledge of their physiography, and he suggested also that the blackness of flowers to ultra-vio-let light might play some economic part in their growth, and that further experiments in this direction would be useful.