PHOTOGRAPHING THE UNSEEN

Evening Post, Volume CXIV, Issue 16, 19 July 1932, Page 6

PHOTOGRAPHING THE UNSEEN

Recently we reproduced in, "Tlie Post" a "photograph of fairies"— one of those which provoked much discussion several years ago when the late Sir Arthur Conan Doyle stoutly defended their reality. With the question of whether these pictures are genuine or faked we do not wish to deal; but it is interesting to note a development in photography which appears almost as remarkable, In "The Times" recently there appeared an article—with an example—of photographing the invisible. The example was an old parchment taken from the palace of the exrSultan of Turkey. It contained traces of writing which were quite undecipherable. The parchment had clearly been washed and scraped to get rid of the original writing and make it available for a new communication. Photographed by ordinary processes it appeared almost completely blank; but when photographed by the special process it was! revealed clearly as a letter from Louis XVI. of France to "the .great Emperor of the Mussulmans." The "luminogram" was made by means of invisible light that passed through a silver screen before reaching the phptographic plate. This js not entirely a new development. In 1913 Dr. Koegel discovered that erased writing could be brought out by short.-wave ultra-violet rays., The latest process, evolved by a London handwriting expert, enables similar pictures to be obtained in a few seconds. Imaginative writers at times have told of processes by which the images of the past could be recaptured—the sound waves set in motion centuries ago again made effective on the ear and the light waves on the eye. These ideas are purely imaginative, but the recording of impressions unseen by the eye is a fact, attested by clear and undeniable photographs. As Hamlet remarked, "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy."