. Röntgen rays and electro-therapeutics : with chapters on radium and phototherapy . thenecessity of reducing the size of the pictures for use in this has been overcome by Walter, of Germany, who places the originalsize negative in the frame and views it with different prisms. (Fig. 115.) There is yet another method of viewing these stereoscopic transpar-encies or prints. The reduced pictures mounted in frames are placed onan endless chain, and are viewed by the operator who looks through the 240 ELECTEO-THERAPEUTICS. prisms. The advantages of this method are : That the number o
. Röntgen rays and electro-therapeutics : with chapters on radium and phototherapy . thenecessity of reducing the size of the pictures for use in this has been overcome by Walter, of Germany, who places the originalsize negative in the frame and views it with different prisms. (Fig. 115.) There is yet another method of viewing these stereoscopic transpar-encies or prints. The reduced pictures mounted in frames are placed onan endless chain, and are viewed by the operator who looks through the 240 ELECTEO-THERAPEUTICS. prisms. The advantages of this method are : That the number of pic-tures is practically unlimited, unnecessary light is excluded, and thatprints as well as transparencies may be employed. Lately I have made some plastographic views from these stereo-scopic negatives. The plastographic method consists in superimposingone print in green over another in crimson, which offers a haziness to thenaked eye, but when viewed through eye-glasses (one of a green colorand the other of crimson), a very beautiful picture with marked relief Pi |i I I I ^1. Fig. 115.—Prism stereoscope of Walter. details is afforded. I believe this process will be useful for stereo-scopically illustrating medical journals and scientific books. There isanother method of combining stereoscopic pictures without an instru-ment, which can easily be acquired by crossing the visual axes. Placethe skiagraph in front, hold up the index finger in the middle linebetween the eyes and the skiagrams, and while looking at the top ofthe finger, a third picture will appear in the centre, offering a mostbeautiful stereoscopic effect. E. Advantages of Steeeo-skiageaphy. An ordinary skiagraph is composed of superimposed shadows ofdifferent densities, which appear flat on the negative or print, and in ad-dition contains many shadows appearing indistinct and weak, but inthe stereoscopic pictures the superimposition will be more distinctand visible. Two plates exposed at different angles are
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradiolo, bookyear1910
