52 SCIOPTICON MANUAL. 



The new Woodbury slides are exactly quarter plate 

 size (3i x 4), which gives room at the sides for naming 

 and for handling, and which in turn gives assurance of 

 their being inserted in proper position. 



Fortunately each half of a stereoscopic view is 3 inches 

 square, so that lantern slides, of standard size, can be 

 printed by contact from stereoscopic negatives. Although 

 the demand for lantern slides has never warranted ex- 

 tensive travel for desirable negatives, yet the stereoscope 

 has sent photographers "viewing" high and low, and 

 everywhere; on the Alps, in the Yosemite, in the valley 

 of the Nile, on open Polar Seas, and often (as intimated 

 by one of their own number) into distressingly narrow 

 straits. 



Glass transparencies made for the stereoscope, when 

 cut in two, with clear glass covers instead of ground- 

 glass, are extensively used for lantern slides. Many of 

 these, especially of the imported views, are very fine, 

 and leave nothing to be desired when used in the Sciop- 

 ticon. But as a heavy deposit of silver is not particu- 

 larly objectionable in the stereoscope, many of these 

 pictures can only be satisfactorily shown upon the screen, 

 with an intense chemical light, if with that even. When 

 the demand for these fine views for the lantern is suffi- 

 cient to turn the attention of photographers to their 

 production, we may look for more good pictures, and 

 we hope at a cheaper rate. 



THE SEALED PICTURE. 



A drop of Canada balsam between two disks of plate- 

 glass, on one of which is a beautifully colored photo- 

 graph, is skilfully managed so as to allow the plates to 

 come almost in contact, with a film of the balsam filling 

 all the space between j this makes the picture beautifully 



