ZF-AJR/T TIKIIR/D. 



PLAIN GLASS SLIDES. 



The above cut shows the exact size and shape of the 

 transparency, the mat, the glass, and the binding of the 

 Woodbury, the American, and the Scientific Sciopticon 

 Slides. In French slides the lateral measure of the trans- 

 parency is a little less. 



54 



