

INTRODUCTORY 



is a macroscopic photograph of a microscopic 

 object." Macroscopic denotes an object of 

 minute proportions, but visible to the naked 

 eye, or by means of a pocket lens, and does 

 not require the use of a microscope. An en- 

 larged drawing of such an object to the extent 

 of a few diameters is termed a macrograph: 

 if made by the aid of cameras, why not a 

 photo-macrograph? There is an endless num- 

 ber of such objects, which may be enlarged 

 by the aid of a suitable camera and photo- 

 graphic lens from one to about ten diameters 

 the limit of a pocket lens of one-inch focus. 

 I have ventured to coin the word photo- 

 macrograph in this connection, and descrip- 

 tions of the method of making them, together 

 with illustrations, will be found in Chapter V, 

 under Negative Making. 



It may not be generally known that photo- 

 micrographs were made long before Da- 

 guerre's discovery of photography itself, in 

 fact, about one hundred years ago. In 1802 

 Thomas Wedgwood and Humphry Davy 

 afterwards the celebrated Sir Humphry made 

 a number of photo-micrographs, or macro- 

 graphs, by throwing enlarged images of small 

 objects through a solar microscope upon sur- 

 faces of paper or white leather sensitized with 



