THE CAMERA, ETC. 49 



Having finished our description of the apparatus 

 required in photo -micrography, we wish finally to 

 impress on the reader the necessity of making them 

 as well and accurately as possible, and not to attempt 

 their manufacture himself unless he is a good 

 mechanic. 



We now pass to the arrangement of the dark 

 room. The outlay is very small and will amply re- 

 pay the photographer. Any spare room may be 

 selected for its erection, preferably on the ground 

 floor, near, or if possible in, the apartment set apart 

 for photo-micrography and the instruments used for 

 that purpose. 



About six feet from one wall and twelve from the 

 other, a post A, fig. 21, reaching from floor to ceil- 

 ing is erected, two more posts B and C are placed 

 opposite to it against the walls, and two or three 

 long laths are fastened at equal intervals horizontally 

 between A and B. 



FIG. 21. 



Half way between A and C another post D is 

 fixed, and about seven feet from the floor a cross 



