CH V.] DRAWING WITH THE MICROSCOPE. 119 



needs less rather than greater magnification, the drawing surface may 

 be brought nearer the mirror of the camera lucida by piling books or 

 other objects on the drawing board. If one takes the precaution to 

 draw a scale on the figure under the same conditions, its enlargement 

 can be readily determined (§ 177). 



If one has many large objects to draw at a low magnification, then 

 some form of embryograph is very convenient. The writer has made 

 use of a photographic camera and different photographic objectives for 

 the purpose. The object is illuminated as if for a photograph and in 

 place of the ground glass a plain glass is used and on this some tracing 

 paper is stretched. Nothing is then easier than to trace the outlines of 

 the object. See also Ch. VIII. 



REFERENCES. 



Beale, 31, 355 ; Behrens, Kossel and Schiefferdecker, 77 ; Carpenter-Dallinger, 

 233 ; Van Heurck, 91 ; American Naturalist, 1886, p. 1071, 1887, pp. 1040-1043 ; 

 Araer. Monthly Micr. Jour., 1888, p. 103, 1890, p. 94; Jour. Roy. Micr. Soc, 1881, 

 p. 819, 1882, p. 402, 1883, pp. 283, 560, 1884, p. 115, 1886, p. 516, 1888, pp. 113, 809, 

 798; Zeit. wiss. Mikroskopie, 1884, pp. 1-21, 1889, p. 367. 1893, pp. 289-295. 

 Here is described an excellent apparatus made by Winkel. See Zeiss' catalog 

 No 30, and the 15th (1896) edition of the Bausch & Lomb Optical Company for 

 improved forms of the Abbe camera lucida and for improved drawing boards to 

 accompany it. 



