i68 



DRAWING WITH A CAMERA LUCIDA 



[Ch. VI 



100 "' 



U,e mia«»ope. The ™i™. must hav. i^ edg« in planea paraUel 

 with tte edges of the drawing board also (Sg- »* 



5„». Drawing ^^^M^TZl^^Jl^^ -^ 

 r.;: JS»X,To -Hhetag. Jth. drawing penc. ca„ 



Fig. 102. Beknhard's Drawing Board mr the Abbe Camera LucmA. 

 (From the Catalogue of Zeiss). 



This drawing board can be elevated and tipped it can also be inclined, carrying 

 the microscope with it. 



be seen with about equal distinctness. This may be accomplished 

 with very low powers (i6 mm. and lower objectives) by covering the 

 mirror of the microscope with white paper when transparent objects 

 are to be drawn. For high powers it is best to use a substage con- 

 denser Often the light may be balanced by using a larger or smaller 

 opening in the diaphragm. One can tell which field is excessively 

 illuminated, for it is the one in which objects are most distinctly seen. 



