LABORATORY AND TEACHING METHODS 



66l 



drawing board Z (Fig. 234). Having determined tlie camera extension required by 

 means of a special set screw provided, an allowance of 2.8 cm. is made for the 

 height of the plate above the drawing board. The arm clamping the camera to 



Fig. 235. — Edinger's drawing apparatus arranged for microscopic drawing. 



the pillar is then raised until the collar fits over the draw tube of the microscope 

 body T, or over M, when working with the microsummars, thus ensuring a light- 

 tight connection. It is advisable to support the bellows by the strap pieces shown in 



