CH. 



\\TTH THE MICROSCOPE 



153 



the range must be still further increased. For a moderate increase 

 in size the drawing surface may be put farther off or, as one more 

 commonly 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 condi- 

 tions, its enlargement can be readily determined ( 207). 



FIG. 133. Room and Apparatus for Drawing with the Projection Micro- 

 scope. R. Radiant, an arc lamp with carbons at a right angle ; L. t. Lamp 

 and microscope table ; C. Condenser zv it h W. a large water bath between the 

 lenses to absorb the heat rays; S. w. Stage and stage water bath on which 

 rests the object and keeps the object cool by radiation as well as by absorption ; 

 O. The objective representing the microscope ; M. Mirror at 45 on a draw- 

 ing table, (Dt.). As the microscope is horizontal so that the axial ray is 

 reflected downward at right angles by the 45 mirror there is no distortion. 

 The scale of the drawing is added exactly as described in I 207. 



A very satisfactory way to draw at low magnifications is to use 

 a simple microscope and arrange a camera lucida over it as over the 

 ocular. In this way one may get drawings at almost any low mag- 

 nification. 



