CH. X] 



PROJECTION APPARATUS FOR DRAWING 



323 



459. Drawing table with attached 45 degree mirror. One of 



the simplest and most convenient arrangements for the magic 

 lantern and the microscope is to have a large mirror attached to 

 the drawing table. The table and mirror can then be moved 

 toward or from the projection apparatus to aid in getting the 

 desired magnification (fig. 182). 



FIG. 181. KORISTKA'S SIMPLE DRAWING OUTFIT. 

 (From Koristka's Microscope Catalogue). 



This drawing outfit can be connected with the house lighting system. 

 / Nernst lamp for illumination. 



2 Condenser connected with the lamp-house. 



3 Stage of the microscope. 



4 Projection objective. 



5 45 mirror for reflecting the rays down upon the horizontal drawing 

 surface. 



6 Horizontal drawing surface. The drawing-board slides along the axis, 

 thus making it possible to vary the distance and hence to increase or diminish 

 the size of the drawing at pleasure. 



When sitting down to draw, a convenient height for the table is 

 76 cm. (2^ ft.). The one shown in fig. 182 has a top 100 cm. long 

 and 75 cm. wide (39 x 30 inches). 



The plate glass mirror is 75 cm. long and 60 cm. wide (2^ x 2 ft.) . 

 It is permanently fixed at 45 degrees inclination; and to avoid the 

 sharp angle at the base of the mirror it is raised from the table 10 

 to 15 cm. (4 to 6 in.). 



The mirror itself is in a strong wooden frame, and it is supported 

 by vertical and horizontal pieces, as shown in figure 182. 



