THE MICROSCOPE. 



90, the pin G being withdrawn, so as to leave the bar D F G 

 with the stage and its appendages free to turn on the joint E with 

 the arm E c. The body it and the bar D F G will then be brought 



Fig. 39. 



into the horizontal position. The stage will then be vertical, and 

 the object will be held in its position by the springs. 



The illumination of the object may be produced either by the 

 reflector or lens in the manner already described ; or, if they are 

 removed from the bar D F G, the stage may be presented directly 

 to the light of the sun, the clouds, or a candle or lamp. 



In some cases, however, when it is necessary to obtain a more 

 intense illumination, an apparatus represented at s s' is employed, 

 consisting of two convex lenses placed in the ends of a conical 

 tube which slides upon the bar, by means of a square piece at the 

 end of the arm t. 

 76 



