MICROSCOPIC OBJECTS. 



195 



about 2i inches ; their aperture is 1 inch. The glass at 

 c is fixed in a separate tube, and made to sUde within 



Fig. 2. 



Fig. ] , 



Goring' s Megaloscope, one-sixth its real size, 



that which holds the others ; thus it can be used either at 

 a certain distance or in close contact with them ; in the 

 latter case the power of the combination is double what 

 it is in the former. These three glasses are all achro- 



