MAGNET WITH REVERSED TELESCOPE. 



47 



object, as a star. Second, that if that telescope be 

 shifted laterally so as to receive the rays from one part 

 of the parallel pencil instead of another, it still receives 

 them in the same direction: so that minute adjustment 

 of the lateral position of that telescope is not necessary. 



Fig. 18. 



In Figure 18 therefore B represents a magnet 

 suspended by a suspension-thread : C a small frame 

 firmly attached to it, carrying a fine wire, or two wires 

 crossing each other, and thus producing a fine point for 

 observation : D another frame clamped to the magnet 

 and carrying an object-glass whose focus is exactly at 

 the place of the wires carried by C. The rays of light 



