126 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



Fig. 134. 



structed by Mr. Troughton, when the telescope does not 

 exceed twenty inches, or two feet focal length. The tele- 

 scope-tube, A A, is in two parts, and connected together by 

 a sphere, B, which also receives the larger ends of two cones, 

 C C, placed at right angles to the direction of the telescope, 

 and forming the horizontal axis. This axis terminates in two 

 cylindrical pivots, which rest in Y's fixed at the upper end 



