G@. W. Hough on Cataloguing and Charting Stars, 169 
Each of these pins has a notch cut in the middle, of the form 
which would result from placing the vertices of two cones to- 
Rn By this arrangement, there can be no loss of motion ; 
ides, it affords great facility in changing the rod from one pin 
to another. 
The rod (/) is connected with the clamp arm by dropping the 
, Rotch (z), fig. 2, on one of the pins. 
The other end of the rod is attached to the lever (J), fig. 1. A 
sectional view of the mechanism for this purpose is seen in fig. 8; 
(4, t) being two screws having con- 3. 
s 
tectly to the lever (2). a 
The lever (4) is supported on the — oe 
horizontal post (e), fig. 1; gisa : 
Set screw for clamping to any part of the post (e); 2 and 7 are 
Weights for counterpoising the lever in any position. 
; © supporting axis of 6 is seen in fig. 4, where mm are two 
__ ‘*rews having conical points. By this arrangement, we avoid 
4 “088 of motion, and have but very little friction, 
2 _In fig. 1, kis an electro-magnet operating the arm (d), at the 
EMA of Which, and parallel to the axis of the cylinder, is at- 
*ehed the cross piece j, 
The dials seen A fig I indicate minutes and seconds. 
_ Att Jour. So.—secoxp Senms, Vou. XXXVIII, No. 113—Sept., 1864 
22 é 
