H, M. Parkhurst on a Star-Mapper. 165 
the map shall exactly carry the star-point across the field of 
view. Unless it is desired to record the right ascension of the 
ter of the map, shall be parallel to the star-point-bar. Fig. 2 
represents the connecting levers, as seen 
from the left. K represents a cross section 
of the further end of the arm of the star- 
key, playing, as thus seen, horizontally to 
the right and left. It is connected by a 
rod with a universal joint at each end, to 
the right-angled lever pivoted at A. 
perpendicular rod adjustible in length com- 
municates the motion to a horizontal lever, 
whose center C may be adjusted in height. 
urning on the same center C is a bar D, 
which communicates the motion through 
a rod EH, of variable length, with universal 
points, to the star-point-bar B, previously hea 
adjusted, a cross section of the further end of which is rep- 
resented in the figure. The angle of the bar D to the hor- 
izontal bar may be adjusted by a clamp upon the connecti 
bar. By the adjustment of this angle, and of the position 
of the mapper, the connecting rod must be brought into 
the plane of the motion of the bars B and D, and at right an- 
gles with them. 
2. 
may be m 
made, either by varying the effective length of the bar B, or 
of the bar D, or both. 
