192 L. R. Gibbes on the Occultator. 
. 
a few inches square, having two lines traced on it with a writ- 
place of observation, until by the eye placed above that point 
and close to it its image is seen to coincide with the interse- 
anc’ again reappear, as in an occultation. The use of the mi- 
pice ration gives the best results, as the eye cannot the? 
fail to be in the proper position above the point indicating the 
place of observation, 
_ 1 use the same method for adjusting in position a 
the chart, and this parallelism I test b 
the projections of a certain point in t i 
tant inclined positions of the 
