on the singular Figure of the Planet Saturn. 279 
June 1. It occurred to me that a more accurate measure 
might be had of the latitude in which the greatest curvature 
takes place, by setting the fixed thread of the micrometer to 
the direction of the ring of Saturn, which may be done with 
great accuracy. The two following measures were taken in 
this manner, and are more satisfactory than I had taken before. 
The first gave the latitude of the south-preceding point of 
greatest curvature 43 0 26'; and the second 43 0 13'. A mean of 
the two will be 43 0 20'. 
June 2, I viewed Jupiter and Saturn alternately with a mag- 
nifying power of only 300, that the convexity of the eye-glass 
might occasion no deception, and found the form of the two 
planets to differ in the manner that has been described. 
With 200 I saw the difference very plainly ; and even with 
160 it was sufficiently visible to admit of no doubt. These low 
powers show the figure of the planets perfectly well, for as 
the field of view is enlarged, and the motion of the objects in 
passing it lessened, we are more at liberty to fix our attention 
upon them. 
I compared the telescopic appearance of Saturn with a figure 
drawn by the measures I have taken, combined with the pro- 
portion between the equatorial and polar diameters determined 
in the year 1789;* and found that, in order to be a perfect 
resemblance, my figure required some small reduction of the 
longest diameter, so as to bring it nearly to agree with the 
measures taken the 27th of May. When I had made the ne- 
cessary alteration, my artificial Saturn was again compared 
with the telescopic representation of the planet, and I was then 
satisfied that it had all the correctness of which a judgment of 
* See Phil, Trans, for 1790, page 17. 
