355 
of the Georgian planet. 
of the respective radii of the satellites, and the impression of 
the fine point whereby the angle of position is obtained will 
be of eminent use ; for by putting one leg of the compass 
upon this point, and extending the other to the centre of the 
circle, we shall in the present case have 4,8 1 inches for the 
measure of the required distance, which as the radius of the 
circle is six inches, will be parts of it ; and in such parts 
all the distances which are given in the foregoing observa- 
tions have been expressed. 
I have called this manner of obtaining the angles of posi- 
tion and proportional distances, the identifying method, that 
it may remain distinguished from strict computation ; there 
is, however, so much real calculation mixed with it, that I 
may confidently draw the following interesting conclusions 
from it. 
I. With the light of my 20 feet telescope, the first satellite 
generally becomes invisible at the distance of a little more 
than half its greatest elongation ; I suppose it to be when the 
identified measure of it is from 302 to about 310. 
II. The second satellite becomes invisible at very nearly 
half the distance of its greatest elongation ; I suppose it to be 
when its identified distance is from 295 to about 303. 
III. An interior satellite as large as the first, must be 
more than half the greatest elongation of the first satellite 
from the planet ; and if it be smaller, it must be at so 
much greater a distance from the planet, to be seen at its 
greatest elongation. Nor can there be any chance for seeing 
it two nights together, when the orbits are contracted by 
projection. 
