of ascertaining the Magnitude of small celestial Bodies. 41 
also f Ursse majoris and other stars equally round, and as 
well defined. 
REMARKS. 
( 1. ) As these diameters are undoubtedly spurious, it follows 
that, with the stars, the spurious diameters are larger than the 
real ones, which are too small to be seen. 
Sept. 9, 1779. The two stars of e Bootis are of unequal dia- 
meters ; one of them being about three times as large as the 
other. 
(2.) From this and many estimations of the spurious dia- 
meters of the stars* it follows, not only that they are of 
different sizes, but also that under the same circumstances, their 
dimensions are of a permanent nature. 
August 25, 1780. The large star of y Andromedae is of a 
very fine reddish colour, and the small one blue. 
(3.) By this and many other observations it appears, that 
the spurious diameters of the stars are differently coloured, 
and that these colours are permanent when circumstances are 
the same. 
Nov. 23,. 1779. I viewed a Geminorum with a pow r er of 449, 
and saw the two stars in the utmost perfection. The vacancy 
between them was about i-| diameter of the largest. I found 
when I looked with a lower power, that the proportion between 
the distance and magnitude of the stars underwent an alteration. 
With 222, the vacancy was diameter, and with 112, it was 
no more than 1 diameter of the smallest of the two stars, or 
less. 
(4. ) By many observations, a number of instances of which 
* See Catalogues of double Stars. Phil. Trans, for 1782, p. 1 1 5 ; and for 1785, 
page 40. 
MDCCCV. G 
