of ascertaining the Magnitude of small celestial Bodies. 55 
As far as the imagination will enable us to compare objects 
we see in succession, the magnitudes appeared to be in an 
arithmetical progression. 
23d Experiment. 
I examined a Geminorum with 410,5, and with the outside 
rays the stars were considerably unequal, and 1^ diameter of 
the largest asunder. With all the mirror open they were 
more unequal, and i\ diameter of the largest. With the inside 
rays they were very unequal, and i|- of the largest asunder. 
These experiments show that, if it had not been known that 
the apparent disks of the stars were spurious, the application of 
the improved criterion of the apertures would have discovered 
them to be so ; and that consequently the same improvement 
is perfectly applicable to celestial objects. 
OBSERVATIONS ON THE NATURE AND MAGNITUDE OF MR. 
harding’s lately discovered star. 
It will be remembered that in a former Paper, where I 
investigated the nature of the two asteroids discovered by 
Signior Piazzi and Dr. Olbers, I suggested the probability 
that more of them would soon be found out ; it may therefore 
be easily supposed that I was not much surprised when I was 
informed of Mr. Harding’s valuable discovery. 
On the day I received an account of it, which was the 24th of 
September, I directed my telescope to the calculated place of the 
new object, and noted all the small stars within a limited compass 
about it. They were then examined with a distinct high mag- 
nifying power ; and since no difference in their appearance was 
perceivable, it became necessary to attend to the changes that 
