187 
PHYSICAL AND MATHEMATICAL SECTION. 
April 26th, 1866. 
E. W. Binney, F.R.S., F.G.S., President of the Section, in 
the Chair. 
A paper entitled “ Results of a Comparison of the Magni- 
tudes of the Bedford Catalogue with those of the Mensurae 
Micrometricse and the Bonner Sternverzeichniss,” by George 
Knott, Esq., F.R.A.S., was communicated by Mr. Baxen- 
dell. 
The question of the relation between the magnitude scales 
of different observers is one of considerable interest and im- 
portance, and has engaged the attention of several able 
astronomers. It is not my intention in this paper to go into 
the subject generally, but simply to submit the results of a 
comparison of the magnitudes of the late Admiral Smyth’s 
Bedford Catalogue with those assigned to the same stars by 
the late Prof. Struve in the Mensurce Micrometricce, and by 
Dr. Argelander in the Bonner Sternverzeichniss. I may 
remark that I was induced to undertake the comparison by 
the perusal of an interesting paper by Mr. Pogson, the pre- 
sent Director of the Royal Observatory at Madras, in vol. xvii. 
of the Monthly Notices of the Royal Astronomical Society, 
in which he has given a short table of corresponding magni- 
* 
tudes of Struve, Bond, Herschel, and Smyth, as referred to 
Proceedings — Lit. & Phil. Society. — Vol. V. — No. 16— Session 1865-6. 
