378 Proceedings of' the Cambridge Philosophical Society. 
beds. A series .of beds, composed of limestone and shale, suc- 
ceed the last, apparently unconformable to the coal-measures. 
These are characterised by the prevalence of bitter-spar and a 
deep red tinge. Upon the^n is placed a rude mass of argilla- 
ceous and’ siliceous materials, presumed to belong to the lowest 
beds of the new red- sandstone. 
A portion of a paper by C. Babbage, Esq., M. A,, was read. 
On the Use of Signs in mathematical reasoning.'''^ 
Art. XXVIII.— scientific INTELLIGENCE. 
I. NATURAL PHILOSOPHY. 
ASTRONOMY. 
1. Comet 1819, that seems to have passed over the Sun . — 
We have already had occasion (Vol. II. p. 379« ; Vol. III. 
p. 399. ; and Vol. V. p. 216.) to give an account of this comet, 
which has been diligently observed in America as well as in 
Europe. Professor Fisher observed it from the 2d to the 30th 
duly ; and Mr Bowditch from the 3d to the 22d, and they de- 
duced from their observations the following elements : 
Prof. Fisher. 
Mr Bowditch. 
Perihelion distance, - - 0.3366878 
Time of passing the Perihelion, June 27. 
0.3363866 
Mean time at Greenwich, 
llh 56' 23" 
13^ 30' 20" 
Inclination of orbit. 
80° 56' 17" 
80° 56' 7" 
Longitude of Ascending Node, 
273 39 18 
273 54 32 
Place of Perihelion, 
Motion direct. 
286 21 33 
286 27 11 
If the correctness of these elements is admitted, the comet, when 
lit crossed the ecliptic, must also have passed over the sun’s di^. 
Professor Fisher has given the following elements of this transit : 
Mean time of apparent beginning of the Transit, June 25. 10^ 15' 20" 
Ditto of end, - - - - 13 53 44* 
According to Mr Bowditch’s elements, the comet must have 
passed the centre of the sun’s disc at 7 o’clock in the morning of 
June 26. at Greenwich Memoirs America7r Academy 
Arts and Sciences^ vol. iv. p. 313. 318. 
