Astronomical Society of London. 468 



The Officers. — President. Sir Humphry Davy, Bart. — 

 Treasurer. Davies Gilbert, Esq. — Secretaries. William 

 Thos. Brande and Taylor Combe, Esq. 



The elections were as last year unanimous. 



Dec. 5. The Croonian Lecture was continued. 



Dec. 12. On Metallic Titanium; by W. H. Wollaston, 

 M.D. V.P.R.S. — On the Difference of Structure between the 

 Human Membrana Tympani and that of the Elephant; by 

 Sir E. Home, Bart. V.P.R.S. 



Dec. 19. On the Chinese Year; by J. F. Davis, Esq. 

 F.R.S. — On Rocks that contain Magnesia; by Charles Dau- 

 beny, M.G.S. Professor of Chemistry, Oxford. Part only of 

 this paper was read, and the Society adjourned to the 9th of 

 January 1823. 



ASTRONOMICAL SOCIETY OF LONDON. 



Dec. 13. The following papers were read: 



1. On the Measurement of Altitudes by the Barometer; by 

 Professor Littrow. 



The object of this paper was to point out a more simple 

 process than any now in use, applicable to the service of tra- 

 vellers, without logarithms or voluminous tables. The author 

 animadverted on the processes already in use, and proceeded 

 to state that he liad assumed the well known formula of La- 

 place as the basis of his calculations, but with a new and less 

 complicated form of expression. From this he constructed 

 several Tables l)y which the approximate heights might be 

 immediately determined, and of these several exam})les were 

 given. 



2. Observations on the Comet of January 1821. By .1. Ni- 

 collet of Paris. 



3. On the Ap]ilication of Machinery to the Computation of 

 Mathematical Tables. By Cliarles Babbage, Esq. F.Fi.S. 

 Secretary Astron. Soc. 



Tl)is was a supplement to a former paper laid before the 

 Society, to explain some further properties which had been 

 developed in the use of this machinery ; such as, that it was 

 capable of taking advantage of a peculiar projieity of ihe^ or- 

 ders of diftl:'renccs of the sine of an arc, so as to form tables of 

 the sines of arcs from beginning to end, with great certainty 

 and simplicity. The author then alluded to another class of 

 tables dependent on laws which hatl never yet been reduced 

 to analysis, but which were produced by the machinery. On 

 examination of I hcsc, and in(]uiring into their solution, he suc- 

 ceeded in ai riving at it by tv,o diflercnt processes of great 

 simplicity, while \\\c analytical equations to wliicli they could 



alone 



