Royal Academy of Sciences of Paris. 1 39 



leaving, however, the precise time at which the accident happened 

 still undetermined, and not only the observations themselves, during 

 some indefinite period, the subject of doubt and suspicion, but pro- 

 bably the whole series of no utility or avail. 



Mr. Baily considers that there are also some advantages attending 

 the form of this pendulum. For, being uniform in its dimensions, 

 without any protuberant bob or projecting tail-piece, it is not so 

 liable to accident as the ordinary pendulum, where those parts pre- 

 sent opportunities for injury. It is also capable of being packed in 

 a more convenient case, and thus rendered more easy of transporta- 

 tion, when required as a travelling instrument. But he states that if 

 we view it in the light of an instrument intended for the observatory, 

 as a means of determining the length of the simple pendulum, where 

 both knife-edges are necessary for the solution of the problem, the 

 advantages will be more apparent. For, in the construction of the 

 pendulum here proposed, none of the parts slide over one another : 

 there are no shifting weights, no moveable screws : every thing is 

 fixed and stationary, and consequently more peculiarly adapted for 

 the determination of so nice and difficult a problem. 



As these pendulums are formed without any tail-piece, it became 

 necessary to adopt some other mode of determining the arc of vibra- 

 tion. This, Mr. Baily has effected by making the edge of the pendu- 

 lum, which is perfectly straight, answer the purpose of the point in 

 the tail-piece of the ordinary pendulum : and by this method he was 

 also enabled to enlarge the divisions of the scale (which is a diagonal 

 one), sO that the hundredth part of a degree occupies the length of 

 three-tenths of an inch, and consequently can be read off with the 

 greatest ease. 



[The remainder of the Proceedings will be continued in our next Number.] 



ROYAL ACADEMY OF SCIENCES OF PARIS. 



December 10. — The ordonnance of the king approving of the no- 

 mination of M. Savart was read. — M. Anatasi communicated a 

 new plan for the towing of ships. — M. l'Abbe* Lachevre objected to a 

 part of M. Damoiseau's report respecting his chronological tables. — 

 M. Chevreul, in the name ofa Commission, made a very favourable re- 

 port respecting the memoir of MM. Dumas and Boullay, jun. On the 

 formation of sulphuric aether. — MM. DumSril and Dupuytren gave 

 an account of the interesting essays by Dr. Senn of Geneva, respect- 

 ing the treatment of diseases of the larynx. — M. Geoffroy Saint-Hi- 

 laire read a memoir on a small kind of crocodile living in the Nile, its 

 organization and habits, and the motives which occasioned its being 

 anciently honoured with the appellation of the Sacred Crocodile.— M. 

 Cauchy read a memoir on the development of functions and rational 

 fractions. — The observations of Mons. Giroux of Buzareingue, on the 

 reproduction of domestic birds, were read. 



December 17. — M. Cassini, in the name ofa Commission, made a 

 favourable report respecting Mons. A. Brongniarfs memoir On the 

 spermatic granules of vegetables. — M. Chevreul gave an account of 

 several notices of M. SSrullas relating to the bromides of arsenic, anti- 



T 2 monv, 



