70 Proceedings of Philosophical Societies. [Jan. 



MM. Molard and Ampere read a report on the new lamp in- 

 vented by Lord Cochrane ; but the Academy being informed 

 that a similar investigation had been undertaken by orders of the 

 Minister of Marine, suspended further proceedings on the sub- 

 ject, and ordered the committee to give their assistance to the 

 commissioners appointed by the Minister. 



M. Girard gave in the report of a committee on the alido- 

 graphe of M. de Saint-Far. This instrument resembles the 

 common plane table, with the addition of a graduated arc, which 

 may be read off to minutes, and to which a telescope may be 

 adapted, in order to enable it to serve the purpose of a theodolite. 



M. Cauchy read a memoir on the resolution of polynomials 

 into real factors of the second degree. 



Oct. 20. — The death of M. Genty, Correspondent of the 

 Academy, was announced. 



M. Coquebert-Montbret concluded his report on the voyage of 

 M. Krusenstern round the globe. 



A memoir by M. Opoix on a method of preserving butter fresh 

 was read, and was referred to M. Thenard. 



Oct. 27. — M. Sorlin presented a memoir on spherical trigono- 

 metry, which was referred to MM. Legendre and Delambre. 



M. Girard read a memoir on the flowing of ether and certain 

 other fluids through capillary glass tubes. 



M. Bosc presented the report of a committee on a statistical 

 description of the district of Maremmes, by M. Guillet. In 

 this paper the most important article is a relation of the manage- 

 ment of the oyster pools. The oysters are obtained by dredging 

 off Oleron and the Isle of Aix, and such as are small and round 

 are selected to be fattened in the pools. These pools are spaces- 

 on the river bank from 800 to 900 yards square in extent, and 

 are surrounded with a dam to keep out the tide. The successful 

 management of these pools depends on four circumstances : 

 first, not to overcrowd the pools with oysters : secondly, to 

 transfer the oysters once a year from the exhausted pool to one 

 which has been vacant for an entire twelvemonth before : thirdly, 

 to increase the depth of water during winter, that the oysters 

 may not be hurt by the frost : fourthly, to prevent the rain-water 

 from finding its way into the pools. Three years at least are 

 required to bring the oysters to a marketable state, and the 

 longer they remain the more fat and delicate they become. 



MM. Laplace and Coquebert-Montbret were appointed to 

 draw up the bill of mortality, to be inserted in the memoirs of 

 the Academy, according to custom. 



