'220 Proceedings of rhilusophical Societies. [March, 



acknowledging that they are composed with much order and 

 clearness. The 59 plates accompanying the text are perfectly 

 well drawn. Each diagram presents even to the minutest par- 

 ticular every construction that it is necessary to execute, in 

 order to obtain the solution of the problem, and yet there is not 

 the least confusion. In a word, this work appears to us, in 

 every respect, worthy the approbation of the Academy. We 

 wish this skilful engineer may receive from government such 

 encouragement as will enable him to publish his work, and also 

 that he may finish those he has already undertaken, and which 

 are to contain the applications of descriptive geometry to the 

 arts of the carpenter and of the stone-cutter." 



A Treatise on Survei/iiig ; by M. Puissant. Second Edition. 

 — The first edition of this work having been speedily exhausted, 

 the author has, in preparing the second, enriched it by some 

 important additions. La Base du Si/stcme Mctiiqite, la Meca- 

 niqiie Celeste, and the Memoirs of M. Legendre, are the fruitful 

 mines from whence he has frequently drawn. It would, how- 

 ever, be wrong to suppose that, even in those cases, he has 

 merely acted the part of a copyist, the new and elegant demon- 

 strations which he gives of the already known formul;?, and the 

 connexion he has established between theories, that had often 

 iieen presented separately and by different geometricians, prove 

 that M. Puissant had, before he took up the pen, deeply studied 

 the methods of geodesy. The Committee are of opinion that the 

 new work of this skilful engineer deserves, in every respect, the 

 approbation of the Academy. 



Model of a Machine far raising Water hi/ the combined Action 

 of the Weight of the Atmosphere on. the Surface of the lower 

 Reservoir, and the Refhix of that Water in an ascending Pipe, 

 inserted in a Kind of intermediate Reservoir, filed bif Means of 

 the Vacuum occasioned in it by the said Mechanism ; by Messrs. 

 Lacroix and Peulvay. — Committee, Messrs. de Prony, Charles, 

 and Girard, Secretary, 



The Committee begin by explaining by what means the want 

 of the usual pistons, valves, and suckers, have been supplied. 

 From the description they afterwards give of all tlie parts of the 

 machine, and the methods of bringing it into action, they con- 

 clude it may be reduced to a sort of wheel furnished with a 

 certain number of wings, capable of opening as they turn round 

 to form successively as many partitions. The idea of this sort of 

 pump appears to them very analogous to a plan that Conte car- 

 ried into execution 12 years before his departure for Egypt. 

 They even think the machine of Conte was rather more simple ; 

 the new model nevertheless proves the artists to be ingenious 

 and intelligent. If the invention be not as new as they seem 

 persuaded of, yet it cannot be denied that their sucking and 

 forcing pump may, in certain cases, be advantageously substi- 

 tuted for the common pumps, and that the authors have 



