380 Proceedings of Philosophical Societies. [Nov. 



the levelled points brought nearer to each other. The level of 

 the intersections of every street was thus obtained, and after- 

 wards that of the intermediate spaces. The points which were 

 found to be on the same level were then joined by straight lines, 

 which produced a number of irregular polygons, whose traces 

 showed the intersection of the surface with several horizontal 

 planes, each of which was raised a metre above the other ; so 

 that these curves show the limits of the grounds that would 

 be successively inundated if the water of the Seine were to rise 

 metre by metre above its ordinary level. 



Memoirs on the Navy, and on the Civil Enginery of France 

 and England containing an Account of two Journeys made by the 

 Author to the Sea-Ports of England, Scotland, and Ireland ; by 

 jVI. C. Dupin, of the Academy of Sciences. — This collection is 

 much more interesting than its title would lead one to suppose. 

 The account of the two journeys contains only the historical 

 and descriptive part ; and it makes one wish for a more extensive 

 work, which indeed the author promises, and which will also 

 contain the theoretical part. This account is succeeded by a 

 notice relative to the construction of the breakwater at Plymouth, 

 and a description of the Caledonian canal, interesting to every 

 class of readers ; a plan of a large work already in great forward- 

 ness on the naval architecture of the 16th and 19th centuries ; 

 experiments on the flexibility and elasticity of wood ; a very 

 extensive memoir on the re-establishment of the Naval Academy, 

 with much useful advice ; another memoir on the actual state of 

 the maritime museum established in the arsenal of Toulon, and 

 on the works of Puget which are preserved in that arsenal ; and 

 lastly, a description of the machines for the naval service con- 

 structed at Rcchfort from the plans of M. Hubert. The whole 

 is accompanied with reports which have been made to the 

 Academy of Sciences, the Academy of Arts, and by the naval 

 officers at Toulon, when the author submitted his different works 

 to their inspection. The History of the Institute will exhibit the 

 reports which were read to the two Academies ; and, therefore, 

 Ave confine ourselves to the transcription of the conclusion of 

 that made by the naval officers. " The commissioners think 

 that the general plan of the author is well adapted to produce a 

 good, useful, and interesting work, worthy of the encouragement 

 of a great nation (this refers to a vie~>>- of naval architecture) ; 

 and they hope the Minister for the Marine will not refuse to the 

 young author noble and honourable encouragements, the priu* 

 cipal of which have been just pointed out.'' They said a little 

 before this, " that it was. desirable M. Dupin should be enabled 

 to examine the principal sea-ports of France and foreign coun- 

 tries, in order to form an impartial judgment of what concerns 

 them, to collect together the most important materials, and to 

 put them in practice with that unshaken constancy which the 



