AKCIUTF.CTURE, &C. 



CEtivrcs de M. Gavthei/, 4c. 

 T/ie Works of M. GaiUkey, 3 vols. Ato. 

 plates. — Vol. 1, 2, Construction of 

 , Jiridges ; Vol. 3, on Navigable Canals: 

 9'fitbLished by his nephew, M. JNavier, 

 ^uengineer in ordinary of highways and 

 ■abridges. Printed by Fermin Didot, 

 ■ Far is. 1813-16. 



After a well dvawn-up biographical 

 notice of M. Gautiiey by his nephew, 

 we enter upon the work of the author, 

 COtninenciiii; with an historical descrip- 

 tion of the principal stoiie-hririges built 

 by the ancients and moderns in various 

 parts of ilie world, from the Emilian 

 bridf^e at Rome, built in the time of 

 Sylla, to the present time; to which the 

 autlior has added engravings of 153 of 

 the principal ones, all reduced to one 

 scale, with engravings of twelve aque- 

 ducts, amongst which we certainly ex- 

 pected to find the celebiatcd one of Al- 

 cantara, near Lisbon. 



This part of the work is not only 

 hij^lily interesting in a historical point of 

 view, but also as it regards the sciences. 

 In it we trace the dawn of bridge-build- 

 iiig, from the prnctice of the Eiiyptians, 

 who were ignorant of the nianner of 

 turning an arch, and formed their bridges 

 of pillars and large stones laid as a plat- 

 forui from pillar to pillar, to tlie elegant 

 constructions of the eighteenth and nine- 

 teenth centuries, when tbe strength of 

 arches and the resi^tance of stone in 

 every form and position were rendered 

 ilie object of inatheiTiatical demonstra- 

 Hon. We see the progress of the art, 

 and by what slow degrees it attained its 

 present advanced state ; we witness 

 tiic aberrations of genius :it different ue- 

 fiuds, darting from the beaten track ; 

 now failing for want of practical know- 

 ledne (/f the nature and resistance of 

 dillerent stones in ditVerent forms and 

 poiiitiiins; now, ha[>p;lv, combining prac- 

 lital knowledge witii a beautiful theory, 

 and forming an epoch in the science. 

 To liiese descriptions the author has 

 jwiiied that of liOO bridges in France, 

 of wliich tlie brtadili of the river ex- 

 ceeds twenty metres (the metre is 39,301 

 iiifhei linulish). We pass over the part 

 which more exclusively concerns France, 

 lo devote our a(tentii)n to what relates 

 10 bridge.building as a science. The 

 aeaciW'i book treats of the manner of as- 

 certaining the dimensifjiis proper to be 

 given 10 britlfies uiuItT all possdile cir- 

 conistanccH, and what are the variations 

 (o be practised under particular ones. 

 " One of the most important points," 

 •hserves M. Gauihey, " is the dtiouchc, 



Bet r aspect of French Literature. 6i7 



or water-way, necessary to be given tr> 

 bridges." Had this subject been well 

 understood, London-brifige bad beea 

 differently constructed. JVI. Gauttiey 

 gives the algebraic formula for determin- 

 nig it, which the liniits of this article do 

 not permit us to translate. 



The section on the resistance of stone 

 is highly curious and important ; he enu- 

 merates 180 species of stone, and gives 

 the specilic gravity and the resistance of 

 a cube of five centimetres (about two 

 inches). We find that tlie resistance i$ 

 not as the specific gravity ; (or the stone 

 of Caserta, in Italy, whose specific gra- 

 vity is 2,718, only supported the weight 

 of 14865 kilogrammes (about 30,000 

 pounds avoirdupois); while the gres blanc, 

 or white free-stone (specific grav. 2,476) 

 supported 2S086 kilogrammes; and 

 white statunry marble(spec. gra». 2,695) 

 supported only 8176 kilogrammes; and 

 the white stoneof Seissel,in France,(spec. 

 grav. 2,020, and resistance only 904 kil, 

 and pumice-sione (spec, grav, 0'556) 

 bore 690 kit.: the basaltes of Auvergne 

 gave 2,884, and 51945 kil. 



The next table is perhaps still more- 

 important. It is on the resistance of 

 cubes of five centimetres of the same 

 stone, taken at difi'erent depths in the 

 bed or quarry. This table presents very 

 curious results : the greatest resistance is 

 afforded by stone from (he middle of the 

 bod, while the specific gravity follows 

 no fixed rule; it is, however, always the 

 greatest in the middle of the bed, and 

 generally the least at the bottom. The 

 author gives four sets of experiments on 

 as many stones, taken at twelve, ten, 

 six, and five different depths, according 

 to the thickness of the bed or quarry, 

 and in all of tliem the specific gravitj ,i« 

 greatest near the middle, lea^^t<tji9.iKtp'y . I 

 and least at the bottom. , ,; 



Tiible IV. presents a set of expcri* 

 ments on the resistance of solids, ac- 

 cording to the surface of the base. Table 



V. on the influence of the figure of the 

 base on the resistance of solids of stone. 

 The result is, that the circle of all figure* 

 of an equal area is the strongest, i'able 



VI. exjieriments on solids of stone of 

 different heights, and on solids of stone 

 divided horizontally, or composed of a 

 determinate number of parts, attached in 

 layers, or hurizoin;illy ; from which it is 

 proved that one cube opposes a greater 

 resisuiiice than two placed on each other, 

 and two greater than three, &C. 



This partial analysis is sutficient to 

 convey an idea of the nature and import- 

 ance of (he present wotk to ail civil 

 engineer*. 



Ih 



