21 G

HISTORY OF ENGINEERING.

Book I.

national improvements could not fail of being successful : each enterprise submitted to theboard is duly and properly considered, with reference to works, that might be in futureundertaken ; one uniform system is laid down for bridges and their construction, andvolumes have been written on the properties of stone, cements, hydraulic mortars, thethrust and pressure of arches of every kind of curvature. Timber has been examinedthoroughly with respect to its strength, toughness, and powers of resisting, torsion, antimuch larger scantling than ever tried in this country, have been tested by the engineers ofFrance . The best works upon engineering are found among the writers of France andItaly , and should he studied by all who desire to excel in the profession. Rondelet,Bruyere, Rrony, Boistard, Borard, Gauthcy, and Perronct, particularly should be enu-merated for their high attainments and professed knowledge of the subjects upon whichthey treat. Before the establishment of this important body, the roads in France werescarcely defined, and the bridges were left to the control and management of the localmasons, who executed their repairs or reconstruction in a manner devoid of both proportionand solidity.

L’nder the Emperor Napoleon , great advances were made in the management of allpublic works; his penetrating eye soon discovered what was wanting, and his industriousand business-like habits changed the routine observed in the building of bridges, the for-mation of roads, construction of lighthouses, beacons, telegraphs, arsenals, canals, workingof mines, and the reducing of metals.

France is divided into eighteen districts, and placed under the inspection of this estab-lishment.

The roads are classed or divided into three orders, as the Royal road, for which the statepYovides, the departmental roads, which are kept in repair by the respective provinces, andthe rural roads, which are maintained by the immediate inhabitants of the district throughwhich they pass.

The Royal roads are subdivided into three classes, the first of which is 42 Frencli feet inwidth: of this class there are 28, or altogether 1258 leagues; of the second class, whicharc 66 feet in width, there are 717 leagues; of the third class there are 5241 leagues.

The rivers, as far as used for the purposes of navigation, are under the same direction,and 1877 leagues are annually reported upon.

The canals finished extend over 870 leagues, and those under construction amountaltogether to near 2000 leagues and constitute another branch to which the engineers ofthis government hoard have to attend; and that due attention may he paid to this highlyimportant subject, the duties are divided into lines, and are annually reported upon.

The first line passes by the south and east of France , comprising the Rhone , the Saonc,and the Canal of Monsieur, which unites the latter river with the Rhone .

"I he second line passes by the south and north of France , and comprises all that is at-tached to the Rhone and Saone in that quarter ; the canal of Bourgoyne, which unites theS.ione to the Yonne ; the Seine ; the Oise ; the canal of Mnnecamp and Chauny ; the CanalCrozat; the canal of St. Quintin, joining the Oise to the Eseaut; the canal of the Somme or of the Duke d’Angouieine; the course of the Escourt; and all the canals in the neigh-bourhood of Calais.

The third line, in the centre, on the south, comprises the Rhone , the Canal Lateral,course of the Saone , Canal du Centre , of Dijon , Chalons on the Saone , which unite theLoire with the Saone ; Canal de Berri; of Dijon ; and Bee d’Allier ; the canal which joinsthe Loire from Bee d’Allier to Briare; the Canal Briare and the Loing ; the course ofthe Seine and Oise .

The fourth line, passing by the south and north-west, comprises the Rhone , the Saone .the Canal of Burgundy, the Yonne , and the Seine , to the mouth.

The fifth line, passing from the south to west, through the centre of France , has theRhone , the course of the Saone , the Canal of the Centre, the canal de Berri, the branchcanal to the Basse Loire , from Tours to Nantes , and the canal of Nantes to Brest.

The sixth line, passing by the south and south-west, has the canal of Marseilles , to theport of Bouc by the Lake tie Berre ; the canal de Bouc to Arles ; the branch canal to theRhone , from Arles to Taras^on; the canal de Beaucaire, the canal de la Raddle, the canalof Mauguio and ties Etangs, the canal of Languedoc , and its extension to Moissac byMontaubon ; the Garonne from Moissac to Bordeaux .

Seventh line, passing from La Manche to the sea, by Gascoigny and the Mediterranean,or the canal from Dunkerque to Bayonne and Marseilles ; the canal de Bowrhourg, thenavigation of the Aa; the canal of Aire to Bassee, joining the Lys, to the 11. Deule ; thecanal of Deule ; part of the course of the Searpi; canal of Scnsce ; the course of the Eseaut:the canal of St. Quentin; the canal of Crozat; the course of the Oise ; canal of the Oise tothe Seine ; canal of St. Denis and St. Martin ; the Seine as far as the canal of Loing; canalsof Loing and Orleans; the Loire from Orleans to the mouth of the Vienne ; the Vienne toChatellerault ; the canal of Roitou, joining the Vienne to the Charente , by the ('lainriver; the Charente to Angouleme ; the canal from Angouleme to Libournc; the Dm-