After crossing the Fresquil, the canal passes along the northern side of the river Aude and the town of Trebes, to the commencement of the long level near the town of Oionzai. In this last distance, it has descEndecl 22 locks, and crossed five streams, from the Black Mountain. The long level commences at the lock of Argens, near Olan zac, crosses the torrent Repudte, passes along, the skirt of the mountain by Ventenac, and across the river Cesse, on the east side of which the canal of Narbonne °ranches ofi'. The canal then proceeds, by considerable windings, to the north of Capestang, ancl around the point of the mountain Ecurene. It then crosses the narrow ridge of Malpas by a tunnel 181 yards in length, und proceeds to the top of the chain of 8 locks at Fonseranne. This level is 17 miles in length.—After passing thls chain of locks and a single one, the canal crosses the river Orb, on the south side of the town of Beziers: it then takes a southerly direction, crosses the river Libron, and proceeds to the river Herault, north of Agde. After crossing it, and bending round the south side of the small lake Bagnes, it enters the western extremity of the large lake Thau, and through it passes to the port of Ccttc, on the shore of the Nlediterranean. In this last distance there are 5 locks.
From the summit at Naurouse, to the port of Cette, the distance is 121-4 English miles, and the fall 62; feet. Tne total length ut this canal is 148 English miles. The lake Thau is about 9,-; miles in length, and 3 in breadth. The western end is so shallow, that the canal is carried 31 miles in it between artificial dykes.
Beyond the western extremity the river Garonne is difficult to navigaie. Between Toulouse and Bourcleaux, a distance of 40 leagues, there are two places where boats drawing 20 inches water can scarcely pass in sum mer. In passing upwards the boats are hauled by 25 men, and require 15 day5 between Bourdeaux and Tou louse.
Originally there were only three aqueducts construct ed, to carry the streams under the canal, all the others having been taken into it. Bit from 1681, when the na vigation was opened, to 1688, the mischiefs from this were so evident, that M. Vauban, who, by direction of the king, cxamined the whole, recommencied 52 more. The finest was that uf Cette, of which Belidor has given a plate, and which has been repeatedly copied into FITTIC it and English publications.
The greatest works on this navigation are, the reser voir at St. Fen Cul ; (see Plate CCCCX11.;) the basins at Casteinaudary ; 102 locks, of which 8 are connected at Fonseranne, and one circular, 90 feet in diameter, at Agde ; 55 aqueducts; the rafts and weirs across the rivers Libron, Orb, Ste. ; the tunnel through the ridge
at Alalpas ; and 92 road bridges. In many of the bridges there were no hauling paths; and the locks vary in rise, from 5 to 12 feet. The canal, when perfect, is 64 feet broad at the surface of the watcr, 34 at the bottom, and 6 feet 5 inches deep. The first stone of the canal works was laid in April 1667, and the first voyage made upon it after it was completed, was on the 30th June 1681.
The vessels which navigate it are 85 feet long, from 17 to 19 feet broad, draw 5 feet 4 inches water, and carry 100 tons. They take from 6 to 7 days to go from Agde to Toulouse; but they do not travel in the night.
Canal of Narbonne.
Connected with the great canal is that of Narbonne. In 1664, the inhabitants contributed a considerable sum towards the expense of the great canal ; but Riquet car ried it immediately to the place of his birth, Bczicrs, with the view of reaching a better port at Cette. This canal of Narbonne now proceeds from the great level near Argelins, leaving the river Cesse on the right. In making this canal, much expense is unnecessarily incur red in placing the locks at regular distanccs fionn each other. The depth of the lake Sejcan, from the mouth of the canal to the beacon, is from 4 to 6 feet. From this point commences the canal which the Romans ex cavated to the channel La Nouvelle, for thc distance of about a mile and a quarter. The canal is carried round the flat shore of the isle of St. Lucie for about 31 miles. The opening of the Grave varies in depth from 7 to 12 feet. There are seven locks upon this canal of Narbonne, and three upon La Robine.
To the north-east of the port of Cette, the canal de Grave commences, a quarter of a league from Montpe lier, at Port de Juvenal, upon the Lez. In the three miles before it joins the lake Palavas, it has three locks; beyond that lake it joins a canal which proceeds to Cette, by the lakes Thau and Agde. There have been various projects for other canals here. From Aiguemort they now proceed to sea by the canal of the Great Robine, four miles to the Grau du Roi. They go to Pecais by the canal Bourgidon of five miles. The canal of Silve real is 44 miles, and goes from the Little Rhone to Pe cais. The cabal of Lunel is 41. miles in length.
On the east side the Rhone, the Fosse Crapone, of 40 miles, is not navigable. Its engineer, the celebrated Adam de Crapone, about the same time, (1554 to 1558.) formed the project of uniting the two seas by the Some and the Loire, which t% as begun by Henry II.
The canal of Provence, from the Durance at Aix to Marseilles, which would be 70 miles, was begun in 1752, but abandoned after three miles were cut.