Of the more southern district, the canal of Languedoc forms the principal feature. From the account given by General Andreossy and others, it appears to have origi nated with Francois Andreossy in 1660, when he commu nicated the design to P. Riquet ; that after having made a journey to Italy, he returned and continued to complete the survey and designs till 1664. The project was pre sented to the. minister Colbert in this ycar, and by his orders the whole track and design, examined by Al. Clerville, Commissary-General of Fortifications in 1665, who, in 1666, made a report, without mentioning the name of Anclreossy. Riquet contracted upon this report and plan, although Anclreossy hacl previously discovered its imperfections, and corrected his original design, and Riquet obtained authot ity to adopt this improved plan, by which the commissary was excluded from further in terference. The first adjudication or contract, from the Garonne to 747 yards above the bridge of Trebes upon the Aude, was made to Riquet 14th of October, 1666. In 1668 Riquet requested leave to proceed also with the part of the navigation which was eastward of Trebes.
Clerville also examined the country, and formed another defective project, which was accepted by Riquet under condition of being at liberty to improve it, which was done by abandoning. it altogether for the more per fect one by Anclreossy.
The track of the canal lies across the isthmus which connects the peninsula of Spain with the south of France, consisting of a sort of valley between the northern skirts of the Pyrenees and the Rhone. One branch of this valley passing in an easterly direction, is occupied by the rivers Fresquil and Antic, and leads from the summit of the isthmus, at Naurouse, to the flat shores of the 'Medi terranean, which are partly occupied by lakes, and partly cut through by rivers falling from the great mass of high land to the northward, called the Black Mountain. On the other side of the summit, the river Lers passes, in a north-western direction, to the city uf Toulouse, on the great river Garonne, which falls into the Bay of Bis cay a little way north of the city of Bordeaux. By this track, therefore, a communication by water is opened be tween the Mediterranean and the ocean, which avoids the circuitous and not unfrequently dangerous sea voy ages around the whole of Spain by the Straits of Gib raltar.
With the view of supplying the summit with water, the Black Alountain was inestimable. Its extent of high land was great, and much of it covered with forests, which lessened evaporation. Facing the canal track,
there were numerous streams sufficiently high to be col lected and carried to the summit of the isthmus, which was accomplished by means of a drain or feeder ten feet wide at the bottom, and three deep of running water, taking in eight separate streams. Above three miles is cut in rock ; and at Campmases, there is a tunnel 125 yards in length, and 9 feet diameter. It afterwards falls into the channel of the Laudot, which it follows three miles to the great reservoir of St. Ferr€ol. After leav ing this, it continues in the Laudot until it joins the fee der from the river Sor. After which, they proceed across the plain in a feeder 12 feet wide, and 3 feet deep, of running water, to the basin of Naurouse. The whole length of these feeders is 38; miles, although in a direct line only 17. The feeder across the plain was originally made for navigation, and had 14 locks ; but these were given up, and used as a feeder only. There was at first an extensive octagonal basin or reservoir at Naurouse, 426 yards in length, by 320 in breadth, with 7 feet depth of water ; but it has been long filled up with mud, and planted with poplars. The feeder now passes along side of it to the summit of the canal.
In giving a brief description of the canal line and -works, we shall begin at the western end. 'Fite canal is connected with the river Garonne, below the mill-weir of Toulouse. It passes round the western side of the city, ascending by eight locks. After leaving "Foulouse, the canal is carried along the southern side of the river Let's, ascerding by 13 more locks to Villefranche, where it crosses the Lers, and rises by 5 other locks, making in all 26 locks, and 207 feet rise front the Garonne to the summit. The distance is 23j English miles; the sum mit level is only 31- miles.
From the sununit, the canal passes along the southern side of the valley of the Fresquil, beyond Castelnaudary, to the point where that river falls into the Aude near Carcassonne, having in this distance crossed the Treboul, and five smaller streams, and descended by 37 locks, On account of the inhabitants of Carcassonne objecting to the canal approaching their town, it was carried to the north of it. But in 1778, these ignorant men became sensible of their error, and proposed to contribute to wards the expense of changing the line, so as to pass close to the town. This was adopted, and commenced before the Revolution. It was suspended, however, foe some time, but has since been resumed, and probably completed.