The eastern extremity of this canal is in the small river Carren, near its junction with the Forth, where spring tides rise about 18 feet. At this place, called Grangemouth, there is a tide lock and basin. The lat ter is inconveniently small, and the entrance altogether imperfect. From Grangemouth the canal passes on the western side of the town of Falkirk, and from thence to the summit of the before mentioned low pass, a distance of about 10i miles, having ascended 156 feet by 20 locks. From this point the canal proceeds, on the summit level, for 18 miles, to the city of Glasgow, at Port Dundas. It also continues one mile beyond this place, to the Monk land Canal Basin, but in this last distance there is one regulating lock. About 2i miles north of Port Dunclas, the branch to the Clyde goes off. It passes the Kelvin by'a magnificent stone aqueduct, (see Plate CCCCXI V. Fig. 3 and 4,) and proceeds to the tideway at Bowling Bay, having descended by 19 locks. The length of this branch is 84 miles. The distance between Grangemouth on the Forth, and Bowling Bay on the Clyde, is 35 miles. The locks arc 74 feet in length, and 20 in breadth, and when the canal is quite full, has 8 feet water on the sills.
This canal has proved a useful acquisition to the coun try, and of late years profitable to the proprietors. It is an instance of the efficacy of public aid. A loan of 50,000/. enabled it to be completed and brought into use. That sum has long- since been repaid with interest, and there is now an annual revenue, varying between 40,000/. and 50,000/. The principal articles are_corn, timber, sugar, herrings, and passage-boats.
It has already been observed that the eastern termi nation of this canal is imperfect. Instead of ending in the narrow and muddy channel of the Carron, at some distance from the Forth, the shore of which, at that place, is itself unfavourable, the canal should be conti nued to Borrowstounness, situated upon the main es tuary, where the depth of water is greater at low water, and 'other circumstances more favourable ; and as a I 1 act has been obtained for this extension, its evident advantage3 will, no doubt, in time, ensure its execu tion.
Although the canal now described opens a very va luable communication between the estuaries of thc Forth and Clyde, and also with the city of Glasgow, yet having its eastern termination at Grangemouth, the immediate intercourse between the great cities of Edinburgh and Glasgow, and also that of a great extent of the inter vening rich and populous country, was left subject to land carriage. This evident imperfection long engaged the attention elf the enlightened inhabitants of these two great cities, and many schemes were proposed to com plete an inland navigation between them. Different views of this important subject produced various and prolonged discussions. and for several years kept va rious canal projects afloat. That which has been at last adopted, consists in proceeding from lock No 16, or the fourth below the eastern termination of the Forth and Clyde Canal summit, and ascending 110 feet, by I 1 locks, to a height which enables the line afterwards to be car ried imtnediately south of the town of Falkirk and Lin lithgow, to the lowest practicable summit of that part of the country, and afterwards through a beautiful and rich district to the western suburb of the city of Edin burgh—in all a distance of about 30 miles, upon the same level as that near Falkirk. This canal was planned
by Mr. Hugh Baird, the resident engineer upon the Forth and Clyde Canal; and Mr. Telford, who was occasionally consulted, approved of it, and recot»mended the addi tional plan of continuing the line from Falkirk to the eastern extremity of the Forth and Clyde summit, and considering the connecting lock, No. 16, as for the Grangemouth trade only. By this mode, the whole dis tance between the cities of Edinburgh and Glasgow will be distributed into two long levels, one of 28 and the other of '26 miles, separated at Falkirk by six locks. This, if executed, will permit the intercourse between the two cities to be carried on without interrtipting the thorough trade to Grangemouth, and instead of taking water from it, will give an increase to the summit level of the Forth and Clyde Canal. There are three large aqueducts and one short tunnel in this canal.
From the eastern termination at Edinburgh, it is pro posed to complete a communication, either by a canal or railway, with the town of Leith ; and extensions may also be made into East Lothian to the eastward, and into Stir lingshire to the westward.
On the northern side of the Clyde valley, and imme diately east of Glasgow, the Monkland Canal affords a cheap communication between the city, and the col lieries in the parishes of Old and New NIonkland, dis tant about 12 miles. It was suggested to the magis trates 1769 : they etnployed the justly celebrated Mr. James Wait, thcn resident in Glasgow, to make the ne cessary surveys and plans; an act was obtained, the cor potation took shares in a joint-stock company, and the canal was carried 10 miles. For two miles from the basin at Glasgou it is level. At Blackhill it ascended 96 feet an inclined plane ; and from the top of this hill thc canal proceeds 8 miles upon a level. In 1770. Messrs. William Stirling anti Sons, (having previously purchased the whole cat,a1 stock.) along with the proprietors of the Form and Clyde. procured a second act, with powers to make a junction hetween the navigations, build locks at Blackhill, extend the Nlonkland Canal to the river Cal der. and thereby rendering it an aqueduct for the Forth and Clyde. This canal is 24 feet wide at the bottom, 34 at the top, and has 4 feet 6 inches of water. .At Black hill thcre are 8 locks of 12 feet rise, and at Sheepford two more, of I I feet 6 inches each. Coal is. the chief article or carriage, and some iron ; also manure from Glasgow. The annual revenue has increased gradually to about 12,000/.