The entire length of the Mersey is 56 miles. For the first 37 miles of this distance, the river has a tortuous course, ill-adapted for navigation, and passes through an almost exclusively agricultural country. From Runcorn to the sea, the form of the river is that of a bottle, of which the wide expanse between Runcorn and Liverpool forms the body, and the narrow part opposite Liverpool the neck. Through this neck there annually passes nearly twenty million tons of shipping, including entrances and clearances.
The unassisted efforts of nature have hitherto maintained the navigable channels of the Mersey, so that the conditions of navigation remain practically uniform. The bar, however, is gradually moving in a seaward direction, while maintaining its general form and characteristics. In Liverpool Bay there is a great range of tide, which insures a depth of at least 30 feet over the bar once in every twelve hours, even on the lowest neaps. Some two or three million cubic yards of upland water every twelve hours are discharged into the estuary, chiefly by the Mersey and the Weaver, which, with 710 million cubic yards on a high spring tide, maintains the normal capacity of the estuary, and counteracts the process of silting. Some 17,300 acres of a deposit of sand in the estuary are above the low-water mark. Through this the upland water forms and maintains a channel in its course to the sea, and any serious exclusion of this tidal water would be likely to so far injure the sea channels as to interfere with the trade and shipping of the port.
The Mersey is the outlet for several important canal navigations, including the Weaver Navigation Canal, near Weston Point, the Bridgwater Canal at Runcorn, the Sankey Canal at Widnes, the Shropshire Union Canal at Ellesmere, the Leeds and Liverpool Canal at the Docks, and the Manchester Ship Canal, now under construction, at Eastham. The position of these several canals in relation to the river may be traced in a map accompanying a paper read by Mr. Lyster, the engineer, before the Institution of Naval Architects. These canals are important factors in assisting the growth of the trade of the Mersey. The Leeds and Liverpool is, however, the only canal that has a direct connection with the Liverpool Docks.
By this canal Liverpool has water communication with the important town of Leeds, and thence, by the Aire and Calder Canal, with Hull and the other ports on the Humber. By the Shropshire Union Canals the Mersey is connected with the network of canals in the Midland Counties and with the River Severn.
In Camden’s time Liverpool must have been a very obscure place. The author of ‘Britannia’ dismisses it almost in a sentence, observing that “from Warrington, the River Mersey, spreading abroad, and straightwaies drawing in himselfe again, with a wide and open outlet, very commodious for merchandise, entereth into the Irish Sea, where Litherpoole, called in the elder ages Lipen-poole, common Lirpoole, is seated, so named, as it is thought, of the water spreading itself in manner of a poole.”
With the exception of the Thames—which it rivals, and with which for a number of years past it has run a neck-to-neck race—the Mersey is, so far as its volume of business is concerned, the most important river in the world. This, however, is an attainment of comparative modern origin. The first wet dock was constructed at Liverpool, in 1708-9, on the site now occupied by the Custom House. In the latter part of the same century several other docks were constructed. The dock estate has now an area of 1078 acres, the whole of which is appropriated to basins, docks, quays, and premises worked in connection therewith.
The Weaver.
The history of the navigation of the river Weaver, which adjoins the Mersey in Cheshire, supplies a notable example of what may be made of an originally insignificant and tortuous stream in order to adapt it for the requirements of commerce. The river has been canalised between Northwich and Chester, twenty miles of the navigation being artificial navigation, and the other thirty miles being river proper.
In 1721 three Cheshire gentlemen obtained the first Act of Parliament for making the river Weaver navigable. The depth then provided for was only 4 feet 6 inches, and boats of more than 40 to 50 tons could not enter.
About the year 1760, the navigation was carried down so as to enable vessels to enter at nearly all tides, and in 1810 the river was further improved by the Weston Canal, which is four miles long, enabling vessels of much deeper draught to enter without navigating a dangerous part of the old river. This canal forms a junction with the Bridgwater Docks at Weston Point, and a dock was formed in connection with it so as to enable vessels to wait for the tide.