Page:History of merchant shipping and ancient commerce (Volume 2).djvu/451

 and from which goods can be obtained for home consumption, or for re-exportation.

But Liverpool, including Birkenhead, has a far larger amount of dock accommodation than any other port in Great Britain, or, indeed, in the world and no works of a similar character, of either ancient or modern times, can be compared with them. Gibbon has described the port of Ostia, to which we have already referred, with its docks, as the boldest and most stupendous works of Roman magnificence; but, so far as we can now trace, they were in the extent of their accommodation altogether insignificant when compared with the docks which at present line the banks of the river Mersey. These extend on its eastern shore upwards of five miles in length, and the works now contemplated or in course of construction will add at least another mile in length to these already gigantic undertakings.

Though the entrance to the estuary of the Mersey is encumbered by sand-banks, there is at low-water spring-tides a depth over the bar of eleven feet, and as the water rises twenty-one feet in neap and thirty-one feet in spring-tides, there is ample depth for vessels of the largest size over its shallowest and most dangerous part. The channel is also well defined by numerous buoys, beacons, lightships, and lighthouses, and vessels entering the harbour have the advantage of the services of the most daring and experienced pilots to be found in this or in any other country, who are constantly cruising about, in their well-equipped cutters, in search of inward-bound vessels long before they reach that