SEATON-SLUICE, or HARTLEY-PANS, a sea-port (small), in the township of HARTLEY, parish of EARSDON, eastern division of CASTLE ward, county of NORTHUMBERLAND, 6 miles (N.) from North Shields. The population is returned with Hartley. It is situated at the mouth of a rivulet, called Seaton-burn, where the late Sir Ralph Delaval, with great difficulty and expense, formed a new haven, and to prevent its being choked with sand, constructed an immense sluice upon the brook, with flood-gates to retain the water, from the flow of the tide till the ebb, when a sufficient body is collected every twelve hours, to cleanse the bed of the harbour, and remove from it every impediment to its navigation. Considerable improvements upon the original plan were subsequently made by Lord Delaval, who also formed a second entrance, which is crossed by a draw-bridge nine hundred feet in length. From twelve to fifteen vessels, of three hundred tons burden each, can now ride in safety at this port, and sail in or out with any wind. Coal is shipped here for the London and other markets, in very large quantities, from the neighbouring collieries. There are extensive glass-bottle works, malt-kilns, and a brewery, and there were formerly considerable manufactories for salt and copperas. The Presbyterians havea place of worship here. A blockhouse and battery were erected dxiring the late war, for the defence of the port, which is subordinate to that of Newcastle. A whale, upwards of fifty feet long, was taken on this coast, in 1766.