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DOCKYARDS 491 is terminated by a masonry head with beacon light, of the harbour; the last starts from the shore at a point and two entrances, each 700 feet in width, serve for the somewhat east of the convict prison, and runs southerly navigation of shipping in entrance and exit. The defensive for a length of 3320 feet. harbour thus completely enclosed, partly by natural means, These three breakwaters, with a united length of rather partly by the great artificial works now carried out, covers more than 1-| miles, are each built of massive concrete an area of 2200 acres to the one-fathom line, of which blocks in the form of a practically vertical wall, founded 1500 acres have a depth of not less than 30 feet at low upon the solid chalk and rising to a quay level of 10 feet water, and is probably one of the finest artificial harbours above high water Two entrances, one 800 feet and the other in the world. There is no dockyard at Portland, but the watering and coaling appliances for the supply of the fleet are of considerable importance and extent, the latter having lately been greatly improved by the construction of a coaling jetty and camber for the storage of both sea-borne and landborne coal and its handling by modern hydraulic appliances. Dover. —The Admiralty pier at Dover, so familiar to passengers by this route to or from the Continent, was the first instalment of the scheme for a large harbour of refuge recommended by the Royal Commissions of 1844-45. This pier was commenced in 1847, and practically completed in 1871, having a total length of about 2000 feet. As an engineering structure it has proved successful, as, with the exception of the destruction of the parapet in 1877, no material damage has been caused by the heavy seas to which it has constantly been exposed. The remainder of the scheme was not, however, completed. The Royal Commission of 1881 on the employment of convicts again recommended the construction of a large harbour at Dover, but beyond the erection of a convict prison nothing further was done for some years. In the meanwhile the Dover Harbour Board, with a view to improving the existing condition of the port, commenced the scheme indicated on the plan and entitled the “ commercial harbour,” consisting of an east pier, which runs parallel to the general direction of the Admiralty pier, and will ultimately enclose in conjunction with the latter a sheltered water; area of some 75 acres. This work was commenced in 1893, and is now approaching completion. The enclosed harbour for the accommodation of H.M'. navy, for which funds were voted by Parlia- 600 feet in width, are provided m the positions shown on the ment in 1895 and subsequent years, is indicated on the plan. The foreshore at the foot of the cliffs between the Castle plan. It will be seen that the water area enclosed jetty and the root of the eastern breakwater is in jirocess of amounts to 610 acres, exclusive of the commercial harbour, reclamation by means of a massive sea-wall founded upon of which 322 acres have a depth of not less than 30 feet at low water. The enclosing breakwaters are three in the chalk. These great works were begun in 1897 (Fig. 2). Gibraltar. The details of the defensive harbour here number, the most westerly one being an extension in a are closely connected with the general scheme of dockyard south-easterly direction of the existing Admiralty pier extension, and will be found described under the reference ora length of 2000 feet; the southern breakwater is to Gibraltar which follows. The enclosed water area at isolated, and is 4200 feet in length, curving round shore- Gibraltar is less than that at Dover in the proportion of wards at its eastern end to accord with the direction of the third breakwater, which forms the eastern boundary about 440 to 610 acres, but neither harbour is comparable with Portland in area.