The barks employed are stout craft, rigged with a great lateen sail and a jib or stay-sail. The apparatus, or "engine," as it is called, for detaching the coral from the rocks and hauling it aboard, consists of a huge wooden cross, heavily weighted, and furnished with numerous, sack-like, meshed lines. This implement is thrown overboard in likely spots, trailed astern, and drawn up by means of a capstan. Diving-bells and vessels suited for submarine navigation have been proposed and tried as substitutes for this crude fashion, but have not come into use. A large boat may collect 650-850 lb. of coral in a season.
It has been estimated that the Sciacca bank yielded, between the 1st June and 31st August 1875, 264,000 lb. of coral, which sold for at least 92,400/. The bank was said to be 550 yd. long and about 30 yd. thick. Statistics concerning the Italian coral industry, publisbed in 1871, gave the number of boats as 300 from Torre del Greco, 60 from Leghorn, and 100 from Liguria and Sardinia ; the number of persons employed, 6000 ; the catch for each boat necessary to defray all cost, 200 kilo. at an average value of 48s., or 480/. ; and the receipts of coral at Italian ports, 160,000 kilo., value 380,000/. The Alghero banks in 1873 employed 239 boats, which gathered 25,384 kilo. of red coral, and 9536 of white, total value, 160,080/. ; in 1874, 159 boats took 12,260 kilo. of red and 6758 of white, total value, 93,960/. The Cagliari fishery occupied 180 boats in 1875, whose take was estimated at below 1,000,000 fr.
The coral-fisheries of Austro-Hungary are exclusively on the coast of Dalmatia, the island of Zlasin being the centre. Each boat obtains some 80-100 lb. yearly, the total value being placed at 6000-10,000 florins (of 2s.). The pale-red and very thick Dalmatian coral is much esteemed.
Spanish fishermen collect annually about 25,000 lb. of coral, worth 20,0001., around the Cape Verde Islands.
The coral-banks on the Algerian coast lie in a depth of 12i-100 fathoms, in the neighbourhood of La Calle, the Gulf of Bona, Cap de Fer, Djidjelly, Bougie, Cape Matifu, Tenes, Cape Ferrat, Cape Falcon, Habibas Island, and Cape Figalo. About H of the boats engaged are Italian ; they are stout sailing-craft of 6-14 tons, with a crew of 10-12, while smaller boats with 4-6 hands work the coast-fisheries. The total number of boats in the years 1868-76 varied between 202 and 388. Foreign vessels pay 800 fr. for a licence to fish, except Italian, which pay only 40 fr. The yearly product is stated by the fishermen at 30,000-40,000 kilo.; and the total value of the Algerian and Tunisian fisheries is computed at 2,500,000 fr. annually. The value of the Algerian exports is placed at 80,000/. per annum ; the quantity in 1878 was 34,288 kilo., in 1879, 17,876 kilo., value 536,280 fr. Each reef is divided into tenths, one of which is worked in a year ; thus a period of 10 years intervenes between the harvests from the same spot. On the coast of Tunis, between Biserte
and Tabarque, are annually obtained some 25 metric quintals (of 1.96 cwt.) of coral, varying in value from 80 to 90 fr. a kilo. The ground is worked chiefly by Italian and Greek boats, and the product is taken to Torre del Greco and Livorno.
The coral of the Red Sea is not of the valuable kind. A rich bank is said to have been discovered on the Japanese coast, whose product possesses the peculiarity of being white in the centre and at all the lateral.points ; but it is apt to scale or break off.
In the N. African fisheries, coral is divided into the following classes :—(a) " Dead " or "rotten," including the roots adhering to the rock, and covered with vegetable and mineral incrustations, worth 5-20 fr. a kilo.; (b) " black," which gives a polished black surface, suited for mourning jewellery, and fetches fr. a kilo. ; (c) " in case," or coral which has been assorted and cleaned when taken from the sea, consisting of branches of all sizes, and worth 45-70 fr. a kilo,; (d)" choioe," or finest, selected, large branches, valued at 400-500 fr. a kilo.
The imports of coral into the United Kingdom in 1870 (the latest specific) Return) were :-1600 lb. of" fragments," 418 lb. of "whole," 652 lb. of "negligees," and 958 lb. of "beads," the total being 3628 lb., value 14,878/. ; the figures fluctuate immensely, having been 8106 lb. in 1868, 1087 lb. in 1863, and 16,385 lb. in 1861. These statements take no account of the quantities of valuable coral brought in passengers' luggage. In the 10 years ending 1876, France imported 21,596 kilo. of rough coral, value, 1,890,356 fr., and 14,553 kilo. of worked, unmounted coral, value 5,078,062 fr. British India, in 1879, imported 79,643 lb. of real coral, value 81,862/. Quantities are exported from India into Thibet, in pierced grains of round or oval form, the darkest colours being most esteemed. China imports various kinds from Singapore, Sumatra, and the Samar Islands, black being preferred.
An imitation of coral for ornamental work may be made by dipping twigs in a mixture composed of 4 parts of rosin, 3 of bees-wax, and 2 of vermilion, melted together.
The London market value of coral fluctuates very widely. The finest rose-pink specimens range between 80/. and 120/. an oz.; small pieces of ordinary red are worth about 21. an oz. ; while small fragments (collette) for necklaces bring about 5s. an oz.
Bibliography.—K. Mobius, Die echten Perlen ' (Hamburg : 1857) ; T. von Hessling, ' Die Perlmuschel and ihre Perlen ' (Leipzig : 1859); H. Laeaze-Duthier, Histoire naturelle du Corail ' (Paris : 1864) ; C. R. Markham, The Tinnevelly Pearl Fishery' (Jour. Soc. Arts, Vol. xv., No. 747, Lond. : 1867) ; P. L. Simmonda, Commercial Products of the Sea' (Lend.: 1879); M. Lindeman, Die Seefischereien ' (Gotha : 1880). (See also Gems).