Читать книгу The Book of the Pearl. The history, art, science, and industry of the queen of gems онлайн

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The oysters are found in well-known and permanently located banks or paars in the upper end of the Gulf of Manaar, in the wide shallow plateau off the northwest end of the island and directly south of Adams Bridge. The hard calcrete bottom is formed mostly of sand combined with organic remains in a compact mass and with more or less coral and shell deposits. The density of the water, as determined by Professor Herdman (to whose important and valuable report^[133] we are indebted for much information), is fairly constant at 1.023, and the temperature has a normal range of from 82° to 86° F. during the greater part of the year. The charts and records refer to about twenty paars, but most of these have never yielded extensively, either to the English or to the Dutch. In the aggregate, they cover an area fifty miles in length and twenty miles in width. Most of them are from five to twenty miles from the shore, and at a depth of five to ten fathoms. The principal paars are Cheval, Madaragam, Periya, Muttuvaratu, Karativu, Vankalai, Chilaw, and Condatchy. Only three have afforded profitable fisheries in recent years, i. e.: Cheval, Madaragam and Muttuvaratu.