Island

i'land, a body of land surrounded by water. A island differs from a continent only in size. Now that Australia is regarded as a continent, Greenland, with an area of 500,000 square miles, is the largest island. Borneo, New Guinea, and Madagascar rank next. Great Britain is sixth in size; Cuba, thirteenth; Newfoundland, twelfth; Iceland, fifteenth; Ireland eighteenth.

Islands are classified usually as continental and oceanic. The former fringe the continents and are geologically connected with them. They are separated from the mainland usually by shallow seas. Save Iceland, all the islands named above are continental in origin. Continental islands are found to have the same animals and plants as the mainland of which they have formed a part. They contain rocks like granite and limestone. Oceanic islands are usually the summits of submarine volcanic islands. Their rocks are basaltic, formed of cooled lava. St. Helena, the Fiji Islands, Iceland, Stromboli, and the Hawaiian Islands are of this sort. Many low, flat islands prove to be of coral growth. They are coral reefs growing on a firm base that comes to within not less than twenty fathoms from the surface. Not infrequently flat islands are formed off the mouth of rivers by material carried down by the current and tossed back by the waves and tide.

Omitting the little known bodies of ice and land north of Hudson Bay, and the Antarctic land and ice polar cap, the following is a list of important islands and area of each in square miles: