of these and coated with mud from its fertilizing volcanoes, supports 587 inhabitants to the square mile; but this exceptional average is due to rare local productivity.  Java’s little neighbors to the east, Bali and Lombok, each with an area of only about 2100 square miles, have a density respectively of 338 and 195 to the square mile.  This density rises suddenly in small Amboina (area 264 square miles), the isle of the famous clove monopoly, to 1000,[952] drops in the other Moluccas, where Papuan influences are strong, even to 20, but rises again in the pure Malayan Philippines to 69.  In the Philippines a distinct connection is to be traced between the density of population and smallness of area.  The explanation lies in the attraction of the coast for the sea-faring Malay race, and the mathematical law of increase of shoreline with decrease of insular area.  Since 65 per cent. of the whole Philippine population inhabits coastal municipalities, it is not surprising that the 73 islands from ten to a hundred square miles in area count 127 inhabitants to the square mile, and those of less than ten square miles, of which there are nearly a thousand, have a density of 238.[953]

This same insular density, supported by fertility, fisheries and trade, appears again in the West Indies, and also the contrast in density between large and small islands down to a certain limit of diminutiveness.  The Greater Antilles increase in density from Cuba through smaller Haiti and Jamaica down to little Porto Rico, which boasts 264 inhabitants to the square mile.  In the smaller area of the Danish Indies and Guadeloupe about this same density (215 and 274) reappears; but it mounts to 470 in Martinique and to 1160 in Barbadoes.[954]

[Sidenote:  Island resorts.]

Climate advantages often encourage density of population on islands, by attracting to them visitors who make a local demand for the fruits of the soil and thereby swell the income of the islands.  For instance, about the densely populated region of the Gulf of Naples, Procida has 14,000 inhabitants on its one and a half square miles of area, while fertile Ischia and Capri have 1400 to the square mile.  Here a rich volcanic soil, peaks which attract rain by their altitude and visitors by their beauty, and a mild oceanic climate delightful in winter as in summer, all contribute to density of population.  Sicily, Malta and Corfu also gain in the same way in winter.  The Isle of Man owes some of its recent increase of population, now 238 to the square mile, to the fact that it has become the summer playground for the numerous factory workers of Lancashire in England.

[Sidenote:  Density of population affected by focal location for trade.]