northeast trade winds, which temper the heat. The topography causes local climatic differences and the natives even speak of the ‘rigors of winter’ in the upper altitudes. The annual range of temperature is from 100°, which is very rare, to 50°, which is sometimes reported among the mountains. The mean annual temperature at San Juan, on the north coast, ranges from 78° to 82°. The climate would seldom be oppressive if it were not for the constant high humidity. Rain falls almost daily, the annual precipitation at San Juan averaging 60 inches. Nearly two-thirds of the precipitation falls in the summer and autumn. The rain increases from San Juan eastward, is heaviest on the highlands, which arrest much of the precipitation, so that the south slope of the island is much drier, and in some regions irrigation is necessary for the cultivation of crops. Among the causes that interfere with agricultural prosperity are hurricanes. Between 1515 and 1899 eighteen very destructive hurricanes occurred. The especially disastrous hurricane which visited the island on Aug. 8, 1899, caused large loss of life and immense damage to crops, and 250,000 persons were compelled for some time to depend upon the Government for food.
Near the ocean the soil is quite sandy; it becomes loamy as it extends inland, and gradually changes from a sandy to a clay loam on ascending the lower foot hills. The soil of most of the coastal plains is rich alluvium, which gradually merges into the clay loam of the hills. The ferruginous clay of the mountains is a source of abundant supply of plant food.
Flora. The island is famous for the number and size of its trees. The fine forests of the higher region resemble those of other islands of the West Indies, but are almost destitute of parasitic vegetation excepting orchids. The trees include several species of palms, a beautiful tillandsia whose wood, called sabrino, is used for timber, a hard wood called ausubo, which is much used for the frames of buildings, hard and soft Spanish cedar and ebony, the West Indian sandalwood, the laurel, willow, and many woods useful for construction. About thirty medicinal plants are utilized, twelve plants for condiments, twelve for dyes and tanning, and eight for resins, and many large trees produce edible fruits. The pastures are covered with nutritious grasses,
Fauna. The native fauna is very limited, there being no large mammals excepting those which are domesticated. There are no noxious reptiles and few insect pests. Flamingos and other water birds abound along the coast; and in the mountains are many birds, including doves. Fish of valuable species are abundant both in the fresh water and along the coasts. The gigantic tortoise is closely allied to the famous large tortoise of the Galapagos Islands.
Geology and Mineral Resources. The island has three geological elements: (1) A central system of deeply ribbed and corrugated mountains with V-shaped gorges and ridges; (2) lower hills along the north and south coasts; (3) coastal plains with alluvial soil extending from the foot of the central mountains across the line of foothills to the sea. The central mountains are formed of volcanic ejecta—tuffs and conglomerates—with occasional dikes and interbedded bluish limestone, which, however, is of rare occurrence. These mountain rocks, which are of Cretaceous and possibly early Eocene age, are entirely decayed at the surface, breaking down into a red clay resembling that of the southern Appalachians. The foothills are all of later Tertiary and Pleistocene age, and are composed entirely of rocks of sea origin, consisting of the peculiar type of tropical white limestones of a chalky, marly, and shelly nature. The island abounds in clay suitable for ordinary brick and earthenware. Good building sand is found, but little of it is sufficiently pure for glass-making. The white limestones of the coastal plain supply excellent lime. The building stones are volcanic boulders and limestone. Houses made of boulders have a picturesque and rubbled appearance. Those constructed of limestone are always stuccoed, and the most elaborate buildings are made of limestone, including all of the public buildings and fortresses. Beautiful marble of great hardness is quarried near Juana Diaz, but as yet is used only for structural purposes, such as bridge piers. Sandstone is comparatively rare, but fine flagstone is abundant all over the island. Gypsum is used extensively for stucco, plaster, and fertilizer. A large area of the southern coast abounds in phosphates, but the industry has developed only on Mona Island, off the west end of Porto Rico, where it is estimated that there are nearly 500,000 tons of guano and phosphates in the caves already explored. Only about 50,000 tons of these fertilizers have as yet been extracted. Near Ponce and elsewhere numerous caves are filled with rich deposits of guano, which are now being worked. Lignite is found, but the fuel resources have not yet been investigated. Sufficient salt for the needs of the island may easily be obtained from many lagoons near the sea by natural evaporation of the brine. The principal deposits are the salines of Coama, Guanica, and Sierra de Piñones de Cabo Rojo. Invalids resort to a number of mineral springs, chiefly at Ponce and Coamo.
No mining of metals is yet carried on. Those most frequently found are gold, carbonate and sulphide of copper, and magnetic oxide of iron. Since the discovery of the island, gold has been washed in small quantities from many rivers, especially in the north and east. Experience has shown that the placer deposits are not rich or extensive. At one place north of Juncos there is a large deposit of magnetic iron ore.
Agriculture. Sixty-three per cent. of the population is engaged in agriculture. Although the soil is very fertile, the methods of cultivation are crude and primitive. Modern agricultural implements, since the advent of the Americans, are slowly finding their way into the rural districts. The area of the island is 2,347,520 acres, of which only about 20 per cent. is cultivated, 51 per cent. being devoted to pasture, 7 per cent. waste land, and 22 per cent. covered with roads, streams, towns, and forests. Of the cultivated lands, 61,556 acres are in sugar cane, 122,358 acres in coffee, 4222 acres in tobacco, 93,508 in beans, rice, and maize, and 17,176 in fruits. The principal crops are sugar, coffee, and tobacco, whose mean annual production and value for the four years 1898-1901 were: Sugar, 67,582 tons, worth $4,520,740; coffee, 14,580 tons, worth $2,916,000; tobacco, 3342 tons, worth $367,620. Cane-sugar farming requires large capital, and in Porto Rico, where it is at present the most valuable crop, most of the planting is on large estates, with central mills for grinding. Comparatively
