The average rainfall is 7o inches. For the north coastal region it is about 6o in., for the south about 3o in., and for the central mountain portion about ioo inches. This uneven distribution has been largely overcome by the irrigation systems, which collect in reservoirs the abundant rainfall of the northern side of the mountain ranges and tunnel through to the south plains which thus are regularly watered by irrigation. Winter rains are com paratively light, with a slight increase from February to May and thereafter the general average is maintained throughout the summer months. The rainfall is generally largest from September to November. The rains are sometimes heavy, but are usually of short duration. During the rare passage of a tropical hurricane the period of continuous rainfall may be extended. The average humidity during the day is about 70%, and during the night about 85%.
The trade-winds, aided by the daily recurrence along the coasts of the cool, invigorating sea breeze,- constitute a most beneficent provision in the tropics. This is especially true in Porto Rico. It is situated far out in the Atlantic ocean, nearly I,000 m. from the mainland. Thus it receives in full measure the trade-winds which blow almost constantly from the north-east, veering sometimes to the east and south-east.
Porto Rico is in the storm belt of the Caribbean region and is subject to occasional visits from the West India hurricane. It has suffered severe losses of life and property from these visita tions. Fortunately these visits have been rare. Most of these storms occur from July to October.
The physical conformation of Porto Rico, rising as it does from low coastal plains to mountains sometimes with altitudes of 4,400 ft. covered in most places with a generous and pro ductive soil, is such as to furnish an astounding variety of plant life. The National Forest Reserve at Luquillo, is a typical tropical forest with original growths of all kinds almost jungle like in density and variety of tree and vine and shrub life. Com
pared with this the carefully cultivated orchards of the fruit growers afford a contrast most striking and interesting.
It is probable that before the coming of the Spaniards the entire island was densely wooded. Now little of the original forest growths remain. But there are coffee plantations, coco nut groves, fruit farms and ornamental flowering trees and shrubs both indigenous and imported. There is a long list of what might be considered the common useful trees, among which are the bamboo, palm, cedar, ebony, calabash, whitewood, lance wood, boxwood and logwood. Among the fruit-bearing trees and shrubs are the avocado or alligator pear, orange, lemon, lime, grapefruit, almond, cocoa, coffee, coconut, nispero, pomegranate, gooseberry, raspberry, guava, banana, pldtano, breadfruit, mango and papaya. Almost all the food plants are grown in Porto Rico. Among the medicinal, useful and rare plants may be noted chicory, indigo, vanilla, castor, plumbago, ginger, sisal, mallow, pachouli, salvia, elder and aloe.
Government.—From the date of the discovery of Porto Rico by Columbus, to 1898, when the first military gov ernor was appointed by the President of the United States, 542 governors ruled the island for Spain, the first being Ponce de Leon. Nearly all were army officers and most of them of in ferior rank. By these officers Porto Rico was governed practically on the same plan as other Spanish colonial possessions. The governor was supreme in military affairs, and practically so in civil. The executive, legislative and judicial functions were for most of the time vested in the captain-general. Whatever offices, boards or tribunals existed were used merely for the transactions of routine business. The captain-general's .authority was not limited except in a general way by the laws of the Indies and by royal decrees. This condition existed until 187o, when under a liberal Government Porto Rico was made a province of Spain and given representation by deputies, elected by the people, in the Spanish Cortes. This lasted only four years when the pro vincial deputation was abolished and the island returned to its old status. In 1877 the deputation was re-established, and in 1897 Porto Rico was given an autonomous Government, but it never became operative because of the Spanish-American War and the consequent occupation of Porto Rico by the American army in 1898. The military government of Porto Rico by the United States was of short duration, Oct. 18, 1898, to May 1, 1900. In April 1900 Congress provided for a civil government in what was known as the "Foraker Act," and on May 1, Charles H. Allen was inaugurated the first civil governor.