This is a sort of whirlwind, accompanied by rain, thunder and lightning, sometimes by earthquake shocks, and always by the most terrible and devastating circumstances that can possibly combine to ruin a country in a few hours.  A clear, serene day is followed by the darkest night; the delightful view offered by woods and prairies is diverted into the deary waste of a cruel winter; the tallest and most robust cedar trees are uprooted, broken off bodily, and hurled into a heap; roofs, balconies, and windows of houses are carried through the air like dry leaves, and in all directions are seen houses and estates laid waste and thrown into confusion.

The fierce roar of the water and of the trees being destroyed by the winds, the cries and moans of persons, the bellowing of cattle and neighing of horses, which are being carried from place to place by the whirlwinds, the torrents of water inundating the fields, and a deluge of fire being let loose in flashes and streaks of lightning, seem to announce the last convulsions of the universe and the death agonies of nature itself.

Sometimes these hurricanes are felt only on the north coast, at others on the south coast, although generally their influence extends throughout the island.

In 1825 a hurricane destroyed the towns of Patillas, Maunabo, Yabucoa, Humacao, Gurabo, and Caguas, causing much damage in other towns in the east, north, and center of the island.  The island was also visited by a terrible hurricane in 1772.

Earthquakes.—­Earthquakes are somewhat frequent, but not violent or of great consequence.  The natives foretell them by noticing clouds settle near the ground for some time in the open places among the mountains.  The water of the springs emits a sulphurous odor or leaves a strange taste in the mouth; birds gather in large flocks and fly about uttering shriller cries than usual; cattle bellow and horses neigh, etc.  A few hours beforehand the air becomes calm and dimmed by vapors which arise from the ground, and a few moments before there is a slight breeze, followed at intervals of two or three minutes by a deep rumbling noise, accompanied by a sudden gust of wind, which are the forerunners of the vibration, the latter following immediately.  These shocks are sometimes violent and are usually repeated, but owing to the special construction of the houses, they cause no damage.

Tides.—­For seven hours the tide runs rapidly in a northwest direction, returning in the opposite direction with equal rapidity for five hours.

Orography.—­The general relief of Porto Rico is much inferior in altitude to that of the rest of the Great Antilles, and even some of the Lesser Antilles have mountain summits which rival it.

A great chain of mountains divides the islands into two parts, northern and southern, which are called by the natives Banda del Norte and Banda del Sur.  This chain sends out long ramifications toward the coasts, the interstices of which form beautiful and fertile valleys, composed in the high parts of white and red earths, on the spurs of black and weaker earths, and near the coasts of sand.