In 1650, the population of Habana was hardly more than three thousand, but in the following two or three decades it doubled, owing to a large immigration of Spaniards from Jamaica. During this period, the City rose to be the commercial centre of the Spanish-American possessions and the principal rendezvous of the royal fleets that carried on the trade monopoly between Spain and America. The walls enclosing the City were commenced in 1671 and finished thirty years later. The City was frequently threatened by English squadrons, and actually captured in 1762. At the close of the Seven Years’ War Habana was restored to Spain in exchange for the Floridas. The short period of the British occupation, during which the port was thrown open, greatly [Illustration: LA FUERZA, HABANA.] stimulated the trade of the City and the general commerce of the Island. The modern history of Habana dates from this event. A map of the City at the beginning of the nineteenth century strikingly illustrates its rapid growth. Then the residences were almost all _intramuras_, or within the walls. Large _estancias_ and _huertas_ occupied ground which is now intersected by paved streets and covered with substantial buildings. Even in the past decade a marked change has taken place, amounting to complete transformation in certain sections. The improvements have in many instances been at the expense of picturesqueness and have entailed the loss of several historic landmarks. But the gain in sanitation and convenience has been great. Habana, which under Spanish rule had a death rate exceeding thirty to the thousand, now boasts a lower mortality than that of New York. The first impression made upon the visitor is by the massive character of the architecture. This characteristic is more pronounced than in any other Latin-American city. The building material generally used is a conglomerate of marine material, which hardens on exposure to the air. It is hewn into great blocks and so used in construction. Walls are usually covered with stucco, or plaster, and colored in a variety of tints. Roofs are either flat, or built of the old Spanish red tiles. The effect, which is enhanced by the presence almost everywhere of trees and shrubs, is pleasing in the extreme.