Four years of extraordinary activity transformed the exhausted island into a prosperous country, a reform which we may follow in the memoirs of General Wood. Two years of endeavour extirpated the yellow fever, which had prevailed in Havana since 1762. The Yankees fought the mosquitos, the vehicles of the disease, and their sanitary works and measures decreased the death-rate from 91.3 per 1,000 in 1898 to 20.63 in 1902. In the same period the deaths among the American troops fell from 91.03 to 20.68. They also attacked malaria {319} and tuberculosis, until Havana, as one of them proudly writes, became one of the healthiest cities of America. Pavements, gutters, sewers, the demolition of old buildings and the construction of new; asylums, hospitals, and prisons, gave the island an aspect at once modern and sanitary. The fiscal revenues, formerly badly employed by an unskilful bureaucracy, found useful employment; dilapidations were noted and a railway statute was passed. The Yankees opened up new roads, knowing how far the prosperity of the island depended on them; in 1906, the second year of the occupation, there were only 610 kilometres of carriage-roads in Cuba, while Jamaica, with one-fifth the area, had 10,113.[3] Communications being thus improved, the sugar industry, on which the prosperity of the island depends, developed rapidly. The visitors did not forget to attract immigrants and to reconstruct the ports. The government of General Wood installed modern schools in the old Spanish school-houses, while it built special schools, kindergartens, and technical colleges in the large towns. Under the Spaniards education was obligatory, no doubt, but it was the Americans who brought a lapsed law into force. Fines punished parental neglect. A thousand teachers went to Harvard, in the year 1900 alone, sent thither by General Wood to improve their methods of teaching; new pedagogic methods and a wider culture strongly modified social and political life. The Americans left ten times as many schools as they found, and an education adequate to the race and the Cuban child, who is "impressionable, nervous, and furiously imaginative." Governor Wood requested his country to reduce by one-half the customs rates upon the coffee, fruits, and {320} sugar which the island produced, as the basis of a _Zollverein_ profitable to both countries. He complained, in his memoir, of the indifference of the wealthy towards the communal and political life, which he wished to render more active. A law passed by him regulated the elections in the new Republic.