Montalvo was the first to urge that Cuba be protected not alone with land fortifications and batteries but also by naval vessels. Particularly he wished for a powerful war-galley, which the king did not provide him. In 1576 French raiders attacked Santiago, and were with difficulty repulsed; upon which Montalvo sarcastically reported that if another such attack occurred he would himself be relieved of the necessity of fortifying the harbor and city of Santiago, for the place would cease to exist. A little later a daring French raid was made upon Spanish shipping just outside the harbor of Havana. This greatly incensed Montalvo, and caused him to renew his pleadings for a galley. He urged that the whole Cuban coast should be patrolled by light, swift vessels, preferably frigates, and that strong galleys should be stationed at the chief ports. He would have had the frigates, at any rate, built in Cuba and at least partly paid for by that island; but the Havana municipal council protested against this, demanding that Cuba be entirely exempted from the costs of defending her from enemies. The result was that in the lack of means of defence Cuba suffered more and more from the ravages of privateers and freebooters, which became more frequent as the island increased in population and wealth and thus became better worth raiding.
The third unfavorable feature of the time was the haggling over La Fuerza. Begun by De Soto, and later almost entirely rebuilt, that famous fortress seemed to be under some malign spell which made it a source of injury rather than of benefit to Havana. Year after year passed, appropriation after appropriation was made and expended, and still it remained unfinished. Man after man undertook the task of completing it, only to fail and lose his personal reputation either for efficiency or for honesty. Moreover, as the work proceeded grave faults were developed, both in plan and in construction. The fort, which at first had been denounced as needlessly large, was seen to be entirely too small to shelter a garrison sufficient for the defence of Havana. The original design had been to make it a shelter to which all the people of the town could flee in case of attack, and it might have served this purpose at a time when the people of Havana were numbered by scores, or at most by a hundred or two. But with the figures extending into thousands it became evident that La Fuerza was entirely inadequate to any such purpose. Indeed, it was realized that that design was ill-conceived, for if the place was to grow into a considerable city it would be impracticable and undesirable to make any fortification large enough to hold all the population.
The construction was also faulty. The fort was built of stone, but there had thoughtlessly been chosen for the purpose a stone which had the advantages of being plentiful and so soft as to be easily worked. Unhappily it had also the very serious disadvantages of being so soft that it would probably soon be battered to fragments by cannon balls, and of being so porous that water soaked into and through it as through a sponge. During the rainy season the place was flooded, water standing in pools on the floor, and the magazine being so wet that gunpowder could not be kept there without spoiling; wherefore another building, of wood, had to be provided for that purpose. The same kind of stone was used, moreover, for the reservoir which was to provide fort and city with water, with the result that its contents quickly leaked out. There arose a proverbial saying in the city that the powder magazine was always wet and the water reservoir was always dry; and it was sarcastically proposed that the functions of the two be exchanged. The powder would be kept dry in the reservoir, and there would always be plenty of water in the magazine! Nor was this the only error in construction. The whole structure was said to be dangerously weak, so that if all its guns should be fired simultaneously, the shock might tumble the walls into ruin. The guns were available for use in only a narrow zone; they were of too short range to carry to the other extremity of the harbor, and they were so placed that they could not be depressed so as to hit vessels which had come close in toward the water front of the city. Therefore a hostile ship with long range guns could lie out of reach of La Fuerza and bombard the fort and city at will. Or one could sail swiftly in, running the gantlet of the narrow zone of fire, and gain a place under the walls of the fort where it would be quite safe for the guns of the latter while it could use its own at short range with deadly effect. It was also complained that the parapet was too low to afford shelter to the men serving the guns, and that the four big wooden gates were a source of fatal weakness.
It was presently perceived, too, that fortifications elsewhere than in the heart of the city were needed for adequate defence of the place. Especially were such works needed at the headlands commanding the entrance to the harbor. Without them, a daring enemy might seize one of those spots, bring up some long range guns from his ships, and have not only Havana but La Fuerza itself at his mercy. Montalvo appears to have recognized this need, and to have urged the construction of such forts, especially on the Cabañas hill, but to no avail. Instead, the royal government proposed the construction of a strong wall around the entire city, including the water front. It actually ordered that work to be undertaken, the first step being to destroy a large part of the city, including the church, to make room for the wall. Against this suicidal policy Montalvo effectively protested, declaring that if the city were thus demolished it would never be rebuilt, and also pointing out that the day of walled cities was past. In the face of his representations the wall scheme was abandoned; but his wise suggestions of forts commanding the harbor were not acted upon until years afterward.
It is to be recorded to his credit that Montalvo gave more attention than his immediate predecessors had done to development of some of the natural resources of the island. He interested himself in forestry, and soon had an immense trade in timber and lumber between Cuba and Spain. The exquisite cabinet work of the Escurial, in Spain, was made of wood from the forests of Cuba—mahogany, ebony, ironwood, cedar, and what not. Wood was supplied for other purposes, too, notably for ship-building. It was at this time that interest arose in the great island just off the southern coast, which at that time was so richly clad with pine forests as to receive from Montalvo on that account its present name of "Isle of Pines." During the administration of Menendez the whole island was granted to Alfonso de Rojas for a cattle range, a purpose for which it was admirably adapted, and there are legends to the effect that the water between the Isle of Pines and Cuba was at times so shallow as to make it possible to drive herds of cattle across from the one land to the other. It is to be observed, in passing, that thus early in history was the Isle of Pines recognized as an integral part of Cuba.
Montalvo also did much to promote agriculture, and the raising of swine. He endeavored to revive interest in both gold and copper mining, and seems to have been persuaded that there were enormously rich deposits of the former metal hidden somewhere on the island, in places known only to the natives. He strove diligently and persistently to get from the few surviving Indians information concerning these mines, but in vain. If the Indians knew, they would not tell; but it seems altogether probable that they did not know, and that no such mineral wealth existed on the island.
It was in Montalvo's time, too, that what was destined to become Cuba's greatest industry had its permanent establishment. At various times and places thitherto men had experimented with sugar growing and manufacture, with varying degrees of success. But every such undertaking had after a while been abandoned, either for lack of profit or because of the superior attractions of something else. It was not until 1576 that plantations were established which were never to be abandoned but were to continue in cultivation down to this present time, and that sugar mills of similar permanence were put into operation. The scene of this epochal enterprise was the region around Havana, particularly between Havana and Matanzas. There in the year named at least three mills were established, a fact indicating that a considerable area was planted in cane. These mills were of the most primitive description, each consisting of three wooden