They contracted with the Chinese to bring copper, saltpeter, and other materials.

The casting of artillery is commencing now, and the securing of powder and ammunition; for if his Majesty should not choose to take up this enterprise, nothing will be lost by this, and it will suffice the Chinese that the duties were put at three per cent on whatever materials they bring for implements and munitions of war, and supplies needed here.
Second: A ship will be sent to Malaca to bring the tin and saltpeter needed in addition to that procured in China and powder, and a number of slaves to aid in the foundry work and other labors.
Third: The five thousand Visayan Indians of these islands will be brought together, and some good troops with the necessary arms.
Fourth: In whatever port of the islands the fleet is to enter, there will be ample accommodations, and full supplies for their reception; and, if they come to Cagayan, there are several advantages.

First: they will come directly from Espana, without danger from islands, shoals, or the like.

Second: the river has a good bar and four bracas of water and more, at low tide.

Third: it is on the China side, a two days' sail distant.