18. The commerce in the iron that is necessary for these islands will alone produce, in fifteen or twenty years, more money than what they now have; and if the Indians were compelled to clothe themselves with the fabrics of the land, even with the little commerce that we have the islands would abound with silver. The trade with Nueva España in iron would be extremely advantageous to his Majesty; for the mines of Sonora and other provinces further inland cannot be worked, on account of the transportation from Mexico of the great amount of iron and quicksilver that is necessary; and this, and the expenses which are added for the conveyance of silver to Mexico, leave very little profit to the miners. 19. In carrying the iron from these islands and the quicksilver from Peru to Acapulco or to La Navidad, these effects can be transported in small vessels, and with little expense, to the coast of Guadalajara; they will cost less than if purchased in Mexico; at least thirty or forty pesos will be saved on the transportation of every arroba; and, if on the return trip by the same route the silver is embarked for Acapulco, there will be a great saving of freight in the transportation of this metal. 20. Let a computation be made of the money which must have gone out from the islands since their conquest, in order to purchase the very products in which they abound, and the amount will be incalculable for the items of cinnamon, iron, saltpetre, and other products. Let also computation be made of what the outlays must have been for purchasing wines, mirrors, and the other things which, as I have stated above, could be brought directly from España; and it will be seen that by our own fault we have enriched our enemies, and that we could have annihilated their commerce and increased our own with only the sources of gain which are pointed out in the present exposition. Then let us, even though it be late, have the discernment to avert our total ruin, by striving, with glorious emulation, to secure the greatest prosperity for the Spanish nation. Chapter Fourth: Of the necessity for forming a company in these islands