With these aids to diplomacy, and doubtless also with the help of a dram or two of spirits or of the wine of Oporto, the treaty was soon concluded, and a very shrewd stroke of business accomplished for the King of Portugal; for it gave him the sole right of exchanging gaudy rubbish from Portugal for the precious gold of Ethiopia.

When the contents of the two freight-ships had been unloaded they were beached and broken up by the orders of King John, who wished it to be thought that they had been destroyed in the whirlpools of that dangerous sea, and that the navigation of those rough waters was only safe for the caravels of the Navy.

The fort was built in twenty days, and the expedition returned, laden with gold and ivory; Admiral Azumbaga remained behind in command of the garrison.
This voyage, which was a bold and adventurous one for the time, may be regarded as the first recognition of Columbus as a man of importance, for the expedition was manned and commanded by picked men; so it was for all reasons a very fortunate one for him, although the possession of the dangerous secret as to the whereabouts of this valuable territory might have proved to be not very convenient to him in the future.
Columbus went back to Porto Santo with his ambitions thoroughly kindled.
He had been given a definite command in the Portuguese Navy; he had been sailing with a fleet; he had been down to the mysterious coast of Africa; he had been trafficking with strange tribes; he had been engaged in a difficult piece of navigation such as he loved; and on the long dreamy days of the voyage home, the caravels furrowing the blue Atlantic before the steady trade-wind, he determined that he would find some way of putting his knowledge to use, and of earning distinction for himself.
Living, as he had been lately, in Atlantic seaports overlooking the western ocean it is certain that the idea of discovering something in that direction occupied him more and more.

What it was that he was to discover was probably very vague in his mind, and was likely not designated by any name more exact than "lands." In after years he tried to show that it was a logical and scientific deduction which led him to go and seek the eastern shore of the Indian continent by sailing west; but we may be almost certain that at this time he thought of no such thing.

He had no exact scientific knowledge at this date.