Moreover, Columbus had been absent from Genoa for several years. He had no claims upon any of the Genoese statesmen, and was without influence enough to carry his own ward. An application of any sort coming from such a man would have been treated with deserved contempt; and we may be very sure that, however much Columbus may have loved the old Genoese flag and desired an appropriation, he had far too much good sense to dream of asking any favors from his fellow-countrymen. Undoubtedly he was as anxious to start in search of America while he lived at Porto Santo as he was at a later period, but he knew that only a king would feel at liberty to use public funds in what the public would consider a wild and profitless expedition; and as there was no king whom he could hope to interest in his scheme, he naturally waited until a suitable king should appear. The death of Alfonso provided him with what he imagined would prove to be a king after his own heart, for King John was no sooner seated on the throne than he betrayed an abnormal longing for new countries by sending explorers in search of Prester John. [Æt. 45; 1481–82] This Prester John was believed to be a Presbyterian deacon who ruled over a civilized and Christian kingdom which he kept concealed either about his person or in some out-of-the-way part of the world. The wonderful credulity of the age is shown by this belief in a Presbyterian king whom no European had ever seen, and in a kingdom of which no man knew the situation. It ought to have occurred to the Portuguese king that, even if he could find this mythical monarch, he would not take any real pleasure in his society, unless he were to burn him. King John II. was a pious Roman Catholic, and, next to a Methodist, a Presbyterian king would have been about the most uncongenial acquaintance he could have made. Nevertheless, this Presbyterian myth was indirectly of great service to Columbus. King John, in order to facilitate his search for Prester John, asked a scientific commission to invent some improvements in navigation, the result of which was the invention of the astrolabe, a sort of rudimentary quadrant, by means of which a navigator could occasionally find his latitude. This invention was hardly inferior in value to that of the compass, and it is generally said to have provided Columbus with the means of finding his way across the Atlantic and back to Europe. [Æt. 45–46; 1482–84]