No navigator could have been more careful than Columbus. Ever on the alert, he was far too anxious about the safety of his fleet to neglect one single precaution. As they voyaged, the difference in the saltness of the sea was noted; and though for eleven days the wind blew steadily from aft so that the sails required no trimming, yet all the while Columbus was busy with astrolabe and sounding lead endeavouring to fix his position in regard to the land which they had long since left. From Wednesday, February 13, till the following Saturday, he never slept a wink, being far too anxious to leave the navigation to others. The pilots of the _Nina_ and _Pinta_ on the voyage out used to work out their positions for themselves. On September 19 the _Nina_ made the Canaries to be 440 leagues astern, the _Pinta_ estimated the distance as 420, but on board Columbus’s ship the reckoning was 400 leagues, and this was the most correct of the three. (It should be added that Columbus used Italian miles, reckoning four Italian miles to one league.) He compared notes with the pilots under him, and manœuvred his ship so that the captain of the _Pinta_ was able to pass his chart on board the _Santa Maria_ at the end of a line. Columbus, after conferring with his own pilots and mariners, plotted on the chart the position of the ship. Here and there all the way through Columbus’s journal, both in those lines written by his own hand and in those in another handwriting, there rises up, quite clearly, evidence of the knowledge which this man had been collecting before setting out. “The admiral was aware,” says the Journal, “that most of the islands held by the Portuguese were discovered by the flight of birds.” Just as the Viking seamen had discovered land in exactly the reverse manner--by letting loose birds from the ship. Nor are there lacking plenty of references to the seamanship of these times--the kind of seamanship, we may not unjustly assume, that was employed alike by the Spanish traders who crossed the Bay of Biscay, and sailed up the English Channel to Flanders, and those who went exploring to the southward. No one better than these medieval and Elizabethan sailormen appreciated the importance of having a ship that would heave-to in bad weather or at night. You will remember that dramatic incident at the end of Columbus’s first voyage across the Atlantic, when the distant light, as of a candle going up and down in the hand of someone proceeding from one house to another, indicated that at last the new land had been found. “At two hours after midnight,” says the log, “the land was sighted.” Then (continues the narrative), “they shortened sail, and lay by under mainsail without the bonnets. The vessels were hove-to waiting for daylight.”