"'Small islands, innumerable, scattered among those marked here; these being the principal. Many of these islands are low, and show but little above the water. Sailing is very perilous, and not to be attempted at night.'
"You see, in this course we shall have the advantage of being well out of the ordinary line of passage of the Spaniards, who shape their course more to the southward, make Porto Rico their first landfall, and then have the two great islands, Hispaniola and Cuba, lying straight before them; free, as it seems, by the chart, from any dangers to navigation.
"Roger, from this evening we will compare our log books day by day, so that you may learn where it is that you have gone wrong. But I can guess how it is. The wind is blowing chiefly from the east, and you will never make allowance enough for drift; and I have told you over and over again that, with a light wind on our beam, we drive a mile to leeward for every two we go on our course. There are many ships which will drift nigh a mile for every mile they sail, in light winds. When the wind is brisk, and we are going fast through the water, then we drift but little, not more perhaps than one mile to six or seven."
"But why is that, father? How is it that a light wind blows us away sideways; and that a strong wind, instead of blowing us more, blows us less?"
"That I cannot tell you, Roger. You must leave those questions for wiser heads to settle. I only know that it is so--of that there is no doubt at all; but why, I have not the least idea.
"How does it strike you, Pengarvan?"
The Cornishman shook his head.
"I have thought it over, Captain, many times. It seems to me, sometimes, that I have a sort of notion why it is; but it is not clear, even to myself. I could not put it into words."
The first mate now looked into the cabin.
"Here we are, James. Pengarvan puts her here, opposite these three little islands. I put her here some sixty miles away."