At that time there was a less general understanding of the fundamental principles of weather, even among good seamen, than there is now. For my own part, it has always been difficult for me to remember instructions when they had to be memorized; but when I once have mastered principles my troubles are over. I do not have to search the stores of memory for a formula which fits the occasion, like a formula in chemistry, and I rarely go astray. Captain Nelson had not got far into the subject when he interrupted himself. “Well, Tim,” he said, “that ’s enough for this time. Better be off about your business, and we ’ll have another lesson before long. I want you to learn to navigate a vessel.” This was good news to me. I knew nothing whatever about navigation, or perhaps I should not have been so pleased. When Captain Nelson had given me some instruction, and I plunged into Bowditch by myself, I found that I had plunged into deep water without knowing how to swim. I was not satisfied to do things in a superficial way, according to formula, without knowing what I was doing, or why, and at first I had a heartbreaking struggle with mathematics beyond my preparation for it. But I happened to discover, quite by accident, in the third mate, Mr. Brown, a man who knew all that mysterious country—or those seas. Mr. Brown piloted me through those strange seas with considerable skill and great patience, so that I could attack my navigation with some satisfaction. But I am getting ahead of my story. {109} Flocks of petrels, or Mother Carey’s chickens, were about the ship by noon, with their curious habit of flight, as if walking on the water. By the middle of the afternoon the wind had come in from the eastward, and by dark it was blowing fresh, the wind heavy and wet and increasing. Sail was reduced to reefed topsails, and the Clearchus was put as close to the wind as she would go, making a course a little south of southeast. Sailing on a taut bowline was not one of the strong points of the Clearchus. She labored a great deal, the seas slapped up against her bluff bows, she made much fuss and comparatively little headway, but considerable leeway. There was nothing to do, however, but to make everything snug, and to trust in Providence and the ship; and I turned in with no misgivings, and slept soundly.