"I'll agree to it if it so be Uncle Zenas is willin' to keep ship alone," the keeper replied. "If the wind _does_ haul 'round, it won't be any great hardship if you an' the cook turn out an hour earlier than usual, so's we can get the lantern put to rights early." "You can call all hands at three o'clock, so far as I'm concerned," Uncle Zenas interrupted, "an' then I'll be so far along with my end of the work that I can give you a lift in the lantern." "I don't reckon there's any great need of turnin' out quite so early as that; but Sammy might wake me an hour sooner than usual, so's he could get somethin' of a nap, an' we'll make it all hands 'bout four o'clock." And thus it was arranged when Sidney went to bed, hoping most fervently that he might waken in time to share the watch with Captain Eph; but it so chanced that he did not open his eyes until nearly three o'clock next morning, much to the disappointment. He hurried into the watch-room as soon as possible, however, and there found the keeper studying over the drawing he had made for the purpose of showing how the rays of light were "bent." "What are you doing, sir?" Sidney asked laughingly. "Tryin' to figger this thing out so's to understand it myself," the captain replied grimly. "I put it to you same's I'd heard the inspector talk, but what puzzles me is why the light should go toward the thick end of the prism any quicker than the other way." Captain Eph had before him all the books of the library which might aid in the work, and Sidney found the problem so interesting that it seemed as if he had no more than begun before Uncle Zenas' voice was heard from the room below, as he said petulantly: "It strikes me if I was standin' watch I'd know when it was four o'clock. How do you ever expect to get off on your voyage early, Ephraim Downs, if you can't keep better run of the time than this?" "All right, Uncle Zenas, all right! If you'll call Sammy we'll get our odd chores done up before sunrise," the keeper cried, and the cook replied: "He'd ought'er be awake by this time; I've turned him clean over twice, an' count on pullin' him out bodily if he don't make some kind of a move before I count five." The sound of a heavy body striking the floor below told that Mr. Peters had "moved," and Sidney cried in surprise: "If you'll believe it, I'd almost forgotten that we might go ashore this morning. Has the fog cleared away?" "Every blessed drop of it went to sea when the tide turned, jest as I allowed; but I got so mixed up about the lens that it went straight out'er my mind. Now it's a case of gettin' things inter shape with a hustle." Sidney went into the kitchen, believing he could be of more service there than anywhere else, and, thanks to the will with which the crew worked, the start was made in considerably less than an hour after sunrise.