Whoever imagines he can find the variation within a degree, will very often see himself much deceived. For, besides the imperfection which may be in the construction of the instrument, or in the power of the needle, it is certain that the motion of the ship, or attraction of the ironwork, or some other cause not yet discovered, will frequently occasion far greater errors than this. That the variation may be found, with a share of accuracy more than sufficient to determine the ship’s course, is allowed; but that it can be found so exactly as to fix the longitude within a degree, or sixty miles, I absolutely deny. CHAP. IV. THE TWO SHIPS LEAVE THE CAPE OF GOOD HOPE.—TWO ISLANDS, NAMED PRINCE EDWARD’S, SEEN, AND THEIR APPEARANCE DESCRIBED.—KERGUELEN’S LAND VISITED.—ARRIVAL IN CHRISTMAS HARBOUR.—OCCURRENCES THERE.—DESCRIPTION OF IT. After the disaster which happened to our sheep, it may be well supposed I did not trust those that remained long on shore; but got them, and the other cattle, on board as fast as possible. I also added to my original stock, by purchasing two young bulls, two heifers, two young stone-horses, two mares, two rams, several ewes and goats, and some rabbits and poultry. All of them were intended for New Zealand, Otaheite, and the neighbouring islands, or any other places, in the course of our voyage, where there might be a prospect that the leaving any of them would be useful to posterity. Towards the latter end of November, the calkers had finished their work on board the Discovery, and she had received all her provisions and water. Of the former, both ships had a supply sufficient for two years and upwards. And every other article we could think of, necessary for such a voyage, that could be had at the Cape, was procured; neither knowing when, or where, we might come to a place where we could furnish ourselves so well. Having given Captain Clerke a copy of my instructions, and an order directing him how to proceed in case of separation; in the morning of the 30th, we repaired on board. At five in the afternoon, a breeze sprung up at S. E., with which we weighed, and stood out of the bay. At nine it fell calm, and we anchored between Penguin Island and the east shore, where we lay till three o’clock next morning. We then weighed and put to sea, with a light breeze at south; but did not get clear of the land till the morning of the 3d, when with a fresh gale at W. N. W., we stood to the S. E. to get more into the way of these winds.