Chap. II.]
CHANGE OF TEMPERATURE.
49
1841
the north end of New Zealand, distant rather more than a thousand miles.
We were much surprised to find the temperature both of the air and of the sea rise very considerably on leaving the harbour: the air from 55º to 60º; the surface of the sea from 55º to 63º immediately outside the Heads, which latter temperature continued without variation as we increased our distance from the land, that of the air again falling as the night advanced.
We observed some vivid lightning in the S.E., and apprehended a change of wind, but in this we were fortunately mistaken, the strong westerly breeze prevailing, and carrying us rapidly forward on our course, so that by noon the next day we had run a distance of one hundred and fifty miles, and were, by observation, in lat. 33º 52′ S., long. August 6. 154º 8′ E., dip 62º.41, var. 9º 42′ E.; by which also we found that we had been carried by a current twenty-nine miles to the south, which may in some measure account for the increased temperature of the sea above mentioned. At night, the Terror falling far astern, rendered a reduction of sail necessary, to our great mortification, as we had been struggling hard the whole day to keep a-head of a merchant ship which sailed some hours after us from Sydney, and which we now observed going fast past us, under comparatively easy sail; but our vessels were very deeply laden, considerably below their bearings, having completed to three years' provisions, stores, and fuel, at Sydney; so