so that the ships might have sailed over it.  If I had not measured this depth, I would not have believed that there was a sufficient weight of ice above the surface to have sunk the other so much below it.  Thus it may happen, that more ice is destroyed in one stormy season, than is formed in several winters, and an endless accumulation is prevented.  But that there is always a remaining store, every one who has been upon the spot will conclude, and none but closet-studying philosophers will dispute.[3]

[Footnote 3:  These observations of Captain Cook, in addition to some remarks which were formerly given on the subject, seem conclusive against the supposition of such large masses of ice being the product of rivers, as has not unfrequently been maintained.  They may, however, have proceeded from land in another way, being occasioned by the consolidation of snow into such masses as were of sufficient weight to separate from the declivities where they had been formed.  This undoubtedly may sometimes happen; but the explanation of their origin formerly offered, seems much more entitled to consideration, as a generally operating cause.  The last remark which Captain Cook makes, appears to have been levelled at some would-be-wise heads, who had hazarded reflections about the possibility of some time or other finding an open sea in high latitudes.  But, however illiberally stated, it is in all probability just, though for a reason unknown to Cook.  The chemical reader will perceive we allude to the circumstance of the absorption of heat that takes places during the liquefaction of ice, in consequence of which the temperature of the surrounding atmosphere is reduced so much, as to prevent any more of the ice being dissolved.  A contrary operation, as is now well known, takes place during the congelation of water, and heat is evolved.  Thus then the cold of winter is moderated.  And so, on the whole, the temperature is kept more uniform, than, without such adjustment, would be the case.—­E.]

A thick fog, which came on while I was thus employed with the boats, hastened me aboard, rather sooner than I could have wished, with one sea-horse to each ship.  We had killed more, but could not wait to bring them with us.  The number of these animals, on all the ice that we had seen, is almost incredible.  We spent the night standing off and on amongst the drift ice; and at nine o’clock the next morning, the fog having partly dispersed, boats from each ship were sent for sea-horses.  For, by this time, our people began to relish them, and those we had procured before were all consumed.  At noon, our latitude was 69 deg. 17’, our longitude 183 deg., the variation by the morning azimuths, 25 deg. 56’ E., and the depth of water twenty-five fathoms.  At two o’clock, having got on board as much marine beef as was thought necessary, and the wind freshening at S.S.E., we took on board the boats, and stretched to the S.W.  But not being able to weather the ice upon this tack, or to go through it, we made a board to the east, till eight o’clock, then resumed our course to the S.W., and before midnight were obliged to tack again, on account of the ice.  Soon after, the wind shifted to the N.W., blowing a stiff gale, and we stretched to the S.W., close hauled.