At one P.M. of each day, when the weather was favourable, the ship was hove-to for the purpose of obtaining observations on the temperature of the water at considerable depths, under the superintendence of Lieutenant Dayman.  As these were continued during our outward voyage as far as Van Diemen’s Land, and the number of observations amounted to 69, the results will more clearly be understood if exhibited in a tabular form, for which the reader is referred to the Appendix.  “Two of the Sixe’s thermometers were attached, one at the bottom of the line of 370 fathoms, the other 150 fathoms higher up.  The depth recorded is that given by Massey’s patent sounding machine.  As the same quantity of line was always used, the difference of depth of each day should be trifling, varying only in proportion to the ship’s drift; yet on several occasions the depth recorded by the machine gives as much as 100 fathoms short of the quantity of line let out."*

(Footnote.  Lieutenant Dayman, R.N.)

Boat capsized.

While engaged in sounding, a process which usually occupied three-quarters of an hour, a boat was always at my service when birds were about the ship, and the state of the sea admitted of going after them—­by this means many species of petrels were obtained for the collection.  On one of these occasions, owing to a mistake in lowering the stern boat before the ship had quite lost her way through the water, one of the falls could not be unhooked in time; consequently the boat was dragged over on her broadside, and finally capsized with eight people in her.  Some reached one of the life-buoys, which was instantly let go, the others managed to roll the boat over and right her, full of water.  All were eventually picked up by the leeward quarter-boat; the weather one, from the shortness of the davits, would not clear the ship’s side, but turned over on her bilge, dipping in the water, and was rendered ineffective when most wanted.  This defect in the davits was afterwards remedied by the substitution of other and longer ones, which had formerly belonged to H.M. steam vessel Thunderbolt, wrecked at Algoa Bay a short time previously.

Oceanic birds.

Among many interesting birds* procured in the above-mentioned manner, I may allude to Puffinus cinereus, a European species of shearwater, which was found to be generally distributed across the South Atlantic between the meridians of 28 degrees West and 1 1/2 degrees East; on two successive days, while in the neighbourhood of Tristan da Cunha, myriads of these birds passed the ship to the westward, apparently coming from that island.  A few days afterwards, while 480 miles from the nearest land, we caught a beautiful tern (Sterna melanorhyncha) hitherto considered to be peculiar to Australia.

(Footnote.  For the occurrence of Procellariadae during our outward voyage, with a view to determine the geographical distribution of the species met with by me, see Contributions to Ornithology by Sir W. Jardine, Bart. page 94.)