Chap. V.]
TEMPERATURE OF THE OCEAN.
137
1841
whilst making the usual experiments on the temperature of the sea; it was found to be setting to the southward (true), nine miles in the twenty-four hours. Some pieces of seaweed, with barnacles attached to them, were brought on board. The barometer attained the unusual height of 30.45 inches, with a moderate N.E. wind and overcast sky. At night the cry of penguins was heard, and again the luminous patches in the sea were numerous and brilliant.
This morning we had a very light breeze from the Dec. 4.N.E., and towards noon it fell perfectly calm, with the surface of the ocean beautifully smooth; thus affording a most favourable opportunity of trying its temperature at a great depth. A new line had been prepared for the purpose, and thermometers were attached to it at intervals of one hundred and fifty fathoms: we had no soundings with eleven hundred fathoms, and beyond this I did not venture to send the thermometers. In hauling the line in it broke, and two of the new thermometers which had been sent out to me for the purpose of deep sounding, were lost; we had still three others left, and the opportunity was too good to be lost, notwithstanding this accident. Another line was immediately prepared, and the thermometers which were sent down to a thousand and fifty fathoms came up again quite safe, after sustaining such enormous pressure, and recording the temperature at that deep region of the ocean to be exactly 40º, or thirteen degrees below that of the surface. The tem-