RIO NEGRO. HI 
The temperature at the surface was 44°, and when the thermometer 
came up it showed but 28°. The sounding was perpendicular, and 
the thermometer had been examined by two or three persons before 
going down, so that we were assured there was no mistake. So 
remarkable a circumstance surprised me not a little. It was too 
late to attempt another sounding that night, and I regretted in the 
morning to find myself on soundings in eighty fathoms water. The 
temperature at that depth did not fall below 46°, whilst at the surface 
it was 49°. 
The coast of Terra del Fuego presents the same general character 
throughout, of high, broken, and rugged land, which appears of a 
uniform elevation of about one thousand or fifteen hundred feet, with 
here and there a peak or mountain covered with snow, rising to some 
four or five thousand feet. The whole wears a sombre and desolate 
aspect. It may be said to be iron-bound, with many high and 
isolated rocks, that have become detached from the land apparently 
by the wear of ages. Numerous unexpected indentations occur all 
along the coast, many of them forming harbours for small vessels, 
and some of them very safe ones. 
On Captain King's report of Orange Harbour, I had determined to 
make that our place of rendezvous previous to our first Antarctic trip, 
and accordingly all the vessels were ordered to proceed thither. We 
had his directions, although we were without the chart. I felt 
confident I might repose full reliance in them, from his well-known 
ability ; and I now offer an acknowledgment of their value and 
general accuracy. 
The channels formed by the islands are deep, with no anchorage 
except in the coves near the rocks ; but a vessel is generally safe in 
passing through, as there are no dangers but those which show 
themselves, and wherever rocks are, kelp will be found growing upon 
them. To pass through the kelp without previous examination is 
not safe. It borders all the shores of the bays and harbours, and 
effectually points out the shoal water. 
It was my intention to pass within or to the north of the Hermit 
Islands into Nassau Bay, but the wind did not permit our doing so. 
This bay forms a large indenture in the southern coast of Terra 
del Fuego, a few miles to the northward of Cape Horn ; it is about 
thirty miles east and west, by eight miles north and south, and is 
somewhat protected from the heavy seas by the Hermit Islands. 
Around the bay are found some harbours, sheltered by small islands, 
and surrounded by precipitous rocky shores, with occasionally a small 
