RIO NEGRO. 105 



The week we .ay off the bar, we experienced much fog, and found 

 the current strong, two and a half knots on the flood and ebb. The 

 former runs to the southwest, the latter in the contrary direction. The 

 roadstead may be considered a very unsafe anchorage, except in the 

 fine season. The gales come from the southeast, with a heavy sea. 

 By taking advantage of the flood tide, and standing off to the southward 

 and eastward, there will be found little difficulty in getting off shore, to 

 avoid the danger a vessel would be exposed to. 



While engaged at this place, I felt great uneasiness for the safety of 

 the boats, the officers employed having but little experience in managing 

 them. The fogs and strong current rendered it extremely difficult to 

 proceed rapidly with our survey : many of the boats were detained out 

 over night, and others reached the ship with difficulty. 



On the night of the 30th of January, the weather assumed a 

 threatening appearance. The wind changed to the eastward, with a 

 falling barometer ; the sea rising, accompanied by a heavy fog, with 

 the absence of three boats, caused me much anxiety. During the night 

 the wind increased to a gale from the southeast. At daylight the 

 Peacock made signal that the boats had reached her in safety. It had 

 now became necessary for the squadron to leave this dangerous 

 anchorage. Taking advantage of the tide, we effected it without diffi- 

 culty, getting off under our storm-sails; three of the vessels were 

 obliged to slip their cables. The barometer during the gale fell to 

 20-600 in., which was lower than we had seen it since our departure 

 from the United States. Towards evening, when the weather mode- 

 rated, we again sought our anchorage. One of the boats returned to 

 the Vincennes with but half her crew ; the rest, it was reported to me, 

 had deserted. Two boats with officers were accordingly despatched 

 for the purpose of apprehending them, as soon as we anchored. The 

 men were found by the Guachos without difficulty. They accounted 

 for their absence, that they had, while waiting on the beach, been 

 enticed into the interior in chase of some game ; and the fog coming on 

 suddenly, they had lost their way, missed the boat, and were obliged to 

 pass the night on the prairie. The boats in returning to the ships 

 narrowly escaped accident in passing through the rollers on the bar, 

 and it was with great difficulty they reached the ship at midnight. 

 Their lengthened absence caused no little anxiety for their safety to all 

 on board. 



Dr. Pickering on this occasion at my request visited a cave he had 

 mentioned to me as existing, for the purpose of ascertaining its tempe- 

 rature, believing it would give some more accurate information as to 

 vol. i. 14 



