RIO NEGRO. 107 
growing into spines, the smallness of the leaves and their texture, 
which is dry, coriaceous, and hardly deciduous, together with the 
general brown aspect of the landscape, all denote a vegetation adapted 
to endure or escape drought. 
There was formerly some trade here with Boston and New York 
in hides, horns, hones and tallow, in exchange for cotton and woollen 
goods of a warm fabric, hardware, crockery, boots and shoes, a few 
articles of furniture, spirits and tobacco, all of which are bartered at 
an enormous profit. Considerable quantities of salt are shipped 
round to Buenos Ayres. Vessels discharging or taking in a cargo 
here, pay twelve and a half cents per ton. Vessels stopping without 
discharging pay half duty ; vessels for refreshments are permitted to 
remain twenty-five days free of duty, after that time they pay half 
duty. This duty includes pilotage and all other charges; but the 
governor seems to have the power to exact the full duty whenever he 
thinks proper. 
Sarsaparilla abounds in this section of the country. 
As the bar is a shifting one, no permanent directions can be given, 
nor can any survey be relied on. The annual freshets and gales of 
wind that take place from May to October, often change the position 
of the bar. According to the pilots, it had recently undergone a 
change, and there was three feet less water on it than had been 
before. Even the direction had been altered from southeast by 
south, to southeast by compass. 
The week we lay 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 
failing barometer ; the sea rising, accompanied by a heavy fog, with 
