94 RIONEGRO. 



I have Utile doubt but this remarkable change and fall of tempera- 

 ture, were caused by the near approach to icebergs, some of which 

 have been at times seen nearly in this latitude, 38° 55' S., longitude 

 54° 30' W. After this we had fine pleasant weather, until our arrival 

 off the Rio Negro, the temperature of the air and water having fallen 

 en degrees during our progress from Rio. 



On the 22d we experienced a heavy dew. Our observations con- 

 firmed the remarks of Captain King, that it is accompanied by a 

 northerly wind, or change to that quarter. 



We next passed over the position assigned the Ariel Rocks on the 

 charts, and sailed two degrees on their parallel, but saw no indication 

 of them. 



In approaching the coast, the soundings were remarkably regular, 

 decreasing about a fathom in three miles. After passing to the south 

 of the river La Plata, they were composed of fine gray sand, with 

 pebbles and shells, while to the north they were of blue mud. Sound- 

 ings were had in fifty fathoms water, one hundred and fifty miles off 

 the coast. 



On the 25th we discovered the coast, which is a line of low sand- 

 hills, without trees, and it exhibits little appearance of vegetation. In 

 the evening we anchored off the bar, in eight fathoms water, just after 

 which we experienced one of the remarkable squalls of this coast, that 

 rose from the southward and westward : it was attended with much 

 lightning and thunder ; quantities of sand and insects were blown off 

 from the land ; but little rain fell. The barometer indicated this squall 

 by a depression of two-tenths of an inch. The wind soon changed 

 and brought fine weather, the thermometer falling six degrees during 

 the change. 



Having been led to believe we should be boarded by pilots on our 

 anchoring off the bar, I was a good deal surprised to find none, and 

 no endeavour making to board us, although the sea was quite smooth. 

 The only appearances of inhabitants which we could see with our 

 telescopes, were a few horsemen suspiciously reconnoitring us from 

 the flagstaff on the top of the hill. I then concluded to despatch the 

 Sea-Gull under Lieutenant-Commandant Ringgold into the river, for 

 the purpose of having communication with the town, directing him to 

 take the channel leading to the northward and westward, as shown 

 by the only chart we had, whilst I followed in the Flying-Fish, with 

 the scientific gentlemen ; it proved to be the wrong one, and on the 

 tide falling the schooners both grounded. Our situation was not the 

 most agreeable ; for, in the event of the sea rising, we should have 

 been exposed to all the fury of the surf, without any escape from the 



