156 Association of American Geologists and Naturalists. 
latitude. He remembered however, having encountered in November, 
1825, off the entrance to the Rio de la Plata, in latitude 35° south, longi- 
tude 49° west, or thereabouts, a number of icebergs, some of which 
were of large magnitude ; a reference to the chart would, he observed, 
show to what a vast distance from their piace these floating masses 
had been driven by wind and current. 
In the month of August, 1827, while crossing the Grand Banks, in 
latitude 46° 30/ north, longitude 48° west, Mr. C. passed within less 
than a mile of a large berg which was stranded in between eighty and 
ninety fathoms water. The wind was light, but a heavy swell was 
running from the westward, and the huge pile could be distinctly.seen 
to rock and shake violently as it ground heavily down into its bed with 
every surge. Owing to its longest diameter facing the swell, the mass 
had an oscillatory or semi-rotary back and forward motion upon its ver- 
tical axis, according as the sea broke upon one or the other extremity, ° 
which it did with so much force at times as to turn the berg apparently 
full half round; in this situation it would remain till another heavy 
surge striking the opposite.end would force it.back and round in the 
other direction. The vessel was sufficiently near for Mr. C. to perceive 
distinctly, large fragments of rock and quantities of earthy matter im- 
dded in the sides of the iceberg, and to see from the fore yard, that 
the water for at least a quarter of a mile round it, was full of mud, stirred 
up from the bottom by the violent rolling and crushing of the mass. 
This movement was accompanied by a harsh grating noise, with occa- 
sional cracking reports, resembling those produced by blasting rocks, 
which ‘might have been heard ten or twelve miles. The height of this 
berg was estimated by Mr. C., at from fifty to seventy feet, and its length 
at four hundred yards. While examining it through the glass, it was 
observed to incline suddenly more than usual, and in the next moment, 
with acrash and roar that were truly fearful, and amid a whirlwind of 
spray and foam, the whole enormous pile rolled over on its side, tearing 
up with it, no doubt, large quantities of matter from the neti ee 
loading the sea with mud and sand for more than a mile in all dire 
from its bed. On the 27th of April, 1829, Mr. C. passed, in aa 
36° 10 north, longitude 39° west, near the middie: of the: eR Stream, 
set in an east-south , an 
to bea quarter of a mile see" from. eighty to one ieiadiod iad high. 
pyramids. and castellated ridges, whose ‘eharacter Peat oe momenta 
A horizon- 
eee ee “A strong breeze, and numero salle 
