Bibliography. 163 
that distance from the barrier. That these were recently detached is proved by 
their stratified mlarinnies ; while those at a greater distance had lost their prim- 
tiv 
ve form, were much worn, and showed many more signs of decay. Near the 
extreme point of he barrier pene in longitude 97° E., latitude 62° 30’ S., and 
where it begins to trend to 1 rd, vast collet of these islands wote 
rapidly to the north. 
until we reached latitude 619 S. The Peacock was the first to ors et pe 
upon the track by which we had gone south; the last seen by her w 3 
The Vincennes, on her return fifty days later, saw them in 51° 8. The ones 
‘about the same time, in 53°98. The observation in the Vincennes gives a dis- 
tance of ten degrees of latitude, or six hundred miles to be passed over in fifty 
days, which would give about half a mile an hour; or, taking the Peacock’s ob- 
servations, a more rapid rate would be given, nearly three-fourths of a mile. 
Many icebergs were met in the latitude of 42° S., by outward-bound ships to 
Sydney, in the month of November; these, I learned, were much worn, and 
showed lofty pinnacles, exhibiting no appearance of — ever been of a tabular 
form. These no doubt are such as were detached during a former season, and 
being disengaged from the barrier, would be naturally, early the next season, 
ifted by the easterly current as well as the westerly wind, and would pursue the 
direction they give them. They would therefore be driven to the northeast as 
3 the southwest winds prevail, and when these veer to the westward would 
receive an easterly direction. It is where these winds prevail that they are most 
poopy 4 found by the outward-bound vessels—between the latitudes of 40° 
d 50° 
#Re time the period of time required for the formation of these ice-islands, 
much light cannot be expected to be thrown on the subject; but the few 
rived from rae spate lead to some conclusions, Many of them were measured, 
tad abeits aititnde So to-be from fifty to te, tre naan and fifty feet ; eighty dis- 
whest, and in the smallest aie 
which appeared to avenge a little more than t ving ay in thickness. Supposi 
the average fall of snow in these ‘high latitudes to be an inch a ee or thirty a 
a year, the | than thirty years toform. They were 
seen by us in all the stages of their growth, and all bore unequivoc ocdl marks of 
the same origin. The distance from the land at which they were forming, fully 
satisfied me that their fresh water could be derived only from the snows, 
“ The movement of the ice along the coast is entirely to the westward, and all 
the large ranges of ice-islands and bergs were found in that direction, while the 
eastern portion was comparatively free from it, A difference was found in the po- 
sition of the floe-ice by the different vessels, seine rather by the wind than by the 
tide. When the Vincennes and Porpoise passed the opening by which the Pea- 
cock entered, it was found closed, although only twenty-four hours had elapsed. 
It has been seen that the ice had much movement during the time the Peacock 
was beset by it, and the bay was all but closed when she effected her escape. 
Another instance occurred, where the Porpoise, in about the longitude of 130° E., 
