ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxxv 
off Victoria Land so suddenly that it was for the moment supposed 
to be an island not before observed. 
The amount of mineral matter borne away from this region by ice 
during the lapse of centuries, must tend to cover the bottom of the 
southern ocean not only with fragments of large size, but also with 
the finest mud, and this over extensive areas where no other means 
are apparent, under existing conditions, for the distribution and ac- 
cumulation of such detritus. An iceberg was noticed in latitude 
66° S. nearly covered by mud and stones. One large block of 
voleanic rock was estimated to weigh many tons. We may expect 
that not only angular but rounded blocks would sometimes be 
thus transported, for the beaches upon which the surf breaks in 
summer would be frozen in winter, and worn masses might occa- 
sionally be caught up in the ice, removing away from the shore, and 
be carried within the power of some iceberg to pick them up, and by 
capsizing bring them to the surface and transport them. Occasionally 
also we may anticipate that a part of the barrier itself, previously 
attached to, and partly covering a beach, formed before the ice ad- 
hered to that part of the land, may from local causes break away 
and be carried northwards. In all cases the mineral matter borne 
away by the icebergs would cover all inequalities in the bottom of 
the ocean which it may fall upon, and thus the resulting accumula- 
tion may be a mixture of large and small fragments, angular and 
rounded (some perhaps scratched), mingled with mud and sand, the 
whole arranged in the most irregular manner, large masses of rock 
strewed over and scattered through clay. 
With respect to the turning up of blocks of large size by the 
capsizing of the icebergs off these southern lands, Captain Wilkes, 
of the United States’ Explormg Expedition, which descended into 
the Antarctic regions in 1840, considers that he landed upon an up- 
’ turned iceberg, part of the icy barrier, weathered by storms, about 
eight miles distant from the main land, in latitude 65° 59' 40" S. 
On this he found boulders, gravel, sand and mud or clay, the larger 
specimens being described as of red sandstone and basalt. There 
was also a kind of icy conglomerate, the matter cementing the stones 
being formed of hard compact ice. One piece of rock imbedded in 
it was estimated at about five or six feet in diameter. The same 
navigator also mentions many icebergs discoloured by earth. Indeed 
the evidence of the frequent overturn in these regions of icebergs 
which had been aground, bearmg the mud, gravel and fragments of 
rock on the bottom upwards, appears complete, and is very import- 
ant as regards the distribution of detritus by means of icebergs. 
As not without its geological bearmg we may here glance at the 
formation of the barrier itself. All the drawings made and informa- 
tion received point to its accumulation in layers, in at least that part 
of it projecting beyond the land into the ocean. The portion above 
water is generally described as from 150 or 180 to 200 or 210 feet. 
Captain Wilkes refers the formation of the ice in the first place to 
ordinary field ice, upon which layers accumulate, varying from 6 
inches to 4 feet in thickness, from rain, snow and even fog, so that 
