346 THE ANTARCTIC MANUAL. 
Nore on a Rock SEEN ON AN IcEBERG IN 61° 8S. Lat. 
By Cuaries Darwin, Esq. 
Having been informed by Mr. Enderby that a block of rock, em- 
bedded in ice, had been seen during the voyage of the schooner Eliza 
Scott in the Antarctic Seas, I procured through his means an interview 
with Mr. Macnab, one of the mates of the vessel, and I learnt from him 
the following facts: On the 13th of March, when in latitude 61° 8., and 
longitude 108° 40’ E., a black spot was seen on a distant iceberg, which, 
when the vessel had run within a quarter of a mile of it, was clearly 
perceived to be an irregularly-shaped but angular fragment of dark- 
coloured rock. It was embedded in a perpendicular face of ice, at 
least 20 feet above the level of the sea. That part which was visible, 
Mr. Macnab estimated at about 12 feet in height, and from 5 to 6 in 
width; the remainder (and from the dark colour of the surrounding 
ice, probably the greater part) of the stone was concealed. He madea 
rough sketch of it atthetime. The iceberg which carried this fragment 
was between 250 and 300 feet high. 
Mr. Macnab informs me that on one other occasion (about a week 
afterwards) he saw on the summit of a low, flat iceberg a black mass, 
which he thinks, but will not positively assert, was a fragment of rock. 
He has repeatedly seen, at considerable heights on the bergs, both 
reddish-brown and blackish-brown ice. Mr. Macnab attributes this dis- 
colouration to the continued washing of the sea; and it seems probable 
that decayed ice, owing to its porous texture, would filter every impurity 
from the waves which broke over it. 
Every fact on the transportation of fragments of rock by ice is of 
importance, as throwing light on the problem of “erratic boulders,” 
which has so long perplexed geologists; and the case first described 
possesses in some respects peculiar interest. The part of the ocean where 
the iceberg was seen is 450 miles distant from Sabrina land (if such land 
exists), and 1400 miles from any certainly known land. The tract of 
sea, however, due south, has not been explored ; but assuming that land, 
if it existed there, would have been seen at some leagues’ distance from a 
vessel, and considering the southerly course which the schooner Eliza 
Scott pursued immediately prior to meeting with the iceberg, and that of 
Cook in the year 1773, it is exceedingly improbable that any land will 
hereafter be discovered within 100 miles of this spot. The fragment of 
rock must, therefore, have travelled at least thus far from its parent 
source ; and, from being deeply imbedded, it probably sailed many miles 
farther on before it was dropped from the iceberg in the depths of the. 
sea, or was stranded on some distant shore. In my journal, during the 
