I 
458 
BERGS. 
couple of acres, with the orifices of these perforating 
crystallodromes. 
"We did not often meet with the pinna- 
cled character, which is so frequent in the 
Alps ; a fact which may be due, perhaps, 
to the absence of the alternate freezing- and 
thawing which attend the alternation of day 
and night. 
When the berg was nearly melted down to the wa- 
ter's edge, the accumulation was more apparent, and 
the arrangement of drift upon its surface resembled 
that which the sketches I subjoin were intended to 
indicate. 
The berg is beyond all doubt a most important 
agent in modifying the soundings upon the coast. The 
grounded bergs olf Disco are known to leave troughs, 
plowed by their projecting tongues, as they float and 
ground with the rise and fall of the tides. Where the 
bottom is of mud and till, as is the case on the west 
coast generally, this action must be very marked ; for 
on a berg I surveyed trigonometrically in July, which 
had grounded in soundings of five hundred and twen- 
ty feet, the great tap-root that anchored it to the bot- 
tom admitted of an easy rotation, and the berg swung 
upon its axis with each change of the tide. That 
such great tongues, though irregular in their shape, 
do in fact rock and rotate with the movements of 
the berg, might be inferred, indeed, from the facettes 
that are worn, on the imbedded material ; many of 
