G. F. Wright—The Muir Glacier. if 
the glacier from the east the transverse crevasses diagonal to 
the line of motion increase in number and size until the whole 
surface is broken up into vast parallelograms, prisms and 
towers of ice, separated by yawning and impassable chasms 
scores and hundreds of feet’ in depth. Over this part of the 
ice the moraines are interrupted and drawn out into thinner 
lines, often appearing merely as patches of debris on separate 
masses of ice. This portion of the ice-current presents a lighter 
colored appearance than other portions, and the roughened 
lines of motion can be followed, as far as the eye can reach, 
through distant openings in the mountains to the north and 
the northwest. 
The comparative rapidity of the motion in this part of the 
ice is also manifest where it breaks off into the water at the 
head of the inlet. As already said, the perpendicular front of 
ice at the water’s edge is from 250 to 300 feet in height. From 
this fiont there is a constant succession of falls of ice into the 
water, accompanied by loud reports. Scarcely ten minutes 
either day or night passed during the whole month without our 
being startled by such reports, and frequently they were like 
thunder-elaps or the booming of cannon at the bombardment 
of a besieged city, and this though our camp was two and a 
half miles below the ice-front. Sometimes this sound accom- 
panied the actual fall of masses of ice from the front, while at 
other times it was merely from the formation of new crevasses 
or the enlargement of old ones. Repeatedly I have seen vast 
columns of ice, extending up to the full height of the front, 
topple over and fall into the water. How far these columns 
extended below the water could not be told accurately, but I 
have seen bergs floating away which were certainly 500 feet in 
length. At other times masses would fall from near the sum- 
mit breaking off part way down, and splashing the spray up to 
the very top of the ice, at least 250 feet. The total amount of 
ice thus falling off could not be directly estimated, but it is 
enormous. Bergs several hundred feet long and nearly as 
broad, with a height of from twenty to sixty feet, were numer- 
ous and constantly floating out from the inlet. The steamer 
met such one hundred miles away from the glacier. The 
smaller pieces of ice often so covered the water of the inlet 
miles below the glacier that it was with great difficulty that a 
canoe could be pushed through. One of the bergs measured 
was sixty feet above water and about four hundred feet square. 
The portion above water was somewhat irregular, so that prob- 
ably a syiumetrical form thirty feet in height would have con- 
tained it. But even at this rate of calculation, the total depth 
would be two hundred and forty feet. The cubical contents of 
the berg would then be almost 40,000,000 feet. Occasionally, 
