330 IOWA STUDIES IN NATURAL HISTORY 
shorn domes while Park Rock and Harper Rock stand half buried 
in the ice front. Due to these prominent rock masses the ice- 
front has a more or less lobate aspect, but this character, the 
position of the subglacial cave, and other features are constantly 
shifting. The rate of flow of the ice is variously reported, Park 
gives sixteen feet per day, and Bell in the government geographi- 
eal report cites a much smaller figure. 
After a difficult climb up the northwest corner we reached the 
surface from which there is a magnificent view both up anid 
down the valley. The rock walls of the valley show smoothing 
by ice for hundreds of feet above the present ice surface. The 
ice is highest in the center of the glacier whence the surface 
slopes gently down the sides which, however, are not in contact 
with the rock wall in the lower part of the glacier but end in a 
steep broken ice cliff. The surface ice was granular and much 
pitted but footing was not difficult except on the steeper slopes 
where sun cups helped materially. These are dish-shaped, con- 
cave depressions, six to twelve inches across and deepest beneath 
the lower edge. 
There is very little surface moraine due to its having been 
swallowed up by the numerous crevasses. The latter in most 
cases extend longitudinally along the center of the ice but out 
near the margins they run more or less diagonally. The crevasses 
range from a few inches to two or three feet across, most of 
them being less than a foot. Since they extend mainly in a 
north and south’ direction, their width is affected to some extent 
by the sun’s rays. In length they vary from a few feet up to 
hundreds of feet, and in depth they also vary. Some are full of 
quiet clear water, in others the water is in motion, others are 
dry. In a few of them water could be heard but not seen, and 
pebbles dropped into the larger dry ones rattled for several 
seconds before coming to rest. In places there are small well- 
like depressions eight or ten inches across and of unknown depth. 
Into one of these much surface water gathered and fell with con- 
siderable noise. Doubtless had our visit been made six months 
later the surface of the ice would have been much wetter. Dust 
wells were common and small pebbles were seen at bottoms of 
holes much too deep for the sun’s oblique rays to penetrate. 
At a distance, of about a mile above the terminus, the ice sur- 
face rises abruptly 150 to 200 feet. This results in, a fine ice 
cascade in which the ice is fissured, cracked, and broken into 
