Glacier Work.—Scoit. 221 
stance, the five glaciers of Mt. Shasta; the largest of these 
called' Whitney glacier, after professor J. D. Whitney, of 
Harvard University, has a length of about two miles, and 
a width of from 1000 to 2000 feet. 
As mig-ht be expected the glaciers found in the lati- 
tude of the equator are much smaller. Numerous glaciers are 
known to exist, however, in the Andes of Ecuador. They 
attain their greatest size upon the mountains of Antisana^ 
Cavambe and Chimborazo, the latter having eleven distinct 
ones. 
Velocity of FIozv. 
A consideration of the second point embraces the well 
known fact that glaciers are nearly always in motion, thovigh 
under certain conditions the rate is very slow. Observations 
made upon glaciers in the Alps seem to show the average of 
the measured rates of flow is from one to three feet per day 
depending upon the size of the glacier, the larger moving fast- 
er. One of the early notes in this connection is made by Henry 
Thomas La Beche.* A ladder left by the geologist Horace 
Benedict de Saussure at Col. du Geant, in 1787, \yas discovered 
in the Mer de Glace, the continuation of the same glacier, 
having advanced about nine miles during the intervening 
forty-five years, or an average of nearly three feet per day. 
Observations made upon vVmerican Alpine glaciers show about 
the same rate of movement. 
The motion of the Greenland ice sheet is said to resemble 
an inundiation, as there appears to be a general movement 
of the whole mass of ice from the central regions toward the 
sea. Its force is concentrated largely at a few points, and 
to an extraordinary degree. These points are the fjords 
through which the annual surplus ice is carried away and dis- 
charged into the sea as icebergs. 
Danish explorers measured the velocity of seventeen 
glacier tongues in the ice fjords of Greenland, repeating such 
measurements in both cold and warm seasons, and thereby 
showed that the movement was not influenced by seasons. 
Further, glaciers which produced bergs showed a movement 
averaging from thirty to fifty feet per day throughout the 
year. The great glacier of the ice fjord of Jacobshaven 
•Manual of Geology-, 1832. 
