THE GLACIERS OF MT. RAINIER 



659 



and for that matter also on the other ice 

 streams of Mount Rainier, are the 

 "glacier tables." These consist of slabs 

 of rock mounted each on a pedestal of 

 snow and producing the effect of huge 

 toadstools. The slabs are always of 

 large size, while the pedestals vary from 

 a few inches to several feet in height. 



CARBON GLACIER. 



In many ways the most interesting of 

 all the ice streams on Mount Rainier is 

 the Carbon Glacier, the great ice river 

 on the north side, which flows between 

 those two charming natural gardens, 



the great hollow, however, and so simple 

 are its outlines that the eye finds 

 difficulty in correctly estimating the 

 dimensions. Not until an avalanche 

 breaks from the 300-foot neve cliff 

 above and hurls itself over the precipice 

 with crashing thunder, does one begin 

 to realize the depth of the colossal 

 recess. The falling snow mass is several 

 seconds in descending, and though 

 weighing hundreds of tons, seemingly 

 floats down with the leisureliness of a 

 feather. 



These avalanches were once believed 

 to be the authors of the cirque. They 



Photo by Geo. V. Caesar. 



THE GREAT AMPHITHEATER OF CARBON GLACIER 



THE HEADVVALL MEASURES 3.600 FEET IN HEIGHT. GREAT AVALANCHES FALL PERIODICALLY FROM THE 

 SNOW CLIFFS ABOVE, WHICH THEMSELVES ARE 200 TO 300 FEET HIGH. 



Moraine Park and Spray Park. The 

 third glacier in point of length, it heads, 

 curiously, not on the summit, but in a 

 profound, walled-in amphitheater, inset 

 low into the mountain's flank. This 

 amphitheater is what is technically 

 known as a glacial cirque, a horseshoe- 

 shaped basin elaborated by the ice from 

 a deep gash that existed originally in 

 the volcano's side. It has the distinc- 

 tion of being the largest of all the 

 ice-sculptured cirques on Mount Rainier, 

 and one of the grandest in the world. It 

 measures more than a mile and a half in 

 diameter, while its head wall towers a 

 sheer 3,600 feet. So well proportioned is 



were thought to have worn back the 

 head wall little by little, even as a 

 waterfall causes the cliff under it to 

 recede. But the real manner in which 

 glacial cirques evolve is better under- 

 stood today. It is now known that 

 cirques are produced primarily by the 

 eroding action of the ice masses em- 

 bedded in them. Slowly creeping for- 

 ward, these ice masses, shod as they are 

 with d6bris derived from the encircling 

 cliffs, scour and scoop out their hollow 

 sites, and enlarge and deepen them by 

 degrees. Seconding this work is the 

 rock-splitting action of water freezing 

 in the interstices of the rock walls. This 



