92 OUR NATIONAL PARKS 



fences and guideboards, is so unmistakably indi- 

 cated as are these channels of the vanished Tuo- 

 lumne glaciers. 



The action of flowing ice, whether in the form 

 of river-like glaciers or broad mantling folds, is 

 but little understood as compared with that of 

 other sculpturing agents. Rivers work openly 

 where people dwell, and so do the rain, and the 

 sea thundering on all the shores of the world ; 

 and the universal ocean of air, though unseen, 

 speaks aloud in a thousand voices and explains 

 its modes of working and its power. But gla- 

 ciers, back in their cold solitudes, work apart from 

 men, exerting their tremendous energies in silence 

 and darkness. Coming in vapor from the sea, 

 flying invisible on the wind, descending in snow, 

 changing to ice, white, spiritlike, they brood out- 

 spread over the predestined landscapes, working 

 on unwearied through unmeasured ages, until in 

 the fullness of time the mountains and valleys are 

 brought forth, channels furrowed for the rivers, 

 basins made for meadows and lakes, and soil 

 beds spread for the forests and fields that man 

 and beast may be fed. Then vanishing like 

 clouds, they melt into streams and go singing 

 back home to the sea. 



To an observer upon this adamantine old mon- 

 ument in the midst of such scenery, getting 

 glimpses of the thoughts of God, the day seems 

 endless, the sun stands still. Much faithless fuss 



