Geology and Botany of Northern Pacific Railroad. ~G9 



has been ascended, however, several times, and its labyrinths 

 sufficiently explored to prove that it carries from eight to twelve 

 glaciers, some of which are many miles in length and will bear 

 comparison with those of the Alps. 



Every traveller who enters the Puget's Sound region from the 

 south, is sure to be struck by the turbid, milky appearance of 

 the water of the Cowlitz River, along which the railroad runs 

 for miles. This character it shares with all streams which drain 

 glaciers, and has caused the Swiss mountaineers to give to the 

 water of such streams the name of '*' (iletscher Milcli." This 

 turbidity is due to the sediment produced by the constant grind- 

 ing action of these enormous masses of moving ice, set with 

 stones, upon their beds, and attests the sometimes disputed effi- 

 ciency of glaciers as eroding agents. The Puyallop, White River, 

 ;md other streams which come down from Mt. Tacoma, are alike 

 milky, and each shows that one or more glaciers are continually 

 grinding away at its head. On the contrary, the streams which 

 do not come from glaciers and are supplied by rain only and 

 that filtered through the decaying vegetation of the dense forests, 

 curry very little sediment, and that chiefly carbonaceous matter. 

 These are clear but brown, and the contrast which the water of 

 such streams presents to that of the rivers which drain the gla- 

 ciers, is very striking, justifying the names borne by two such, 

 of Black and White Rivers. 



It has been contended by some writers, as before mentioned, 

 that the extension of glaciers in former times was due simply to 

 an increase in the amount of precipitated moisture ; but it is 

 easy to see that the heavy rainfall of Washington Territory might 

 be increased indefinitely with no considerable elongation of the 

 glaciers. But even with the rainfall remaining as it is, if a de- 

 pression of temperature should take place, carrying the present 

 conditions of winter through the year, the glaciers would soon 

 creep down into their old beds, fill all the valleys of their drain- 

 ing streams, and finally coalesce to form one grand glacier which 

 would flow out through the Strait of Fuca to the ocean. 



Following the coast northward from Puget Sound, we find 

 the glaciers coming down lower and lower, until in Alaska they 

 reach, the sea-level. No one can claim that this is because the 

 precipitation is greater there, since observations show that it is 



