1876] Are We Drying Up? 517 
passing through that region on the railroad could fail to notice 
them. The publication of the detailed maps of this region by 
the Fortieth Paralleél Survey will, no doubt, furnish data for 
estimating with considerable precision how large an area was 
formerly covered with water, and how numerous and extensive 
the different bodies of water were. 
It is not to be expected that in our western territories there 
should be any proof obtained of a diminution in the quantity of 
_ water having taken place during the historic period. The char- 
acter of the aboriginal inhabitants and the perishable character 
of their dwellings forbid this. Yet there are traditions pointing 
in this direction, as noticed in the Geology of California, volume 
1, the mountaineers insisting on the former connection of Mono 
and Walker’s Lakes. However this may be, it is certain that 
the sharp and well-defined character of the terraces in this region 
indicates very clearly that the diminution of the volume of the 
Water must have been an extremely recent phenomenon. 
It is not possible at this time to enter upon a discussion of the 
question of the connection of this desiccation with the so-called 
glacial phenomena. It has seemed natural, of course, for geolo- 
gists to connect the terraced condition of the rivers in the north- 
fastern States with the melting of the ice of the glacial period. 
. As far as the problem at present under discussion is concerned, 
_ tt makes no difference whether we do or do not consider the 
desiccation in question as one of the sequence of events to which 
the glaciation of a portion of the northern hemisphere belongs. 
"hat we are specially interested in is, whether the desiccation 
5S still going on. If, as seems highly probable from what has 
been advanced in the previous pages, the quantity of water on 
the surface, over large areas, has considerably diminished, cer- 
tainly in the very latest geological times, and also in part within 
a the historic period, then it is not likely that the former glacia- 
tion and the present desiccation can be considered as so inti- 
mately connected in their general cause that the latter cannot 
fake place except as a sequence of the former. The absence of 
-Y very distinct proof of a much greater extension at any time 
of the ice masses over the ranges of Central Asia must be taken 
mo consideration in connection with the extensive and rapid 
“tying up of what has been and is now going on in that region. 
the same may be said in reference to the Great Basin and our 
Own Western territory. At the time of the greatest extension 
of the glacial masses in that region, but an insignificant propor- 
