162 GUIDEBOOK OF THE WESTERN UNITED STATES. 
Near Cheney a branch line turns to the north and runs to Medical 
Lake and Coulee City, in the heart of the Big Bend country, so called 
because it lies inside of the great westward bend of 
Columbia River. The two railways just mentioned 
lie only a short distance to the left, but beyond 
Cheney they bend to the east and can not be seen 
again from the Northern Pacific line, although they 
parallel this line to Columbia River near Pasco. Cheney is situated 
on the great lava plain of eastern Washington. Near the railway 
the traveler sees little but bare rock, but he can catch glimpses here 
and there of the low rolling hills that constitute the great wheat belt 
of this part of the State. The railway follows in a general way a 
slight depression in the surface, but the traveler may 
Cheney. 
Elevation 2,345 feet. 
Population 1,207. 
St. Paul 1,521 miles. 
Tyler. be surprised at riding over such a wide stretch of 
Elevation 2,301 feet. country without seeing any flowing creeks or even 
Population 421*, 
creek channels. In humid regions there is a creek 
channel in every valley. Even in the arid country 
of the Southwest there are established watercourses, which, though 
frequently or generally dry, take care of the occasional flood waters; 
but here there are only shallow irregular valleys, and no stream 
channels are to be seen. True there may be here and there, strung 
out in a more or less definite line, a series of shallow basins holding 
swamps or even shallow lakes, but these have no outlets above 
ground, and if they are connected at all the connection must be by an 
underground channel. It is evident that during most of the year 
there is little running water in this region, as the annual precipitation 
decreases from 18 inches at Spokane to 7 inches at Pasco. Most of 
this is absorbed by the soil,’ and the remainder finds its way into the 
open layers between the sheets of dense lava and reappears as 
springs in some neighboring canyon or coulee. 
A possible explanation of the peculiar scouring of the surface rocks 
into basins without any definite stream channels is that it was done 
by ice. This subject is more fully considered in the footnote given 
on page 163. 
St. Paul 1,532 miles. 
‘F. C. Calkins states: ‘It [the soil] is | the water is held in them by adhesion 
so porous that rain or melted snow is 
quickly absorbed by it, so that a smaller 
proportion is | t by run-off or by evapora- 
tion from puddles than would be lost if 
it were more clayey and impervious, and, 
on the other hand, it is not loose enough 
to allow the water to sink rapidly and 
become unavailable, as it does in a deep 
sandy soil. The spaces between the 
particles of the fine loam are so small that 
or capillary attraction and yields to the 
force of gravity only slowly and to a com- 
paratively small extent.’? Therefore @ 
large proportion of the slight precipita- 
tion is kept sufficiently near the surface 
to be used by the growing wheat, and 
successful grain culture is possible with 
a rainfall that would be insufficient in a 
soil of less advantageous physical consti- 
tution. 
