piRiN.noN] CLIMATIC CONDITIONS. 47 
That the expense attendant on ditch construction in Seward Penin- 
sula is justifiable in certain cases is not to be denied. That the most 
profitable method of converting the water into power has always 
been applied is, however, decidedly open to question. The subject 
will be further discussed under the head of ;i Hydraulic mining." 
The average annual rainfall in California at various points on the 
west slope of the Sierras is approximately as follows: 
Inch.-. 
Sacramento 19 
A.ul >urn - - - 20 
3olfax 54 
Disco 60 
Summit 48 
jo 28 miles 
Fig. 
-Map of part of Seward Peninsula. 
Toward the north the rainfall increases in amount, and toward the 
puth it decreases. 
Table 2, giving the rainfall in Alaska, shows that there is a difference 
rainfall between the coast and the interior gold districts that is too 
riking to need comment. Comparison of the interior rainfall may 
made with that at St. Michael's station, which is the nearest point 
mailable representing Seward Peninsula conditions, yet the annual 
Iiount of rainfall at St. Michael is still very small compared with 
at in California. 
