DISCUSSION : FORESTS, RESERVOIRS, AND STREAM FLOW 499 
decrease. Simply as an illustration of this general truth, two of Mr. Chi 
the longest records which the writer has been able to find in our own 
country are given in Table 238. In deference to Mr. Leighton’s 
penchant for 10-year periods, the means for each decade are also 
given, though in a few cases they are based upon partial records. 
TABLE 23.—Recorps or RAINFALL aT PHILADELPHIA, Pa., AND 
Marietta, OnI0. 
Phila- . Phila- eat Phila- ‘ 
Year. delphia Marietta.|| Year. delphia. Marietta,|| Year. delphia. Marietta. 
47.39 48.19 
37.26 84.76 
34,53 37.53 
36.75 80.50 
33 58 46.36 
42.69 85.99 
30.21 36.78 
45.58 59. 
39.17 48.62 
39.34 38. 
33,53 41,68 
37.24 42.14 
42,17 87.32 
44.06 56.2 
-60 40.95 
84.02 60,99 
89.59: 46.33 
19 40,76 
34,78 34.83 
37.65 39,94 
40.34 30.08 
39.96 43.78 
40.91 38.43 
38.63, | 38.20 
45.54 87.62 
49.76 |.csecesees 
41.50° |" "41.96 
39:76 | 26.01 
41.61 46.38 
51.87 | 40.68 
wee veese| 38,14 
45.01 40.96 
Means for whole period == Philadelphia, 41.63; Marietta, 42.84. 
Mr. George P. Marsh, in “The Earth as Modified by Human Ac- 
tion,” presents the strongest possible arguments for the conventional 
forest theory—in fact, his zeal in this cause often leads him into ex- 
travagances that rival those of the present day; but upon this particu- 
lar subject he is compelled to say: 
“I am unable to refer to a single instance where the records of the 
rain. gauge, for a considerable period before and after the felling or 
planting of extensive woods, can be appealed to in support of either 
side of the question. The scientific reputation of many writers who 
en 
tten- 
