1876.] Plain, Prairie, and Forest. 583 
namely, Southern Wisconsin, Illinois, Eastern Iowa, Missouri, 
and Arkansas, there is no deficiency of rain-fall indicated. Be- 
ginning in the densely-wooded region of Northeastern Maine, 
and following along through the forest-covered districts of North- 
ern New Hampshire and Vermont, New York, the southern 
part of Upper Canada, the southern part of Michigan, Ohio, 
Indiana, and so on as far as the Des Moines River, we find 
spread upon the chart a uniform tint of color, designating an 
annual rain-fall, over the whole area indicated, of from thirty-two 
to forty-four inches. This same shade of color extends down 
and covers almost the whole of the densely-wooded Appalachian 
ranges in Pennsylvania, Virginia, and North and South Caro- 
lina. Looking at the curves which imperfectly divide the region 
in question, giving a greater amount of detail, we see that not 
only is the annual precipitation in general quite as great in the 
prairie region as in most of the ordinarily well-wooded parts of 
the country, but that when local causes have within certain areas 
given rise to an excess or deficiency, as compared with the gen- 
eral range of from thirty-two to forty-four inches, there is no 
corresponding difference in the relative abundance or scarcity of 
the forests. Thus the upper heavily-timbered part of Michigan 
shows a decided deficiency of rain-fall, while the only region in 
that State in which prairies occur over any considerable amount 
of surface, namely, the southwestern corner, is precisely that 
where the amount of rain is exceptionally large. Wisconsin, 
again, shows the same kind of anomaly, for here the prairie 
region is seen to have the largest amount of precipitation of any 
portion of the State. Once more: in Iowa, there is a district 
which is almost entirely covered with forests, namely, the north- 
eastern corner ; here, by a curious coincidence, the Smithsonian 
charts indicate a decided deficiency of rain; while farther west, 
in a line extending northwest from Iowa City, there is a large 
area of considerable extent marked as receiving from forty-four 
to fifty-six inches, and over which, as repeated explorations have 
convinced us, there is no corresponding increase in the amount 
of timber. Still more striking facts of the same kind may be 
had in abundance in Southern Missouri and Northern Arkansas, 
a region of abundant prairies and of precipitation as great as 
that of the wettest part of the Atlantic coast. Further state- 
ments of this kind do not seem to be necessary to justify the 
Conclusion that in the prairie region there is no deficiency in the 
annual amount of rain, and that some other cause for the absence 
