INTRODUCTION. 
69 
it will bo very nearly diiect, and will very well represent the isotherm of 
59°. It is noticeably parallel to the Smoky Mountains and the coast, and 
is midway between them. And thus a system of lines connecting the 
different points of equal mean annual temperature would represent 
graphically one of the chief characteristics of the climate and show its 
intimate dependence upon topographical conditions. And similar charts 
for the seasonal and monthly means would bring to light many unsus- 
pected peculiarities of the different regions and would develop most im- 
portant bearings upon their special agricultural adaptations. 
The representative stations, whose columns of averages are closely cor- 
respondent with those of the different divisions, are Poplar Branch for 
the eastern, Oxford for the middle and Asheville for the western. Such 
stations are of course the most important, and are indicated by these re- 
sults as the proper points for permanent and completely furnished me- 
teorological observatories. 
It may be noted further that the columns for the spring and autumn 
means are, at almost all the stations, very nearly the same as the annual, 
and the average of the two is still nearer to it. 
The influence of the Atlantic on the climate of the coast stations is ob- 
servable chiefly in diminishing the difference between the temperature of 
summer and winter, and this is effected by an elevation of the latter; but 
this is only seen in the stations south of Iiatteras. The difference in the 
January and July means for this part of the coast is about 33°, while the 
corresponding figures for the middle region is about 40°. The effect of 
the mountains upon the difference of the summer and winter means is 
similar, but less, the amount being about 35° ; it is produced, however, 
chiefly by depressing that of the summer. 
And it may be here observed that the difference in the general features 
of the coast region north of Iiatteras, (the Sound region), and the lower 
coast is so marked as to justify the separation of these tracts into two 
climatic sub-divisions. 
It is also worthy of note that the hottest month is July, and the coldest , 
December. In the uorth^- v portions of the continent January is the 
coldest month. 
The average July temperature lor the whole Northern Hemisphere is 
71° ; and that for January, 49° ; the former figure represents the cor- 
responding fact for the western division of North Carolina, and the latter 
for the southern coast. 
