J. D. Dana—Lnmestone Belts of Westchester County, N. Y. 21 
situated near the Pacific coast; the next seven stat 
situated among the mountains; the next seven stations are 
table shows the results obtained. The first three stations are 
ions 
1,000 and 8,000 feet; and the last twelve stations are elevated 
less than 1,000 feet above the sea. 
next proceeded in the manner described in my twelfth 
paper, page 90. I determined the mean annual range of the 
barometer at a point on the Pacific coast, and also the range at 
a point in the Mississippi valley, each having the same latitude 
as one of the mountain stations. Between the two results thus 
s 
the barometric fluctuations observed at Salt Lake City should 
be increased by 8 per cent, and those at the other mountain 
ceo viz: Virginia City, Cheyenne, Denver and Santa Fe, 
shoul i 
metrical than when no correction is applied. 
n preparing the materials for this article I have been assisted 
by Mr. Henry A. Hazen, a graduate of Dartmouth College of 
the class of 1871. 
Art. II.—On the Geological relations of the Limestone Belts of 
Westchester County, New York; by James D. DaNa. 
WESTCHESTER County is comprised within the Green Moun- 
tain region; and my studies of the County have been carried 
on with special reference to the subject of Green Mountain 
geology.’ 
In commencing my observations in Western New England, I 
had in view the following points : 
1) To determine the limits of the series of rocks associated 
' For my former papers, see this Journal, third Series, iv, 362, 450, 504; v, 47, 
84; vi, 257, 1872, 1873; xiii, 332, 406; xiv, 36, 132, 202, 257, 1877; xvii, 375; 
and xviii, 61, 1879; xix, 191, 1880. 
? 
