92 EF. Loomis—Reduction of Barometric Observations. 
The value of the pressure coefficient which best satisfies the — 
di 0418 
observations at Colle aldobbia and Alessandria is 6 
and that of the temperature coefficient is x47. 
It will be noticed that in all of the preceding cases (except 
California) the error arising from assuming that the mean tem- 
perature of the air column is equal to the half sum of the tem- 
er and lower stations is quite small. I 
question from other parts of the 
ological Memoirs, vol. ii, p. 135, is is caine a table showing the 
vertical decrement of temperature in the Himalaya Mountains 
for each month of the year at intervals of 1000 feet up to 12,000 
feet. 
which column secon 
for each 1000 feet of season for the three winter months, and 
column third shows the same for the three summer months. 
Height in feet. 
Winter. 
Sum’er. 
Height in feet. 
l 
Winter. Sum’er. 
0 to 1,000 
1,000 to 2,000 
4°-00 | 
3°98 | 
3°91 
4,000 to 5,000 
5,000 to 6,000 
16,000 to 7,000 
2°-08 | 3°57 
2°30 | 3°30 
2°54) 2:97 
2,000 to 3,000 
3,000 to 4,000 3-77 | 2°59 
7,000 to 8,000, 2°83 | 
From these numbers we ma that in winter, for an elevation 
umn greater than the half sum of the hg see at the u pet 
smaller in amount. 
The ave sere value of the barometric coefficient deduced 
from the observations at the five stations employed in this 
investigation, is san ode the value of the thermometric 
coefficient is =g1y;5- ce the Laplace formula becomes 
(=m 
H = 60870 ft. x log. Dx (14+0°002606 cos 2 1) 
| H-+452252 
11 
Aas a 
20886860 —) 
wast al al te 8 
From this source I oe derived the following table, in 
s the mean decrement of temperature 
