AMERICAN JOURNAL OF SCIENCE. 
[THIRD SERIES.] 
Art. I.— Contributions i Meteorology: being trey dete Srom 
an examination of th ervations of the d States Signal 
Service, and from ities sources; by ELias Spot Professor 
of Natural Philosophy in Yale College. Fifteenth paper, 
with Plate I. 
[Read before the National Academy of Sciences, Washington, April 19, 1881.] 
Reduction to sea-level of barometric observations made at elevated 
stations 
DuRtne the past eight years a (ae portion of my time has 
been devoted to investigating the course of storms in their pro- 
gress across the Rocky Mountains, and in my first paperastorm 
was traced from Portland, Oregon, eastward to Lake Superior. 
During these eight years, I have had the constant services of 
a paid assistant, who has expended a vast amount of labor in 
attempting to discover the best method of tracing storms across 
the mountains. Some of the results of these investigations 
have been communicated in preceding papers, particularly Nos. 
8, 9 and 13. 
In order to study this subject more thoroughly, I have made 
a careful examination of the reduction to sea-level of the 
ometrie observations made on Mt. Washington. I first pre- 
pers a table showing the reduction to sea-level, according to 
unwoody’s Tables (8. S. Report for 1876, p. 364), for the oat 
Am. Jour. Sct. Sehesie Series, Vou. XXII, No. 127.—Juny, 1881. 
