E. Loomis—Observations of the U. S. Signal Service. 17 
column 3d the height of the barometer; column 4th the direction 
and force of the wind; column 5th the rainfall during the pre- 
ceding 8 hours; column 6th the direction and distance of the low 
center from the place of observation; column 7th the station 
where the low center first made its appearance; column 8th the 
date at which the low center reached the Atlantic Ocean; col- 
umn 9th the latitude of that point; and column 10th the direc- 
tion and force of the wind on Pike’s Peak at the date given in 
column 2d. 
It will be noticed that the highest velocity of the wind at 
Corinne and Salt Lake City was 31 miles per hour, and the 
average velocity at the dates mentioned was less than 11 miles 
per hour. Southerly winds were three times as frequent as 
northerly winds. In only six of the cases did the wind blow 
from any eastern quarter, and its greatest velocity from this 
quarter was four miles per hour. 
e amount of rain or snow attending these storms was very 
small, the average during the eight hours preceding the dates 
of observation being less than 0°05 inch. In eight cases rain or 
snow is mentioned in the column headed “state of the 
copa when no entry is made in the column headed “ rain- 
In a few cases the low center appears to have passed directly 
over the station of observation, but generally it passed a little 
north of Salt Lake, and in no case did it pass south of it. 
the twenty-nine storms here enumerated, the stations at which 
a first indications of the low area are noticeable are as fol- 
OWS: 
Portland, Or., 17 cases. | San Diego, 1 case. 
Portland, Or., & Virginia City,. 3 cases. | Fort Benton, 1 case. 
Portland, Or., and Fort Benton, 1 case. | Bismark,..._..-- 2 cases. 
San Francisco, 3 cases. | Fort Sully, 1 case. 
appeared simultaneously at Portland, Or., and Virginia City or 
Fort Benton, and it is probable that these storms came from 
the Pacifie Ocean, but came from a latitude north of 50°, so 
that they appeared in the United States on both sides of the 
Rocky Mountains at about the same time. There remain only 
four cases, viz: Nos, 13, 20,22 and 25. In these cases the dis- 
turbance apparently originated on the east side of the Rocky 
Mountains and thence extended to Salt Lake and the Pacific 
coast. In none of the cases’ did the low appear to originate 
between the Sierra Nevadas and the Rocky Meastdinn 
n all but three of these storms the low area can traced 
to the Atlantic Ocean, which it reached in a latitude betwee 
Am. Jour. ‘aa mee Surizs, VoL, XX, No. 115.—Juty, 1880, 
