8 FE. Loomis— Observations of the U. S. Signal Service. 
of the observation; and column 4th the station at which the 
observed height of the barometer was least. This station was 
not generally at the center of the low area, but is presumed to 
have been not far distant from the center; column 5th shows 
the height of the barometer at the station named in column 4th; 
column 6th shows how much the barometer at the given date 
was below its mean height for that month as deduced from the 
observations of six years; column 7th shows how much the 
thermometer on the north side of the low area was depressed 
below its mean height for the hour of observation; column 8th 
shows how much the thermometer on the south side of the low 
area rose above its mean height for the hour of observation ; 
column 9th shows the average humidity of the winds on the 
north side of the low area; column 10th the average humidity 
on the south side of the low area; column 11th shows the direc- 
tion and velocity of the highest wind reported at any station 
on the north or west side of the low area; column 12th the 
direction and velocity of the highest wind reported at any station 
on the south or east side of the low area; column ows 
the total rain-fall at all the stations east of the Rocky Moun- 
tains during the preceding eight hours; column 14th shows the 
total rain-fall at all the stations included within the same low 
area; and column 15th shows the direction of the center of the 
rain area from the center of low pressure for a time preceding 
the date of observation by four hours. en the center of 
low pressure is near the boundary of the United States it is 
generally impossible to determine from the observations where 
is the center of the rain area; and in such cases a blank is left 
in column 14th. When the center of the rain area coincided 
sensibly with the center of low pressure the syllable cent. is 
inserted. Table III contains similar particulars respecting six 
storms whose course was nearly from north to south. The last 
case in each of the tables was taken from the International 
series of observations in which the observations are given for 
only one hour of each day, and the rain-fall is the amount re- 
ported for the preceding twenty-four hours. 
On comparing these two tables we find important differences 
in several particulars. In each case of Table IT, with the excep- 
tion of the last, the barometer became more depressed as the 
storm moved northward, and at the last observation of each 
case the average depression of the barometer below the mean 
was 0°26 inch greater than at the first observation. In each 
case of Table III the depression of the barometer increased for 
16 hours or more, and then decreased, with the exception per- 
haps of the last case where the storm is only followed to Dodge 
City. In the other cases, the average depression of the barom- 
eter at the last observation was somewhat less than at the first 
