APPLIED TO METEOROLOGICAL OBSERVATIONS 
127 
Table I. — Showing the corrections to be applied to the Monthly Mean of the daily 
readings of the barometer at any hour, to deduce the true mean reading for the 
month from the observations taken at that hour. 
Local meaa 
time. 
January. 
February. 
March. 
April. 
May. 
June. 
July. 
August. 
Sept. 
October. 
Nov. 
Dec. 
in. 
in. 
in. 
in. 
in. 
in. 
in. 
in. 
in. 
in. 
in. 
in. 
Midnight. 
0-000 
— 0-001 
-0 002 
-0-008 
— 0-005 
0-000 
0-006 
-0-010 
0-005 
-0-005 
0-011 
— 0-004 
1 A.M. 
+ 0-001 
+ 0-004 
+ 0-013 
0-000 
+ 0-002 
+ 0-004 
0-000 
0-000 
0-000 
+ 0-004 
0-005 
+ 0-001 
2 
+ 0-002 
+ 0-008 
+ 0-020 
+ 0-007 
+ 0-004 
+ 0-005 
+ 
0-003 
+ 0-007 
+ 
0-005 
+ 0-010 
+ 
0-003 
+ 0-006 
3 
+ 0-005 
+ 0-012 
+ 0-023 
+ 0-010 
+ 0-005 
+ 0-004 
+ 
0-005 
+ 0-011 
+ 
0-010 
+ 0-015 
+ 
0-008 
+ 0-010 
4 
+ 0-011 
+ 0-014 
+ 0-022 
+ 0-011 
+ 0-005 
+ 0-001 
+ 
0-005 
+ 0-014 
+ 
0-012 
+ 0-020 
+ 
0-013 
+ 0-012 
5 
+ 0-015 
+ 0-015 
+ 0-019 
+ 0-011 
+ 0-006 
— 0-002 
+ 
0-006 
+ 0-011 
+ 
0-014 
+ 0-022 
+ 
0-016 
+ 0-014 
6 
+ 0-015 
+ 0-012 
+ 0-012 
+ 0-006 
+ 0-006 
-0-006 
+ 
0-002 
+ 0-005 
+ 
0-010 
+ 0-018 
+ 
0015 
+ 0-011 
7 
+ 0-010 
+ 0-007 
+ 0-005 
-0-003 
+ 0-006 
-0-010 
— 
0-004 
0-000 
+ 
0-001 
+ 0-008 
+ 
0-010 
+ 0-006 
8 
+ 0-003 
0-000 
— 0-004 
— 0-008 
+ 0-003 
-0-012 
— 
0-008 
-0-007 
— 
0-006 
-0-003 
+ 
0-003 
+ 0-004 
9 
— 0-008 
-0-008 
— 0-010 
— 0-011 
-0-007 
— 0-012 
— 
0-010 
— 0-008 
— 
0-011 
— 0-009 
— 
0-005 
— 0-010 
10 
— 0-010 
— 0-015 
-0-015 
— 0014 
-0-009 
— 0-011 
— 
0-010 
-0-009 
— 
0-013 
-0-014 
— 
0-007 
— 0 015 
11 
— 0-014 
— 0-016 
-0-015 
— 0-011 
— 0-006 
-0-009 
— 
0-009 
— 0-008 
— 
0-010 
— 0-014 
— 
0-005 
-0-015 
Noon. 
-0-005 
-0-012 
— 0-010 
— 0-008 
-0-002 
-0-006 
— 
0-006 
— 0-005 
__ 
0-005 
— 0-010 
+ 
0-002 
— 0-009 
1 P.M. 
+ 0-002 
— 0-006 
-0-005 
— 0-004 
0-000 
-0-003 
— 
0-003 
0-000 
0-000 
-0-003 
+ 
0-007 
+ 0-003 
2 
+ 0-005 
+ 0-003 
0-000 
+ 0-003 
+ 0-003 
+ 0-003 
+ 
0-001 
+ 0-003 
+ 
0-004 
+ 0-004 
+ 
0-011 
+ 0-008 
3 
+ 0-004 
+ 0-006 
+ 0-003 
+ 0-009 
+ 0-006 
+ 0-007 
0-005 
+ 0-005 
+ 0-008 
+ 0-005 
+ 
0-010 
+ 0-010 
4 
+ 0-002 
+ 0-008 
+ 0-005 
+ 0-004 
+ 0-010 
+ 0-013 
+ 
0-009 
+ 0-009 
+ 
0-010 
+ 0-003 
+ 
0-008 
+ 0-009 
5 
0-000 
+ 0-006 
+ 0-004 
+ 0-014 
+ 0-014 
+ 0-017 
+ 
0-013 
+ 0-011 
+ 
0-011 
0-000 
+ 
0-004 
+ 0-006 
6 
— 0-003 
+ 0-002 
0-000 
+ 0-011 
+ 0-015 
+ 0-017 
+ 
0-013 
+ 0-011 
+ 
0-006 
— 0-005 
0-000 
+ 0-002 
7 
-0-005 
-0-004 
— 0-006 
— 0-007 
+ 0-010 
+ 0-014 
+ 
0-010 
+ 0-005 
0-000 
-0-008 
— 
0-006 
— 0-003 
8 
-0-006 
-0-006 
-0-012 
— 0-0C5 
0-000 
+ 0-008 
+ 
0-004 
— 0-005 
0-005 
— 0-011 
— 
0-012 
-0-006 
9 
— 0-007 
-0-008 
— 0-015 
-0-009 
-0-006 
+ 0-003 
— 
0-001 
— 0-010 
— 
0-009 
— 0-014 
— 
0-017 
-0-009 
10 
— 0-005 
-0-007 
— 0-012 
— 0-012 
-0-008 
— 0-002 
_ 
0-005 
— 0-015 
— 
0-011 
— 0-012 
— 
0-019 
— 0-010 
11 
-0-004 
-0-005 
-0-010 
— 0-012 
— 0-008 
— 0-002 
— 
0-012 
-0-015 
— 
0-011 
-0-009 
0-017 
-0-009 
The sign + denotes that the number is to be added, and the sign — denotes that 
the number is to be subtracted. 
The double sets of + and — signs in every month show that there are two maxima 
and two minima in the daily variation in the reading of the barometer, and conse- 
quently the fact of a triple maximum and a triple minimum at times occurring, is 
due to accidental circumstances and to irregular daily oscillation. 
Four times daily the reading of the barometer is at its mean value ; these times in 
the several months are as follows : — 
h 
m 
h 
m 
h 
m 
In January ... 
at 8 
0 A.M. 
at 
0 
40 P.M. ; 
and at 5 
0 P.M. 
In February... 
at 8 
0 A.M. 
at 
1 
40 P.M. ; 
and at 6 
20 P.M. 
In March 
at 7 
35 A.M. 
at 
1 
50 P.M. ; 
and at 6 
0 P.M. 
In April 
..at I’' 0” A.M. ; 
at 6 
40 A.M. 
at 
1 
40 P.M. ; 
and at 7 
20 P.M. 
In May 
at 8 
20 A.M. 
at 
1 
0 P.M. ; 
and at 8 
0 P.M. 
In June 
..at midnight ; 
at 4 
20 A.M. 
at 
1 
40 P.M. ; 
and at 9 
20 P.M. 
In July 
..at 1*“ 0“ A.M. ; 
at 6 
25 A.M. 
at 
1 
40 P.M. ; 
and at 8 
45 P.M. 
In August ... 
..at 1*" 0™ A.M. ; 
at 7 
0 A.M. 
at 
1 
1 0 P.M. ; 
and at 7 
35 P.M. 
In September 
..at I** 0™ A.M. ; 
at 7 
30 A.M. 
at 
1 
0 P.M. ; 
and at 7 
0 P.M. 
In October ... 
at 7 
50 A.M. 
at 
1 
1 0 P.M. ; 
and at 5 
0 P.M. 
In November 
..at I** 40™ A.M. ; 
at 8 
20 A.M. 
at 11 
40 A.M.; 
and at 5 
45 P.M. 
In December 
..at 0’' 40™ A.M. ; 
at 7 
40 A.M. 
at 
0 
45 P.M. ; 
and at 6 
5 P.M. 
