9 
ME. F. CHAMBEES ON THE DIUENAL YAEIATIONS OF 
sent either a north or a south wind, according as its sign is positive or negative, and 
similarly for the east or west wind calculated from (2). The algebraical averages of the 
north and south and of the east and west component winds may then be taken sepa- 
rately for any given period, and these will, when combined, truly represent the average 
velocity and direction of the wind for that period. Such averages have been calculated 
for each hour of the day in the whole period from June 1867 to May 1870, or three 
complete years. They are given in the following Table, along with the corresponding 
averages of most of the other meteorological elements. 
Table I. — Mean Values of Meteorological Elements for each hour of the day from 
May 1867 to June 1870, and their Mean Diurnal Variations for the same period. 
Bombay 
Civil 
Hours. 
Wind. 
Bombay 
Civil 
Hours. 
Barometer 
pressure. 
Pressure of 
vapour. 
Pressure of 
dry air. 
Temperature 
of air. 
Mean 
N. or S. 
com- 
ponent. 
Variation 
of N. or 
S. com- 
ponent. 
Mean 
E. or W. 
com- 
ponent. 
Variation 
ofE. or 
W. com- 
ponent. 
Reduced to 32° F. 
Mean. 
Varia- 
tion. 
Mean. 
Varia- 
tion. 
Mean. 
Varia- 
tion. 
Mean. 
Variation. 
0 
to 1 
1-03 
N. 
104 
s. 
4-46 
w. 
1-79 
E. 
0 
29-824 
+0-004 
0-781 
-0 002 
29 043 
+ 006 
O 
773 
O 
-21 
1 
„ 2 
1-07 
N. 
1 00 
s. 
3'96 
w. 
2-29 
E. 
1 
•810 
— 
•010 
•777 
— 
•006 
•033 
-•004 
76 9 
-2-5 
2 
„ 3 
093 
N. 
114 
s. 
3 56 
w. 
2-69 
E. 
2 
•797 
— 
•023 
•773 
— 
•010 
•024 
-•013 
76-7 
-2-7 
3 
„ 4 
M0 
N. 
0-97 
s. 
309 
w. 
3-16 
E. 
3 
•791 
— 
•029 
■768 
— 
•015 
•023 
-014 
763 
— 3T 
4 
» 5 
1-27 
N. 
0-80 
s. 
252 
w. 
3-73 
E. 
4 
-793 
— 
•027 
•762 
— 
•021 
•031 
-006 
761 
-3-3 
5 
„ 6 
1-27 
N. 
0-80 
s. 
1*96 
w. 
4-29 
E. 
5 
•804 
— 
•016 
•756 
— 
•027 
•048 
+ 011 
75-8 
-3-6 
6 
„ 7 
100 
N. 
107 
s. 
119 
\v. 
5 06 
E. 
6 
•822 
+ 
■002 
•754 
— 
■029 
•068 
+ 031 
75 7 
-3-7 
7 
„ 8 
0-73 
N. 
1-34 
s. 
0-86 
w. 
5-39 
E. 
7 
•844 
+ 
024 
•760 
— 
•023 
•084 
+ •047 
76 4 
-30 
8 
„ 9 
0-77 
N. 
1-30 
s. 
109 
w. 
516 
E. 
8 
•864 
+ 
044 
•767 
— 
•016 
•097 
+•060 
77-9 
-15 
9 
„ 10 
0-67 
N. 
1-40 
s. 
216 
w. 
409 
E. 
9 
•877 
+ 
•057 
•772 
— 
•011 
•105 
+ •068 
79-4 
00 
10 
„11 
043 
N. 
1-64 
s. 
4 39 
w. 
1 86 
E. 
10 
•876 
+ 
•056 
•774 
— 
•009 
•102 
+ •065 
80-7 
+ 13 
11 
„ 12 
083 
N. 
1 24 
s. 
712 
w. 
087 
W. 
11 
•862 
+ 
•012 
•777 ’ 
— 
•006 
•085 
-I- -04 8 
820 
+ 2-6 
12 
„13 
1-67 
N. 
0-40 
s. 
992 
w. 
3-67 
\V. 
12 
•839 
+ 
•019 
•783 
•000 
■056 
+ 019 
83-2 
+3-8 
13 
„14 
209 
N. 
0-02 
N. 
11-39 
w. 
514 
w. 
13 
•816 
•004 
•795 
+ 
•012 
021 
-•016 
84-0 
4-4-6 
14 
„15 
3-17 
N. 
M0 
N. 
12-72 
w. 
6-47 
w. 
14 
•793 
— 
•027 
•805 
+ 
•022 
28-988 
-049 
84-3 
+4-9 
15 
„16 
393 
N. 
1-86 
N. 
12-99 
w. 
674 
w. 
15 
•778 
— 
•042 
•807 
+ 
•024 
•971 
-•066 
84-3 
+4-9 
16 
,, 17 
4-70 
N. 
2-63 
N. 
12 66 
w. 
6 41 
w. 
16 
•773 
— 
•047 
•811 
+ 
•028 
•962 
-075 
837 
+4-3 
17 
„ 18 
4-83 
N. 
2-76 
N. 
11-59 
w. 
5-34 
w. 
17 
•778 
— 
•042 
•803 
+ 
•020 
•975 
-•062 
821 
+2-7 
18 
„ 19 
4-87 
N. 
2-80 
N. 
1002 
w. 
3-77 
w. 
18 
•791 
— 
•029 
•802 
+ 
•019 
•989 
-•048 
80-4 
+ 1-0 
19 
„ 20 
4-40 
N. 
2-33 
N. 
8-39 
w. 
2-14 
w. 
19 
•809 
— 
•Oil 
■800 
+ 
•017 
29009 
-•028 
79-5 
+0-1 
20 
!. 21 
3-43 
N. 
1-36 
N. 
7-32 
w. 
1 07 
w. 
20 
•82'6 
+ 
•006 
•800 
+ 
•017 
•026 
-•Oil 
79-0 
-0-4 
21 
„ 22 
2-47 
N. 
0-40 
N. 
6-36 
w. 
0 11 
w. 
21 
•839 
+ 
•019 
•795 
+ 
■012 
•044 
+ •007 
78-5 
-0-9 
22 
,, 23 
1 73 
N. 
0-34 
S. 
5-52 
w. 
0-73 
E. 
22 
•842 
+ 
•022 
•787 
+ 
■004 
•055 
+■018 
78-0 
-1-4 
23 
o 
1-20 
N. 
0 87 
S. 
4-76 
\v. 
1-49 
E. 
23 
•835 
+ 
■015 
•782 
— 
•001 
•053 
+ ■016 
775 
-19 
207 
N. 
625 
IV. 
29-820 
0-783 
29037 
79-4 
The observations of the barometer and thermometers were made seven minutes and 
five minutes respectively after the full hour. 
These variations are also represented graphically by figures 1, 2, 3, 4 and 5, Plate 
XXXIV. 
3. From the hourly values of the variation of the barometer given above, the con- 
stants in the first three terms of the right-hand member of Bessel’s formula, 
E = Bj sin (# + C,) + B 2 sin (2$ T C 2 )-{- B 3 sin (35 -(- C 3 ) -f- &c., . . . (.3) 
have been calculated and found to be 
B,=-0179, Cj=337 17, 
B 2 =-0385, C 2 =157 13, 
B a =-0014, C 3 = 25 0; 
