HOURLY OBSERVATIONS OP AIR TEMPERATURE AND PRESSURE. 
639 
Table A. — Mean Values (reckoned from Mean Midnight) of the %:>, q Coefficients for 
the First Four Orders of Harmonic Components of the Diurnal Inequality of 
Temperature at Greenwich, for each Month of the Year, obtained from 20 Years’ 
Observations from 1849 to 1868 . 
MoutlLS. 
Pv 
2i- 
Pi- 
Pi- 
P-.i- 
Pi- 
Pi- 
'if 
Mean 
temp. T. 
January . 
0 
-1-45 
o 
-1-20 
+ 
o 
-64 
+ 
O 
-69 
o 
•24 
_ 
O 
•26 
+ 
•04 
+ 
O 
•04 
38-9 
February 
-2-39 
-2-06 
+ 
-88 
+ 
•89 
— 
•23 
— 
•17 
•00 
— 
•07 
39 7 
March 
-3-71 
-2-82 
+ 1-02 
+ 
•87 
— 
•06 
+ 
•13 
•12 
— 
•19 
41-5 
April .... 
-5-46 
-3-51 
+ 
1-04 
+ 
•56 
+ 
•27 
+ 
•36 
— 
•15 
— 
•08 
47-2 
May .... 
-6-34 
-3-61 
+ 
-63 
+ 
•17 
+ 
•50 
+ 
•38 
— 
•01 
+ 
•09 
52-7 
June .... 
-6-69 
-3-83 
+ 
-50 
+ 
•04 
+ 
•46 
+ 
•39 
+ 
•10 
+ 
•17 
59-8 
July .... 
-6-58 
-4-08 
+ 
-57 
+ 
•23 
+ 
•50 
+ 
•38 
— 
•01 
+ 
•12 
62'5 
August . 
-6-06 
-3-83 
+ 
-95 
+ 
•53 
+ 
•38 
+ 
•39 
— 
•16 
+ 
•01 
61-9 
September . 
-O-60 
-3-21 
1-49 
+ 
•83 
+ 
•06 
-H 
•25 
— 
•23 
— 
•23 
57-5 
October . 
-3-61 
-2-04 
+ 
1-35 
+ 
•74 
— 
•25 
— 
•04 
— 
•10 
— 
•10 
50-9 
November . 
-2-29 
-1-60 
+ 
-96 
+ 
•67 
•35 
— 
•18 
+ 
•03 
+ 
•01 
42-8 
December . 
-1-22 
-1-07 
+ 
•59 
+ 
•47 
— 
•25 
— 
•21 
+ 
•06 
+ 
•05 
40-8 
Mean 20 years 
-4-282 
-2-738 
+ 
-885 
+ 
•557 
+ 
•066 
+ 
•118 
— 
•046 
— 
•015 
49-69 
