Causes and Effects of Variation in the Bange of Temperature. 345 
The constants of the first three harmonic terms in the diurnal curves 
of barometric pressure (deduced as above) for the greater, and for the less, 
ranges of temperature are set forth in Tables 3 and 4 respectively. It 
appears from these Tables that a difference in the monthly mean range of 
temperature makes no material difference in the phase times of either the 
24-hour wave (Vi), the 12-hour wave (Vg), or the 8-hour wave (V3). The 
amplitudes {it^, u^, W3) are nevertheless more or less dependent upon the 
range of temperature, besides depending — the first and third in particular 
— upon the time of year. 
The following are the ratios, 70a/tii3, of the amplitudes pertaining to the 
greater range of temperature to those pertaining to the lesser range : — 
M - m 
U2 
Us 
a//3 
a'/i 
Jan 
0 
6-1 
1-224 
•996 
1-000 
Feb 
6-1 
1-273 
1-142 
1-909 
Mar 
5-4 
1-132 
1-055 
•923 
6-5 
1-075 
•967 
•976 
May 
7-5 
1-263 
•988 
1-315 
3-7 
1-177 
-958 
1-074 
July 
5-5 
1-135 
1-041 
1-071 
Aug 
31 
1-153 
•983 
1-196 
Sept 
5-5 
1-189 
1-024 
0^794 
Oct 
4-4 
1-074 
1-047 
10-000 
Nov 
3-9 
1-051 
1-063 
1-611 
Dec 
3-1 
1-022 
•941 
1^471 
5-1 
1-139 
1^015 
1-162 
Judging by Tables 3 and 4 the direct dependence of the second and 
third harmonic terms upon the range of temperature must be slight at the 
best. On account of its regularity the ratio a/ ft given above is much more 
satisfactory for the first harmonic term than it is for the other two. 
Averages for all the months in which a — ft exceeds its mean value ( = 5°-l) 
or falls short of it are : — 
No. of 
M-m 
«2 
Cases. 
a//3 
0 
7 
6-2 
1^184 
1-030 
5 
3-8 
1^095 
•998 
