178 
demonstrated, by means of the eleven formulae (9) in which now 
the constants assume the values: | 
| == 20. 67, i ра, b= 14 
It appears from the formulae (11) and (12) that the difference 
between the arguments of the two series ought to be: 
A= 00 X 12.95 ; 
when, therefore, the results given by both series are cot- 
clusive to such a degree as to show constant values for the 
quantity : 
А — ра 
this formula will afford a very simple and expeditious wal 
of calculating Z, which is identical with the usual method in 
physical and astronomical researches: it will appear howevtt 
from the results given below that, in order to obtain such an 
accuracy, a hundred-yearly period would probably hardly 
be sufficient, and we have therefore to fall back upon the 
certainly less accurate method of deriving the quantity R from 
the amplitudes. 
4, a. Daily means of barometric pressure. 
The 10 formulae are: 
Amplitude Argument 
mm. 
7.3 0.685 194° 1 
2 7.629 149950” 
5 3.452 151924 
4 5.159 7940" 
5 1.516 920957 
6 2.076 952219! 
7 4.516 90258” 
8 1.207 551555 
9 1.785 16541 
10 6.515 117°47' 
