3i6 The American Geologist. November, 1904. 
•causes the dammed-up light-waves in the ecliptic around the 
earth to vary in harmony with its own variation and also, 
further, to transmit the same periodicity to the oscillation of 
the lunar orbit. 
Maximum and miminum inclination and Maximum and miminum solar act- 
oscillaiion of the lunar orbit. ivity during the same period. 
Max. i868-'7i Max. 
:Min. i875-'78 Mm. 
^lax. i88o-'83 Max. 
1868 Nov. 
5^ 
0" 
5" 
1869 Feb. 
-0 
17' 
54" 
1875 Dec. 
4° 
58' 
42" 
1876 Mar. 
_o 
5 
16' 
45" 
1880 Apr. 
5° 
0' 
2" 
" Dec. 
_ 
17' 
41" 
1883 July 
_ 
s 
0' 
7" 
•' Oct. 
,- 

1/ 
50" 
1887 Nov. 
4° 
59' 
28" 
1888 Tan. 
- 

16' 
59" 
1892 Feb. 
4° 
59' 
18" 
" Oct. 

18' 
0" 
Min. i887-'88 Min. 
Max. 1 890- '93 Max. 
\\'e have above called attention to the fact, that the prob- 
aljle cause of this periodical oscillation of the lunar orbit, 
would prove to be the cause of its whole inclination to the 
ecliptic. That this really is the case, seems to be well demon- 
strated by the fact that the weaker the light-force the less 
the inclination, and that the stronger the light-force, the greater 
the inclination. The reasonable conclusion follows that the 
light-zone around the earth is the prime cause on account of 
which the moon intersects the ecliptic. 
The periodical oscillation of the lunar orbit, as here pre- 
sented, verifies the theory of the meteorologists, which holds 
that cyclones are of a magneto-electric character, and are 
originallv caused bv the Stui, since they follow the rising and 
falling solar activity in their force and frequency. 
We may add, further, that if the varition in the radiation 
of light causes the periodical variation in the oscillation of 
the lunar orbit, there can be no doubt abovit the manifestation 
of the light-force in meteorological phenomena. Hence we 
should find that all these oscillations are very closely related, 
originating from the same central force, the Sun, and having 
the same characteristics. 
The following example of the oscijlating energy of tor- 
nadoes and other severe storms may be of interest to call at- 
tention to in this connection : 
