A^cbiikir Theory. — MislocL-lcs. 315 
iiuim and niaxiinuin inclination (luring- that solar niaxinnmi. 
In December. 1875, the minimum of the inclination fell to 4' 
58' 42" and its maximum in ]\rarch,, 1876, reached only 5° 16' 
45'. which, tlms. was during- the minimum activity of the 
Sun; and this was the lowest niininuim and maximum in- 
clination duriui;- that period. The inclination during this 
minimum activity of the .Sun was i' 2^" less than it was dur- 
int^- the maximum solar activity in Xovember, 1868. 
Jn like manner tlie inclination was i' 19" greater during 
the solar maxinunn in February, 1869. than it was during 
the minimum in 1876. In April, 1880. when the Sun's ac- 
tivity was close to its maximum, the minimum of the inclina- 
tion fell to 5° o' 2" and was, consequently, i' 20" above what 
it was during the preceding solar minimum in December, 
1875. In July. 1883, when the Sun's activity still was at its 
hight. the inclination of the lunar orbit fell only to 5° o' 7" 
and rose in October of the same year to 5° 17' 50". whicli was 
the highest point during that solar maximum. 
During the following solar minimum, the mininuim in- 
clination fell, in Xovember, 1887, 39" lower, antl in January, 
1888, its maximum was 51" lower than during the preceding 
solar maximum in 1883. 
It is important to notice, that as the Sun's minimum ac- 
tivity was higher during this epoch than in 1876-77, so the 
inclination of the lunar orbit also stood higher. 
As the Sun's activity now began to increase, the inclina- 
tion of the lunar orbit became relatively greater. Thus in 
April, 1889, its minimum w^as again the same as in Julv, 1883. 
or 5° o' 7" and its maximum in December, 1890, 5" higher 
than in October, 1883, or 5° 17' 55", but during the maximum 
solar activity in 1893 it reached the exceptional extreme of 
5° 18' to the ecliptic. 
These data from the ephemerides have been furnished bv 
Mr. W. T. Carrigan of the Nautical Almanac Office in Wash- 
ington. 
They are presented below in tabular form together with 
the solar maxima and minima. 
This shows, conclusively, that the periodical variation in 
the oscillation of the lunar orbit is coincident with the oscil- 
lation of the solar activity, which, as we have shown above. 
