34 COSMOS. 



increasing intensity, declination and inclination cannot there- 

 fore be ascribed to the sun in connection with its thermic 

 influence. 



The annual means deduced from observations at Munich 

 and Gottingen, have enabled the active director of the Royal 

 Bavarian Observatory, Professor Lament, to deduce the 

 remarkable law of a period of 10^ years in the alterations of 

 declination. 83 In the period between 1841 and 1850, the 

 mean of the monthly alterations of declination attained very 

 uniformly their minimum in 1843|, and their maximum in 

 184S|-, Without being acquainted with these European 

 results, General Sabine was led to the discovery of a periodi- 

 cally active cause of disturbance from a comparison of the 

 monthly means of the same years, namely from 1843 to 1848, 

 which were deduced from observations made at places which 

 lie almost as far distant from one another as possible (Toronto 

 in Canada, and Hobarton in Van Diemen's Land). This 

 cause of disturbance was found by him to be of a purely 

 cosmical nature, being also manifested in the decennial 

 periodic alterations in the sun's atmosphere. 83 Schwabe, 

 who has observed the spots upon the sun with more constant 

 attention than any other living astronomer, discovered (as I 

 have already elsewhere observed), 84 in a long series of years 

 (from 1826 to 1850), a periodically varying frequency in the 

 occurrence of the solar spots, showing that their maxima fell 

 in the years 1828, 1837, and 1848, and their minima in the 

 years 1833 and 1843. "I have not had the opportunity," 

 he writes, " of investigating a continuous series of older 

 observations, but I willingly subscribe to the opinion that 

 this period may itself be variable." A somewhat analogous 

 kind of variability periods within periods is undoubtedly 

 observable in the processes of light of ther self-luminous- 

 suns. I need here only refer to those complicated changes 

 of intensity, which have been shown by Goodricke and 

 Argelander to exist in the light of /3 Lyras and Mira Ceti. M 



82 Lament, in Poggend. Annalen, Bd. Ixxxiv, s. 579. 



83 Sabine, On periodical laws discoverable in the mean effects of the 

 larger magnetic disturbances, in the Phil. Transact, for 1852, pt. i, p. 121. 

 Vide supra, p. 75. 



84 Cosmos, voL iv, p. 398. 



85 Op. cit. voL iii, p. 228. 



