104 Major-General Sabine on the Cosmical Features 



the character of the variation both of the solar spots and of the 

 magnetic disturbances is not so precisely conveyed as it might 

 be, when certain single years are named as definite epochs of 

 maximum and minimum. The character of the variation is, 

 more approximately, that the years which end in 3, 4, and 5, 

 are for the most part years of both minimum magnetic disturb- 

 ance and minimum apparition of spots on the sun's disk. This 

 last we may see in M. Schwabe's Table*, when we view 

 together the columns indicating, on the one hand, the number 

 of groups of spots seen in each year; and, on the other hand, 

 the number of days in the year free from spots. In like man- 

 ner the years ending in 8, 9, and are for the most part distin- 

 guished by the nearly equal prevalence of the opposite extreme, 

 both of magnetic disturbances and of the number of groups of 

 spots, scarcely any day occurring in which the sun's disk is 

 without spots. The intermediate years, viz. those ending with 

 1 and 2, and with 6 and 7, are usually years of medium in both 

 respects — the two first generally exhibiting a diminishing, and 

 the two last an increasing progression. The difference in the 

 amount of magnetic disturbance in the years of maximum and 

 minimum is approximately in the proportion of 5 to 2. 



In our entire ignorance of the nature of the physical changes 

 in the photosphere of the sun, of which the spots are a manifes- 

 tation, we are not entitled to anticipate confidently that a variation 

 which has shown itself with so much regularity since M. Schwabe's 

 observations commenced in 1826, will continue to recur with 

 the same regularity in subsequent years ; nor ought we too con- 

 fidently to infer that, even if the same general regularity be 

 maintained, there may not be years in which apparent anoma- 



* 







Days free 

 from spots. 



Days of 







Days free 

 from spots. 



Days of 



Year. 



Groups. 



Observa- 

 tion. 



Year. 



Groups. 



| Observa- 

 tion. 



1826. 



118 



22 



277 



1843. 



34 



149 



312 



1827. 



161 



2 



273 



1844. 



52 



111 



321 



1828. 



225 







282 



1845. 



114 



29 



332 



1829. 



199 







244 



1846. 



157 



1 



314 



1830. 



190 



] 



217 



1847. 



257 







276 



1831. 



149 



3 



239 



1848. 



330 







278 



1832. 



84 



49 



270 



1849. 



238 







485 



1833. 



33 



139 



267 



1850. 



186 



2 



308 



1834. 



51 



120 



273 



1851. 



151 







308 



1835. 



173 



18 



244 



1852. 



125 



1 



337 



1836. 



272 







200 



1853. 



91 



4 



299 



1837. 



333 







168 



1854. 



67 



65 



334 



1838. 



282 







202 



J 855. 



38 



146 



315 



1839. 



162 







205 



1856. 



34 



193 



321 



1840. 



152 



3 



263 



1857. 



98 



52 



324 



1841. 



102 



15 



283 



1858. 



188 







335 



1842. 



68 



64 



307 



1859. 



205 



o 



343 



