450 RECTIFICATIONS AND ADDITIONS. 



the years 1821 1830) the most entire confirmation of 

 the decennial magnetic declination period, and its con- 

 nection with the similar period of relative paucity and 

 frequency in the solar spots. (Arago's Meteorological 

 Essays (Translation), London, 1855, pp. 355 357.) As 

 early as the same year (1850) in which Schwabe, at 

 Dessau, published his periods of the solar spots (Kosmos, 

 Bd. iii. S. 402 ; Eng. p. 291), and even two years before 

 Sabine himself first (in March 1852, Phil. Trans, for 1852, 

 pt. 1, p. 116 121 ; Kosmos, Bd. iv. S. 174 ; Eng. note 

 73) connected the magnetic decennial period with that 

 of the solar spots, he had made the important discovery 

 that the sun appears to act by its own proper magnetic 

 force upon the earth's magnetism. He had found (Phil. 

 Trans. 1850, pt. 1, p. 216 ; Kosmos, Bd. iv. S. 132 ; Eng. 

 p. 143) that the magnetic intensity is greatest, and the 

 needle approaches most nearly to a vertical direction, 

 when the earth is nearest to the sun. The knowledge 

 of such a magnetic influence of the central body of oar 

 planetary system, not acting indirectly through the pro- 

 duction of heat, but directly by its own magnetic force, 

 as well as by variations in its photosphere (in the mag- 

 nitude and frequency of funnel-shaped openings in the 

 solar photosphere), gives to the study of terrestrial 

 magnetism, and to the network of magnetic observa- 

 tories with which (Kosmos, Bd. i. S. 346, Bd. iv. S. 72 ; 

 Eng. vol. i. p. 334, present volume, p. 78) Russia and 

 Northern Asia have been covered since the resolutions 

 of 1829, and the colonies of Great Britain since 

 1840 1850, a higher cosmical interest. (Sabine, in 

 the Proceedings of the Royal Society, vol. viii. No. 25, 

 p. 400, and in the Phil. Trans, for 1856, p. 362.) 



