Jupiter's Equinoxes and Sun Spots 



By William A. Spalding. 



About the year 1825, Heinrich Samuel Schwabe, an ama- 

 teur astronomer of Dessau, Germany, began to observe and 

 record sun-spots. He pursued his investigation for twenty- 

 five years, and, in 1851, published the results of his labors. 

 From the data thus presented a periodicity in sun-spot 

 phenomena was first deduced. The subsequent investigations 

 of Prof. R. Wolf of Zurich, and others, confirmed the deduc- 

 tions of Schwabe. fixing the period from maximum to maximum 

 at approximately 11 1-9 years. 



This close approach to Jupiter's period of revolution— 

 11.86 years — at once directed suspicion to that planet as the 

 inciting cause of sun-spot phenomena, and. pari passu, other 

 members of the solar system were involved in the inquiry. 



De La Rue, Stewart, and other investigators, attacked 

 the problem with great vigor, and promulgated theories assign- 

 ing sun-spot phenomena to the perturbative influence of var- 

 ious planets, or to the influence of several planets when in 

 conjunction; but the theories thus proposed have not been 

 accepted by the scientific world, because they are not consid- 

 ered as conclusively proven. 



In 1886, J. H. Kedzie published a book entitled. "Specu- 

 lations on Solar Heat, Gravitation and Sun-Spots." He pre- 

 sented a theory that the period of maximum sun-spots is in 

 some way correlated with Jupiter's passage of the perihelion 

 point in his orbit; i. e., the closest approximation of that 

 planet to the sun. His tables, however, showed a wide range 

 of variation, and he was compelled to admit that the period of 

 maximum sun-spots seemed to lag considerably behind Jupi- 

 ter's perihelion passage. 



Following the investigations of De La Rue and Stewart 

 in their efforts to attribute the cause of sun-spots to the joint 

 intluence of various planets. Prof. John H. Tice, Superintend- 

 ent of Public Schools of St. Louis, Mo., in 1862, took up this 

 line of research, with the hope of discovering the cause of the 

 eleven years sun-spot period and also of extending the inquiry 

 to see whether there might be a similar periodicity in telluric 

 and atmospheric disturbances. In other words, his hypothesis 

 was that the same great cause lies behind sun-spots, magnetic 



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