272 SPECIAL RESULTS IN THE URANOLOGiCAL 



speculations which after ages have realised), so we find as 

 early as the middle of the fifteenth century, in the writings 

 of Cardinal Nicolaus, of Cusa, in the second book of the 

 treatise " De docta ignorantia," the opinion clearly expressed, 

 that the body of the Sun is only an earthy kernel surrounded 

 by a luminous shell as by a fine veil, and having in the 

 middle (between the dark kernel and luminous shell?) a 

 mixture of water-bearing clouds and clear air similar to our 

 atmosphere ; and that the power of radiating forth the light 

 which animates vegetation on the surface of the Earth 

 belongs not to the earthy kernel or nucleus of the Sun, but 

 to its bright surrounding covering. This view of the phy- 

 sical constitution of the Sun, which has hitherto attracted so 

 little notice in the history of astronomy ( 466 ), has a great 

 resemblance to the views which prevail at the present 

 time. * 



I have shown in an earlier volume, in the notice of 

 "historical epochs in the physical contemplation of the 

 Universe" ( 467 ), that the spots on the Sun were first seen 

 and described in print, not by Galileo, Scheiner, or Harriott, 

 but by Johann Fabricius of East Priesland. Both the 

 discoverer, and also Galileo, as is shown by his letter to the 

 Principe Cesi, written on the 25th of May, 1612, knew that 

 the solar spots belonged to the Sun itself; nevertheless, ten 

 and twenty years later, a Canon of Sarlat, Jean Tarde, and 

 a Belgian Jesuit, maintained that the spots were transits of 

 small planets : by the one called Sidera Borbonia, and by the 

 other Sidera Austriaca ( 468 ) . Schemer was the first to adopt 

 the use in observations of the Sun of the blue and green shade- 

 glasses ( 469 ) which had been suggested 70 years before by 

 Apian (Bienewitz), in the " Astronomicum Csesareum," and 

 had long been made use of by. the Belgian navigators ; the 



