5 66 THE POPULAR SCIENCE MONTHLY. 



what seemed a star is, in reality, a mass of small stars intermixed with 

 a diffused nebulosity. 



It is very remarkable circumstance that Galileo, whose small tele- 

 scope, directed to the clear skies of Italy, revealed so many interest- 

 ing phenomena, failed to detect 



" That marvellous round of milky light 

 Below Orion." 



It would not, indeed, have been very remarkable if he had simply 

 failed to notice this object. But he would seem to have directed his 

 attention for some time especially to the region in the midst of which 

 Orion's nebula is found. He says : " At first I meant to delineate the 

 whole of this constellation ; but, on account of the immense multitude 

 of stars being also hampered through want of leisure I left the 

 completion of this design till I should have another opportunity." He 

 therefore directed his attention wholly to a space of about ten square 

 degrees, between the belt and sword, in which space he counted no 

 less than 400 stars. What is yet more remarkable, he mentions the 

 fact that there are many small spots on the heavens shining with a 

 light resembling that of the Milky-Way (complures similis coloris 

 areolce sparsim per cethera subfulgeant) ; and he even speaks of nebulae 

 of this sort in the head, and belt, and sword of Orion. He asserts, 

 however, that, by means of his telescope, these nebulae were dis- 

 tinctly resolved into stars a circumstance which, as we shall see 

 presently, renders his description wholly inapplicable to the great 

 nebula. Yet the very star around which (in the naked-eye view) this 

 nebula appears to cling, is figured in Galileo's drawing of the belt and 

 sword of Orion ! 



It seems almost inconceivable that Galileo should have overlooked 

 the nebula, assuming its appearance in his day to have resembled that 

 which it has at present. And, as it appears to have been established 

 that, if the nebula has changed at all during the past century, it has 

 changed very slowly indeed, one can scarcely believe that in Galileo's 

 time it should have presented a very different aspect. Is it possible 

 that the view suggested by Humboldt is correct that Galileo did not 

 see the nebula because he did not wish to see it ? " Galileo," says 

 Humboldt, " was disinclined to admit or assume the existence of star- 

 less nebulae." Long after the discovery of the great nebula in An- 

 dromeda known as the " trauscendently-beautiful queen of the nebu- 

 lae" Galileo omitted all mention in his works of any but starry 

 nebulae. The last-named nebula was discovered in 1614 by Simon 

 Mai-ius, whose claims to the discovery of Jupiter's satellites had greatly 

 angered Galileo, and had called forth a torrent of invective, in which 

 the Protestant German was abused as a heretic by Galileo, little aware 

 that he would himself, before long, incur the displeasure of the Church. 

 If we could suppose that an unwillingness, either to confirm his rival's 



