NEBULJE. 327 



the girdle to the beginning of the right leg (a Orionis), I re- 

 cognize the multiple star above the star i. The instruments 

 employed by Galileo did not magnify more than from eight 

 to thirty times. It is probable that as the nebula in the 

 sword is not isolated, but appears, when seen through imper- 

 fect instruments or a hazy atmosphere, like a halo round the 

 star 0, its individual existence and configuration may have 

 escaped the notice of the great Florentine observer. He was 

 moreover little inclined to assume the existence of nebula?. 62 

 It was not until fourteen years after Galileo's death, in the 

 year 1656, that Huygens first observed the great nebula of 

 Orion of which he gave a rough sketch in the Sy sterna Satur- 

 nium, which appeared in 1 659. " While," says this great man, 

 " I was observing, with a refractor of twenty-five feet focal 

 length, the variable belts of Jupiter, a dark central belt in 

 Mars and some faint phases of this planet, my attention was 

 attracted by an appearance among the fixed stars, which, as 

 far as I know, has not been observed by any one else, and 

 which, indeed, could not be recognized, except by such 

 powerful instruments as I employ. Astronomers enumerate 

 three stars in the sword of Orion, lying very near one ano- 

 ther. On one occasion when, in 1656, I was accidentally 

 observing the middle one of these stars through my telescope, 

 I saw twelve stars instead of a single one, which, indeed, 

 not unfrequently happens, in using the telescope. Three of 

 this number were almost in contact with one another, and 

 four of them shone as if through a mist, so that the space 

 around them, having the form drawn in the appended figure, 

 appeared much brighter than the rest of the sky, which was 

 perfectly clear, and looked almost black. This appearance 



62 Cosmos, vol. ii. p. 714. 



