THE GREAT NEBULA IN ORION. 83 



occurrence with powerful telescopes. Three of these 

 stars seemed to be almost in contact, and with these 

 were four others which shone as through a haze, so 

 that the space around shone much more brightly than 

 the rest of the sky. And as the heavens were serene 

 and appeared very dark, there seemed to be a gap in 

 this part, through which a view was disclosed of 

 brighter heavens beyond. All this I have continued 

 to see up to the present time [the work in which these 

 remarks appear the Sy 'sterna Satumium was publish- 

 ed in 1659], so that this singular object, whatever it is, 

 may be inferred to remain constantly in that part of 

 the sky. I certainly have never seen anything resem- 

 bling it in any other of the fixed stars. For other 

 objects once thought to be nebulous, and the Milky 

 Way itself, show no mistiness when looked at through 

 telescopes, nor are they anything but congeries of stars 

 thickly clustered together.' 



Huyghens does not seem to have noticed that the 

 space bet\veen the three stars he described as close 

 together is perfectly free from nebulous light insomuch 

 that if the nebula itself is rightly compared to a gap in 

 the darker heavens, this spot resembles a gap within 

 the nebula. And indeed, it is not uninteresting to 

 notice how comparatively inefficient was Huyghens' 

 telescope, though it was nearly eight yards in focal 

 length. A good achromatic telescope two feet long 

 would reveal more than Huyghens was able to detect 

 with his unwieldy instrument. 



Dominic Cassini soon after discovered a fourth star 



G 2 



