NEBULiE. 3^ 



gion of the heavens. That which he names Nebulosa Ori 

 mis, and dehneates in the vicinity oi NebidosaPr^sepe, hi. 

 expressly declares to be an accumulation of small stars (s^e^ 

 larum consiipatarum) in the head of Orion. In the draw- 

 ing which he gives in the Siderius Nuncius, § 20, extend- 

 inl from the girdle to the beginning of the right leg {a On- 

 onis), I recognize the multiple star d above the star i. ihe 

 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 

 imperfect instruments or a hazy atmosphere, like a halo round 

 the star d, 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 nebulae^* 

 It was not until fourteen years after Gahleo s death, m the 

 vear 1656, that Huygens first observed the great nebula ol 

 Orion, of which he gave a rough sketch in the Systeina Satur- 

 nium, which appeared in 1659. "While,'' says this great 

 man, " I was observing, with a refractor of twenty-five leet 

 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 pow- 

 erful instruments as I employ. Astronomers enumerate three 

 stars in the sword of Orion, lying very near one another. On 

 one occasion, when, in 1656, 1 was accidentally observing the 

 middle one of these stars through my telescope, I saw twelve 

 stars instead of a single one, which, indeed, not unfrequentiy 



(Opere di Galilei, PaJova, 1744, toni. ii., p. 14, No. 20) "which you 

 lav^e me inclades the girdle and sword o Orion and consequently alo 

 fhe star 6: but it is difficult, owing to the striking inaccuracy of the 

 draw n- to recognize the three small stars in the sword (the middle 

 oS of wWch is e\ and which appear to the unaided eye to be placed 

 ?n a strli^ht line. I conjecture that you have correctly designated the 

 B?a? fand that the bright star to the right and below, or the one imme- 

 dfateiy above it, is 0^ Galileo expressly says, " In P^-o m\eg^^^^^^ 

 Orionis Constellationem pingere decreveram: vervim. ^^ mgenti stel- 

 larum copia, temporis vero inopia obrutus, aggressionem banc m aliara 

 occaTionem distuli." Considedng Galileo's observation of the constel- 

 latirof Orion, we are the more°struck by the circumstance that he 

 40rtars wh?ch he thought he had counted between the ginl^e and^he 

 Bword of Orion in a space often square degrees (Neni,F»^a dt Gahet 

 vol ' , p. 208), should subsequently (accordmg to Lambert, Com.Z.| 

 Briefe 1760, p. 155) have led himto the erroneous estimate of l,6o0,00a 

 fgL L w^hole Ornament. (Struve, ^-r^^^X^^';^^^^ 

 lb.) 



