2.B . Mr, Herschel on the 



thofe of the third at treble the diftance, and fo forth. It is liot 

 necelTary critically to examiue what quantity of light or mag^ 

 nitude of a ftar ititltles it to be eftimated of fuch or fuch a pro- 

 portional diftance, as the common coarfe eftimation will anfwer 

 our prefent purpofe as well ; taking it then for granted, that a 

 ]ftar of the feventh magnitude is about feven times as far as 

 one of the firfl, it follows, that an obferver, who is inclofed 

 in a globular clufler of flars, and not far from the center, will 

 never be able, with the naked eye, to fee to the end of it : fof", 

 fince, according to the above efliimations, he can only extend his 

 view to about feven times the diflance of Sirius, it cannot be 

 expe6ted that his eyes fhould r^ach the borders of a clufter 

 which has perhaps not lefs than fifty ftars in depth every whefe 

 around him. The whole univerfe, therefore, to him will be 

 comprifed in a fet of conflellations, richly ornamented with 

 fcattered flars of ail fizes. Or if the united brightnefs of a 

 neighbouring clufler of ftars (hould, in a remarkable clear 

 night, reach his fight, it will put on the appearance of a finall, 

 faint, whitifli, nebulous cloud, not to be perceived without 

 the greatefl attention. To pafs by other fituations, let him 

 be placed in a much extended ftratum, or branching cluflrer of 

 millions of flars, fuch as may fall under the III"^ form of ne- 

 bulae confidered in a foregoing paragraph. Here alfo the hea- 

 vens will not only be richly fcattered over with brilliant con- 

 flellations, but a fhining zone or milky way will be perceived 

 to furround the whole fphere of the heavens, owing to the 

 combined light of thofe ftars which are too fmall, that is, t<Jo 

 remote to be feen. Our obferver's fight will be fo Confined, 

 that he will imagine this fingle colledlon of ftars, of which be 

 does not even perceive the thoufandth part, to be the whde 

 contents of the heavens. Allowing hini now the ufe of a 

 4 common 



