236 On the Appearance of' the Stars when viewed Cursorily. 



ter, (iii. 292,) Messrs Herschel and South are not the first who 

 have noticed it. I shall not debate the priority of discovery, 

 but proceed to apply the fact to our observations on the heavens 

 with the unassisted eye. 



The expressions of Mr Ferguson already quoted, and the 

 judgment of every attentive spectator, prove that the number 

 of stars appear to be reduced on fixing the eye steadfastly on 

 any portion of the heavens. Now, the application of the prin- 

 ciple appears to me as simple as it is evident, and I scarce 

 look out on the sky without being confirmed in my opinion. 

 The stars seen in a hasty view of the heavens, are chiefly ob- 

 served by oblique vision, and the number visible to the naked 

 eye (as I hope I have satisfactorily proved,) is actually in- 

 creased. I cannot quote a stronger instance than the Pleia- 

 des, and it is one which I have very frequently observed. 

 While the eye is many degrees from them in the heavens, it is 

 attracted by the compressed blaze of light which they exhi- 

 bit. Fix the eye steadfastly upon them, and they almost va- 

 nish from the sight, and six or seven stars, so faint as to be 

 just discernible, is all that remains. The telescope shows very 

 numerous stars surrounding these six or seven, and very near 

 as bright and conspicuous as them, which one may therefore 

 consider in the first degree of invisibility ; the oblique vision 

 supplies this, and instead of a few twinklers, we behold a com- 

 pressed starry heaven of themselves. This I think is a proof 

 so satisfactory as to amount almost to demonstration. It is 

 certainly the most striking exemplification of the principle I 

 have observed in the heavens; but I have experimentally found, 

 that, if you review almost any spot of the Milky Way, that vast 

 tract of stars, in the method just mentioned, it will almost 

 seem depopulated before your eyes. The lesser stars " hide their 

 diminished heads 1 ' before the penetration of direct vision; and 

 I cannot help thinking, that this explanation is applicable to 

 that confused whiteness which we observe on a slight view, 

 without going so far as to imagine with Dr Derham, that it 

 arises from planets circulating round these very distant suns. 

 The telescope sufficiently proves that there are plenty of stars 

 one stage less than visible in this singular tract, which must con- 

 tribute infinitely more than the atoms of planets (if such ex- 



