34 INDEX CATALOGUE. 



Herschel, W. : Abstracts of Memoirs— Continued. 



A.D. Vol. JP. 



the ripening period of the globular form, and total insu- 

 lation ; from which it is evident that the milky way 

 must be finally broken up and cease to be a stratum of 

 scattered stars. 

 The state into which the incessant action of the clustering 

 power has brought it at present is a kind of chronometer 

 that may be used to measure the time of its past and 

 future existence; and although we do not know the rate 



1814 104 284 of going of this mysterious chronometer, it is neverthe- 

 less certain that since the breaking up of the milky way 

 affords a proof that it cannot last forever, it equally bears 

 witness that its past duration cannot be admitted to be 

 infinite. 

 This paper is accompanied by Plate IX, p. 284, with 17 

 figures. 

 Fig. 1 = H. v, 46. 10 = H. iii, 697. 



2 = PI. iii, 67. 11 = H. ii, 101. 



3 = H. ii, 706. 12 = H. ii, 500. 



4 = H. i, 143. 13 = H. viii, 44. 



5 = H. iv, 4. 14 = H. viii, 4. 



6 — H. iv, 35. 15 = H. vi, 36. 



7 = H. iv, 42. 16 = H. vi, 5. 



8 = H. iv, 69. 17 = M. 72. 



9 = H. iv, 33. 



1.817 107 302 Astronomical Observations and Experiments tending to in- 

 vestigate the Local Arrangement of the Celestial Bodies in 

 Space and to determine the Extent and Condition of the 

 'Milky Way. 

 The construction of the heavens can only be known when 

 we have the situation of each body defined by its three 

 dimensions. Of these three the ordinary catalogues give 

 but two, leaving the distance or profundity undetermined. 



303 The method of parallaxes has given the distance of the sun, 



planets, etc. The parallax of the stars has also received 

 attention. With regard to more distant objects, as small 

 stars, compressed clusters, and nebulae, these methods are 

 of no avail. 

 I. Of the local situation of the stars of the Heavens. 



304 It is evident that we cannot mean to affirm that the stars 



of the fifth, sixth, and seventh magnitudes are really 

 smaller than those of the first, second, or third, and that 

 we must ascribe the cause of the difference in the appar- 

 ent magnitudes of the stars to a difference in their rela- 

 tive distances from us. ■ On account of the great number 



