20 INDEX CATALOGUE. 



Herschel, W. : Abstracts of Memoirs — Continued. 



A D. Vol. P. 



I7S4 74 448 The solar motion explained by the situation of the sun in 

 the milky way. 



448 Local distribution of nebulae — nebulas surrounded by spaces 



vacant of stars. 



449 Strata of Cancer and Coma Berenices described. 



"With this memoir is a plate of figures of nebula?. Plate 

 xvii, fig. 1, M. 98; 2, M. 53; 3, H., ij, 28, [resolvable;] 

 4, H., i, 18 ; 5, H., iii, 15 ; 6, H., iv, 5 ; 7, H., iv, 2 ; 8, 

 H., iv, 3; 9, 10; 11, H., i, 13; 12, 13, 14, 15? 



Also Plate xviii, construction of the heavens — cloven disc. 



1785 75 213 On the Construction of the Heavens. 



214 Theoretical view of the formation of nebula?. 



Form I. Condensation of neighboring stars about a cen- 

 tral and larger star: globular forms. 



215 Form II. Condensation of neighboring stars about a nucleus 



of contiguous stars : condensed irregular forms. 

 Form III. Condensation about a stream of stars, producing 

 a form coarsely similar to the prototype : extended, 

 branching, compound forms. 



216 Form IV. Compound forms derived from the mutual at- 



traction of clusters. 



V. Vacancies will then arise in the surrounding space. 



Objection to the above views; they tend to show a gradual 

 destruction of the universe. Kesponse, that space is in- 

 finite and that the occasional destruction of one star 

 may operate to give life to the rest. 



217 Optical appearances to an observer within a nebula of the 



third form. 

 219 Kesults of observation — star gauges. 

 221-240 Gauges throughout the 24 h in K. A. Eesult3 given in 



detail. 

 241 The stars being supposed to be nearly equally scattered, 



and their number in a field of view of known angular 



diameter being given, to determine the length of the 



visual ray. Solution of the problem. 



243 Another solution. 



244 Proof that the sun is situated in a compound nebula of 



Form III. 



253 Section of our siderial system. 



254 Origin of nebulous strata. 



256 M. 80 and M. 4 on the edges of vacancies. 



257 Phenomena at the Poles of our nebula. 



