33 



I. 



THE REALMS OF SPACE, AND CONJECTURES REGARDING THAT 

 WHICH APPEARS TO OCCUPY THE SPACE INTERVENING 

 BETWEEN THE HEAVENLY BODIES. 



THAT portion of the physical description of the universe 

 which treats of what occupies the distant regions of the 

 heavens, filling the space between the globular cosmical bodies, 

 and is imperceptible to our organs, may not unaptly be 

 compared to the mythical commencement of ancient history. 

 In infinity of space, as well as in eternity of time, all things 

 are shrouded in an uncertain and frequently deceptive twi- 

 light. The imagination is here doubly impelled to draw 

 from its own fulness, and to give outline and permanence to 

 these indefinite changing forms. 8 This observation will, I 

 trust, suffice to exonerate me from the reproach of confound- 

 ing that which has been reduced to mathematical certainty 

 by direct observation or measurement, with that which is 

 founded on very imperfect induction. Wild reveries belong 

 to the romance of physical astronomy; yet the mind fa- 

 miliar with scientific labours, delights in dwelling on sub- 

 jects such as these, which, intimately connected with the 

 present condition of science, and with the hopes which it 

 inspires, have not been deemed unworthy of the earnest atten- 

 tion of the most distinguished astronomers of our day. 



By the influence of gravitation, or general gravity, as well 

 as by light and radiating heat, 9 we are brought in contact, as 



8 Cosmos, vol. i. p. 71. (Compare the admirable observa- 

 tions of Encke, Ueber die Anordnung des Slernsy stems, 1 844, s. 7. ) 



9 Cosmos, vol. i. pp. 145, 146. 



VOL. III. D 



