PORTION OF THE COSMOS. COSMICAL SPACE. 31 



astronomers of the present day worthy of serious exami- 

 nation. 



It may be assumed with great probability that we are in 

 communication, through the influence of gravitation and 

 through light and radiant heat,( 55 ) not only with our own 

 sun, but also with all the other shining suns of the firmament. 

 The important discovery of the measurable resistance opposed 

 by a space-filling fluid to a comet of a five years' period of 

 revolution, has been completely confirmed by exact numerical 

 accordances. Inferences founded on analogies may serve to 

 fill a part of the wide chasm which separates the assured re- 

 sults of a mathematical natural philosophy, from conjectures 

 directed to the extreme, and therefore obscure and desert, 

 boundaries of all scientific development of thought. 



l^rom the infinity of Space, which indeed was doubted by 

 Aristotle, ( 56 ) follows its immeasurability. Only separate 

 parts have been accessible to measurement ; and the results, 

 which surpass all our powers of realisation, are brought to- 

 gether with complacency by those who take a childish plea- 

 sure in large numbers, and even imagine that, by means of 

 images of physical magnitude creating astonishment, they 

 peculiarly enhance the sublimity of astronomical studies. 

 The distance of the star 61 Cygni from the sun is 657000 

 semi-diameters of the earth's orbit, a distance which light 

 takes rather more than ten years to traverse, whilst it comes 

 from the sun to the earth in 8 minutes 17*78 seconds. Sir 

 John Herschel conjectured, from an ingenious combination 

 of photometric estimations, ( 57 ) that, supposing stars of 

 the milky way which he saw glimmer in his twenty-foot 

 telescope to be newly formed luminous bodies, they would 

 have required 2000 years thus to have sent us their 



