388 British Association, 



these very close stars are,in fact acting as suns to one another and re- 

 volving round their common centre of gravity,each of them probably 

 carrying with it a whole system of planets and comets, and, per- 

 haps each carried forward through space like our own sun. It 

 became then a point of great interest to determine whether 

 bodies so far removed from us as these systems observed Newton's 

 law of gravity and to this end ,it was necessary to observe the 

 angles and distance's of a great number of these douluble stars scat 

 ered everywhere through the heavens, for the purpose of obtain- 

 ing data to compute their orbits. This has been done, and chiefly 

 by private observers ; and the result is that these distant bodies 

 are found to be obedient to the same laws that prevail in our own 

 system. 



The Nebulae are as it were, systems or rings of stars scattered 

 through space at incredible distances from our star system, and 

 perhaps from one another ; and there are many of these myster- 

 ious clouds of light, and there may be endless invisible regions of 

 space similarly tenanted. Now, the nearest fixed star of our star 

 system whose distance has been measured, is the brightest in the 

 constellation Centaur, one of the Southern constellations, and this 

 nearest is yet so far removed, that it takes light, travelling at 

 the rate of about 192,000 miles per second, three years to arrive 

 at the earth from that si ar. When we gaze at it, therefore we 

 see it only as it existed three years ago ; some great convulsion 

 of nature may have since destroyed it. But there are many 

 bright stars in our own system, whose distance is so much great- 

 er than this, as a Cygni for example that astronomers have not 

 succeeded in measuring it. What, then must be the distance of 

 these nebulse, with which so much space is filled ; every compon- 

 ent star in which may be a sun, with its own system of planets 

 and comets revolving around it, each planet inhabited by myriads 

 of inhabitants ! What an overpowering view does this give us of 

 the extent of creation ! The component stars of these nebulae 

 are so faint, and, apparently, so close to'gether, that it is neces- 

 sary to use telescopes of great power and with apertures so large 

 as to admit a great amount of light for the observation. We owe 

 it more especially to four individuals that telescopes have been 

 constructed at a great cost and with great mechanical skill, suf- 

 ficiently powerful to penetrate these depths of space. Those four 

 individuals are the Herschels, father and son, Lord Rosse, and 

 Mr. W. Lassell. That praiseworthy nobleman, Lord Rosse began 



