170 COSMICAL ARRANGEMENTS. 



mass, with others much smaller in its compa- 

 rative vicinity. The small bodies may then 

 move round the larger, but this will do nothing 

 towards making it a sun to them. Their motions 

 might take place, the whole system remaining 

 still utterly dark and cold, without day or summer. 

 In order that we may have something more than 

 this blank and dead assemblage of moving clods, 

 the machine must be lighted up and warmed. 

 Some of the advantages of placing the lighting 

 and warming apparatus in the centre are obvious 

 to us. It is in this way only that we could have 

 those regular periodical returns of solar influence, 

 which, as we have seen, are adapted to the con- 

 stitution of the living creation. And we can 

 easily conceive, that there may be other incon- 

 gruities in a system with a travelling sun, of 

 which we can only conjecture the nature. No 

 one probably will doubt that the existing system, 

 with the sun in the centre, is better than any 

 one of a different kind would be. 



Now this lighting and warming by a central 

 sun are something superadded to the mere me- 

 chanical arrangements of the universe. There 

 is no apparent reason why the largest mass of 

 gravitating matter should diffuse inexhaustible 

 supplies of light and heat in all directions, while 

 the other masses are merely passive with respect 

 to such influences. There is no obvious con- 

 nexion between mass and luminousness, or tern- 



