INTRODUCTION. 9 



Since the fixed stars are prodigious spheres of fire, like our sun, 

 and at inconceiveable distances from each other as well as from us, 

 it is reasonable to conclude they are made for the same purposes 

 that the sun is; each to bestow light, heat, and vegetation, on a 

 certain number of inhabited planets, retained by gravitation, within 

 the sphere of its activity. 



What a sublime idea does this suggest to the human imagination, 

 limited as are its powers, of the works of the Creator I Thousands and 

 thousands of suns, multiplied without end, and ranged all around us, 

 at immense distances from each other, attended by ten thousand 

 times ten thousand worlds, all in rapid moiion, yet calm, regular, 

 and harmonious, invariably keeping the paths prescribed them ; and 

 these worlds peopled with myriads of intelligent beings, formed for 

 endless progression in perfection and felicity. 



If so much power, wisdom, goodness, and magnificence, be dis- 

 played in the material creation, which is the least considerable 

 part of the universe, how great, how wise, how good must HE be, 

 who made and q-overns the whole ! 



SECT. II. 



OF THE DOCTRINE OF THE SPHERE. 



Having, in the foregoing section, treated of the Universe in 

 general, in which the earth has been considered as a planet, we 

 now proceed to the doctrine of the Sphere. In treating this sub- 

 ject we shall consider the earth as at rest, and the heavenly bodies 

 as performing their revolutions around it. This method cannot 

 lead the reader into any mistake, since we have previously explain- 

 ed the true system of the universe, from which it appears, that it 

 is the real motion of the earth which occasions the apparent motion 

 of the heavenly bodies. It is besides attended with this advantage, 

 that it perfectly agrees with the information of our senses. The 

 imagination therefore is not put on the stretch ; the idea is easy 

 and familiar ; and in delivering the elements of science, this object 

 cannot be too much attended to. 



N. B. In order more clearly to comprehend what follows, the 

 reader may occasionally turn his eye to the annexed plate of the 

 Artificial or Armillary Sphere. 



The ancients observed, that all the stars turned (in appearance) 

 round the earth, from east to west, in twenty-four hours ; that the 

 circles which they described in those revolutions were parallel to 

 each other, but not of the same magnitude ; those passing over the 

 middle of the earth being the largest, while the rest diminished in 

 proportion to their distance from it. They also observed, that there 

 were two points in the heavens which always preserved the same 

 situation. These points they termed celestial poles, because the 

 heavens seemed to turn round them. In order to imitate these 

 motions, they invented what is called the Artificial or Armillary 

 Sphere, through the centre of which passes an Axis, whose ex- 

 tremities are fixed to the immovable points called Poles. They 

 farther observed, that, on the 20th of March and 23d of September,, 

 the circle described by the sun was at an equal distance from bmfe 



Vol. T, C 



