A HISTORY OF 



tinued without his immediate assistance. 

 This quality is called attraction ; a sort of 

 approximating influence, which all bodies, 

 whether terrestrial or celestial, are found to 

 possess; and which in all increases as the 

 quantity of matter in each increases. The 

 sun, by far the greatest body in our system, is, 

 of consequence, possessed of much the great- 

 est share of this attracting power ; and all the 

 planets, of which our earth is one, are, of j 

 course, entirely subject to its superior in- 

 fluence. Were this power, therefore, left 

 uncontrolled by any other, the sun must 

 quickly have attracted all the bodies of our 

 celestial system to itself; but it is equally 

 counteracted by another power of equal ef- 

 ficacy; namely, a progressive force, which 

 each planet received when it was impelled 

 forward by the divine Architect, upon its first 

 formation. The heavenly bodies of our sys- 

 tem being thus acted upon by two opposing 

 powers ; namely, by that of attraction, which 

 draws them towards the sun; and that of 

 impulsion, which drives them straight forward 

 into the great void of space ; they pursue a 

 track between these contrary directions ; and 

 each, like a stone whirled about in a sling, 

 obeying two opposite forces, circulates round 

 its great centre of heat and motion. 



In this manner, therefore, is the harmony 

 of our planetary system preserved. The sun, 

 in the midst, gives heat, and light, and cir- 

 cular motion, to the planets which surround 

 it : Mercury, Venus, the Earth, Mars. Jupiter, 

 Saturn, and Herschel, or the Georgium Sidus, 

 perform their constant circuits at different 

 distances, each taking up a time to complete 

 its revolutions proportioned to the greatness 

 of the circle which it is to describe. The 

 lesser planets also, which are attendants upon 

 some of the greater, are subject to the same 

 laws ; they circulate with the same exactness ; 

 and are, in the same manner, influenced by 

 their respective centres of motion. 



Besides those bodies which make a part 

 of our peculiar system, and which may be 

 said to reside within its great circumference, 

 there are others that frequently come among us, 

 from the most distant tracts of space, and that 

 seem like dangerous intruders upon the beau- 

 tiful simplicity of nature. These are Comets, 

 whose appearance was once so terrible to 



mankind ; and the theory of which is so little 

 understood at present : all we know is, that 

 their number is much greater than that of the 

 planets; and that, like these, they roll in 

 orbits, in some measure obedient to solar in- 

 fluence. Astronomers have endeavoured to 

 calculate the returning periods of many of 

 them; but experience has not, as yet, con- 

 firmed the veracity of their investigations. 

 Indeed, who can tell, when those wanderers 

 have made their excursions into other worlds 

 and distant systems, what obstacles may be 

 found to oppose their progress, to accelerate 

 their motions, or retard their return ? 



But what we have hitherto attempted to 

 sketch, is but a small part of that great fabric 

 in which the Deity has thought proper to 

 manifest his wisdom and omnipotence. There 

 are multitudes of other bodies, dispersed over 

 the face of the heavens, that lie too remote for 

 examination: these have no motion, such as the 

 planets are found to possess, and are there- 

 fore called fixed stars; and from their extreme 

 brilliancy, and their immense distance, philo- 

 sophers have been induced to suppose them 

 to be suns, resembling that which enlivens 

 our system. As the imagination also, once 

 excited, is seldom content to stop, it has fur- 

 nished each with an attendant system of pla- 

 nets belonging to itself; and has even induced 

 some to deplore the fate of those systems, 

 whose imagined suns, which sometimes hap- 

 pens, have become no longer visible. 



But conjectures of this kind, which no rea- 

 soning can ascertain, nor experiment reach, 

 are rather amusing than useful. Though we 

 see the greatness and wisdom of the Deity in 

 all the seeming worlds that surround us, it is 

 our chief concern to trace him in that which 

 we inhabit. The examination of the earth, 

 the wonders of its contrivance, the history of 

 its advantages, or of the seeming defects in 

 its formation, are the proper business of the 

 natural historian. A description of this earth, 

 its animals, vegetables, and minerals, is the most 

 delightful entertainment the mind can be fur- 

 nished with, as it is the most interesting and 

 useful. I would beg leave, therefore, to con- 

 clude these common-place specula' it ns. with 

 an observation which,! hope,is not entirely so. 



An use, hitherto not much insist vd upon, 

 that may result from the contemplation of ce- 



