THE PLURALITY OF WORLDS. 



53 



we were for the first time introduced to this glorious earth with its balmy atmo- 

 sphere its pure and translucent waters the life and beauty of its animal and 

 vegetable kingdoms with its attraction upon the matter of our own bodies just 

 sufficiently great to give them the requisite stability, and yet not so great as to 

 deprive them of the power of free and rapid motion with its intervals of light 

 and darkness, giving an alternation of labor and rest nicely corresponding with 

 our muscular power with its grateful succession of seasons, and its moderate 

 extremes of temperature, so justly suited to our organization : with all this 

 fitness before us. could we hesitate to infer that such a place must have been 

 provided expressly for our habitation ? If, then, the discoveries of modern 

 science disclose to us in each planet, which, like our own, rolls in regulated 

 periods round the sun, provisions in all respects similar if they are proved to 

 be habitations similarly built, ventilated, warmed, illuminated, and furnished 

 supplied with the same alternations of light and darkness by the same expe- 

 dient with the same pleasant succession of seasons the same geographical 

 diversity of climates the same agreeable distribution of land and water can 

 we doubt that such structures have been provided as the abodes of beings in 

 all respects resembling ourselves ? The strong presumption raised by such 

 proofs is converted into a moral certainty, when it is shown from physical anal- 

 ogies of irresistible force that such bodies are the creation of the same Hand 

 that raised the round world and launched it into space. Such, then, is the na- 

 ture of the evidence which science offers on this interesting question. Let us 

 endeavor to strip it of such technical forms of language and reasoning as are 

 intelligible only to the scientific, and to present it so as to be easily and 

 agreeably comprehended. 



If we look at a plan of the solar system, the first glance will impress us with 

 an idea that the earth is an individual of a class ; that that class is the planets ; 

 that the sun is an object provided for different purposes, and the same may be 

 said of the satellites. We take this impression from the simple fact that the 

 planets, including the earth among the number, move round the sun as a centre 

 in circles all in the same direction, and nearly in the same plane ; while the 

 satellites or moons (in a manner which we shall hereafter notice) revolve re- 

 spectively round the planets. The impression is irresistible that the planets, 

 including the earth, form a class ; but let us see the purposes in the economy 

 of nature which are fulfilled by this common character given to the motion of 

 the planets and the position of the sun. We find, upon considering the quali- 

 ties of organized bodies, and especially the species of the animals and vegeta- 

 bles upon the earth, that the maintenance of their physical well-being is essen- 

 tially dependant on the uniformity and regularity with which they are supplied 

 with the two great physical principles of light and heat. Should these, or 

 either of them, be subject to any extreme variations, such vicissitudes would 

 be incompatible with the organization of the species. There is a cold on one 

 hand and a heat on the other, under which no organized body could continue 

 to exist, and there are still narrower limits within which it is necessary to 

 confine the temperatures they are exposed to in order to secure the perfec- 

 tion of their physical health. There are also degrees of light, the intensity 

 of which would be incompatible with the continued perfection of the organs of 

 vision. 



We see, then, how essential to the well-being of the infinite varieties of crea- 

 tures that people this globe, a uniform regulation of light and heat is. How, 

 then, is this great and important end attained 1 If we had a fire which at once 

 supplied light and heat in our neighborhood, and that circumstances obliged us 

 continually to shift our position in regard to it, but at the same time so to order 

 our movements as to receive from it a uniform intensity of light and heat, how 



