203 Proposal for the 'Eslahlishment of 



animal life. Evaporation of water jrivcs coolness to a creat 

 portion of air, which, from excessive heat, would other- 

 wise lay waste the torrid regions. 



Heat, so necessary to the sustenance, and so conducive to 

 the comfort of living beings, contributes incessantly to pro- 

 duce countless modifications of earth, air, and water, and 

 is itself incessantly controlled bv their reagencies. 



Moderate cold and moderate heat are terms nearly con- 

 vertible. Where the moderation of either is required, a 

 moderate degree of the other becomes re(juislte. — See 

 further, Paley, Nat. Theology, chap. xvii. and xxi. 



5. Planetarium. This machine is intended to represent 

 the relative situations of the sun and the planets, (one of 

 which is the earth.) at different periods of time. The 

 planets are restrained by their relations to the sun in their 

 respective orbits. The sun dispenses light and heat to all. 

 We may refer, by analogy, to other planets, the advantages 

 which we fully experience from our relations to the sun. 

 The revolutions of the earth round its axis cause the vicis- 

 situdes of day and night. But the darkness, the coolness, 

 the troiiquil repose of night, are no less requisite to the well- 

 being of man and other animals, than the cheering in- 

 fluences of the day. The earth's orbit, or path round the 

 sun, has such relation or inclination to the equator, and the 

 axis of the earth is placed in such relation to its orbit, that 

 the sun becomes at difl'erent periods of the year per|/endi- 

 cular to different portions of the globe, and thus produces 

 the continual succession and order of the seasons, cherishing 

 all nature, and making life delightful. 



The stagnation of the ocean is prevented, and the ebb and 

 flow of the tides effected, by the influence of the moon as 

 vvell as of tlie sun. 



'J'he planets are all placed in definite relations one to an- 

 other, and each affects the other bv mutual attraction, 

 *' This subsi:^ting law of attraction falls within liiTiits which 

 utility requires : — If the planet Saturn had attracted the earth 

 in a proportion iucfeusing according to its distarue (instead 

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