a National MuseUm. 297 



different powers, or different effects of one power, itself 



controlled and modified by aM-pervading Intelligence. 



Crane^ Inclined Plane, Lever, Pulley, Screw, &:c. 



B. 



4. Terrestrial dole. 



5. Celestial Sphere, Orrery. 



4. Abont four-fifths of the surface of the globe consist of 

 water. This large propo! lion of water displays various re- 

 lations to the sustenance and welfare of animated beings- 

 It supports vast multitudes, whose whole oreanization, 

 under very different forms, is peculiarly adapted to that 

 element. Some of its inhabitants require salt in addition to 

 the water they inhabit. The well-being of others requires 

 fresh water. The welfare of others requires occasional 

 change from the former to the latter. Some animals to 

 which water is principally necessary require occasional re- 

 sidence in air. Some commonly respiring air, and dwelling 

 on land, seek their principal sustenance and comfort in the 

 water. The organization of these is variously adapted to 

 either element. Fresh water, as drink, is requisite to the 

 maintenance of most land animals. It is highly important, 

 if not essential, to the maintenance of man. Its relations to 

 our comfort are innumerable. It is necessary to veeeta- 

 tion. It contributes to the formation of earthy inanimate 

 solida, perhaps to the solidification of the greater part of 

 the habitable globe. 



The earth in its turn prevents the water from putrefying 

 by affording, conjointly with the air, and with the influ- 

 ences of the sun and moon, facility to its continual mo- 

 tion ; straining it through crevices and pouring it along de- 

 clivities. The surface of the earth assists evaporation : its 

 cavities cool and condense vapours. 



The relations of earth to the wants and comforts of all 

 living beings are innumerable. ' 



The air which surrounds the globe is requisite to the sup- 

 port of life, and to the well-being of all living creatures. 

 The heat retained by the earth preserves a great portion of 

 ^he air from being chilled to the destruction of vegetable and 

 ^ animal 



