MASS AND MOTION. 17 



of any one production of the globe, we must under- 

 stand something about the general economy of the 

 whole. The growth and habits, nay, the very exist- 

 ence of plants and of animals, depend so much upon 

 soil and atmosphere, and upon the distribution and 

 degree of humidity and of solar heat, that the natural 

 history of the earth, as part of the solar system, is one 

 of the first and most essential elements of natural 

 history. Fortunately, too, it is one of the most inter- 

 esting, as well as the most easily understood. 



The mass of the earth, the velocity with which it 

 rolls onward in its orbit and turns upon its axis, the 

 simplicity of the laws by which those motions are sus- 

 tained, the varied phenomena and the highly important 

 results which thence are produced, are perfectly as- 

 tonishing, and offer a demonstration of Almighty power 

 which no man that understands will dare to question. 

 Some idea of the power with which the earth moves may 

 be formed, when it is considered that the following 

 expression for the tons of matter that it contains 

 is under the truth, 245 trillions, 612,754 billions, 

 894,281 millions, 574,281 tons; that its motion is 

 nearly two millions of miles every day ; and that 

 were it to meet with an obstruction of its own bulk 

 and weight, the shock would dash them both to 

 atoms. Yet notwithstanding all this rapidity and 

 force, no inconvenience is sustained by the smallest 

 and feeblest creature upon its surface ; but that the 

 motions arising from other causes are never in the least 

 disturbed, and the whole moves on with the same 

 tranquillity as if the globe were immovable ; and that 

 c 2 



