C. B WATtRTXC 75-(45) 



The valley of the upper Mississippi for hundreds of 

 miles is dug through solid bed rock. The gorge below 

 Niagara, as well as the canons of the western rivers, have 

 been formed by running water. " Our own Catskills owe 

 their form and beauty to the same causes. In the Alps 

 between Geneva and Chaniberry, near the railroad to 

 Mt. Cenis, is a mountain several thousand feet high, 

 whose summit was once the bottom of a valley, the strata 

 which form the top, lying in curves, the ends of which 

 point upwards. The mountains whose flanks were the 

 the sides of the valley, are gone. Prof. Dana in his 

 Manual of Geology \ (page 647) speaks of a mountain ten 

 thousand feet high in the Appalachian chain so leveled 

 by these agencies, that there is no evidence of its exist- 

 ence in the surface-features of the surrounding coun- 

 try. The vapor carried up by the air falls as snow or 

 rain, and, partly by mere washing, and partly by freez- 

 ing in the interstices of the rocks, breaks up and carries 

 away mountains. 



Like causes produce like effects. Hence, if air and 

 water once existed in the moon, they must have pro- 

 duced effects similar to those which we see from the 

 same agents on the earth. These effects ought to be great- 

 ly intensified in the moon, because the extremes of heat 

 and cold ever since it attained its present slow rotation, 

 have been far greater than on our globe. Moreover, the 

 eroding and leveling effect of the frost should have gone 

 on far more rapidly there than here, because the moon 

 lias thirteen winters to the earth's one. We should there- 

 fore expect a general leveling of the lunar surface, far 

 beyond similar effects here, since the moon, on this the- 

 ory, is much older than the earth, counting age from the 

 time each arrived at a temperature which would not of 

 itself destroy life. 



But it is impossible to conceive a landscape bearing 

 fewer marks of such erosion, than does that which is seen 

 on our satellite. It abounds with abrupt, perpendicu- 

 lar mountains, huge seams of igneous rocks pushed into 

 all conceivable forms, from parallel lines to ringed 

 craters, as they are called, which are now as abrupt and 

 sharp as on the day of their formation. 



The telescope reveals just such appearances as geology 

 would teach us to expect on a globe which had passed 



