APPLICATIONS OF THE MICROSCOPE. 129 



Stream, where it is four knots the hour, to be 

 2000 fathoms in depth, and to reach down, to 

 the bed of the ocean with that velocity and 

 pressure, the scouring action of water under 

 such a weight and motion would fret and wear^ 

 break and tear up the very bed and bottom of 

 the sea." 



7. " Many are the great truths of Nature, 

 which, when once suggested, appear so obvious 

 and simple, that we wonder why reason did not 

 suggest them, or common sense point them out 

 before. So it appears with this cushion ofstiU 

 water, which seems to be everywhere interposed^ 

 between the bottom of the deep sea and its cur- 

 rents. We are surprised now that it never 

 occurred to us that it must be so ; how, if it 

 were not so, the scouring action of such cur- 

 rents upon the bed of the ocean would have 

 worn it into deep scores, furrows, and gashes, 

 which, the deeper they grow, the faster they 

 would wear, until finally the solid crust of oiw 

 planet would have been worn through. Thus, 

 while the deep places would grow deeper, the 

 shallow places would grow shallower, the pro- 

 portion of land and water surface would be 

 I 



