ON THE MISSISSIPPI. 193 



a velocity of 3 inches per second will just begin to work upon 

 clay, and that of 3 feet will sweep along shivery angular stones 

 of the size of an egg, and as according to our theory, the 

 evil ought to be perpetually upon the encrease, in as much as 

 the velocity augments with the depth, it must have resulted 

 that by such incredible velocities as are deducible from the 

 theory, the bowels of the earth must have been long since torn 

 up, and this globe have been no longer a lit habitation for man : 

 a system so pregnant with consequences contradictory to the 

 order and regularity which are the residt of the laws of nature, 

 must be abandoned. Without the aid of philosophy it must 

 have been remarked by every common observer, that the mosf 

 furious torrent (directed into a new channel) after breaking up 

 and tearing every thing before it, does at length fashion its own 

 bed, in respect to breadth and depth, so as to be perfectly 

 adapted to the momentum of its waters; it is no longer a furi- 

 ous torrent, but a mild placid stream. Nature aims continu- 

 ally at an equilibrium; in rivers which have for a course of 

 ages occupied the same channel, the accelerations and resist- 

 ances are so perfectly counterpoised, that a complete equability 

 of current takes place for a great extent (i. e.) so far as the re- 

 gimen of the river has established itself; abrasion at the bot- 

 tom of the river ceases; this can only be the consequence of 

 reduced velocity, contrary to our theory, which demands ve- 

 locity encreasing with the square-root of the depth. Mathe- 

 maticians and engineers who have calculated upon so false a 

 theory have been most egregiously disappointed in their ex- 

 pectations; a canal was projected to supply the city of Edin- 

 burg with water, the celebrated M'Laurin calculated the quan- 

 tity it ought to deliver, and the no less celebrated Desaguliers 

 who was to conduct the enterprise, and whose theoretick prin- 

 ciples were somewhat corrected by experimental knowledge, 

 reduced to nearly one half the calculation of the former; the 

 work was executed to the satisfaction of both, and the result 

 was, that the actual quantity of water delivered was ,-, of that 

 calculated by M'Laurin and 4. of that of Desaguliers. 



The great improver of the Steam-Engine, Mr. "Watt, in- 

 forms us, that a canal of 18 feet wide at the surface, 7 feet 



