308 



AGRICULTURE. 



BOOK I. 



SECT. II. OF THE FORMS OF THE MOST SECURE NATURAL 

 SHORES AND BANKS OF RIVERS, WITH THE CAUSES OF 

 THEIR SECURITY. 



In examining the sea-shore, or the banks of rivers, we uni- 

 formly find, that the least liable to be damaged are such as 

 have a gentle, easy slope from the bed of the sea or river to the 

 top of the shores (as Plate X. fig. 1. a.), or such as are com- 

 posed of solid perpendicular rocks (as fig. 5.) ; both of which 

 I shall consider separately . 



1. The sloped batiks, or inclined planes, on the sea- shore are 

 least liable to accident from the surge and high tides, when 

 they are covered with a coating of sand or gravel. Those on 

 rivers are best defended from extraordinary floods when they 

 are uniformly covered with close pasture grass to the edge of 

 the water. The strength of these banks depends upon the 

 length of the slope ; their durability on the uniformity of its sur- 

 face, one part not being rougher or harder than another. — From 

 the length of the slope, the river, as it increases or decreases, 

 and the tides, as they ebb and flow, act but a short time on 

 one part of their surface. The greater the weight of water on 

 the bank, the more it is pressed down, and the firmer it is ren- 



