202 AGRICULTURE. BOOK I. 



the strata towards the hollow B B, and from their termination 

 on the sides of the hill under impervious clay or loam. Errors, 

 similar to those adopted in the first drains cut in these fields, 

 are common every where, and occasion vast expence ; number- 

 less instances, both in England and Scotland, might be ad- 

 duced ; but let the above suffice to caution those who proceed to 

 this business, to devise a proper plan ere they attempt any part of 

 the work. Much might be said as to the practical operation of 

 this branch of draining ; such as the form of the drain,, the cut- 

 ting, filling, covering, repairing, &c. but the whole of this part 

 of the volume is only calculated to contain a few general 

 hints chiefly respecting design. 



The draining of lakes, bogs, morasses, or fens, is less expensive, 

 and often more simple, than the foregoing. It depends upon 

 finding a sufficient outlet for the main drain; from which 

 others are cut in proper directions, so as to lay the whole dry. 

 Much information may be obtained on this subject by travel- 

 ling through Lincolnshire and Ayrshire, and in those two coun- 

 ties by inspecting what has been done by Sir Joseph Banks* at 

 Revesby Abbey, and J. Smith, Esq. at Swineridge Muir. No 

 species of draining pays so well as the draining of fens, marshes, 



* Sir Joseph Banks has acquired land worth upwards of 60,000/. and will gain 

 much more, 



