i6o D R I N K I N G P O O L S. 7. 



5, Covering. The firft coat is of com- 

 mon earlh, to aflilt in keeping out the 

 drought, and to make a bed for the flones ; 

 to prevent their piercing, and thereby injur- 

 ing the flicet of clay. This coat may be 

 three or tour inches thick, according to the 

 nature of the flones with which it is to be 

 covered. If thefe be large and irregular, 

 more earth is requifite than when the flones 

 are fmall or flat. The leaneft mofl infertile 

 foil is litteft for this piirpofc. Worms and 

 WEEDS are ea.iially to be feared •, and a rich 

 foil is genial to both. Jn this point of view 

 two coats of clay arc much preferable to a 

 coat 01 clay ajid a coat of rich mould. 



Pond-makers feem not to be fufficiently 

 aware of the mifchievoufnefs of weeds: in- 

 deed fomc ponds will remain for leveral years 

 in a manner free from them. But I have 

 feen others in which weeds, even docks (near 

 the edge) have grown luxuriantly. It is 

 probable that the tap-rooted weeds flrike 



through 



by wlikh means the two coats became, by the fubfc- 

 <luont beatings, incorporated in one thick ilicet. A 

 fubftantial me; hod, this, of which the prcicnt appears 

 to be. rather a rclincnicnt than Jin improvcineiit. 



