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made with fufficient declivity, or the ditch not 

 cut deep enough, the current will be flopped, 

 and the drains rendered ufelefs by the water 

 llagnating, or flowing back when the outfall 

 attains a level fomething above the mouth of 

 the drain. 



in Very wet feafons under-drains are liable 

 to blow up, unids a fufficient drip or fall is 

 given. Thereiore choofe the loweft part of 

 your grouna to begin your outfall, which, as 

 betore ob(erved,you will take care to make fuf- 

 ficiendy deep and large to receive any extra 

 quantity of water that can poiiibly fail. From 

 your outfall you will proceed to work upwards 

 with the number of drains neuefiary, always re- 

 coilcdtmg that tne greater the drip or fall, the 

 more rapid the current of water : and you may 

 with very little trouble, by a common level, 

 know to an inch the declivity you can give 

 your drains of any fort. To be careful in the 

 conftrudion of your drains at firft, is what I 

 muft particularly advife ; as the want of pre- 

 caution in this inftance is often attended Vv'ith 

 a very heavy expence. 



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