382 JUNE. 



the example, and shew that the work will answer 



Marl is of various sorts, and lies in various 

 strata ; in some places, it is a soft, fat, soapy sub- 

 stance ; in others, it is hard as chalk, which are 

 called stone-marls : sometimes you find it white, 

 sometimes grey: also blue, yellow, and a dark 

 brown. In some counties you have shell-marl, 

 which is composed of nothing but decayed shells. 

 The depths at which it lies are various : sometimes 

 only three feet from the surface ; at others, ten or 

 twelve : and in some places so deep, that it will not 

 answer to get it at all. The strata are also of dif- 

 ferent thickness, from two feet to twelve feet deep; 

 but the general circumstances in which all true 

 marls agree, and which denote them to be real, is 

 the effervescence with acids. 



If it is uncertain what strata are under a farm, 

 it is ever advisable to use the screw-borer, to dis- 

 cover what soils are within reach. By means of 

 that instrument, you discover, at a trifling expence, 

 if there be any marl at command. 



The best way of conveying it on to the land, 

 if it does not lay very deep, is to open a sloping 

 mouth, sinking the pit gradually, wide enough for 

 a cart to drive in and out ; and, whc n you come to 

 the marl, to work it away circularly, and to keep 

 the pit ten or fifteen feet deep, by which means the 

 expence of filling the carts will be much lessened. 

 The expence of, marling, when it is thrown in this 

 manner into the cart, will be, upon an average, 



three- 



