On burning Clay for Manure. 297 



cessary to mention, that when the kiln is burning with 

 great keenness, a stranger to the operation may be apt to 

 think that the fire is extinguished ; if therefore any per- 

 son, either through impatience or too great curiosity, 

 should insist on looking into the interior of the kiln, he 

 will certainly retard, and may possibly extinguish, the 

 fire. For, as I mentioned before, the chief secret con- 

 sists in keeping out the external air from the fire." 



The person communicating the letter signs himself 

 " E. D." and says that " several farmers leave out alto- 

 gether the air pipes and holes, or tubes, and only make 

 plain walls of green sods. The size of the kiln is fifteen 

 by twenty-five feet, and some are even larger, when the 

 weather is fine and dry. It is only in dry weather that 

 the clay can be burnt to advantage ; for if it is wet, the 

 process is slow ; and unless there is a tolerable quantity 

 of vegetable matter in the clay, it will be liable to burn 

 into hard pieces, like brick ; but a good stiff subsoil, or 

 a clay that has vegetable matter in it, will answer exceed- 

 ingly well." 



The foregoing letter is also published in the " Farmers' 

 Magazine," of Edinburgh, for May, 1815, by Edward 

 Boyd, of Merton Hall, who says, that he has " seen won- 

 derful effects, for years, from ashes upon his own estate," 

 and congratulates the farmers of Galloway upon their be- 

 ing enabled to supply the Glasgow market with fat mut- 

 ton (when it cannot be got elsewhere) by the use of tur- 

 nips raised by ashes. 



In a subsequent letter from Mr. Craig, inserted in the 

 Edinburgh Farmer's Magazine, for May, 1815, p. 143, 

 he says, " On the 28th instant, (February, 1815,) I pull- 

 ed and weighed a square chain of the Swedish turnips ; 



2Z 



