298 THE PRACTICAL PLANTER. 



more to its advantage ; as by little pressure it 

 will not be so apt to shoot as when burthened 

 with a ponderous coping. 



The calcined cinders above mentioned 

 would be eminently useful in this case. 

 Slates, either the hard blue, or the grey, or 

 any durable light stone of the slaty kind, are 

 next to be preferred. 



But the common mode, especially in this 

 case of dry stone walls, of coping with sod, is 

 by no means advisable. It may tend to 

 keep the uppermost stones together for a 

 time, until water penetrate the turf; but af- 

 terwards, it is of mischievous consequence to 

 the wall. The water, passing downwards, 

 is lodged in its heart, and absorbed by the 

 stones ; when hard frosts ensue, it is drawn 

 towards the lime on the surface, and when a 

 thaw suddenly succeeds, loosens it and bursts 

 forth. 



3dly, DRY STONE WALLS ENTIRELY, are 

 the most common of any, in parts where 

 lime is hard to purchase. It may be unne- 

 cessary to say more of them, than, that the 

 best endeavour to set them well, according to 

 the given materials, or size of the stones. 



