PART VIII, PICTURESQUE PLANTING. 543 



is practised in Berwickshire and East Lothian, where it is pro- 

 ductive of many other advantages. 



Walls are generally formed of earth or stone. Some are made 

 of stone alone ; others of stone and lime ; others of turf, or of 

 turf and stone in alternate layers. Some are erected upon the 

 surface, as all common walls ; others are sunk into the ground, 

 as the ha' ha', or sunk fence, &c. &c. When lime is employed 

 in walls, if, in place of slacking it, and letting it lie to mellow 

 or sour for some weeks, no more were slacked and made ready 

 for use than what was worked up the same day ; — if the sand 

 were clean and rough, and well incorporated with the lime, and 

 were the coping put carefully on, these walls would last an in- 

 conceivable length of time. Lime used in this way binds im- 

 mediately ; and the longer it stands the harder it becomes. The 

 surface of such walls would acquire a coating of mosses which 

 would add greatly to their beauty, and prevent decay. Our 

 ancestors used lime in this way ; and their buildings, both wall 

 fences and houses, though under every disadvantage^ remain as 

 monuments of their superior knowledge in this particular. But 

 modern builders in general destroy their mortar before they use 

 it ; it is saturated with fixed air, or, in common language, has lost 

 hand before it is put in the walls : hence the weakness*, and 



* In autumn 1804, during a windy night, a house in Duke-street, Edinburgh, 

 fell down ; partly occasioned by the wind, but chiefly from the moisture of the 



