36 TRAXSACTION'S OF KOVAL SCOTTISH ARRORICULTURAL SOCIETY. 



three hundred days in the year, yield approximately two thousand 

 tons of ash. 



As regards the actual acreage of land under bracken in 

 Scotland no data are available, but it may be taken that there 

 are at least the equivalent of twenty thousand acres of fully 

 stocked bracken land, from which ash could be readily made 

 available. In the experimental tests with bracken one ton was 

 produced per ten acres, so that a total of some two thousand 

 tons of bracken ash could be guaranteed. 



From the above three sources a total of nine thousand tons 

 could be put on the market within the year, at a moderate cost, 

 and with no disturbance to existing industries. 



Certain other small sources of supply might be mentioned ; for 

 example, the material obtained in clearing up the leaves, twigs, 

 hedge clippings and shrubs from policy grounds and gardens, 

 yields, on burning, an ash which has a high potash content. 

 Further, if an efficient and economic means of burning sawdust, 

 chips and bark could be devised, a large and fairly valuable 

 supply of ash could be obtained. In this connection, it should 

 be mentioned that the parts of a tree richest in potash salts are, 

 first, the leaves or needles and buds, next, the bark, then the twigs 

 and branches, and finally, the timber. 



Method of Production. 



Perhaps the most important point in connection with this is the 

 fact that no plant is necessary, the work being done as in ordinary 

 "clearing and burning" operations. Heaps of "brush" are 

 made on places where there is a good flat bottom for the fire, 

 and where easy access is obtained to a large amount of material 

 (Plate VII. Fig. i). The fires are started and are kept going for 

 two or three days until the particular area is cleared. It is found 

 better to have two or three fires than to have one large fire, since 

 labour is saved in dragging. The fires each night should be 

 well " banked" with green material, and in wet weather may be 

 covered with sheets of old corrugated iron. Where fires are 

 made on sloping land, a shallow trench should be excavated on 

 the top side to carry off surface water. The fires require no 

 special attention until burning is almost complete, when the 

 embers should be stirred occasionally until all the ash is in the 

 form of a fine white powder. 



The organisation of labour for this presents no difficulty. 



