Scottish Arboricultural Society. 569 



The yew and holly made a very superior charcoal, as they were very heavy, 

 held well together, and had good heating qualities as fuel. There was a 

 traditional antipathy to fir being used, and larch in particular, owing to a 

 belief that it sparked, but this tradition, like many others, was false. He 

 had seen larch charcoal frequently tested, and on no occasion did it ever 

 emit a single spark, although the resinous nature of these trees rendered 

 them not so safe as the hard woods, and care should^be taken to have them 

 well mixed with the latter when being charred. He believed that every 

 forester had at his command a supply of wood that would make good 

 serviceable charcoal, suitable for all cooking purposes, and that its quality 

 would be very much imj^roved if he could find time to strip the bark off the 

 wood before charring. It was also worthy of remark that a good means 

 of preserving the heavier charcoal from crumbling down was to split 

 instead of sawing up the wood when preparing it for the kiln. Consider- 

 ing the method of charring, he said that the usual way to do it was in the 

 open air in kilns, formed by piling the wood together and then covering it 

 over with turf. After explaining the process in detail he said that this 

 plan was perfectly safe and practicable, having been carried out for the last 

 fifty years at least at Dalkeith Park, and the charcoal had given general 

 satisfaction. But this year it had been given up for various reasons. In the 

 first place it was killing work for the men, strong fellows being at the end 

 of three months often brought to the lowest verge of physical prostration. 

 Another reason was that it had to be done in the summer season, when 

 the days were longest, audit so happened that this was also the oak-peeling 

 season, when men could ill be spared. A third reason was that it entailed 

 a great waste of material. Every kiln took a load of turf to cover it, very 

 little of which could ever be used a second time. Then for every ton of 

 charcoal produced there was a loss of two tons of wood, wdiich either dis- 

 appeared in combustion, or was reduced so small as to be unfit for use. It 

 had been proved that four tons of wood when charred on correct principles, 

 Avould yield one ton of good charcoal, and as by this system six tons were 

 required to produce the same quantity, the waste would be seen to be a 

 very serious item. Having abandoned this open-air system, they had adopted 

 that of charring the wood in two large cylinders or retorts, similar in every 

 respect to those used at the powder works. These retorts were seven feet 

 long by three feet six inches in diameter. The w^ood was cut in two lengths, 

 averaging from two to six inches in thickness, the smaller sizes being 

 laid on the bottom and the heavier at the top, because of the flues being so 

 constructed that the fire struck the top of the retort first. Care being taken 

 to exclude air, the fires were set agoing. On an average it was found that 

 sixteen hours were required to char the wood properly. "When this had 

 been done the fire was drawn out and the retorts allowed to cool for five or 

 six hours. The lids were then removed, and the charcoal drawn smartly out 

 into large pans, which were at once closed with a tight-fitting cover, so 

 that in a very short time the fire was effectually smothered out. At some 

 places the vapour expelled from the wood was condensed, and formed the 

 basis of many useful products. It was unnecessary to point out the advan- 



