191 1.] Increasing the Durability of Timber. 



285 



and conifers as a rule take up less than broad-leaved trees. 

 The wood that is subjected, more than any other, to the pro- 

 cess of creosoting, is Baltic Yellow Deal, otherwise known as 

 Baltic Red Wood, which is precisely the same species as 

 Scots Pine. This is the wood chiefly used for railway 

 sleepers and telegraph posts, so that enormous quantities 

 have to be treated annually. As a rule the railway companies 

 specify that each cubic foot shall contain one gallon of creo- 

 sote, and for estate purposes this is as far as one can afford 

 to go, seeing that creosote now generally costs 4<i. or more 

 per gallon, and therefore by the absorption of a gallon the 

 cost of the wood is raised by this amount, apart from con- 

 siderations of labour and interest on plant. Certain soft 

 woods, however, can absorb up to four gallons of creosote per 

 cubic foot, and many will take up two gallons. Apart from 

 the cost, there is little to be gained by exceeding one gallon, 

 for in the course of time the excess, beyond what the wood 

 can really hold, will simply flow out into the soil and be lost. 



The great value of creosoting for estate purposes consists 

 in this, that it so prolongs the "life " of low-class timber as to 

 enable such material to be used for fencing and other pur- 

 poses. Spruce and Scots Pine thinnings, for instance, which 

 will only last for three or four years if used as posts (called in 

 Scotland stobs, and in some parts of England stumps), in 

 their natural state will, if creosoted, remain serviceable for 

 from twelve to fifteen years. Larch thinnings, although more * 

 durable than spruce or pine, should also be creosoted before 

 being used as posts. There are several broad-leaved species 

 that furnish large quantities of small wood on many estates, 

 which, in their natural state, are not worth the labour of using 

 for fencing purposes, and yet which are thoroughly service- 

 able when creosoted. To, this group belong Alder, Beech, 

 Hornbeam, Sycamore, Ash, Birch, and Poplar. Even 

 coppice oak has little durability when in its natural state, and 

 ought always to be creosoted before use. 



On small estates the cost of erecting and working a pres- 

 sure creosoting plant is prohibitive, but excellent results can 

 be obtained by simpler methods. Many make use of an iron 

 tank erected on brickwork in such a way that the creosote 

 can be raised to near the boiling-point by means of a fire 



