172 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



24. Notes on Creosoting, 



By A. T. GiLLANDERS. 



Various methods for the perservation of timber have been 

 adopted, but it is not intended in this paper to discuss their 

 respective merits. It is assumed here that for general estate 

 purposes creosoting is one of the best methods. 



As a general rule on an estate the best of the timber is sold, 

 and what is unsaleable is creosoted and manufactured for 

 home requirements. The object of the creosoting process 

 is to prolong the life of the timber ; but the process must be 

 preceded by the drying or seasoning of the timber ; for not only 

 does this facilitate the creosoting process, but the seasoning is 

 also in itself a preventive to decay. 



The felling of timber is generally carried out during the 

 winter months, because it is supposed that there is then less 

 sap in it. Experiments have, however, 'proved that this 

 assumption is not strictly correct, so far as the solid constituents 

 of the sap are concerned, for these have been shown to be 

 most abundant during December and January. All practical 

 men, nevertheless, prefer to cut the more valuable classes of 

 timber during the dormant season, as there is then less risk of 

 deterioration than when the sap is in a more active condition. 

 In the ordinary course of the exploitation of coniferous forests, 

 however, with a moveable sawmill plant, cutting and felling 

 are most successfully carried out in summer, say from the 

 beginning of April till the end of October. The timber may 

 either be felled sometime before it is sawn, or it may be felled 

 and sawn up at once. In the first case, the timber becomes to 

 some extent seasoned in the log, and the drying process may 

 be accelerated by partially barking or squaring the logs. In 

 the second case, the sawn timber must be stacked at once. It 

 cannot be too strongly emphasised that whatever method be 

 adopted in creosoting, the timber must be thoroughly dried 

 before the process is begun. In the case of timber which is 

 dried in the open air, it is to be noted that in addition to the 

 drying process there is a certain amount of re-absorption of 



