56 



This leads to some remarks on the seasoning of timber. When trees have been felled 

 they should at once be roughly hewed and placed under cover, some distance above the 

 ground, in order to enable a free circulation of air and the slow evaporation of the water in the 

 sap vessels, so as to prevent as far as practicable the checks or openings of the woody fibres, 

 which, if left exposed to the influence of the solar action, are often so large and numerous 

 as greatly to impair the value of timber. 



Or, if to be water-seasoned, the timber should, if practicable, be immersed longitudinally 

 or parallel to the course of running water. So circumstanced, the sap in the vascular 

 organism is soon displaced by water, and this change of occupancy is continued till the timber 

 is fully seasoned or deprived of its immediate putrifactive agents. This change will also 

 take place in timber submersed in still water, but a greater length of time is necessary for 

 its accomplishment. Sea water is sometimes employed for tlie same purpose ; but it is too 

 impure, imparting to timber which has been seasoned in it a disagreeable viscosity, particu- 

 larly when placed in moist situations. 



It is, when artificially prepared — that is, from salt deprived, by recrystalization, of its 

 magnesia, lime and sulphuric acid, and is dissolved to a saturation in rain or river water — the 

 cheapest, and one of the best preservatives of timber ; next to this, copperas (sulphate of iron) 

 and alum (super-sulphate of potash and alumina) may be ranked as cheap and valuable. All 

 used singly, or the two latter, with some other saline preparation, which will reciprocally 

 decompose each other, and deposit one or both of their bases in the sap vessels of the timber. 

 When either of these substances are to be applied, singly, it will be necessary to prepare 

 reservoirs of sufficient capacity to contain the timber required to be operated on. 



These reservoirs may be formed by banking in portions of flat land from the floodings 

 of tide water, or by excavating the earth and puddling to prevent leakage. They should 

 be wholly isolated from surrounding water ; but circumstanced so that a supply may at all 

 times be at command to replace the ordinary consumption and losses occasioned by evaporation 

 and otherwise. 



When prepared and filled with saturated solutions either of common salt, (chlorate of soda,) 

 or copperas, or alum, or any other material which may be preferred, the timber is to be 

 placed in the reservoirs, there to remain until the sap vessels have become filled with the 

 solution presented and until required for use. 



But should this process fail, strong, air-tight wooden or iron vessels, filled first with 

 timber, then with the requisite saline solution, and then exhausted by means of the common 

 air pump, or expanded by heat so as to expel the air from the sap vessels, would be found 



