THE PRESERVING OF TIMBER FOR ESTATE PURPOSES. 87 
The process presents no difficulties, and any man of ordinary 
intelligence, accustomed to work saw-mill or farm machinery, could, 
with a little experience, carry it on successfully. 
To ensure good results with the process described in the foregoing 
pages, it is essential that the timber should be properly seasoned, and 
free from moisture. By creosoting unseasoned timber, the result is 
that decay is hastened in place of being checked, for the creosote can 
only penetrate into the dry outer portion of the wood, and closes up 
its pores, while the sap is retained unchanged in the centre of the 
wood, where it ferments and causes decay. Young wood, containing 
a large proportion of sap-wood, can be creosoted without difficulty, 
if care be taken to have it thoroughly dry before treatment. 
Care must also be taken that creosote of proper quality is used. 
Genuine creosote can be made only from coal-tar, and the shale oil 
and bone oil which are sometimes used in place of it should be 
avoided. 
The durability of timber, when properly creosoted, is very great. 
Telegraph poles which were standing for thirty-five years, railway 
sleepers embedded in ballast for from twenty-five to twenty-eight 
years, and fencing—erected for thirty years—have all been found 
perfectly sound when taken down. The timber in each case was 
Baltic redwood, which had been properly seasoned, and then 
creosoted with heavy oil. 
In practice, the quantity of creosote injected per cubic foot of 
timber varies with the purpose to which it is to be applied. Red 
pine, used for railway sleepers, bridges, fencing, etc., receives from 
8 to 10 lbs., but when it is to be used for marine purposes, and 
exposed to the attacks of worms, it receives from 10 to 12 lbs. per 
cubic foot. 
All timbers are not equally absorbent, and the quantity of 
creosote which can be injected into them varies considerably 
under different conditions. Beech has been known to absorb 
18 lbs. per cubic foot ; Scots pine in small pieces has taken 19 lbs. ; 
bat red pine will generally absorb about 16 lbs. when dry, though 
only 6 or 7 lbs. when moist. Spruce and silver fir are somewhat 
difficult to creosote uniformly. Some experiments made by Mr 
Aspinall at Dublin with large blocks, showed an absorption of 
74 lbs. per cubic foot ; others with small pieces of dry wood gave 
results varying from 9 to 134 lbs., but only about 7 lbs. when the 
wood was moist. Pitch pine will not take more than 6 or 7 lbs. ; 
oak about 6 lbs.; and some hard woods not more than 2 or 3 lbs. 
