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Increasing the Durability of Timber, [july, 



underneath the tank. Immersion in such hot creosote for 

 eight or nine hours will confer on wood most of the benefits 

 got from two or three hours' treatment in a pressure chamber. 

 The tank should be protected against rain by means of 

 a light roof, and care must be taken against fire, creosote 

 being highly inflammable. 



Even a tank where the creosote can be heated is, however, a 

 more elaborate arrangement than is necessary upon a farm or 

 quite small estate. While heating assists in driving the 

 creosote into the wood, cold creosote will enter almost as 

 far, if more time be allowed. Even where only a few hundred 

 posts (stobs) are being used, it pays well, unless the wood 

 is mature larch or oak, to provide a tank in which the lower 

 part of each post can be treated. Remembering that the 

 upper part of the post will, in its untreated condition, usually 

 last for many years, it is the lower part that chiefly requires 

 treatment ; that is to say, the posts may be set vertically in 

 the tank, with their upper half or so above the liquid. If 

 it is desired to treat gates, hurdles, and rails, the tank must 

 be proportionately longer and deeper, but a very simple 

 arrangement suffices to treat the lower half of a fencing 

 post. An ordinary intermediate fencing post is generally 

 placed in the ground to a depth, at most, of about 2 

 feet, so that the part "between wind and water" will 

 be treated if it is immersed in creosote to a depth of 2} 

 feet. A suitable receptacle for the creosote is a galvanised 

 iron tank 8 feet long, 2 J- feet wide, and 3 feet deep. This 

 will hold 150 to 200 ordinary posts placed vertically, 

 and will when required also admit of about a dozen 

 straining posts being laid horizontally in it. When the 

 posts are set in the trough the liquid is fairly rapidly 

 absorbed, and as the level falls more creosote must be added. 

 The posts should stand in the liquid for three or four weeks, 

 and if a fresh lot is inserted without loss of time it is evident 

 that two to three thousand can be passed through in a year. 

 Four ordinary posts will absorb about a gallon of 

 creosote, so that the cost of material for each post is only 

 about one penny, and the labour and interest on the cost of 

 the trough is practically negligible. It is desirable that the 

 process should be conducted away from buildings, but a 



