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On the Preservation of Timber. 9 
of a pump under powerful pressure. After a certain time, which 
is regulated by the kind of timber, the amount of pressure, and 
the degree of penetration required, the liquid is drawn ofF by 
means of a cock, and the contents of the cylinder are withdrawn. 
The stationary character of this apparatus leads to considerable 
expense, as the timber must often be conveyed to and from great 
distances to the locality where the cylinder is fixed. This ob- 
jection has been overcome by Armstrong, who has patented an 
improved arrangement for mounting the vessels and apparatus 
on a carriage and wheels for running on railways and common 
roads, whereby they are rendered portable and readily moved to 
places where the timber is lying. 
Class Y. Capillary Action. — Another step in advance was 
taken by M. Boucherie (where the circumstances admit of the 
adoption of his plan), who renders the natural circulation of 
the tree available for the admission of the preservative liquid 
into trees still standing or recently felled. It has been found, 
however, that while the liquid easily penetrates the more porous 
pith-wood, it seldom reaches the heart or centre portions. Certain 
irregularities in the penetration obtained by this method, when 
assisted by sawing in a proper direction, produce a beautiful 
appearance of a veined and marbled character. The application 
of this process is simple ; two incisions are made near each other 
at the base of the tree, and covered with a water-tight cloth band, 
which is supplied with the preservative liquid from a small cask. 
(Fig. 3.) The ascent of the liquid is very rapid. 
A somewhat similar plan consists in placing a tree recently 
felled in nearly a horizontal position, and covering its larger ex- 
tremity with an impermeable sack, which is retained in its 
position on a collar made of clay, by means of a strong ligature 
or band. (Fig. 4.) The preservative liquid is conveyed to this 
sack by a pipe from a cask at a higher elevation, and it forces 
out the sap in the timber, filling the open channels as it is car- 
ried forward. In some species of wood the passage of certain 
liquids does not occupy more than a few minutes, as in the oak ; 
while in pines and firs the woodv fibre, in the form of long tubes, 
allows a much more regular infiltration of the liquid. 
M. Boucherie has modified this plan in the following way : — 
he takes, for example, a block of timber twice as long as an 
ordinary railway-sleeper, and saws it down the middle to 
within an inch or so of the opposite side, then gently raises the 
upper part of the block by a wedge ; the slit opens, when he 
inserts a piece of rope dipped in tar : the block is now allowed 
to resume its position, when the two sides of the slit approach 
and firmly grasp the tarred rope. An auger-hole is then made 
