70 
slight inclination) in a row on skids, and fastened to the latter by clamps. 
Along each row of logs runs a pipe, connected with an elevated tank 
which 'contains the antiseptic solution. Around the periphery of the 
end of the log nearest the pipe a greased rope is then laid and pressed 
against it by a plank which is drawn tight against the log by clamps. 
Thus a cylindrical chamber is formed into which the solution is ad- 
mitted by a rubber hose connecting the pipe with the chamber. The 
admission of the solution may be stopped by clamping the hose. When 
the solution is first admitted the air contained in the chamber is allowed 
to escape through a small opening near the top of* the chamber, and 
then the solution enters the open ducts in the wood, pushing the sap 
before it, and finally escapes at the opposite end, where the mixture of 
sap and solution drips into a trough placed along and tinder the ends 
of the logs. 
When logs cut to double lengths are to be treated, after having been 
placed on the skids they are sawed very nearly but not quite through 
in the middle. Wedges are then used to raise them at the middle so as 
to open the saw-cut wide enough to admit the introduction of a greased 
rope, which is placed around the circumference of the cut. The wedges 
are then taken out to allow the cut to close up, and thus to com- 
press the rope and to form a close chamber. The solution enters this 
chamber through a short tube driven into a hole which is bored slant- 
ingly a few inches from the cut, through the end of one of the logs. 
Eubber hose leads from the hole in the log to the pipe. The air is al- 
lowed to escape from the chamber by using a pin to make a small hole 
at the top of the greased rope, which is then plugged. Of course two 
troughs have to be placed along and under the outside ends of the logs, 
where the liquid leaves the logs. The troughs carry the escaping solu- 
tion to a tank, where it is restored to its normal strength. But as the 
solution in passing through the logs is mixed with the sap it will, even 
if the scum is removed with ladles and the fluid filtered through woolen 
cloth, soon become impregnated with foreign substances to such an ex- 
tent that it cannot be safely used any longer. 
This may be remedied to some extent by filtration. At the foot of 
the trestle carrying the tanks are placed as many filtering tanks as 
there are tanks on the trestle. The filtering tanks are closed by covers, 
which can be readily raised when the filtering material is to be intro- 
duced, and then closed and firmly anchored to the tank. 
The fluid delivered by the troughs is pumped into one of the upper 
tanks, from which it is conducted by a pipe to the bottom of a filtering 
tank, whence, under a head due to the elevation of the tank, it passes 
upward through the filtering material and through a pipe starting from 
the cover of the filtering tank to a pump which raises it again to a sec- 
ond tank on top of the trestle. There the solution is brought to the 
normal strength and then starts on a new round. Such filters have to 
be cleaned daily. 
