Part tV.] R. S. Pearson: Antiseptic Treatment of Timber. 59 
The remaining sleepers were treated by giving the former class 6 hours’, 
and the latter 1 hour’s immersion. It is noticeable that, when allowing 
the very dry sleepers more than 2 hours in a bath of oil, the amount of oil 
absorbed is not materially increased, which is no doubt due to the fact 
that the timber has reached its maximum power of absorption in Open 
Tanks, a state of affairs known as, “ absorption to refusal.” 
Similar tests were carried out with the Pinus excelsa sleepers, which 
gave the following results 
TABLE XIX. 
1 
Average 
absorption, 
per sleeper, 
of 17 sleep¬ 
Species. 
ers in the 
1st three 
lines, and 
of 8 sleep¬ 
Temperature of Solignum 
and Liquid Fuel oil. 
Period of immersion. 
ers in the 
4th line. 
| - ' 
j 
lbs. 
[ 
Pinus excelsa heart-wood sleepers, 
7-5 
65°C. dropping to 39°C. 
1 12£ hours. 
10 to 12 months out of the 
floating stream, converted 2 
9-5 
68° C. „ 45° C. 
! 12 „ 
years before treatment. 
9-8 
74°C. „ 46°C. 
12 
10-0 
84° C. „ 52°C. 
12 
Average of 59 broad gauge 
sleepers. 
Pinus excelsa sap-wood sleepers, 
= 9-2 
8-7 
68° C. „ 55°C. 
6 
10 to 12 months out of the 
floating stream, converted 2 
years before treatment. 
Pinus excelsa, a mixed lot of sap 
17-7 
73°C. „ 48°C. 
9£ „ 
and heart-wood sleepers, 
10 to 12 months out of the 
floating stream, converted 2 
years before treatment. 
By treating heart-wood and sap-wood separately fairly regular results 
of absorption were obtained, the last batch of mixed heart and sap- 
wood gave most irregular results, the absorption by the latter being 
excessive and averaging double that of the former. 
[ 189 ] 
