Part IV.] R. S. Pearson: Antiseptic Treatment of Timber. ?1 
1. Treatment of sleepers with mixed oils. 
(i) Special experiments carried out with Finns lonqifolia 
SLEEPERS TREATED IN OPEN TANKS. 
The interest taken by the Railway Authorities in the experiments 
described in Part III, combined with their urgent need for sleepers, 
enabled Mr. Hart, the Inspector-General of Forests, to arrange a contract 
by which the Forest Department was to supply the State Railways 
with a million treated Finns longifolia broad gauge sleepers within 
four years. The possibility of carrying out the contract was facilitated 
by the fact that the United Provinces Forest Department was anxious 
to place large quantities of this timber , on the market from the newly 
formed Kumaon Circle. In connection with this work, three installa¬ 
tions have been erected at Kathgodam and Tanakpur on the Rohil- 
kund and Kumaon Railway, and at Hardwar on the Oudh and Rohil- 
khand Railway.* . 
To ascertain the period of immersion necessary, in order to make the 
sleepers take up 15 lbs. of oil each, experiments were carried out as soon 
as the first unit of the new plant was in working order. The oil used 
was a mixture of equal parts, by weight, of Green oil, which is a good 
grade of creosote, with high boiling fractions and Liquid Fuel with a 
Petroleum base. Soon after starting the experiments it was ascertained 
that to obtain more uniform absorption of the oil, it was necessary to 
divide the sleepers into two groups, according to whether they contained 
sap-wood in addition to heart-wood or not. Little difficulty has been 
experienced in doing so, and this procedure has been in force up to date. 
* Note._ The works have recently been closed, owing to creosote not being available 
from Europe. 
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