76 
Indian Forest Records. 
[Vol. VI 
The above experiments, though only carried out on a small scale, 
indicate that it is possible to treat Dipterocarpus pilosus ‘ Hollong,’ 
Terminalia belerica Bhumra,’ and Cynometra polyandra or ‘ Ping 5 by 
the Open Tank process. Of these timbers, Terminalia belerica is mechani¬ 
cally hardly strong enough to be used for sleepers; Dipterocarpus 
pilosus is a good straight-grained timber which, owing to the large 
pores in the timber readily absorbs any solution in which it is placed. 
Cynometra polyandra is a hard timber, and it therefore came as some¬ 
what of a surprise that it took up the oil so readily. Terminalia 
myriocarpa and Artocarpus Chaplasha do not lend themselves to treat¬ 
ment in Open Tanks; in fact, attempts to treat the former timber 
under pressure were equally unsuccessful. This is to be regretted as 
both are sound good timbers, though not sufficiently durable for sleeper 
work, unless previously treated with a suitable antiseptic. The remain¬ 
ing species, namely, AItingia excelsa took up relatively small quantities 
of oil, though it would probably lend itself to pressure treatment. 
These sleepers, together with a number of sleepers treated under 
pressure, the record of which work is given in the next chapter, were 
laid down in the Assam-Bengal Railway in October and November 1915, 
and are to be kept under observation. As they have not been in the line 
a year, their condition is not recorded. 
(Hi) Treatment of Dipterocarpus turbinatus, c Gurjan ’ broad gauge 
SLEEPERS OBTAINED FROM THE ANDAMANS, IN OPEN TANKS. 
A scheme having been put forward to supply the State Railways 
with treated Dipterocarp sleepers from the Andamans, a sample lot of 
seasoned broad gauge Gurjan sleepers were submitted, for testing their 
power of absorption in Open Tanks. . Twenty sleepers were immersed 
for 24 hours in a mixture of Green oil and Liquid Fuel oil, heated for 
5 hours to 72°C. and allowed to cool down in the bath for a further 
period of 19 hours. This resulted in the sleepers taking up an average 
of 1ST lbs. each. One or two of the sleepers took up an excessive 
amount of oil, amounting to 28 lbs., while a few only took up 4 to 6 lbs ; 
on the whole, however, the absorption was fairly regular. It is evident 
that this species of timber is not difficult to treat even in Open 
Tanks, though probably quicker and better results would be obtained 
by treating it under pressure. 
2. Sleepers treated with Cresol-Calcium. 
In December 1910, the North-Western Railway laid down, as an 
experiment, 499 Swedish pine sleepers treated with Cresol-Calcium. 
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