Part I."] Pearson: Antiseptic treatment of Sleepers. 
25 
while those treated with Earth Oil and Creosote which have been 6 to 
7 years in the line are in fair condition. The mode of deterioration of 
‘ Kanyin ’ sleepers is similar to that of ‘ In,’ and therefore the sleepers 
require to be laid with bearing plates, and the holes and adzed surfaces 
treated with the antiseptic. 
{v) Treated ‘ Hollong ’ steepers. 
Dipterocarpus pilosus. ‘ Hollong ’ is the most likely sleeper wood 
in Assam, when considered for treatment, as it is plentiful, and 
can be procured near the line. A fair number of this species of 
sleepers were treated both under pressure and in open tanks, with Assam 
Earth (Eesidue) Oil and Green Oil. Their life in an untreated state is 
less than four years ; the treated sleepers were laid in the line five and a 
half years ago, of which 75-4 per cent, are in Class ‘ A ’ and 18-3 per cent, 
in Class ‘ B,’ or 94 per cent, in good order, the remaining 6 per cent, 
have been rejected. Though at present no report has been made of 
excessive rail cut and rot round the spikes, it will probably be found best 
to lay these sleepers with bearing plates and to treat the holes and adzed 
surface at the time of laying in the line. 
(vi) Treated ‘ Sain ’ sleepers. 
Terminalia tomentosa. The results obtained with untreated ‘ Sain’ 
sleepers are extraordinarily variable, and their life may vary from any- 
thing between 3 and 8 years. They are often laid down in an untreated 
state, so that many records are available. If treated, and even not 
heavily so, they give by far the best results of any sleeper as yet experi- 
mented with. Take for instance the results of Powellized ‘ Sain,’ laid 
in five different localities, varying from extremely hot and dry to extremes 
of hot and damp, and after 9 years in the line only 5 per cent, have been 
rejected. This result is the more striking in that nearly all those sleepers 
which make up the 5 per cent, were rejected for mechanical faults, due 
to the fact that the experimental sleepers were not passed before 
treatment and were cut from tops and butts. The life of weU treated 
‘ Sain ’ sleepers cannot yet be fixed, but it will without doubt be found 
to be well over 12 years. ‘ Sain ’ timber is heavy and hard, it holds 
the dog spikes extremely well and requires no bearing plate. As far as 
is at present known a well treated ‘ Sain ’ sleeper is about the best of 
any treated Indian timbers. 
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