Part IV.] R. S. Pearson: Antiseptic Treatment of Timber. 101 
The power of certain Indian timbers to withstand a direct pull applied 
to a dog-spike driven into the sleeper, has recently received attention and 
tests have been carried out in this connection in the Forest Economist’s 
workshops at Debra Dun. The machine employed in carrying out these 
tests is of the usual type used for carrying out tests for transverse, com¬ 
pression and shearing strain, the only alteration necessary being a specially 
devised clutch to hold the head of the dog-spike. The results obtained 
are strictly comparable, as they were carried out on similar lines. Some 
of these results, to illustrate the power of various timbers to withstand 
spike pull, are given below :— 
TABLE XXXIV. 
The figures given below are average of four tests in each case. 
Species. 
Method of driving spikes. 
Direct pull 
in lbs., 
required 
to with¬ 
draw dog- 
spikes, be¬ 
ing the 
average 
of 4 tests. 
Remarks. 
Cedrus Deodara 
| Hole bored f" right 
through sleeper and 
spike driven home. 
4,315 
Spikes released suddenly. 
Ditto 
Hole bored right 
through sleeper and 
spike driven home. 
3,791 
In some cases the spikes 
released suddenly, in 
others slowly. 
Ditto 
Hole bored f" right 
through sleeper and 
spike driven home. 
2,770 
Spike released somewhat 
slowly. 
Ditto 
1 
Hole bored l\" deep 
with §" augur and 
spike driven home. 
3,807 
Spikes released suddenly. 
Ditto 
' 
Hole bored l\" deep with 
¥ augur and spike 
driven home. 
3,959 
Ditto 
Ditto 
Hole bored 1 ¥ deep with 1 
f" augur and spike 
driven home. 
3,709 
Spikes released somewhat 
slowly. 
Chorea robusta . j 
Hole bored | // right 
through the sleeper 
and spike driven 
home. 
5,315 
In one case spike released 
somewhat slowly. 
In other cases spikes 
released suddenly. 
Ditto 
• 
Hole bored right 
through the sleeper ! 
and spike driven 
home. 
5,352 | 
1 
In one case spike released 
suddenly. In other 
cases spikes released 
somewhat slowly. 
[ 231 ] 
