64 
(4) Experiments with 400 spikes on 90 ties allow the conclusion that 
boring increases the adhesion, especially when the bit used is of the 
same size as the spike. 
The following is a resume of the tables, giving the results of experi- 
ments : 
Table I. — Hungarian Oak : dry when the spikes were drawn. 
Bore, inch diameter; rounds to draw spike 3,624.0 
No hole "bored ; pounds to draw spike 3, 691. 2 
Average 3, 657. 6 
Difference, —66.8; diff. : aver. :: 1 : 54.4. 
Table II. — Same Oak : wet wlien spikes were drawn. 
Bore. | inch diameter : pounds to draw spike 4, 399.2 
Xo hole bored : pounds to draw spike 4, 423. 2 
Average 4, 411. 2 
Difference, —24.0 ; diff. : aver. :: 1 : 183.8. 
Table III. — Silesian Oak; wet when spikes were drawn. 
Bore, | inch diameter : pounds to draw spike 4, 104. 
No hole bored ; pounds to draw spike 4, 240. 8 
Average 4, 172. 4 
Difference, —136.8 ; diff. : aver. :: 1 : 30.5. 
Bore, -fj- inch diameter; pounds to draw spike 4,044.0 
No hole bored ; pounds to draw spike 3, 931. 2 
Average 3, 987. 6 
Difference, +112.8 j diff. : aver. :: 1 : 35.4. 
Bore, i inch diameter : pounds to draw spike 4, 648. 8 
No hole bored ; pounds to draw spike 4, 504. 8 
Average 4, 576. 8 
Difference, -{-144 ; diff. : aver. :: 1 : 31.8. 
Table IV. — Pine : impregnated ; dry. 
Bore, -f$ inch diameter; pounds to draw spike 1, 876. 8 
No hole bored : pounds to dra w spike 2. 197. 2 
Average _ 2, 028. 
Difference, — 302.4 ; diff. : aver. :: 1 : 6.7. 
Bore, -§ inch diameter ; pounds to draw spike 1, 843. 2 
No hole bored ; pounds to draw spike 1, 711. 2 
Average 1,777.2 
Difference, -fill : diff. : aver. :: 1 : 13.5. 
Bore, ^ inch diameter : pounds to draw spike 2, 054. 4 
No hole bored ; pounds to draw spike 1, 867. 2 
Average 1,960.8 
Difference, +187.2 ; diff. : aver. :: 1 : 10.5. 
Table Y. — Pine: not impregnated ; dry. 
Bore. inch diameter : pounds to draw spike 1, 696. 8 
No hole bored ; pounds to draw spike 1, 572. 
Average 1,634.4 
Difference, +124. 8 : diff. : aver. :: 1 : 13.7. 
