when driven into different species of Timber. 387 
The third and fourth experiments were made with the same spikes 
respectively as the first and second ; but instead of yellow pine, the 
timber employed was thoroughly seasoned white oak. 
The plain spike driven 32 inches into that timber, required for its 
extraction a force of 3,910 Ibs. and, as before, exhibited no signs of 
movement until the instant of starting, when it suddenly came out 
about 4 of an inch, or as far as the range of motion and the elasti- 
city of the machine would permit. 
The flanched, swelled and grooved spike, driven 33 inches into 
another part of the same piece of plank, from which the plain one 
had been extracted, was drawn out with a force of 3,791 Ibs. A 
slow motion to the extent of ,; or ;'; of an inch was, in this trial, 
perceived to precede the starting of the spike ; and was accompa- 
nied by a gradual protrusion of the fibres of the timber immediately 
around the iron. In these experiments, though the plain spike bore 
the greater absolute weights, yet when the weight of metal is con- 
sidered, it is seen that the relative values of the two are 4.515 in 
the plain, and 5.354 in the grooved form. The various circum- 
stances of the four preceding experiments are seen at a single yiew 
in the following table. 
TABLE I. 
RH = = 7) 
2 % sit |£ (Bz E 
3) cg 8 21 ee Rag 3 Seog 
Ss a & 2d a | Ssias 
3 = f cree ee 2 (So tate 
=e ee 3 a S18 ofgesta Blof 
Re > a un Bae fF losise 
B a 8 3 2 @ {te EISS ; 
S| ¢8 Po w | & lob (Pars alizs REMARKS, 
4 ot 5 co bone g a SS I in sy) ea 
¢i ao | S |e ese sickiy™ 
w@ | 23 3.8 = je (Si S=1o 3 
3 ee i Rr |S [D (MOE Solos 3 
3 S Be ley eee 1 gg a ay 
- be Inch. Inch./Inch. = if 2 = A 
Bur- |Season’d | . pg 
f 1335.)~ a, 
"eo 4tS i298! lapplied, no mo- 
‘ aie * yellow ge si tae 866 2052 2.368 < Oct. ion “previo Boe 2 
ke. | pine. Ze " [the 
(| Fianch- |Season’d | FB lied 
2 J \ed,groov-| Jersey || 375) 30013.375| 108 15962.254, “|< “a oneee 
ed and | yellow | | < 
|| swelled. { pine. | 
( Bur- ason’d) ) | eee sud- 
3)| den’ ite |¢.375|.37518.375 96639104515 « 1} den 
t plain oak 5 fe iesprtre 
\Grooved |Season’d| | ~ 3 
4) and white 375 | .300|3.375 708 3791/5.354 | before spike 
[swelled oak, : | } | Ldre 
Hence it appears, that in lion pine the Grooved and swelled 
form was about 5 per cent. Jess advantageous than the plain, while 
