38 
THE GREAT VALUE OF WOOD DETERMINED BY LONG EXPERIENCE. 
The wood of the White Oak is the one most desired by railroad com- 
panies for ties. In the primitive forests tbe growth was very general 
in those sections of the country where railroads were constructed, and 
its great value has been fully demonstrated by long experience. The 
demand for ties of this wood has been so imperative that large extents 
of territory once covered by this valuable timber have long since been 
denuded; what remains is so scarce and valuable that few companies 
are now able to obtain a supply of second-growth for ties. 
The oak holds a spike with great tenacity, and thus the rail is firmly 
fastened to the tie, a feature the importance of which is entirely over- 
looked by people who have not had practical experience in the matter. 
The wearing down of ties under the rails is not due alone to the ease of 
indentation, but largely to abrasion. The softer the wood the less 
firmly the spike is held, and if there is more or less looseness of tbe rails 
an abrasion takes place more rapidly than when they are held firmly to 
the tie. This fact has been determined by practical tests. Alternate 
ties under the same rail have been bolted to the rail, and the abrasion 
was less rapid on them than on those which were spiked. I am well 
aware of the prevailing opinion in the New England States, where the 
Chestnut is so extensively used for ties, that were they to attempt to 
change to oak ties they could not draw the spikesto make the adjustments 
in their rails, but would break off the heads of the spikes in the trial. 
Against this opinion, however, we have the experience of the main 
lines, with a large mileage and tonnage. They prefer the White Oak, 
experiencing but little trouble in drawing spikes, and they would not 
use any other wood, except that its scarcity and cost have compelled 
them in many cases to do so. 
Durability. — White Oak ties last from six to ten years. S J- veil years' 
duration is considered good under heavy traffic on rails with a 4-iuch 
base. Longer wear of course is had under broad faces of 8 to 10 inches. 
The moisture which collects around the spikes and under the rails 
eventually softens the injured fibers, and fermentation is set up in two 
to three years, depending upon local conditions of moisture and heat 
combined, the most rapid fermentations occurring in localities w T here 
the warm season is the longest. The decay of the ends and central 
cent. ; but in the case of pine the loss in the dry wood was 13.3 per cent., while in 
wet wood it was only 13. G per cent. 
Comparative experiments with heart-timber of fir and pine, as contrasted with 
the outside planks, showed that while in the fir the heart was destroyed more rap- 
idly than the outside layers the reverse was the case in the pine. 
Very unexpected results were obtained when the wood was in contact with various 
substances, as sand, coal-dust, ashes, garden-mold, etc., from which it would seem 
that clear sand is worse for filling-in between the joists than a mixture of sand and 
plaster, while dry rubbish from old buildings is better tilliug material than coal-dust 
The question, then, of the best time of felling, as regards the lasting qualities of 
timber, caunot yet be considered as settled, and the matter of handling timber after 
felling is the point of most importance. — B. E. Fernow. 
