15 
the amount of timber imbedded under the entire mileage and undergo, 
ing a constant process of decay is, therefore, 1,485,000,000 cubic feet. 
Bridge- and trestle-work, timber and poles for piling, cannot be esti- 
mated with the same accuracy, as roads vary indefinitely in topog- 
raphy and material of bridge construction in use, whether wooden or iron, 
piling or stone masonry. As a rule, wooden structures are employed iu 
the first stage of construction of new roads, to be replaced as soon as 
practicable by more permanent material. The roads of the older States 
are, therefore, more substantially built than a majority of southern 
and western roads, in which a far greater percentage of timber is em- 
ployed in construction than on the great trunk lines of the Eastern and 
Middle States. Ou many southern roads, running through low and 
swampy districts, piling is used to a great extent, but accurate figures 
cannot be given as to the timber used for this purpose. An average of 
2,000 cubic feet per mile is considered approximately correct by engi- 
neers consulted on this subject.* Therefore, 187,500 miles of track con- 
tain 375,000,000 cubic feet of bridge and trestle timber. 
As with the preceding items of bridge and trestle construction, it is 
alike impossible to make a correct estimate as to the quantity of tim- 
ber used per mile for station-houses, buildings for all purposes, and 
platforms, all requiring large amounts of timber. The amount of timber 
used in track construction proper is, therefore, — 
It can be safely assumed that for every cubic foot ready for use, 1§ cubic 
feet of round timber is required, t Therefore the amount of round timber 
Central and Hudson River Railroad is 442 miles; but it Las four tracks from Albany 
to Buffalo, besides 551 miles of sidings, making in all 2,043 miles of track to be fur- 
nished with ties, bridge timber, etc. So the length of the Pennsylvania road from 
Jersey City to Pittsburgh is 445 miles; but the road haviug a double track through- 
out and 449 miles of siding, the whole length of the track to be supplied with ties, 
&c, is 1,3:59 miles. A careful comparison of the length of roads and the length of 
their tracks, so far as the latter are reported, warrants the conclusion that 25 per 
cent, should be added to the reported length of our railroads as a whole in order to 
represent fairly the additional demand for rails, ties, etc., made by double tracks and 
sidings, or turn-outs. — N. H. E. 
* The Chicago, Saint Paul, Minneapolis and Omaha Company report their timber- 
work for piling, trestles, bridges, and culverts on 1,600 miles of road as being 1 
foot to every cubic yard of earth- work. Earth- work on 1,600 miles amounts to 15,000 
cubic yards per mile. Two per cent, of its entire length is in bridges of all kinds. 
The average duration of wooden culverts and pile and trestle bridges was eight to 
ten years; of truss-bridges, nine to eleven years. 
t That the allowance here made for the waste of the forests in preparing ties or other 
timber for market is fully warranted, and the waste often much larger, may be seen 
from the following extract from a trustworthy lumber journal : 
"There is no branch of the lumber industries where there is more waste of raw 
material than in making ties. Each tie is split from clear wood, and it takes about 
Cubic feet. 
Ties for 187,500 miles 
Bridge and trestle timber 
1, 485, 000, 000 
375, 000, 000 
Total 
1, 860, 000, 000 
