Handbook of Railroad Construction; For the use of American engineers. / Containing the necessary rules, tables, and formulæ for the location, construction, equipment, and management of railroads, as built in the United States.

by George L. Vose

316. The employment of the several varieties of wood depends more upon the commercial than the chemical character. The following table shows the specific gravity, the nature and the evaporative value of the different species.

Species.	Specific gravity green.	Specific gravity air dried.	Specific gravity kiln dried.	Degrees of heat which may be generated.	Percentage of Charcoal.	Quantity of heat as to volume.	Weight of one cord in lbs.	Relative value as fuel.	Species.
Hickory,				3000	44.69	25	4469	1.00	Hickory.
White Oak,	1.07	0.71	0.66	3000	21.62	25	3821	0.81	White Oak.
Black Oak,				3000	23.80	25	3254	0.71	Black Oak.
Red Oak,	1.05	0.68	0.66	3000	22.43	25	3254	0.69	Red Oak.
Beech,	0.98	0.59	0.58	3000	32.36	25	3236	0.65	Beech.
Birch,	0.90	0.63	0.57	3000		25			Birch.
Maple,	0.90	0.64	0.61	3000	27.00	25	2700	0.57	Maple.
Yellow Pine,				2800	24.63	23	2463	0.54	Yellow Pine.
Chestnut,				3000	25.25	25	2333	0.52	Chestnut.
Pitch Pine,				2800	19.04	23	1904	0.43	Pitch Pine.
White Pine,	0.87	0.47	0.38	2800	18.68	23	1868	0.42	White Pine.
Species.	Specific gravity green.	Specific gravity air dried.	Specific gravity kiln dried.	Degrees of heat which may be generated.	Percentage of Charcoal.	Quantity of heat as to volume.	Weight of one cord in lbs.	Relative value as fuel.	Species.

Of the relative value of wood and coal, we have the following results of experience.

In the engines of the Baltimore and Ohio Railway 2.55 lbs. of pine wood were found equal to one pound of Cumberland coal.

On the Reading Railroad (Pennsylvania), three pounds of pine wood equal to one pound of Anthracite coal.

Mr. Haswell estimates the best varieties of wood fuel to contain twenty per cent. of carbon.

Walter R. Johnson found that one pound of wood, upon an average, evaporated two and one half pounds of water.

The average percentage of coke from American bituminous coal from the above table is seventy-three per cent., and the average percentage of carbon, sixty-seven and one half per cent.

317. The following table shows the relative properties of good coke, coal, and wood.

Name of fuel.	Weight per cubic foot, in lbs.	Degrees of heat generated.	Percentage of carbon, in the fuel.	Economic bulk, or cubic feet required to stow one ton.	Economic, or stowage weight per cubic foot.	Cubic feet of air to evaporate one lb. of water.	Equivalent economic bulk, to evaporate the same weight of water.	Weight of water evaporated per lb.of fuel in ordinary practice.	Relative value as fuel, disregarding the actual cost.
Coke.	63	4300	95	80	28	22.4	13	8½	100
Coal.	80	4000	88	44	51	32.0	10	6	71
Wood.	30	2800	20	107	21	16.0	60	2½	29