Gysser gives the following comparisons of a good peat with various German woods and charcoals, equal weights being employed, and split beech wood, air-dry, assumed as the standard.[14]

Beech wood, split, air dry1.00
Peat, condensed by Weber's & Gysser's method,[15] air-dried, with 25 per cent. moisture.1.00
Peat, condensed by Weber's & Gysser's method, hot-dried, with 10 per cent. moisture.1.48
Peat-charcoal, from condensed peat.1.73
The same peat, simply cut and air-dried.0.80
Beech-charcoal.1.90
Summer-oak wood.1.18
Birch wood.0.95
White pine wood.0.72
Alder.0.65
Linden.0.65
Red pine.0.61
Poplar.0.50

Some experiments have been made in this country on the value of peat as fuel. One was tried on the N. Y. Central Railroad, Jan. 3, 1866. A locomotive with 25 empty freight cars attached, was propelled from Syracuse westward—the day being cold and the wind ahead—at the rate of 16 miles the hour. The engineer reported that "the peat gave us as much steam as wood, and burnt a beautiful fire." The peat, we infer, was cut and prepared near Syracuse, N. Y.

In one of the pumping houses of the Nassau Water Department of the City of Brooklyn, an experiment has been made for the purpose of comparing peat with anthracite, for the results of which I am indebted to the courtesy of Moses Lane, Esq., Chief Engineer of the Department.

Fire was started under a steam boiler with wood. When steam was up, the peat was burned—its quantity being 1743 lbs., or 18 barrels—and after it was consumed, the firing was continued with coal. The pressure of steam was kept as nearly uniform as possible throughout the trial, and it was found that with 1743 lbs. of peat the engine made 2735 revolutions, while with 1100 lbs. of coal it made 3866 revolutions. In other words, 100 lbs. of coal produced 351-45/100 revolutions, and 100 lbs. of peat produced 156-91/100 revolutions. One pound of coal therefore equalled 2-24/100 lbs. of peat in heating effect. The peat burned well and generated steam freely.

Mr. Lane could not designate the quality of the peat, not having been able to witness the experiment.

These trials have not, indeed, all the precision needful to fix with accuracy the comparative heating effect of the fuels employed; for a furnace, that is adapted for wood, is not necessarily suited to peat, and a coal grate must have a construction unlike that which is proper for a peat fire; nevertheless they exhibit the relative merits of wood, peat, and anthracite, with sufficient closeness for most practical purposes.

Two considerations would prevent the use of ordinary cut peat in large works, even could two and one-fourth tons of it be afforded at the same price as one ton of coal. The Nassau Water Department consumes 20,000 tons of coal yearly, the handling of which is a large expense, six firemen being employed to feed the furnaces. To generate the same amount of steam with peat of the quality experimented with, would require the force of firemen to be considerably increased. Again, it would be necessary to lay in, under cover, a large stock of fuel during the summer, for use in winter, when peat cannot be raised. Since a barrel of this peat weighed less than 100 lbs., the short ton would occupy the volume of 20 barrels; as is well known, a ton of anthracite can be put into 8 barrels. A given weight of peat therefore requires 2-½ times as much storage room, as the same weight of coal. As 2-¼ tons of peat, in the case we are considering, are equivalent to but one ton of coal in heating effect, the winter's supply of peat fuel would occupy 5-5/8 times the bulk of the same supply in coal, admitting that the unoccupied or air-space in a pile of peat is the same as in a heap of coal. In fact, the calculation would really turn out still more to the disadvantage of peat, because the air-space in a bin of peat is greater than in one of coal, and coal can be excavated for at least two months more of the year than peat.

It is asserted by some, that, because peat can be condensed so as to approach anthracite in specific gravity, it must, in the same ratio, approach the latter in heating power. Its effective heating power is, indeed, considerably augmented by condensation, but no mechanical treatment can increase its percentage of carbon or otherwise alter its chemical composition; hence it must forever remain inferior to anthracite.

The composition and density of the best condensed peat is compared with that of hard wood and anthracite in the following statement:—