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:--

_In 100 _Carbon._ _Hydrogen._ _Oxygen and _Ash._ _Water._ _Specific
parts._ Nitrogen._ Gravity._
Wood, 39.6 4.8 34.8 0.8 20.0 0.75
Condensed
peat 47.2 4.9 22.9 5.0 20.0 1.20
Anthracite 91.3 2.9 2.8 3.0 1.40

In combustion in ordinary fires, the _water_ of the fuel is a source of
waste, since it consumes heat in acquiring the state of vapor. This is
well seen in the comparison of the same kind of peat in different states
of dryness. Thus, in the table of Gysser, (page 97) Weber's condensed
peat, containing 10 _per cent._ of moisture, surpasses in heating effect
that containing 25 _per cent._ of moisture, by nearly one-half.

The _oxygen_ is a source of waste, for heat as developed from fuel, is
chiefly a result of the chemical union of atmospheric or free oxygen,
with the carbon and hydrogen of the combustible. The oxygen of the fuel,
being already combined with carbon and hydrogen, not only cannot itself
contribute to the generation of heat, but neutralizes the heating effect
of those portions of the carbon and hydrogen of the fuel with which it
remains in combination. The quantity of heating effect thus destroyed,
cannot, however, be calculated with certainty, because physical changes,
viz: the conversion of solids into gases, not to speak of secondary
chemical transformations, whose influence cannot be estimated, enter
into the computation.

_Nitrogen_ and ash are practically indifferent in the burning process,
and simply impair the heating value of fuel in as far as they occupy
space in it and make a portion of its weight, to the exclusion of
combustible matter.

Again, as regards density, peat is, in general