Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1914-12-29
The FUEL VALUE
OF WOOD BY
AIN EXPERT

The fuel value of two pounds OF
wood is roughly equivalent to that of
one pound of coal This is given as the
result of certain calculations now be-
ing made in the forest service labor
atory, which show also about how
many cords of certain kinds of wood
are required to obtain an amount of
heat equal to that in a ton of coal.
Certain kinds of wood, such as hick-
ory, oak, beech, birch, hard maple, ash,
elm, locust, longleaf pine, and cherry,
have fairly high heat values, and only
one cord OF seasoned wood of these
species is required to equal one ton
of good coal.
1t takes cord and half of short
leaf pine. hemiock. red gum, Douglas
fir, sycamore, and soft maple to equal
ton of coal, and two cords of cedar,
redwood, poplar catalpa, Norway pine,
cypress, Eastwood, spruce and white
pine.
Equal weights of dry, non-resinous
woods, however, are said to have prac-
tically the same heat value regardless
of species, and as a consequence it
can be stated as general proposition
that the heavier the wood the more
heat to the cord. Weight for weight
however, there is very little difference
between various species; the average
heat for all that have been calculated
is 1900 calories. or heat units per kilo-
gram of resin will develop 9,400 heat
units, or about twice the average for
wood. AS a consequence, resenous
woods have a greater heat value per
pound than non-resinous woods, and
this increased value varies, of course.
with the resin content.
The available heat value Of a cord OF
wood depends on many different fac
tors. It has a relation not only to the
amount of resin it contains but to the
amount of moisture present. Further
more, cords vary as to the amount of
solid wood they contain. even when
they are of the standard dimension and
Occupy 1913 cubic feet of space. A GER
tain proportion of this space is made
up of air spaces between the sticks,
and this air space may be considerable
in a cord made of twisted. crooked,
and knotty sticks. Out Of the 1913 cubic
feet. fair average of solid wood is
about so cubic feet.
1t is pointed out, however. that heat
value is not the only test of usefulness
in fuel wood and since 95 per cent of
all wood used for fuel is con-
sumed for domestic purposes, large
ly in farm houses, such factors as
rapidity of burning and ease of light
ing are important. Each section of the
country has its favored woods and
these are said to be, in general, the
right ones to use Hickory, Of the nom
resinous woods, has the highest fuel
value per unit volume of wood, and has
other advantages. 1t burns evenly, and.
as housewives say, holds the heat. The
oaks come next, followed by beech,
birch and maple. Pine has q relatively
low heat value per unit volume, but
has other advantages. II ignites read
lily and gives out quick, hot flame. but
one that soon dies down.. This makes
it favorite with rural housekeepers as
a summer wood, because 1t is particu-
larly adapted for hot days in the kitch-
en-.
The fuel qualities of chestnut adapt
it particularly to work in brass foun-
dries, where 1t gives just the required
amount of heat and 1t is therefore in
favor. Coastwise vessels In Florida
pay twice as much for Florida button
wood as for any other. because it burns
with an even heat and with a mini
mum amount Of smoke and ash.