River Falls journal. [volume] (River Falls, Pierce County, Wis.) 1872-2019, 1888-02-02
Green and Dry Wood as Fuel.

LII OOAhNAAs. AAC VI VIZ
class in Physics have just completed
set of experiments to determine the
amount of water contained in green
maple, in maple cut one year ago but
not sheltered and in maple cut one
year and under shelter since the end
of August last. The object of these
experiments was to determine the in
fluence of the water contained upon
the value of the wood as fuel and as
the results may be of interest to some
of your readers they are submitted.
Rupert Parker supplied a specimen
of green maple and a specimen of
unsheltered dry maple cut one year
ago. Percy APP Roberts supplied one
specimen of dry maple cut one year
and sheltered since Aug. last and an
other cut one year but unsheltered.
These blocks were weighed and then
placed in a current of hot dry air as it
came through the register and allowed
to remain days. The following are
the results:
Green wood ........ loss in wg't, 1871 per cent.
Dry wood, unsheltered, . . " 2s.6
ay 2Os
sheltered, 81
These figures, to be reliable, should
be the results of a long series of ex-
periments. They do mean, however,
with woods in the condition we found
them, that to burn 100 lbs. of green
maple requires the evaporation of 80
lbs. of water, to burn 100 lbs. of dry
unsheltered maple requires the evap
Grafton of 20.S lbs. of water and to
burn 100 lbs. of sheltered dry maple
requires the evaporation of o. lbs. of
water. This water in the wood is not
only useless as fuel but requires
large amount of heat, produced by the
wood burned, to change it into steam
and this heat all passes out of the
chimney and is lost for heating pur-
poses. That this amount Of heat is
large your readers may demonstrate
by placing about three tablespoonfuls
of snow-water in tin basin and set
ting it upon a hot stove, noting the
number of seconds needed to bring it
to boiling and then the number re-
CURED to evapOrate it after it has
been brought to boiling. Since the
temperature of the water is 2l2o all
the time it is boiling and since heat is
passing from the stove into the water
all the time it is boiling away if it
takes four or five times as long to boil
the dish dry as it does to bring the
water to boiling, which will be found
to be true, it must require four or five
times the amount of heat to change
the water into steam as it does TO
bring it from freezing to boiling. Now
the amount of heat required to bring
the water in the wood to the boiling
point and the amount required to
change it into steam are the amounts
which will be carried out of the Chin
ney when it goes, and hence are the
amounts which must be lost for heat
ing purposes. Careful experiments
teach that to change pound of water |
at 2l2e into steam at 2l2o requires 986
heat units or heat enough to raise the
temperature of 300 lbs. of water I0o.
This means, when applied to the wood
problem, that had we perfect wood
burner-one which would save all the
heat the wood is capable of producing
the burning of 100 lbs. of green ma
pie, if brought into the house at 320, !
must result in wasting 80. / x(966+lS0)
or 1892. 6 heat units. The burning of
100 lbs. OF unsheltered dry maple, as
above, must result in wasting 20
x(966+ISO) or 23S36.S heat units. The
burning of 100 lbs. of sheltered dry
maple, as above. must result in vast
ing 81 x(966+1s0) or 1042S.6 heat
units.
The burning of the dry sheltered
maple then would be a saving over
the green maple of 1892. 6-1042S.s OF
27504 heat units, which is heat enough
to boil l52 lbs. of ice water. And the
burning of the sheltered dry maple
would be a saving over the unsheltered
dry maple of 23s36.s-I042S.6 g, which
is heat enough to boil "A lbs. of ice
water.
Practically, however, in the case of |
poor stoves which are overfed. the
dry wood would not make so large
saving because the air would leave
the chimney at a higher temperature
than it could if green or wet wood were
used. F. II. KING.
M n and reliable Medicines are the best
wv todepend upon. Aeker's Blood Ell /
ixir has been prescribed for years for all im- /
puritiesof Blood. Inevery formof Scrof. !
ulous, Syphilitic or Mercurial diseases, II is
invaluable. For Rheumatism, has no equal.
J. A McMurphev River Falls Wis