St. Johnsbury Caledonian. [volume] (St. Johnsbury, Vt.) 1867-1919, 1876-11-10

creased Il hundred fold in France since
these Investigations were made. ANY
scientific chemist of experience must
consider the eXpositions made in favor
of wrought iron much i'll the same light
as mares nest"
| Il. F. Babcock, Professor of Chemistry
in Massachusetts College of Pharmacy,
says: 'The eXtravagant statements
which have been made by interested
parties i'll regard to the dangers from
the Use of cast iron in the construction
of furnaces ale wholly without founda-
ton. There is no advantage in wrought
over cast iron for this purpose. Our
furnaces too often emit dangerous gases,
but it is not the east iron, permeated by
these gases at every pore, that is i'll
fault it is the imperfect hampers, the
dust in the air, the opening of the joints
III the furnace. Let us hope we may
hear no more of this great scare about
poisonous gases coming through the
pores of cast iron in furnace pot an
inch thick" Gen. NORM. in reporting
the results of the tests made by the
commission appointed in 1869 by the
Academy of Sciences, after describing
the experiments which indicated slight
permeabllity of gases to both mOdifica-
tions of iron. states: The results indi-
Gated above are produced only when
The metal is brought to Il red heat. The
most immediate effects are those due to
the direct radiation of the surfaces, and
in this respect there is no difference be
tween wrought and cast IRON" 1t should
be added that in the experiments made
i'll France, IL soft coal, yielding more
! OD
used. Anthracite. which is almost uni
versally used for heating purposes in
this section of the country, resembles tO
the greatest degree pure carbon, and If
its combustion is properly managed.
and the gases evolved allowed to reach
the highest point of oxidation, is the
most convenient and economical fuel
within our reach. A word concerning
the other methods sometimes employed
10y us may he i'll place here. In grate
fires the chief disadvantages are but
| little radiating surface is afforded and
the loss of heat attending their use is
very large. GauOt atfirms that only I3
per cent, of the heat evolved by the
combustion of coke or coal in fire places
is utilized. and but Il per cent. when
wood is used. Heating 10y means of
steam OF hot water Is certainly free from
any objections that can he advanced Ia
CRATES and furnaces, but the great ex-
penSe consequent on the Use of these
agents is, at least at present. All insul-
mountable barrier to their general
adoption.
Hot air furnaces, then. appear to be
! the only practical means of household
warming, and if furnaces having the
least possible number of Joints are used.
and proper care is exercised in their
management, are entirely free from
delcterinus sanitary effects. In regard
to their advantages and defects the fol-
loving statements are supported alike
oH scientific and practical experience
|. Furnaces formed of several east
ings bolted together are very liable to
leak gas. owing to the unequal contrac-
ton and expansion of the metal 10y
| changes of temperature.
| =. Cast iron furnaces made of three
pieces tire chamber. body, and radia-
tor each east solid from the best quail
lty of iron. If properly managed, do not
permit the escape of gas the pieces
being firmly united in deep grooved
joints, and these connections. which are
lateral. packed with fire clay.
5. CarhonIc oxide cannot permeatc
cast iron. one-half inch OF more i'll thick
ness, to an appreciablc extent.
!. Air heated 10y cast or wrought iron
furnaces Is as pure when hot as when
originally introduced into the furnace
| provided that the latter is properly CON
structed, and the supply of cold air
well regulated. Doing large amount
of heating with small furnaces is the
cause of the over heating of the sur
faces. and the consequent generation of
! VItiatcd air.
;. In furnaces with brick lined ii;e
chambers. the danger of over heating is
Ies>encd thereby. but, owing to the re-
duccd radiatng surface. the power of
| the furnace is greatly decreased.
Il. Cast and wrought iron exhibit.
when heated to reducsS. the same be
havior to gases (carbonic oxide.) and are
both liable to become over heated.
Z. The construction of small. cheap,
/ light -jointed furnaces. put up 10y mex
peIicnced men, is but poor economy.
and is the chief cause of the evil effects
50 often observed III our general heat
ing apparatus.
:. y large portion of the gas that
frequently communicates the air of our
dwellings. escapes from the furnace
during the introduction of fuel The
sm"kcpipe damper. which should be
perforated. and tit loosely in the pipe,
should be opened, and the lower furnace
door closed when coal is added: and at
all times IL pressure should exist from
without inwards on every part of the
furnace. Respectfully,
j. II. BATTERSHALL.
PHI. ID. Chemist. 26 Pine ST., y. Y.