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Account of American Editions of Fo-
reign Publications.

Art. XIV.

Essays, Political, Economical, and
Philosophical. By Benjamin Count
Rumford. The first American,
from the third London Edition.

[Continued from p. 380.]

IN the sixth essay, Count Rum-
ford enters on the discussion of
the best modes of applying heat to
culinary purposes. He thinks, that
in common cases, seven eights of
the heat which might be generated
from the fuel consumed, is carried
into the atmosphere with the smoke,
and is wholly lost. To ascertain
this, he performed several experi-

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ments, by boiling a given quantity
of water, in close and duly con-
structed fire-places. The results,
compared with the results of ex-
periments for boiling water in open
fire-places, clearly prove, that in
boiling victuals with an open fire,
nearly five times as much fuel is re-
quired as when a closed fire-place is
used and the heat properly managed.

By the use of various improve-
ments, described by the author, it
is evident, indeed, that nine tenths
of the fuel ordinarily consumed,
might be spared. A just concep-
tion of these improvements will be
given by describing, at length, an
apparatus for cookery, erected by
the author's directions in the kitchen
of the House of Industry at Munich.
We intreat the reader's attention to
the particulars of this description,
as it constitutes a complete illustra-
tion, example, and proof of the
Count's principles on this interest-
ing subject.

In the first arrangement of this
kitchen, eight large copper boilers,
each containing 38 English wine
gallons, were placed in two rows,
in a solid mass of brick-work, three
feet high, nine feet wide, and 18
feet long, built in the middle of the
kitchen, so that, from a single fire-
place, situated at one end of this
brick-work, by means of canals,
furnished with iron valves or dam-
pers, and going from it through the
solid mass of the brick-work to the
different boilers, these boilers were
heated, and made to boil with a
single fire; and though none of them
were in contact with the fire-place,
and some of them were distant from
it near 15 feet, yet they were all
heated with great facility, and in a
short time, by the heat which, upon
opening the valves, was made to
pass through the canals.

Each boiler having its separate
canal, and its separate valves, any
single boiler, or any number of
them, might be heated at pleasure,

without heating the rest; and by
opening the valves of any boiler
more or less, more or less heat might
be made to pass under the boiler;
and when no more heat was want-
ing, or when the fire was too strong,
by opening a particular valve, a
communication with a waste-canal
was formed, by which all the heat,
or any part of it, at pleasure, might
be made to pass off directly into the
chimney.

The fire was regulated by a re-
gister in the door of the ash-pit, by
which the air was admitted into the
fire-place; and, when no more heat
was wanted, the fire was put out by
closing this register entirely, and
by closing, at the same time, all the
valves.

The fire-place was of an oval
form, three feet long, two feet three
inches wide, and about 18 inches
high, with a double vault, about
four inches of air being left between
the two vaults; and the fuel was in-
troduced into the fire-place by a
passage closed by a double iron door,
kept constantly shut; and the fuel
was burnt upon an iron grate; the
air which supplied the fire coming
up from below the grate, through
the ash-pit.

The loss of heat in its passage
from the fire-place to the boilers,
was prevented by making the canals
of communication double, one with-
in the other; the internal canal by
which the heat passed, and which
was five inches wide internally, and
six inches high, being itself placed
in a canal still larger, so that the
canal by which the heat passed,
(which was constructed of very
thin bricks), was surrounded with
a wall two inches thick, of confined
air. The surrounding canal being
formed in the solid body of brick-
work, this contrivance of double
canals was entirely concealed. The
double canals and the double vault
over the fire-place, were intended
to confine, more effectually, the heat,

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and prevent its escape into the mass
of brick-work, and its consequent
loss.

Not only the fire-place itself, and
the canals of communication be-
tween the fire-place and the boilers,
were surrounded by confined air,
but it was also employed to confine
the heat in the boilers, and prevent
its escaping into the atmosphere.
This was done by making the covers
of the boilers double. These covers,
made of tin, or of thin iron-plates
tinned, were in the form of a hol-
low cone, the height of which was
equal to one third of its diameter;
and the air it contained was entire-
ly shut up, the bottom of the cone
being closed by a thin sheet of tin-
ned iron. The bottom of the cone
was accurately fitted to the top of
the boiler, which it completely
closed by means of a rim about two
inches wide, which entered the
boiler; which rim was soldered to
the flat sheet of tinned iron which
formed the bottom of the cover.
The steam, generated by the boil-
ing liquid, was carried off by a
tube, about half an inch in diame-
ter, which passed through the hol-
low conical cover, and which was
soldered to the cover, both above
and below, in such a manner that
the air with which the hollow cone
was filled, remained completely
confined, and cut off from all com-
munications with the external at-
mosphere, as well as with the steam
generated in the boiler.

To convince strangers, who vi-
sited this kitchen, of the great ad-
vantage of double covers to con-
fine the heat in the boilers, a single
cover was provided, which, being
externally of the same form as the
others, when placed upon a boiler,
could not be distinguished from
them; but as its bottom was want-
ing, and consequently no confined
air was interposed between the hot
steam in the boiler and the exter-
nal surface of the cover, on being

placed upon a kettle actually boil-
ing, this cover instantaneously be-
came so hot as to burn those who
ventured to touch it; while a double
cover, formed of the same materials,
and placed in the same situation,
was so moderately warm that the
naked hand might be held upon it
for any time without inconvenience.

As it was easy to conceive that
what was so hot as to burn the hand,
upon touching it, could not fail to
communicate a great deal of heat to
the cold atmosphere, which con-
tinually lay upon it, this experi-
ment clearly showed the utility of
double covers.

The steam arising from the
boiling liquids, instead of being
suffered to escape into the atmos-
phere, was carried up by tubes into
a room over the kitchen, where it
was made to pass through a spiral
worm, placed in a large cask full
of cold water, and condensed, giv-
ing out its heat to the water in the
cask; which water thus warmed,
without any new expense of fuel,
was used next day, instead of cold
water, for filling the boilers. That
this water, so warmed, might not
be cooled during the night, the
cask that contained it was put into
another cask still larger; and the
space between the two casks was
filled with wool. The cooling of
the steam, in its passage from the
boiler to the cask, was prevented
by warm coverings of sheep-skins
with the wool on them, by which
the tubes of communication, which
were of tin, were defended from
the cold air without.

By this contrivance, the heat,
which would otherwise have been
carried off by the steam into the at-
mosphere and lost, was brought
back into the boiler, and made to
work the second day.

By other contrivances, the smoke
also was laid under contribution.
After it had passed under the
boilers, and just as it was about

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to escape by the chimney, it was
stopped; and, by being made to
pass under a large copper, filled
with cold water, was deprived of
the greater part of its heat. As
considerable advantages would be
derived from drying the wood, and
even heating it, before it was made
use of for fuel, the smoke from two
of the boilers was made to pass
under a plate of iron which formed
the bottom of an oven, in which
the wood, necessary for the con-
sumption of the kitchen for one
day, and cut into billets of a pro-
per size, was dried twenty-four
hours previous to its being used.

In a kitchen constructed mere-
ly as a model for imitation, five
boilers of different sizes, all heated
by the same fire, were placed in a
semicircular mass of brick-work,
and the smoke, after having passed
under all these five boilers, was
made to heat, at pleasure, either
an oven, or water which was con-
tained in a wooden cask set upright
upon the brick-work. A tube of
copper, tinned on the outside,
which went through the cask, gave
a passage to the smoke, and this
tube was connected with the bottom
of the cask, by means of a circular
plate of copper, through which the
tube passed, and which closed a
circular opening in the bottom of the
cask somewhat larger than the tube.

This circular plate was nailed
to the bottom of the cask, and the
joining made water-tight by inter-
posing, between the plate and the
wood, a sheet of pasteboard; and
the tube was fastened to the plate
with solder. This tube, about six
inches in diameter, as soon as it
had passed the circular plate, and
entered the barrel, branched out
into three smaller tubes, each about
four inches in diameter, which,
running parallel to each other
through the whole length of the
cask, went out of it above, by three
holes in the head of the cask, and

ended in a canal which led to the
chimney.

This tube was thus divided
into branches, in order to increase
the surface, by which the heat of
the smoke was communicated to
the water in the cask. The cask
was supplied with water, by a leaden
pipe, from a reservoir placed in the
upper part of the building; and the
machinery was so contrived, that
when any water was drawn out of
the cask, it was immediately re-
placed from the reservoir; but as
soon as the water in the cask had
regained its proper height, the cold
water from the reservoir ceased to
flow into it.

Nothing so much excited the
surprise of those who visited this
kitchen, as to see water actually
boiled in a wooden cask, and
drawn from it, boiling hot, by a
brass cock. There is reason to
think, that a contrivance of this
kind might be applied to many use-
ful purposes. No contrivance can
be conceived by which heat is com-
municated to fluids with so little
loss: and as wood is not only an
excellent non-conductor of heat it-
self, but may easily be encompassed
by confined air, by furs and other
bodies useful in confining heat, the
loss of heat, by the sides of a con-
taining vessel composed of wood,
might be almost wholly prevented.

Why, for instance, should not
the boilers for large salt-works and
breweries, in which great quanti-
ties of water are heated or evaporat-
ed, be constructed of wood, with
horizontal tubes of iron or copper,
communicating with the fire-place,
and running through them for the
circulation of the smoke?

To prepare the soup furnished
from the kitchen of the House of
Industry, it was necessary to keep
up the fire near five hours, the soup
requiring to be kept boiling above
three hours.

The fuel made use of in this

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kitchen was dry beech wood; a
cord of which, 5 English feet 8 9/10
inches long, 5 feet 8 9/10 inches high,
and 3 feet 1⅓ inches wide, and
which weighed, at an average, about
2724 lbs. avoirdupois, cost, at an
average, 2 dollars and 10 cents.

Of this wood, the daily con-
sumption, when soup was provided
for 1000 persons, was about 1/7, or
more exactly 3/22 of a cord, which
cost about 30 cents; and this gives
1/40 of a cent for the daily expense
for fuel in cooking for each person.

To estimate the daily expense
for fuel in cooking the same quan-
tity of the same kind of soup in
private kitchens, suppose these 1000
persons, who were fed from the
public kitchen, to be separated into
families of five persons each:

This would make 200 families;
and the quantity of wood consumed
in the public kitchen, daily, for
feeding 1000 persons, (=300 lbs.)
being divided among 200 families,
gives 1½ lbs. of wood for the daily
consumption of each family; and,
according to this estimate, one cord
of wood, weighing 2200 lbs. ought
to suffice for cooking for such a
family 1466 days, or four years and
six days.

But upon inquiries relative to
the consumption of fuel in private
families, the author found that five
Bavarian pounds of good peas-soup,
could hardly be prepared at a less
expense of fuel than 15 lbs. of dry
beech-wood of the best quality;
consequently, a cord of such wood,
instead of preparing a soup daily
for a family of five persons for
four years, would hardly suffice five
months.

Hence it appears that the con-
sumption of fuel in the kitchens of
private families, is to that consumed
in the first kitchen of the House of
Industry, in preparing the same quan-
tity of the same kind of food (peas-
soup) as ten to one.* However,
this difference is not occasioned en-
tirely by the difference between the
two methods of managing the fire;
for, exclusive of the effect produced
by a given arrangement of the ma-
chinery, the greater the quantity of
food prepared at once, or the larger
the boiler (within certain limits),
the less will be the quantity of fuel
required: and the saving of fuel
which arises from cooking upon a
large scale, is very considerable.

(To be continued.)

  * Afterwards, on altering the kitchen of the House of Industry, and fitting it up
on better principles, the economy of fuel was carried still farther.