Polynesian. [volume] (Honolulu [Oahu], Hawaii) 1844-1864, 1852-09-18

| n'ooe NS" insSneouS, PTcSeutcu Ill Hlcre
model. 1t does not, like most new invention:
rest in bare experiment Were these its
conditions, the Merchants Magazine would
express no judgment concerning its utility
nor indulge in any speculations as to its sup.
f posed value. We should leave this task tc
: those who are supposed to be better acquaint.
, ed with the science Of mechanics, and with
the practical value of untried inventions, than
: the editor of a commercial journal. We are
not here called upon to perform this task.
celebrated painter has said "Let my
: productions be subjected to the judgment Of
the whole world, but heaven deliver me from
that of my own profession. This may moi
/ in majority of cases, prove 70 be just ap-
prehension; but it is quite certain that there
: is in every profession conservative spirit,
which cings to the knowledge of the past,
and distrusts that which is new and untried
This is strikingly illustrated in the case oi
the steam-engine.
We all know that, at this time, the only
mode in use for producing a rotary motion,
from the reciprocating motonsof the piston
of a stepm-engine, is by means of crank
Ii is equally we'll known, that to enable the
stationary engine to pass the CENTER" a
ponderous fiy-wbeel is employed. Now il
will be hardly credited, that both these me-
thods we're at first condemned by distinguish
ed engineers, as utterly impracticable. In
1777 Mr.. Stewart read paper before the
Royal Society in London, describing me-
thod for obtaining continued circular mo-
ton, for turning all kinds of mills, from the
reciprocating motion of the steam-engine.-
This he proposed to effect by means of a COM
plicatcd contrivance, which practice soon
proved TO be worthless. In the course of
his remarks, he incidentally noticed the me-
thOd of obtaining the circular motion by
means of a crank, which, said he, " occurs
naturally in theory, but in practice would be
impossible.
This paper was, by the council of the So
ciety, referred to Mr.. Smeaton, one Of the
most distinguished engineers of that age
He not only condemned the crank, but the
| fly-wheel also; and. in consequence of these
views, very complicated and expensive means
we're adopted, 10 produce the desired rotary
motion from the reciprocating motion of the
piston, until, at length, from necessity, the
crank and fly-wheel were adopted, and ever
afterwards used.
We have mentioned these circumstances
10 show the wisdom OF the course pursued
by Captain Ericsson in not subjecting his in
| vention to public examination, until he could
present it in shape so conclusive, as TO
satisfy the judgment of practical men; and
to trample down that carping, sneering criti-
cism, with which envy and rivalry sometimes
seek to strangle the productions of inspired
genius. This, in our opinion, he has accom-
plished. We have, with great care, rxamin-
ed this machine; the principles and construc-
ton of which were fully explained to US by
the distinguished inventor. 1t is alike re-
markable for sublimty of conception and
simplicity of detail Like the forces of ma
ture, its operations, although mighty, are
gentle. Two machines upon this plan are
now in operation at the works Of Messrs.
Hogg and Delamater-one of five horse, the
other of sixty korse power.
The latter is the most extraordinary piece
of machinery we have ever seen. 1t has
four cylinders. Two, of seventy-two inches
in diameter, stand side by side. Over each
OF these is placed one much smaller With
in these are pstons, exactly fitting their re-
spective cylinders, and so connected that
those within the lower and upper cylinders
move together Under the bottom of each
of the lower cylinders a fire is applied. No
other furnaces are employed. Neither boil
ers nor water are used. The lower is called
the working cylinder; the upper the supply
cylinder As the piston in the supply cylin-
der moves down, valves placed in its top
open and it becomes filled with cold air
As the piston rises within it, these valves
close, and the air within, unable TO escape as
il came, passes through another set of valves,
into receiver, from whence it is to pass in
to the working cylinder, to force up the work.
ing piston within it. As it leaves the receiv-
er to perform this duty, it passes through
what is called the regenerator, which we shall
soon explain, where it becomes heated to
about four hundred and fifty degrees, and
upon entering the working cylinder, it is fur
ther heated by the fire underneath. We
have said the working cylinder is much lar
ger in diameter than the supply cylinder
Let us, for the sake Of illustration merely.
suppose it to contain double the area. The
cold air which entered the upper cylinder
will, therefore, but half fill the lower one
In the course of its passage to the latter,
however, we have said that it passes through
a regenerator, and let US suppose, that as it
enters the working cylinder, it has become
heated to about four hundred and eighty de-
grees. At this temperature, atmospheric air
expands to double its volume. The same
atmospheric air, therefore, which was con-
tanned within the supply cylinder, is now ca
pable of filling one Of twice its SIZE. With
this enlarged capacity, it enters the working
cylinder.
We still further suppose the area of the
piston within this cylinder to contain a thou
sand square inches, and the area Of the pis-
ton in the supply cylinder above, to contain
but FIVE hundred. The air presses upon this
with mean force, we will suppose, of about
eleven pounds to each square inch; or in
other words, with weight of 800 pounds.
Upon the surface of the lower piston, the