The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1871-01-17
Terms $500 per- annuns, IN Advance.
DAILY PRESS.
PORTLAND.
TUESDAY, JANUARY II, 1871.


Some weeks ago, sent short article to
the PRESS, on condensed air, as an efficient
ana very cheap motive power,-that is to say
cheap when the condensing machinery can
be driven by water. This would hot be expeIl
ent nor cheap, il the mills and factories and
workshops, could be as conveniently placed nc
once on the site of the water power, so as 10
be operated directly by the wheels.
The plan Of driving machinery with con-
densed air, presupposes that there is some To-
cation, such as town or city, where it Is i'm
portant 10 locate the factories, aud not very
far distant, some dheap water power, that can
be employed to conden,e the air. Portland 10
such location for mills and workshops Of
every sort, aud the lower falls on the Pre-
sumpscot, afford every facility for the estab-
lishment of the oondensing machinery.
My attention is called to this subject now,
by an article in the last Scientific American,
on tine boring machines at the Mount Cepls
Tunnel, that are driven by condensed air, aud
work with great efficiency. The article says:
-"It is quite curious and instructive to see
workman connect an elastic tube of about
half an inch diameter with one of these ma.
chimes, andwatch the result when small tap
isturned. A piston rod working in an excee,l-
insly short and samll cylinder, Immediately
flies backwards and forwards with wonderful
rapidity, regulated by small, heavy fly
wheel. Immediatsiy,a ponderous chisel, six
or seven feet loug, and more than an inch in
diameter, is set in motion, and having been
previously placed in position, strikes. a suo-
cession of heavy blows against the stove.--
Fragments begin to fly in all directions. Each
time that the chisel strikes, it is withdrawn Q
little way, very slightly turned, and immedi-
ately strikes again in the same hole
1t Is evident that nothing can resist such an
attack; and indeed holes are bored In this
way in an hour that would otherwise require
a day. As the power is compress
ed air, they not only add no heat 10 TIE in
terror, but render it cooler by the Absorption
of heat by the expansion. 1t would
be quite impossible to carry steam;at high
pressure through pipes four miles long; but
little diminution of force is experienced in
working with them, although all the engines
and condensers, as well as the cylinders for
throwing the air, are outside the mouth Of
the tunnel. The length of the pipe on tho
Piedmont side is about lour and quarter
miles. The pressure Of air commonly ein.
ployed is about 200 lbs. to the square inch."
Four and quarter miles is about the dis.
tance from Portland to the lower Presump-
scot Falls, where an abundance of cheap
water power can be had at all seasons
of the year, never affected by drouth,
where condensing machinery to any extent
might be established, if such plan were
thought feasible and best. I do not affirm,
positively, that such plan would be the best;
but think 1t well worth the trouble OF inves-
tigation, which would be very simple matter
for any competent engineer.
So far, 1 suppose all our.people are agreed;
that nothing would promote our ;growth and
prosperity more than the Introduction Of
manufactures into the city of various kinds.
There is no place in the country more conven-
iently situated than Portland for this. We
have communication by rail and by water
with every part of the world, but steam pow
er is dear, much more so than in Philadelphia
and even in New York, because coal costs us
more. But my opinion is, that we can have
mills, factories and workshops-on the smallest
or largest scale here, driven by condensed air,
as efficiently. and far more cheaply than BY
steam and without danger, inconvenience or
annoy yance to anybody.
With this power the smallest lathe or grind
stone may be operated in attic or cellar by air
condensed like water through ali iron or lead
en- pipe, and at the same time in every other
part of the city, the most ponderous machin- (.
cry may be actuated-as,I believe. The facts,
1 think, are we'll worth investigation. Ths
of facts and figures. ND.