Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1853-01-22
THE NEW MOTOR.

TO the Editors Of tie National Latelligeacer:
GENTLEMEN; Having, with many others, entertained
doubts about the commences Of Capt Ercssons al
legged invention have great pleasure in stating that your
republication from the New York Evening Post Of the
cle in relation TO it has, after due reflection entirely
dspelled my sceptcsm Not with others The article
referred to is so void Of explanatory Details and the de-
scrptive portion so mixed up with statistical and other
matter not necessary to the proper understanding OF the
principle Of the engine but rather confusing it, that few
will rise from perusal of 1t satisfied that all is right
1t may perhaps facilitate full comprehension Of the
subject by comparing it with the steam-engne to state
In what portions resembles the same and in which parts
1t differs from it.
Now, the steamengine has reservoir called boiler,
filed partly with water partly with steam under pressure
Ercssons air engine has also reservoir filed with air
under pressure each of which furnishes the working
cylinders, also common to BOTH the expansble material
by which the motion of the piston is produced The
ter is rendered expansbe by heating the reservoir
tanning it and thence conveyed to the working cyin
der TO operate upon the piston But the air from the
servor OF Ercssons engine forces its way cold from it
and passes through heater, box parttoned off by
many wire MEETINGS. which, being previously heated give
off their caoric to the passing air and thereby increasing
its volume and last quantity Of expansion is added after
entering the heaed working cylinder The steam engine,
thirdly, has forcing pump that to repensh the
water reservoir boiler whilst the Ericsson engine has
for supplying the air reservoir These constitute the
main parts OF the steamengne also of the arengne
All the rest are secondary appurtenances to inf
mite variations, obedience to the purposes they
quired to fulfil
The differences between the two besides the above
namedviz the place of heatingconssts in the different
expansive substances employed which in the steam-en-
CINE is liquid (water in the other elastic fluid,
atmospheric air The water must be first made to
the easti, fluid state before it act motive
agent, whilst air is always in that condition But the
proporonate quantity Of elastic fluid generated by heat
from certain bulk of water is many times greater thar
that increase Of elasticity gained by heating body al
ready in the elastic fluid state the Of supply to thu
reservoirs Of the two engines must be Of very different
proportions Whstin the steam-engine the forcngpumI
is only few inches in diameter, that of the Ericsson
1877 inches 1t must be borne in mind that the amount
to the square inch is the in the reservoir
in the working cylnde which is another coincidence
with the steamengne hut that the volume of the air il
varied by the local differences of temperature.
The relative bulk of tie reservoirs in the two different
engines presents striking dssmilary of proper
tons Whilst that for water and steam occupies larger
space in many engines tan all the other parts that fol-
air is comparatively Insignificant being only calculated
to furnish sufficient full for stroke of the piston
with surplus necessaryto avoid possible exhaustion
need hardly add thai both the working and supply
cylinders operate from end only the first being
open at the top the oth at the bottom and are there
FORE in this respect like the old atmospheric
CINE that worked solely downward by the created
in condensng the steam elow the piston whilst the air
engine piston works solly upwards, making seconc
cylinder necessary for producing the down movement.
And now, Messrs. Editors, cannot close this without
expressing my conviction hat steam, in great measure
" has had its day."
Very respectfully, your most obedent servant,
WIN. WURDEMANN.