New-York tribune., 1884-01-23
LETTERS FROM THE PEOPLE.
pnrARY And REcIPRocATING ENGNEs.
ALFrrER FROM PROFESSOR n. II. THURsToN'
rAL1a. % liz I'LL

A
To me Edftor OF Ths TrtbHne
SIR: A paragraph in Monday TRIBUNE
states that tests Of rotary engine. made here recently
Indicate that II was found vastly moro economical tnah
reciurocating engines" O., than engines o the ordh-
ary and familiar type. This Is not the tact ana u no'
likely TO be the fact hereafter think IT true as was
stated in the report that the engine to which reference
made proved vastly more economical than any eg"eV
s class that have tested or OF which nave ever
scen records That is sufficiently credable. and more
need not be claimed for 10. As compared with rccpro
eating engines did equally good work with engines
Of the latter kind OF equally small power This is the un-
expected and surprising fact shown by the tri re
ported upon.
Advantages have been expected Of the rotary engine
by the advocates OF that form Of motor which are no,
looked for by the we-informed engineer 1t is assumed
that the recprocatng is essentially deIecu'e'
that the conversion of the recprocatnG motion OIL ne
piston into the rotary motion Of the crank and hy-"heei
involves necessarily appreciable loss ot power anu
efficiency; that the variation OF speed OF the recipro
eating parts from state Of rest OF the dead points 10
maximum velocity at hastroke, must necessarily cause
loss of power, increased wear aud tear and dangerous
impact ut high speed and must thus restrict 10 very
serous extent the development OF greater power by the
adoption sf higher velocities Of piston 1t s these no
tions which have been the usual stimulus TO inventors
who have during the past century. been endeavorns 10
produce rotary engines capable OF competing success
fuv with the always standard recprocating machine
The patent records TEEN with such devices many o nc
ingenious, moro of them crude and unmcchameal'
Rotary ngnes have usually provedo be wastefu the
use o, steam subject rapid depreciation in power ana
efficiency and to great loss Of power by friction OF WOik
ing narts Engineers are therefore likely to look with
interest and with little surprise upon mJtor o TINS
class which Is not subject to these defects even though
NAV not prove to the superior OF the best engines OF
the more common type.
Ru the assumed objections to the recprocatng form OF
a1,a font
The conversion of a rcciprooatng motion into rotation
does not necessarily involve loss Of power ana eed not
and i'm good engines does not cause obectonaDe jar o
injury OF the working parts Inc Ill 10 uc M NV, 90, hy
sDecd OF the modern high-spced engine Is n0t sei "
the difficulties OF the kind above described et ne Win M, M
its operation, but rather by the lmposao2 & ., V fste e
more than a certain amount OF power HIouEh mo ,a ,tS
running machinery with absolute celiah! tiht miami
day after day indefinitely. The inertia OF parts
has been generally assumed 10 be detilehl 70 IL t
the irreulaTity Of stcam-disIihutl0n duc 10 tne
speeds greatly exceeding the highest attained ~
tic most radical OF the hgh-speed engine builders on ne
day The rotary engine has not therefore, the auFan-
age in this respect claimed for IT, IN the past y! NAM
engineers as vel as by - IT hs
more than compensated by the apparent llnpoSslnit V
securing that economical dstrn4tmoh& m & So arJ forms
of engine and tho failure OF nearly every lorh oI
rotary i'm competition with tho recprocating engine
when eompared with respect 10 freedom from Internal
friction and leakage OF steam past tho piston, ~
always for the layman. when asked TO put ms
into rotary engines, assume that the machine pos
these defects 10 iata extent uuS,s tnc
has proved 10 he the case by cae' tesls Haue ny
| engineers of known skill and Integrity ,, :,
The engineer In, therefore, pleasantly surprised "nc o
finds one Of this class of engines doing gQod wOra anu ~
will be still more pleasantly suPrsea HHCn ~ ~ % Us er e
difficulties which have hitherto been met III tle en-
deavOr 10 good steam distribution hsh econo!
and perfec regulation such s seen In the best recp
rocating engines combined with tho undenlaOe spec
advantages the rotary engine These latter lnIeul
ments being overcome. the rotary Will supeIseue tue
cinrCcatng engne-but think, not till then exec ePg I
very small mowers. Our small reciprOcatlng engines uo
not compare fayOraby with larger sizes IN iespect either
TO economy exactness OF regulation or power per PouU
| mnrovement; but a small machine OF this class WI
resn nj least the best rotary engines must compete
| solely with the smaller rccprOcating engines
Very respectfully yours, X H. IHI * ION'
ser,as Insiite Of Technology, Hoboken, ~ J' jan