steam-engine 
other types put together. Vertical direct-acting 
engines of large size art- little used, but small en- 
gines of tliis type arc much employed. Steain-en- 
gines of the rotary type are scarcely used except 
for some kinds of steam hoisting-engines. Double, 
triple, and quadruple expansion steam-engines are 
now largely used in marine engineering. Many 
double expansion stationary engines are in use, 
and the erommiinal value of the compound system 
has been demonstrated lioth theoretically and prac- 
tically. Agricultural steam-engine, a portable 
engine with a boiler, often specially adapted toburn 
light fnel, as ehatf or straw, either by itself or in 
connection with wood or coal. Annular steam- 
engine, a steam engine having an annular piston 
working in an annular steam-cylinder, and having 
two diametrically placed piston-rods connected 
with the cross-head, the latter also being connected 
by rods to a guide-block working in the hollow cyl- 
inder forming the center of the annular steam-cyl- 
inder, this guide-block being connected with the 
crank by a pitman. Atmospheric steam-en- 
gine. See atintiKplieric engine, under atmospheric. 
Beam steam-engine, an engine in which a 
working-beam connect* the connecting-rod with 
the crank-pitman, and transmits power from one 
to the other. See beam-engine. Compound 
steam-engine, a steam-engine having two steam- 
cylinders of unequal size, from the smaller of 
which the steam, after use, passes into the larger 
cylinder, and completes its work by expanding 
against the piston in the latter. Concentric 
steam-engine. Same as rotary xteam-enffine. 
Condensing steam-engine, a steam-engine in 
which the exhaust-steam is condensed, for the pur- 
pose of removing the back-pressure of the atmo- 
sphere from the exhaust, and also to economize fuel 
by saving heat otherwise wasted. See condenser, 
and cut under pulswneter. Cornish steam-en- 
gine, a single-acting condensing steam pumping- 
engine, lirst used in the mines of Cornwall. It 
is also used as a pumping-engine for supplying 
water to cities. Steam-pressure is not used to 
raise the water, but to lift a long loaded pump-rod, 
whose weight in its descent is the power employed 
to force up the water. The motion is regulated 
by a kind of hydraulic regulator invented by 
Smeaton, and called a cataract. Direct-acting 
steam-engine, a steam-engine in which the power 
of the piston is transmitted to the crank without the 
intervention of levers, side-beams, or a working-beam. 
5921 
ii. high-p 
for a in pos 
d, passage f 
e-plates f 
' 
Double Expansion Marine Stea 
ure cylinder ; *, low-pressure cylinder ; 
-engine. 
induction- and eduction- 
, , 
position of exhaust from lower end and of induction to upper end of cylinder ; 
steam from a to */ , induction* and eduction-valve for b; J,f, 
' ' 
, 
alves of a and */ f, ', pistons ; h,h', piston-rods 
' ' 
,, bal- 
; i, i', cross-heads ; 
, , ,, , , 
_/,>', slipper-guides for cross-heads; k, ', connecting-rods ; /,/', cranks; m, crank 
shaft : . shaft which drives feed-pump a and also bilge-pump (not shown) on the op- 
posite side; /.worm on main shaft gearing into worm-wheel? on the shaft , and actu- 
ating pump-plungers by crank and pitman connection ; r, r , eccentrics ; s, s ', eccen- 
tric-rods; t, t', links connected by link-blocks with valve-stems M. '; v, crank-lever 
which turns a segmental worm-gear, keyed to the rock-shaft w carrying the rocker- 
anus x, x' t for reversing high-pressure and low-pressure valves respectively ; y, bed- 
plate; z, columns supporting the cylinders ; x', tie-rods for stiffening the columns; a', 
exhaust from low-pressure cylinder to the condenser (not shown) ; a", butterfly throt- 
tle-valve ; b', gear for operating throttle-valve ; c', relief-valves. 
steam-kettle 
the mercury according to the amount of pressure. 
A very common form of gage is that known as 
liourdon's, which consists essentially of a flattened 
metal tube, closed at one end and bent circularly, 
into which the steam is admitted. As such a tube 
tends to straighten itself out by the force of the 
n'eam, the amount of pressure can easily be ascer- 
tained by an attached index-apparatus. Electric 
steam-gage, an attachment to a steam-boiler for 
indicating at a distance the pressure of the steam, 
tine form consists of a bent tube filled with mercury, 
which, as it rises under the pressure, closes a series 
of electrical circuits after the manner of a thermo- 
stat. Another form employs the expansion or move- 
ment of an ordinary steam-pigc diaphragm as a cir- 
1'iiit-closer. The closing of the circuit in each case 
serves to sound an alarm. 
steam-gas (stem'gas), . Same as nn/i- / - 
lii-ntcd nil-mil (which see, under steam). 
Steam-generator (stem'jen'e-ra-tor), n. 
A steam-boiler. 
Steam-governor (stem'guv"er-nor), . See 
i/uri rinir, C. 
steam-gun (stem'gun), . A gun the pro- 
jectile force of which is derived from the 
expansion of steain issuing through the 
shotted tube. 
steam-hammer (stem'ham"er), n. A f org- 
ing-hammer operated by stciini-power. it 
has assumed several forms, but now consists of a 
vertical and inverted steam-cylinder with piston and 
iston-rod (the rod passing through the lower cylin- 
er-head and carrying at the end a mass of metal 
which forms the hammer), an anvil directly beneath 
the hammer and cylinder, a supporting framework, 
and suitable valves for the control of the steam. 
Steam is used to raise and may also be used to drive 
down the hammer. By means of the valve-system, 
steam is admitted below the piston to raise the ham- 
mer and to sustain it while the metal to be forged is 
placed on the anvil. To deliver a blow, the steam is 
exhausted below the piston, and the hammer is al- 
lowed to fall by its own weight. To augment the 
blow, live steam may be admitted above the piston 
to assist in driving it downward. To deliver a gentle 
blow, the exhaust-steam below the piston may be re- 
tained to act as a cushion. Blows can be delivered 
at any point of the stroke, quickly or slowly, lightly or 
H 
^alve 
iiii-Bi-vcuiiuii ui. =/==, oiu-....^. . ........ B piston. The name is sometimes given to reciprocating en- ._.., ,. ,, -.--.^ 
Disk steam-engine a form of rotary engine in which the glneswhichhaveafly-wheeland crank shaft. E. II. Knight, with the full power of the combined weight of the ham- 
steam-pistons act successively against a revolving disk Rotatory steam-engine. Same as rotors/ steam-engine. me r and force of steam-pressure; or the machine may be 
set at an angle to the plane of rotation, thus imparting a Semi-portable steam-engine, a steam-engine which used as a vise or squeezer. All modern steam-hammers 
gyratory motion to a central shaft upon which the disk is is movable with its foundation-plate, as distinguished from o f the type described are modifications of the original 
mounted, the end of this shaft being connected with a an engine mounted on wheels, and from one resting on a 
crank turning in the plane of rotation. Double-acting fixed foundation. Triple expansion steam-engine, 
steam-engine the ordinary form of steam-engine, in a steam-engine that expands its steam in three successive 
which the steam acts upon both sides of the piston. stages and in three separate and distinct cylinders, one 
Double-cylinder steam-engine, a steam-engine hav- taking its steam from the boiler, and each of the others 
ing two steam-cylinders acting in combination with each taking its steam from the exhaust of the cylinder working 
other. See compound steam-engine. Double expansion at the next higher pressure. This type of marine engine 
steam-engine (a) A double-cylinder steam-engine in is found at the present time on many of the swiftest steam- 
which steam is used expansively. (6) A compound steam- ships, but may be in turn superseded by the quadruple 
engine Double steam-engine, a steam-engine having expansion-engine. Vertical steam-engine, a steam- 
two cylinders in which the pistons make either simulta- engine whose piston reciprocates vertically, 
neous or alternate strokes and are connected with the steamer (ste'mer), n. [< steam + -er 1 .] One 
same crank-shaft. Duplex steam-engine. Same as j th t wn i cb steams, in any sense. Spe- 
double steam-engine. High-pressure steam-engine. 
Nasmyth steam-hammer illustrated in the cut. Steam- 
h 
& 
lent steamer, (f) Especially, a vessel propelled by steam ; 
a steamship, (y) A fire-engine the pumps of which are 
worked by steam. (A) A vessel in which articles are sub- 
jected to the action of steam, as in washing or cookery. 
See steam-chest, 2. (1) In paper-making, a vessel in which 
old paper, fiber, etc., are treated in order to soften them. 
(2) An apparatus for steaming grain preparatory to grind- 
ing. (0 A locomotive for roads. See road-steamer. 
Steamer-cap (ste'mer-kap), . Same as /ore- 
High-speed Steam-engine. aild-aft, 2. 
In general it may be said that steamer-duck (ste'mer-duk), n. A South Amer- 
en'gines of considerable power, making one h 
turns per minute and upward, are high-speed engines. er 
Steam-hammer (Nasmyth's). 
a, anvil ;*, frame ; c, hammer-head ; rf, guides; e, piston-rod ; /, 
valve-chests containing valves that control induction of steam to and 
eduction from the cylinder A; A', steam-pipe; e, rock-lever (moved 
tVDeS of Valve-Ke&rs. in geueiu.i u> may uo oaiu i/iiQv WWWWAWW-. .*._ ,~- 
onsiderable power, making one hundred ican duck of the genus Micropterus (or Tacliy- 
.... r- r . ,,; a race-horse. See Micropterus, 2. This 
Horizontal steam-engine, a steam-engine in w ! duck becomes wnen adult incapable of flight, but swims nammere o f the largest class have been made with ham- 
piston works horizontally. Inclined-cylinder steam- T rapidly, with a movement which has suggested the merg we j K hi n g eighty tons. Another type of steam-ham- 
engine, a form of marine engine having cylinders inclined action of a side-wheel steamboat (whence the name). mer Cpns j s t 8 of two horizontal steam-cylinders placed in 
tothe horizontal. Inverted-cylinder steam-engine, a ,*- am _ excava * or ( stem 'eks^ka-va- tor), . line, the hammers meeting over an anvil on which the 
steam-engine in which the cross-head is placed forging rests, 
cylinder. Tl: """SSJSfiSSf !S ._ 2!__"j_' /;=/* im^ g e e foun- steam-heat (stem'het), n. l.I-aflicrmodynam- 
Same as 
*- steam-fountain (stem' 
ics, the total heat required to produce steam 
often non-condensing. See cut in next column. Non- O j w j,jch connects with the boiler, so that the steam raises pipes, or radiators. 
condensing steam-engine, an engine that exhausts its 
steam without condensation. See non-condensing. Oscil- 
lating steam-engine, a steam-engine whose cylinder os- 
cillates on trunnions and has its piston-rod directly con- 
nected with the crank. Double engines of this type have 
been considerably used for marine propulsion, and some 
are still employed. Overhead steam-engine. See over- 
it in four different open .. 
tinct and separate steam cylinders. The pistons of the cyl- 
inders are connected by piston-rods, cross-heads, and con- 
necting-rods with cranks attached to a common shaft, to 
which rotary motion is imparted by the coacting pistons. 
-C 
Steam-gage (AshcrorVs). 
Reciprocating Steam-engine, a steam-engine in which a hol , ow j^, wbc attad , ed to case at a', and receiving condensed 
the power of steam is applied to a reciprocating piston. wateror steam under pressure through;he opening at/^link con- 
nectingYnd of tube a with short arm of rock-lever c, 
upper end a small rack intermeshing withji pinion on the sjvmdle ot 
Revolving-cylinder steam-engine, a steam-engine of 
whichtheivlitulerissomountedthatitiscausedtorotate PP?^ jr'r^ aM ^i,~ d ";-p"ing ; n Vch"a''cts'upo'n the sJYadVe'of sieaui-utfuu. 
by the reciprocation of the piston. Compare rotary steam- J ^> in , er in a direction Spposed to the action of the rack steam-kettle (stem'ket'l), n. A vessel he 
engine. Rotary steam-engine,asteam-enginein which an d p inion: f.diai.onwhichthenguresmdicatepressuresdnpounds) by s t eam an d used for various purposes. 
Steam-hoist (stem' hoist), n. A lift or elevator 
operated by a steam-engine. 
steam-house (stem'hous), n. In oyster-canning, 
a house or room where oysters are steamed. 
steaminess (ste'mi-nes), n. Steamy or vapor- 
ous character or quality ; mistiness. 
Steam-jacket (stem'jak"et), . An inclosure 
adapted for receiving steam, and applying the 
heat of the steam to a kettle, tank, steam-cylin- 
der, etc., surrounded by such inclosure. 
steam-jet (stem' jet), . A blast of steam caused 
to issue from a nozle. 
ich iaatthe steam-joint (stem'joint), . A joint that is 
steam-tight. 
-6 
enfrinc. Rotary steam-engine, . t . 
the piston rotates in the cylinder, or the cylinder upon the above the atmospheric pressure. 
372 
by steam, and used for various purposes. The 
