i; 
steam 
His eyen steepe and rollyng in his heede, 
'I'liat ftemede us a forneys of a leede. 
Chaucer, Gen. ProL to C. T.. 1. 202. 
Stemyn, or lowyn vp. Flammo. Prompt. Parv. , p. 473. 
Two stemynye eyes. '!/nlt, Satires, 1. 63. 
II. trans. 1. To exhale; evaporate. [Rare.] 
In slouthfull sleepe his molten hart to nleiar. 
Spenser, F. Q.,II. vi. 27. 
2. To treat with steam ; expose to steam ; ap- 
ply steam to forany purpose : as, to steam cloth ; 
to steam potatoes instead of boiling them ; to 
Hiram food for cattle; steamed bread. 
steamboat (stem'bot), . A vessel propelled 
by steam-power. 
steamboat-bug (stem'bot-bug), . A water- 
beetle of large size, or otherwise conspicuous. 
[Local, U. S.] 
steamboat-coal (stem'bot-kol), n. Coal broken 
small enough to pass between bars set from 6 
to 8 inches apart, but too large to pass between 
bars less than 5 inches apart. This is the variation 
of size in different collieries in the Pennsylvania anthra- 
cite regions, where this size of coal is rarely prepared 
except to fill special orders, and where alone this term is 
in use. 
Steamboating (stem'b6"ting), H. 1. The busi- 
ness of operating steamboats. 2. Undue hur- 
rying and slighting of work. [Colloq.] 3. A 
method of cutting many boards for book-covers 
at one operation, instead of cutting them singly. 
Steamboat-rolls (stem'bot-rolz), . pi. The 
largest rolls used in breaking coal for the mar- 
ket. Also called crushers and cntsher-rolls. 
See steamboat-coal. [Pennsylvania anthracite 
regions.] 
steam-boiler (stem'boi'ler), . A receptacle 
or vessel in which water is heated and boiled 
to generate steam; particularly, a receptacle 
or vessel in which the water is confined, or iso- 
lated from the external air, in order to gen- 
erate steam under a pressure equal to or ex- 
ceeding that of the atmosphere, for the conver- 
sion of its expansive force into work in a steam- 
motor or -engine, or for heating purposes. 
The kinds of steam-boilers in use are very numerous and 
may he variously classified. In some the parts are rigidly 
loined together by rivets, bolts, stays, tubes expanded into 
lieads, etc. ; in others the parts are easily detachable one 
from the other, as in what are known as sectional boilers. 
Another division may be made, with reference to the treat- 
ment of the contained water, which in one class of steam- 
boilers is heated principally in a single mass of considera- 
ble cubic capacity, and in another is distributed in small 
spaces connected with each other and with the steam-space, 
as in what are known as sectional safety-boilers. A third 
ground of classification is the mode of applying heat. (See 
cylindrical steam-batter, return-flue boiler, horizontal tubu- 
lar boiler, fire-tube boiler, etc., below.) Boilers are made 
of wrought-iron or steel plates and tubes, or of cast-iron, 
or partly of wrought-iron or steel and of cast-iron. Steel 
of moderate tensile strength has lately been much used 
for boilers in which high pressures are maintained ; and 
the present tendency of engineering in power-boilers 
is toward the use of aa high pressures as is compatible 
with good lubrication, or the use of steam at as high a 
temperature as can be employed without decomposition 
of lubricants. Sectional boilers are often made partly or 
wholly of cast-iron, the sections being bolted or screwed to- 
gether ; and cast-iron is also very largely employed for low- 
pressure boilers used for steam-heating. Circulating 
Steam-boiler, a compound boiler in which the connected 
parts are unequally heated, the water rising in the more 
intensely heated parts, and descending in the cooler parts, 
to insure a rapid circulation of the water constantly in one 
direction. Compound steam-boiler, (a) A battery of 
two or more single steam-boilers having their steam- and 
water-spaces connected, and acting together to supply 
steam to a heating-apparatus or a steam-engine. (b) A sin- 
gle toiler, or a battery of boilers, combined with other 
apparatus, as a feed-water heater or a superheater, for 
facilitating the production or for the superheating of 
steam, (c) A sectional boiler. Cornish steam-boiler, 
the cylindrical flue-boiler invented by Smeaton. See re- 
turn-flue steam-boiler. Corrugated furnace steam- 
boiler, a boiler in which the plates exposed to the direct 
radiation from the fire and to the hot gases in the furnace 
are corrugated to give increased strength and to present 
a more extended heating-surface to the fire. Cylin- 
drical steam-boiler, a boiler with an exterior cylindri- 
cal shell, having flanged heads of much thicker iron fas- 
tened to the shell by rivets. Fire- tube steam-boiler, 
a boiler in which the heat of the furnace is partly or 
wholly applied to the interior of tubes which pass through 
the water-space of the boil er. Flue steam- boiler, a gen- 
eral name for all steam-boilers with an internal flueor flues, 
whether vertical, horizontal, or of other construction. 
Horizontal flue steam-boiler, a horizontal steam-boiler 
with one or more flues through its length. (Also called 
return- flue boiler.) If cylindrical also, it is a horizontal cy- 
lindrical flue or return- flue boiler. Horizontal steam- 
boiler, a steam-boiler in which the flues or tubes are in a 
horizontal position. Horizontal tubular steam-boil- 
er, a horizontal boiler with fire-tubes, through which the 
gases of combustion pass in a manner analogous to their 
passage through flues, for which the tubes are substitutes, 
presenting a greater extent of heating-surface than can be 
obtained in the same space by flues, and effectively tying the 
heads of the boiler together. A modern form of this boiler 
is shown in the cuts, which also show the method of setting 
it in brickwork, a is the shell ; b, b, saddles for supporting 
the boiler in the masonry c; d, the furnace-door ; e, ash-pit 
door ; /, clean-out door in the boiler-front/', by which the 
tubes are reached for cleaning; y, ash-pit; h, grate; i, 
steam-dome ; j, safety-valve ; *, steam-pipe ; (, bridge-wall ; 
m, combustion-chamber ; n, back connection for passage of 
Horizontal Cylindrical Tubular Steam-boiler. 
A, vertical longitudinal section; B, vertical cross-sec lion. 
the gases of combustion into the rear ends of the tubes ; o, 
Hue in the masonry ; o', uptake; p, flanged head ; ^, tubes; 
r, side-bars which support the masonry ; s, dead-air spaces 
in the masonwork in which the air acts as a heat-insulator. 
The course of the gases of combustion is indicated by 
arrows Locomotive steam-boiler, a tubular boiler 
which has a contained furnace and ash-pit, and in which 
the gases of combustion pass from the furnace directly into 
horizontal interior tubes (instead of passing first under the 
boiler, as in the horizontal cylindrical tubular boiler), and 
after passing through the tubes are conveyed directly into 
the smoke-box at the opposite end of the tubes. The name 
is derived from the use of such boilers on locomotive en- 
gines, but it is typical in its application to all boilers hav- 
ing the construction described, and used for generating 
steam for stationary or portable engines, as well as for 
locomotives. Marine steam-boiler, a boiler specially 
designed and adapted for supplying steam to marine en- 
gines. Compactness, as little weight as is consistent with 
strength, effective steaming capacity, and economy in 
consumption of fuel are the prime requisites of marine 
boilers. They are usually tubular, and short in proportion 
to their width, and have water-legs at the sides and water- 
spaces below and at the backs of their furnaces that is, 
their furnaces are entirely surrounded by water-spaces 
except at the openings for the doors. Marine boilers are 
now sometimes used with forced draft that is, air is 
forced from the outside into the boiler- or fire-rooms 
(which are sometimes made air-tight) or immediately into 
the fires by powerful blowers. Return-flue steam- 
boiler, a horizontal flue-boiler with one or more interior 
flues through which the gases of combustion are returned 
to the front end of the boiler after having passed to the rear 
from the furnace over the bridge-wall and under the bot- 
tom of the shell. Rotary tubular steam-boiler. See 
rotary. Sectional safety steam-boiler, a sectional 
boiler in which the water is divided into numerous small 
masses connected with one another by passages large 
enough for free circulation from one to the other, but not 
large enough to permit so sudden a release of pressure, In 
case of rupture of one of the sections, as to cause an explo- 
sion. Tubular Steam-boiler, a boiler a prominent fea- 
ture of which Is a series of either fire- or water-tubes. 
Vertical steam-boiler, a steam-boiler in which the heat- 
ing-surface of the tubes or flues is in a vertical position. 
When constructed with flre-tubes, it is called a vertical tu- 
bular boiler. 
steam-box (stem'boks), n. A reservoir for 
steam above a boiler ; a steam-chest. 
steam-brake (stem'brak), n. A brake applied 
by the action of steam admitted to a steam- 
cylinder the piston of which is connected by 
rods to the levers which apply the brake-shoes. 
steam-car (stem'kar), n. A car drawn or driven 
by steam-power ; a railway-car. [U. S.] 
steam-carriage (stem'kar'aj), n. A road-car- 
riage driven by steam-power. 
steam-case (stem'kas), n. Same as steam-chest. 
steam-chamber (stem'cham ;l 'ber), w. 1. A box 
or chamber in which articles are placed to be 
steamed. 2. A steam-chest. 3. A steam- 
dome. 4. The steam-room or steam-space in 
a boiler or engine. 
steam-chest (stem'chest), n. 1. The chamber 
in which the slide-valve of a steam-engine 
works. See cuts under passengtr-engine, rock- 
drill, and slide-valre. 2. In calico-printing, a 
metallic vessel or tank in which printed cloths 
are steamed to fix their colors. 
steam-chimney (stem'chim'ni), . An annu- 
lar chamber around the chimney of a boiler- 
furnace for superheating steam. 
steam-cock (stem'kok), n. A faucet or valve 
in a steam-pipe. 
Steam-coil (stem'koil), n. A coil of pipe, either 
made up flat with return bends or in spiral 
form, used to impart heat to a room or other in- 
closed space or to a liquid, or, by exposure of 
its exterior surface to air-curre'nts or contact 
of cold water, to act as a condenser. 
steam-colpr (stem'kul'or), n. In dyeing, a col- 
or which is developed and fixed by the action 
of steam after the cloth is printed. 
steam-crane (stem'kran), n. A crane worked 
by steam, frequently carrying the steam-engine 
upon the same frame. 
steam-cutter (stem'kufer), n. A ship's boat, 
smaller than a launch, propelled by steam. 
steam-cylinder (stem'sil*in-der), n. The cyl- 
inder in which the piston of a steam-engine 
reciprocates. Starting steam-cylinder. Same as 
starting-engine. 
steam-engine 
steam-dome (stem'dom), M. A chamber con- 
nected with the steam-space and projecting 
above the top of a steam-boiler. From it -the 
steam passes to the cylinder of a steam-engine, or to steam- 
heuting apparatus. See cut under steam-boiler. 
Steam-dredger (stem'drej"er), H. A drcdging- 
machiue operated by steam. 
Steam-engine (stem'en"jin), H. An engine in 
which the mechanical force arising from the 
elasticity and expansive action of steam, or 
from its property of rapid condensation, or 
from the combination of the two, is made 
available as a motive power. The invention of 
the steam-engine has been ascribed by the English to the 
Marquis of Worcester, who published an account of it 
about the middle of the seventeenth century. By the 
French the invention has been ascribed to Papin, toward the 
close of the same century. Papin's plan contained the earli- 
est suggestion of a vacuum under a piston by the agency of 
steam. The first actual working steam-engine of which 
there is any record was invented and constructed by 
Captain Savery, an Englishman, to whom a patent was 
granted for it in 1698. This engine was employed to 
raise water by the expansion and condensation of steam. 
The steam-engine received great improvements from the 
hands of Newcomen, Heighten, and others. Still it was 
imperfect and rude in its construction, and was chiefly 
applied to the draining of mines or the raising of wa- 
ter. Up to this time it was properly an atmospheric 
engine (see atmospheric), for the actual moving power 
was the pressure of the atmosphere, the steam only pro- 
ducing a vacuum under the piston. The steam-engine 
was brought to a high state of perfection by James Watt 
about the year 1782. The numerous and vital improve- 
ments introduced by him, both in the combination of its 
mechanism and in the economy of its management, have 
rendered the steam-engine at once the most powerful, 
the most easily applied and regulated, and generally 
speaking the least expensive of all prime movers for fm- 
A3 4 6 11 12 
Steam-engine (Corliss Engine). 
(The upper figure is a front view, the under a rear view.) 
The steam-valve A and exhaust-valve A' are independent of each 
other, and have cylindrical bearing-surfaces. An oscillatory motion is 
given to them by rods B, connecting with an oscillating disk C (wrist- 
plate) upon the side of the steam-cylinder, which is worked by an in- 
termediate rock-lever D, driven by the eccentric-rod E, connected 
with an eccentric upon the main shaft The motions of the exhaust- 
valves are positive, but those of the inlet-valve are varied by means of 
spring-catches a, which are adjustable to determine the points of open- 
ing and the range of motion of the valves, and are also controlled in 
their disengagement of the valve-stems by the governor F, rock-lever G, 
connecting-rods H. and rock-levers r, all connected together in such 
manner that an extremely small increase or decrease of speed in the 
rotation of the fly-wheel shaft causes the inlet-valves to be released 
and to close correspondingly earlier or later in the stroke. The 
closing is performed by exterior weights suspended from short levers 
on the valve-stems by the rods >fr, the motion of closing being control led 
bydash-pots at rf, only the covers of which are shown. The other 
parts of the engine, which are common to most reciprocating engines, 
are r, the bed-plate ; a, cylinder ; 3, piston ; 4, piston-rod ; 5, stuffing- 
box ; 6, sliding-block or cross-head ; 7, connecting-rod or pitman ; 8, 
rod-end fittedto o, the crank -wrist : 10, fly-wheel : ri, crank keyed to 
12, the crank-shaft ; 13, centrifugal lubricating tube ; 14, steam-pipe ; 
15, lubricator ; 16. exhaust-pipe. 
pelling machinery of every description. The steam-en- 
gine is properly a heat-engine, and the-total work L is ex- 
pressed theoretically by the equation 
L = QG(T, T)/AT,, 
in which Q represents the total heat converted into work 
per unit of weight, O weight of steam, and A the thermal 
equivalent of a unit of work, while T, and Tare respective- 
ly the higher and lower limits of temperature between 
which the steam is worked, T , being the absolute temper- 
ature at which the steam is inducted to the engine, and 
T the absolute temperature at which it is exhausted from 
it. Inspection of the equation shows that the work per- 
formed mast vary directly as the factor (T, T) varies 
that is, the greater the difference which can be main- 
tained between the temperature of induction and that of 
eduction the greater is the amount of work performed by 
any given weight of steam. It is in accordance with this 
law that much higher steam -pressures are now adopted 
than were formerly employed. The factor (T, T) is com- 
monly called the temperature range or .fall. The varieties 
of steam-engines are extremely numerous. (For names 
of various types, with explanations of their characteristic 
features, see below.) The specific differences between 
steam-engines of the same type of construction consist 
chiefly in their valve-gear. (See valve-year, governor, 6, 
regulator, n., slide valve (with cut), and piston-valve.) Of 
the total steam-power employed in modern industry on 
land, that supplied by steam-engines of the horizontal 
type far exceeds that furnished by steam-engines of all 
