STE 
stantly supplied with cold water from a 
pump, T, worked by a rod from the great 
beam, B ; the water from the cistern runs 
off by a waste pipe at the back of the cis- 
tern, not seen in the figures. V is a short 
pipe upon tlie boiler, with a lid and stuffing 
box, a rod passes through it, and has a valve 
within it, pressed down by a lever and 
weight, V. If at any time, when the engine 
is not at work, the steam should be heated, 
so as to be in any danger of bursting the 
boiler, the valve will lift up the weight, 
and allow the steam to escape through the 
pipe, W, into the open air. Y, a lid screwed 
down upon a hole in the boiler, through 
which a man enters tlie boiler to clean it 
occasionally. At Z are two cocks upon the 
ends of pipes going down into the boiler j 
one pipe is longer than the other, the long- 
est reaches into the water, and the short 
one does not ; these cocks are to show the 
height of the water in the boiler, when one 
is turned (if the water is the proper height) ; 
it will deliver steam, and the other water. 
It maybe observed, that when the engine 
is once set to work, the lever, n u, on the 
spindle of the rack is of no use, as the in- 
stant the cock is turned one-fourth round, 
the piston and engine begins to return. 
STEATITE, in mineralogy, a species of 
the Talc genus, is of a white colour ; but it 
presents several varieties through the greys, 
greens, and reds. It occurs massive, disse- 
minated, in crusts, and crystallized. The 
crystals are six-sided prisms, acuminated 
on both extremities by six planes. Specific 
gravity 2.6. The constituent parts are, ac-> 
cording to Klaproth, 
Silica 48.0 
Magnesia.... 20.5 
Oxide of iron 1.0 
Water 15.5 
Alumina 14.0 
99.0 
Loss 1. 
100 
Before the blow-pipe it loses its colour, and 
becomes hard ; but is infusible without ad- 
dition. It occurs in beds and veins in ser- 
pentine, also in irregular shaped pieces, im- 
bedded in rocks belonging to the floetz 
formation. It is found in Norway, Sweden, 
several parts of Germany, and in the united 
kingdom of Great Britain ; also in China. 
It is used in tlie manufacture of porcelain : 
other varieties are used in fulling, and the 
Chinese work it into vessels ef various 
shapes. 
STE 
STEEPLE, an appendage erected gene* 
rally on the western end of a church, to 
hold the bells. Steeples are denominated 
from their form, either spires or towers; 
the first are such as ascend continually di- 
minishing either conically or pyramidally. 
The latter are mere parallelopipeds, and 
are covered a-top platform-like. In each 
kind there is usually a sort of windows, or 
apertures, to let out the sound, and so con- 
trived at the same time as to drive it down. 
STEERAGE, on board a ship, that part 
of the ship next below the quarter-deck, 
before the bulk-head of the great cabin, 
where the steersman stands in most ships of 
war. See the next article. 
STEERING, in navigation, the directing 
a vessel from one place to another by means 
of the helm and rudder. He is held the best 
steersman who causes the least motion in 
putting the helm over to and again, and who 
best keeps the ship from making yaws, that is, 
from running in and out. The perfection of 
steering, indeed, consists in a vigilant atten- 
tion to the motion of a ship’s head, so as to 
check every deviation from the line of her 
course in the first instant of motion, and in 
applying as little of the power of the helm 
as possible. By this she will run more uni- 
formly in a straight path : whereas, if a 
greater eflfort of the helm is employed it will 
produce a greater declination from the 
course, increase the difficulty of steering, 
and make a crooked and irregular track 
through the water. There are three me- 
thods of steering! 1. By any mark on the 
land, so as to keep the ship even by it, 
2. By the compass, which is by keeping the 
ship’s head on such a rhumb or point of the 
compass, as best leads to port. 3. To steer 
as one is bidden, or conned, which, in a 
great ship, is the duty of him who is taking 
his turn at the helm. It is the duty of the 
steersman to watch the head of the ship, by 
the land, by clouds, and by the heavenly 
bodies; because, though the course is in 
general regulated by the compass, the vibra- 
tions of tlie needle are not so instantly per- 
ceived as the sallies of the ship’s head to 
the right or the left. 
STELL.A.RIA, in botany, stitchwort, a 
genus of the Decandria Trigjmia class and 
order. Natural order of Caryophyllei. 
Caryophylleae, Jussieu. Essential charac- 
ter: calyx five-leaved, spreading; petals 
five, two-parted ; capsule superior, one- 
celled, many-seeded, six-toothed at top. 
There are seventeen species. 
STELLATjE, in botany, the, name of th* 
