Astonishing Power Of Steam

If you put a small quantity of water into a tea-kettle, and place it

on the fire, it will disappear in a short time, having escaped in the

steam. But if its escape be prevented by stopping up the spout and

crevices, it will force its way by bursting the vessel in which it was

confined.



If the steam of boiling water be at liberty, the water never attains

more than a certain degree of heat; but if confined n a close vessel,

the additional fire not escaping, the power of the steam is increased,

it re-acts upon the water, and raises the heat so much higher, that it

would keep lead in a melting state; and so penetrating, that it would

soften the marrow-bone of an ox, in a few minutes.



There is an instrument contrived for the foregoing purposes, called

Papin's Digester, from the name of its inventor, and from its

digestive powers on substances exposed to its action. It is a very

strong vessel, made of copper, fitted with a thick close cover, and

fastened down by several strong screws, so as to render it steam-tight

in great degrees of heat. To render it safe, while being used, there

is a valve on the cover, to let out the steam, when it is too violent;

this valve is kept down by a steel-yard, with a weight moveable upon

it, to regulate the degrees of the steam within.



The following account of an accident with one of these instruments,

will give some idea of the great force of steam.



Mr. Papin (the inventor) having fixed all things right, and included

about a pint of water, with two ounces of marrow-bone, he placed the

vessel horizontally between the bars of the grate, about half-way into

the fire. In three minutes he found it raised to a great heat, and

perceiving the heat in a very short time become more raging, stepped

to a side-table for an iron to take the digester out of the fire,

when it suddenly burst with the explosion of a musket. It was heard at

a considerable distance, and actually shook the house. The bottom of

the vessel that was in the fire gave way; the blast of the expanded

water blew all the coals out of the fire into the room, the remainder

of the vessel flew across the room, and, hitting the leaf of an oak

table, an inch thick, broke it all in pieces, and rebounded half the

length of the room back again. He could not perceive the least sign of

water, though he looked carefully for it; the fire was quite

extinguished, and every coal black in an instant.



The following accident was attended with more fatal consequences.



A steam-engine was repairing at Chelsea, and, as the workmen were

endeavouring to discover the defect, the boiler suddenly exploded, and

a cloud of steam rushing out at the fracture, struck one of the men

who was near it, like a blast of lightning, and killed him in a

moment; when his companions endeavoured to take off his clothes, the

flesh came off with them from the bones.