Philada. 18 April 1788
Having spent much Time and thought, as well as having tried many
Experiments on Steam Engines I take the Liberty of laying before
you some of my Ideas on the best Mode of creating Steam, and am
Gentlemen Your humble Servant
| A | A hollow Globe with a worm surrounding it—one End whereof |
passes in at the Bottom of the Globe—the other End of the Worm
is connected with a forcing Pump to supply it with Water—on
the Top of the Globe is a Pipe to convey the Steam to the
Cylinder (or place of Application) having also a regulating
valve—The whole Globe and Worm to be placed in a Stove formed
circular so as to leave a sufficient Room all round it for
Coal and a Grate at Bottom for the air—The Globe is intended
as a Receiver for the Steam that it may be rarified to a
greater Degree—This Mode of creating Steam was conceived by me
last Summer was a twelve month &a Drawing shewn to several
Persons.
| B | Is a Section of a Boiler of a different Construction improved |
on the former plan. It consists of an inside circular Box as
represented at C (steam tight) made of strong sheet Iron
having at its bottom,
on the outside, two Tier of spiral Pipe
as shewn at D & E, and again in their places at F in the
Section of the whole Boiler B. The inside of the Steam Box as
represented in this Section B has 3 Shelves, or circular
Sheets of Iron perforated as at I through all which (as well
thro’ the Bottom of the Steam Box) one End of the uppermost
Tier of the spiral pipe passes and admits the Steam to spread
in the vacancy K when if any Water should be forced up through
this Pipe, it will, on falling thro’ the several Cullender
Shelves to the Bottom of the Steam Box, become perfectly
rarified and created into Steam. L is a Passage for the Steam
to the Receiver M which is a Copper Globe, on the Top of which
is a Tube communicating with the Cylinder (or place of
application) at the Bottom of this Globe is a bent Pipe with a
Safety valve thro’ which the Water may escape if any should
fall into the Globe. N is a forcing Pump to inject a Supply of
warm Water from the Condensers, which are also spiral Pipes,
and immerged in cold Water and have been very successfully
used in Mr. Fitch’s Steam Boat. O is the outside Case—Fire
Place and Chimney Pipe—of Bricks or Sheet Iron. P is thd Ash
hole. Q is the Iron Legs (if the Case is made of Iron)
| Fig 3 Is a Boiler of another Form. 4 is an inverted vessel like a |
Tumbler bottom up—over which is another inverted vessel, so
much wider as to leave about 1½ Inch Vacancy all round,
but this vessel is much deeper than the inside vessel—the two
bottom Edges of these vessels are flanched together, so that
Water may be contained between them and cover the Top of the
inner vessel entirely as shewn by the dotted Lines—they are
placed over a Fire Place 5 having Fire Place 5 having a Flew
all round and terminating at 6 for the Passage of the Fire and
Smoke—the Inside of the innermost vessel will be heated by the
Fire like an oven which will reverberate and pass under the
flanched Edges and rise up the Fleu 7. on the outside of the
second vessel the whole being enclosed at a proper Distance
all round with brick Work or Sheet Iron as may best suit the
purpose and place of fixing the Boiler, so that a thin
circular sheet of Water will be between the outside and inside
Fire—as seen by the dotted Line. A Forcing Pump is to be
applied to supply Water as in the other Boiler which may
either pass through a Worm as described in the inside of the
inner vessel, or may be a single Pipe conducting to the
Top
between the two vessels which Top if made large enough will
serve for a Receiver without a separate Receiver as in Figure
B at M — and is the Pipe communicating with the Cylinder and
the safety valve.