A RECIPROCATING FIRE OR STEAM ENGINE OR MACHINE UPON AN ENTIRE NEW PRINCIPLE FOR THE USE OF MILLS, PUMPS, CRANES, CARRIAGES, AND OTHER PURPOSES WHERE THE FORCE OF FIRE OR STEAM IS REQUIRED
Year: 1791

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
MEAD, of the Parish of Sculcoates, otherwise Scow Scotts, in the County of
York, Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Third, did, by
His Letters Patent under the Great Seal of Great Britain, bearing date the
Twelfth day of August, in the thirty-first year of His reign, give and grant
unto me, the said Thomas Mead, His special licence that I, the said Thomas
Mead, during the term of fourteen years therein expressed, should and law-
fully might use, exercise, and vend, within England, Wales, and the Town of
Berwick upon Tweed, my Invention of "A RECIPROCATING FIRE OR STEAM
ENGINE OR MACHINE UPON AN ENTIRE NEW PRINCIPLE FOR THE USE OF MILLS,
PUMPS, CRANES, CARRIAGES, AND OTHER PURPOSES WHERE THE FORCE OF FIRE OR
STEAM IS REQUIRED;" in which said Letters Patent there is contained a proviso,
obliging me, the said Thomas Mead, under my hand and seal, to cause a par-
ticular description of the nature of my said Invention, and how the same is to
be performed, to be inrolled in His Majesty's High Court of Chancery within
one calendar month after the date of the said recited Letters Patent, as in and
by the same, relation being thereunto had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Mead, do hereby declare that my said Invention is described in
manner herein-after mentioned (that is to say):-

page_text: upper
In the fire-place under some part of the boiler, which may be of the
common construction or any other, at pleasure, is placed a cylindrical vessel or
vessells of metal, the lower ends of which are closed their
ends are
up;
made fast to the boiler and open into the same. In each of these vessells is
deposited another cylindric vessell, the bottoms of which are also closed and
their upper ends open in the boiler. The external surfaces of these vessells are
straight and smooth; near the upper end of each of the exterior vessells is
adapted a packing or wadding, which is made to embrace the interior vessells
close all around, so as to prevent anything from passing into or out of the
exterior vessells at that part; each of the exterior vessells have a communica-
tion with the upper part of the boiler by means of pipes, which may be inter-
cepted at pleasure; each of these vessels have also a communication with a
condensing vessel by means of other pipes passing through the boiler, which
communications may likewise be intercepted, as occasion requires. The opera-
tion is nearly as follows: When the engine is to be put in motion the boiler
is partly filled with water or some other fluid that will yield an elastic fluid or
vapour from heat; the pipes leading from the exterior vessels to the con-
densing vessel and the packing or wadding of the cylindric vessels being
covered with the fluid, and the interior vessels being "filled with part of the
same, a fire is made under the boiler; when the pipes, exterior vessels, and
boiler are sufficiently heated, and a proper quantity of the elastic fluid is
obtained, the communication between the boiler and the exterior vessells are
opened, the interior vessels being drawn up through the packing or wadding,
and the elastic fluid being permitted to pass into the exterior vessels, is there and
in its passage heated and rarified; the communications between the boiler and
the exterior vessels are then shut, and the communications between the con-
densing vessel and the exterior vessels are opened; the elastic fluid is then con-
veyed by means of the other pipes through the denser fluid in the boiler into
the condensing vessel. In its passage through the fluid in the boiler it com-
municates part of its heat to it, causing more elastic fluid to arise in the boiler;
when it arrives in the condensing vessel it comes in contact with a colder fluid
which condenses it, and causes a vacuum in the exterior vessels; the fluid in
the boiler pressing on the interior vessels forces them to descend and to pull
down the beam sector or other apparatus with which they are connected, by
which means the engine is put in motion, the fluid in the condensing vessel is
extracted, and the motion continues as in other engines in general.
f..
What particularly relates to the Invention is, the heating and rarefying the
elastic fluid after it has left the boiler, and afterwards causing it to pass

page_text: through the denser fluid in the same, by which means the engine is kept in
motion with a less consumption of fuel than by other methods now in use, and
at a considerable less expence.
In witness whereof, I, the said Thomas Mead, have hereunto set my
hand and seal, this Third day of September, in the year of our Lord
One thousand seven hundred and ninety-one.
Inrolled the Fifth day of September, in the year of our Lord One thousand
seven hundred and ninety-one.