A ROTATORY ENGINE FOR APPLYING THE POWERS OF FLUIDS AS FIRST MOVERS, AND FOR VARIOUS OTHER PURPOSES
Year: 1805

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN TROTTER,
of Soho Square, in the County of Middlesex, Esquire, send greeting.
WHEREAS His most Excellent Majesty George the Third, by the Grace of
God of the United Kingdom of Great Britain and Ireland King, Defender
of the Faith, by His Letters Patent under the Great Seal of the said United
Kingdom, bearing date at Westminster, on or about the Fourteenth day of this
present November, in the forty-sixth year of His said Majesty's reign, did give
and grant unto me, the said John Trotter, His especial licence, full power, sole
privilege and authority, that I, the said John Trotter, my executors, adminis-
trators, and assigns, and every of us, by myself and themselves, or by my and
their deputy or deputies, servants or agents, or such others as I, the said John
Trotter, my executors, administrators, or assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the term
of years therein expressed, should and lawfully might make, use, exercise, and
vend my Invention of "A ROTATORY ENGINE FOR APPLYING THE POWERS OF FLUIDS
AS FIRST MOVERS, AND FOR VARIOUS OTHER PURPOSES" within that part of the
said United Kingdom of Great Britain and Ireland called England, the Do-
minion of Wales, and Town of Berwick-upon-Tweed, and also in all His Majesty's
Colonies and Plantations abroad, in such manner as to me, the said John
Trotter, my executors, administrators, and assigns, or any of us, should in my
or their discretions seem mect. And whereas among other matters and things
in the said Letters Patent there is contained a proviso whereby it is declared
that if I, the said John Trotter, should not particularly describe and ascertan

page_text: the nature of my said Invention, and in what manner the same is to be per-
formed, by an instrument in writing under my hand and seal, and cause the same
to be inrolled in the High Court of Chancery within six calendar months next
and immediately after the date of the said Letters Patent, that then the said
Letters Patent, and all liberties and advantages thereby granted, should utterly
cease, determine, and become void.
NOW KNOW YE, that in compliance with the said proviso I, the said John
Trotter, do hereby declare that my said Invention, and the manner in which
the same is to be carried into effect and practice, are described in manner
following, that is to say :-
My rotary engine consists of the following parts put together in a workman-
like manner, or one or more of the same may constitute one piece in the
casting, fashioning, or making, where_circumstances or convenience may admit
of such fabrication. (1), A, a circular piece called the outer barrel; (2), B, a
circular piece called the inner barrel; (3), C, a circular piece called the
eccentric; (4), D, a piece called the sweep, which shuts completely across the
space between the inner and outer barrels, so as to intercept the communication
in that part; (5), caps or covers at each end of the said pieces which close the
space between the two barrels, and serve by grooves or other well known
fittings to keep the other parts in their respective places. The situations and
motions of the parts hercin enumerated are as follow:-(1), the barrels are
concentric; (2), the sweep is capable of moving or revolving (either by
an absolute or relative motion) thro' the space between the barrels ;, it
may be either separate from the barrels or it may be fixed to either or
both of them; and in the last-mentioned cases the barrel or barrels to
which the sweep shall or may be so fixed will necessarily move along with
it. The sweep is so well fitted or fixed that no fluid shall pass through the
places of its apposition or junction with the barrels and caps, or as that the
quantity suffered to pass shall be inconsiderable. (3), the eccentric is of such
a diameter, and so wrought, that its concave and convex surfaces shall touch
the inner and outer barrels, and that the places of contact shall not admit any
fluid to pass between the eccentric and each barrel severally, or at least that
the quantity which may so pass shall be inconsiderable. The eccentric is
capable of rotation in its own plane or periphery, but not otherwise, with relation
to the caps, and it has a long perforation thro' which the sweep is put, conse
quently the sweep and the eccentric will always move together.
The operation or effect explained, it may be pointed as distinguishing cha-
racters of my, said engine that whenever the sweep is moved the space which
is comprehended between the barrels and, the eccentric and the posterior or

page_text: hinder surface of the sweep will be continually enlarged, and that the space
which is in like manner comprehended between the barrels and the eccentric
and the anterior or fore surface of the sweep will be continually diminished,
excepting that soon after the sweep has passed at or near the place of contact
between the eccentric and the outer.. barrel, the posterior space will be sud-
denly diminished by the seperation of all that portion thereof which was
comprehended between the eccentric and the outer barrel, in consequence or by
reason of the said place of contact having come to be behind the sweep, and
also that soon after the sweep has passed at or near the place of contact
between the eccentric and the inner barrel; the posterior space will be suddenly
diminished by the seperation of all that portion thereof which was compre-
hended between the eccentric and the inner barrel, in consequence or by reason
of the said place of contact having come to be behind the sweep, and the said por-
tions so seperated will in each case respectively become portions of the anterior
space in consequence or by reason of the interval or distance which will at
the same time be formed or made: between the eccentric and the barrel
immediately before the sweep; whence it is manifest that if any fluid be
forced, by gravity, elasticity, or otherwise, through one or more apertures
from without into the space on one side of the sweep, that pressure will
carry the sweep forward, and the eccentric along with it, together with such
barrel or barrels.as, by the construction as aforesaid shall or may be fixed
to the sweep; and, moreover, if there' be one or more other apertures com-
municating from the opposite side of the sweep in order to allow the said
fluid. to escape; or be carried off, or condensed, or otherwise disposed of, all
such portions of the said fluid as: by the changes of situation of the sweep
herein-before: described shall be separated from occupying part of the space
behind the sweep, and shall.come to occupy' part of the space before the
same, will in fact so escape, or be carried off, or condensed, or disposed of,
and the rotatory motion of the engine will be kept up, and may be applied as a
first mover to..other works so long as a due supply of the said fluid shall
be afforded. And it is further manifest that in case the rotatory motion of the
said engine be produced by any force not applied to its internal parts in the
manner herein-fore described, and any fluid be admitted to communicate with
the posterior space within the same, the said fluid so admitted will flow into or
be absorbed in the said space, which becomes continually enlarged, and will
afterwards be:transferred to and "driven out of the anterior space, which
becomes continually diminished as aforesaid, and that in this application the said
engine,may be used.to raise or give motion to fluids in any direction whatever.
And I do hereby declare that my said engine is to be constructed or

page_text: made with such apertures by me called passages for the introduction and
admission, and for the subsequent escape;-carrying off, condensing, disposing.
of, or driving out such fluid or fluids as shall or may be introduced
therein; and that I do so introduce, for the purposes and uses aforesaid,
various fluids, severally, such as water or other dense fluids, air or steam,
or vapors or other rare and elastic fluids, all or any of which may be produced:
or extricated by heat or otherwise..
And farther, that the said passages, may be opened or made in various
parts of the said engine, as will be sufficiently obvious to any person skilled
in the construction of works of the like nature; but that I prefer making
the said passages in one or both of the barrels as near the sweep as con-
veniently may be, so that one or more passages shall be on one side of the
sweep, and the other passage or passages on the other side thereof; and
in these cases, it will be-requisite that the sweep--should be fixed to-the
one-or-both barrels-in-which-such-passages may be or shall be so made.
And I do further declare, that my said engine is intended to be con-
nected with other works, in order to drive the same as a first mover by
the well known means of connecting first movers, so as to carry on the
various processes and operations of mills, manufactories, the propelling of
vessels, and performing various kinds of mechanical work on board the
same, the deepening of harbours, giving motion to carriages, and of pro-
ducing.other effects, which, on account of their extent, magnitude, number,
and evident practicability, do not require to be enumerated.
"
And further, that in the case wherein my said engine is employed to:
raise or give motion to any fluid introduced thercin, the effects produced
will be of the same description as those of sucking, lifting, or forcing pumps,
fire-engines, forge-and-furnace bellows, ventilators, winnowing fans, and such
other engines as operate by giving motion to fluids... And with regard to the
said circular barrels and eccentric, that I give the preference to the cylindrical
form, but that the cylindrical form is not absolutely necessary, inasmuch as the
said parts may have the form of frustrums of cones, or other figures described -
by rotation, and the said figures, with the dimensions thereof, aró-sufficiently'
indicated by the descriptions and effects herein-before given and pointed out.
And, lastly, with regard to materials and fitting,- that the materials must-be-
taken according to the intended uses, and the judgment of the engineer, who
may use metal, wood, paper, leather, glass, pottery, or any other fit substance.
The fittings must in general be good, and the work true; and it scarcely
need be remarked that steam require closer fitting (or packing, if needful,)
than water, and water requires closer fitting than air for blowing, or fanning,.

page_text: where the pressures are not considerable, and the motion rapid; and that,
when convenience in other respects may make it desirable, a degree of windage
may be allowed between the moving parts respectively.
In witness whereof, I, the said John Trotter, have hereunto set my
hand and seal, this Second day of December, in the year of our Lord
One thousand eight hundred and five, and in the forty-sixth year of the
sion of His said Majesty King Georro the Third