CERTAIN IMPROVEMENTS ON STEAM ENGINES
Year: 1828

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
EVANS the younger, of Moreton Mills, near Wallingford, in the County of
Berks, Paper Maker, send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth
did, by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Fifteenth day of January, One thousand eight hundred
and twenty-eight, in the eighth year of His reign, give and grant unto me,
the said John Evans the younger, His especial licence that I, the said John
Evans the younger, my exors, adñors, and assigns, and such others as I, the
said John Evans the younger, my exors, adññiors, and assigns, should at any
time agree with, and no others, from time to time and at all times during the
term of years therein mentioned, should and lawfully might make, use, exercise,
and vend, within England, Wales, and Town of Berwick-upon-Tweed, my
Invention of "CERTAIN IMPROVEMENTS ON STEAM ENGINES;" in which said
Letters Patent there is contained a proviso that I, the said John Evans the
younger, shall cause a particular description of the nature of my said Invention,
and in what manner the same is to be performed, to be inrolled in His
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as in and
by the same, reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Evans the younger, do hereby describe the manner in which my said
Invention is to be performed, by the following description thereof, reference
being had to the Drawing hereunto annexed, and to the figures and letters
marked thereon (that is to say):-

page_text: cylinder. The steam acts through the opening o against the piston v and
apperture u. The brass stop s, resisting the pressure of steam, gives motion
to the inner cylinder fand shaft E, until it passes half its circumference, or
make half a revolution. The excentric on the shaft E shuts the valve n on
that end and opens it on the other; the steam then acts on the other piston
and aperture as on the former, and gives a regular rotatory motion applicable to
any machinery. After the piston v has passed the pipe Z the steain may be
allowed to escape or pass into condenser. The idea of some engineers is,
that the friction occasioned by any engines made on a rotatory principle will
overcome its power. So far my experiments has proved, that the friction on the
revolving parts is not so great as on the common piston, the power being at all
points equal; whereas engines working with a crank exert the greatest power
at two points, only the fly wheel having to regulate the motion. This engine
has also another advantage; it may be erected at much less expence, and may
be used with any boiler; is easily fixed in any situation, as the whole engine,
with the exception of the boiler, may be made on a frame; so that a small
engine on this principle may be moved to any part in a whole state.
In witness whereof, I, the said John Evans the younger, have hereunto
set my hand and seal, this Twelfth day of July, in the year of our
Lord One thousand eight hundred and twenty-eight.
Signed, sealed, and delivered, by the within-
named John Evans the younger, in the
JOHN (L.S.) EVANS, JUN".
AND BE IT REMEMBERED, that on the Twelfth day of July, in the
year of our Lord 1828, the aforesaid John Evans the younger came before
our said Lord the King in His Chancery, and acknowledged the Specifica-
tion aforesaid, and all and every thing therein contained and specified, in
form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Inrolled the Fifteenth day of July, in the year of our Lord One
thousand eight hundred and twenty-eight.