IMPROVEMENTS IN STEAM ENGINES
Year: 1852

page_text: LETTERS PATENT to David Napier, of Millwall, Engineer, for the
Invention of "IMPROVEMENTS IN STEAM ENGINES."
Sealed the 2nd February 1853, and dated the 18th December 1852.
PROVISIONAL SPECIFICATION left by the said David Napier at
the Office of the Commissioners of Patents, with his Petition,
on the 13th December 1852.
I, DAVID NAPIER, of Millwall, Engineer, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN STEAM ENGINES"
to be as follows: —
The steam, after it has expended its expansive force on a steam
engine, is to pass through a series of thin flat tubes, or any other
convenient shape, made of very thin metal; which tubes or metal
surfaces shall be enclosed in a case, for the purpose of having a
current of air blown over them by fans or any other means, and
from thence under and through the fire in the furnace.

page_text: SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said David Napier in the Great Seal Patent
Office on the 8th June, 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
DAVID NAPIER, of Millwall, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Thirteenth day of December, in
the year of our Lord One thousand eight hundred and fifty-two, in
the sixteenth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said David Napier, Her special
licence that I, the said David Napier, my executors, administrators,
and assigns, or such others as I, the said David Napier, ny execu-
tors, administrators, and assigns, should at any time agree with, and
no others, from time to time, and at all times thereafter during
the term thercin expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN STEAM ENGINES," upon the condition (amongst
others) that I, the said David Napier, by an instrument in writing
under my hand and seal, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said David Napier, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof (that is to say) :-
My improvements in steam engines consist in the steam, after it
has been used in giving motion to a piston in the usual way, passing
through a number of very thin flat tubes, or any other shape; which
tubes are contained in a case, to one end of which case is connected
the bottom of the boiler or furnace; at the other end a fan is attached,
or any other means adapted for sending a current of air over the

page_text: outside surface of these tubes, and (after thereby robbing the steam
of its heat) under and through the fire in the furnace, thereby
saving fuel, the fires being supplied with heated air, and enable
a railway engine to travel the longer journies without a new supply
of water, the water formed by the condensation of the steam being
returned back to the boiler.
What I claim is, causing the steam, after it has been used in
giving motion to a piston, passing through a number of thin tubes,
and a current of air inade to pass over these tubes to rob the steam
of its heat, and that heated air passed through the fire in the
furnace, or vice versa, the steam outside of the tubes, and the air
inside.
In witness whereof, I, the said David Napier, have hereunto set
my hand and seal, this Twenty-seventh day of May, in the
year of our Lord One thousand eight hundred and fifty-
three.
Witness,
CHARLES EDWARD BIRD.
DAVID NAPIER. (L.S.)