AN IMPROVED PROPELLER FOR STEAM AND OTHER VESSELS
Year: 1836

page_text: SMITH'S SPECIFICATION AND MEMORAMDUM OF
ALTERATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
PETTIT SMITH, of Hendon, in the County of Middlesex, Farmer, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Thirty-first day of May, in the sixth year of His
reign, did, for Himself, His heirs and successors, give and grant unto
me, the said Francis Pettit Smith, His especial licence that I, the said
Francis Pettit Smith, my exors, admors, and assigns, or such others as I,
the said Francis Pettit Smith, my exors, admors, or assigns, should at
any time agree with, and no others, from time to time and at all times
during the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, and also in all His said Majesty's Colonies and Plantations abroad,
my Invention of "AN IMPROVED PROPELLER FOR STEAM AND OTHER VESSELS;" in
which said Letters Patent is contained a proviso obliging me, the said Francis
Pettit Smith, by an instrument in writing under my hand and seal, particularly
to describe and ascertain the nature of my said Invention, and in what
manner the same is to be performed, and to cause the same to be enrolled
in His said Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said recited Letters Patent, as in
and by the same, reference being thereunto had, will more fully and at large
annear

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Francis Pettit Smith, do hereby declare the nature of my said Invention to
consist in a sort of screw or worm made to revolve rapidly under water in a
recess or open space formed in that part of the after part of the vessel com-
monly called the dead rising or dead wood of the run. And in further com-
pliance with the said proviso, I, the said Francis Pettit Smith, do hereby
describe the manner in which my said Invention is to be performed by the
following statement thereof, reference being had to the Drawing annexed,
and to the figures and letters marked thereon (that is to say):-
DESCRIPTION OF THE DRAWING.
Figure 1 is a side view of a boat or vessel to which my said Invention is
applied. A, A, is the recess or opening in the dead wood of the run to receive
the screw or worm; B is a broad-threaded revolving wooden screw or worm,
the axis of which are supported on pluminer blocks C, D, one at each end;
and the block D also supports the upright revolving shaft E, which com-
municates with the steam engine or other moving power, and gives motion to
the screw or worm, which screw or worm, placed and arranged as here shewn,
is in fact the improved propeller, but its movements will be better understood
from the description of the remaining Figures.
Figure 2 is an end view of the boat or vessel with its propeller, as seen from
astern. Figure 3 is a separate view of the propeller and the machinery which
gives motion to it. K is supposed to be the main driving shaft of an ordi-
nary marine steam engine; J is a mitred and cogged wheel working into the
initred pinion I upon the upright revolving shaft E, while the mitred pinion G,
at the lower end of the same shaft E, works into the mitred pinion H on the
end of the propeller, which thus obtains the required revolving motion, the
speed of that motion being of course determined by the diameter of the
wheel J as compared with the diameter of the pinion G and the stroke of the
piston of the engine.
Figure 4 is a plan of the plummer block C; and Figure 5, a plan of the
plummer block D.
Figure 6 is a plan of the steadying gear for the shaft E, taken in the line of
the dotted line, and of which there may be more than one, if necessary,
dependent on the length of the upright shaft. It will be observed by this
Figure that the upright shaft is enclosed in a box or case L, M, N, N, wherein
the water in which the vessel floats rises to a a level with the water-line, and
must therefore be made water-tight.
Now whereas it is evident that various other modes of gearing the propeller

page_text: may be adopted, and perhaps if the pinion H were a small pulley, and the
wheel J a large pulley, and a band worked over them, the required speed
might be given to the propeller as effectually and with less machinery ; but I
have had no opportunity of trying this mode on a large scale, and therefore I
have adopted the pinion gear in this Specification, or the propeller may be
worked by hand or other than steam power. And whereas the propeller may
be made of wood, sheet iron, or other suitable material, and with a greater
number of threads or worms, and set at various angles with the central line of
the screw; but whereas I claim as my Invention the propeller herein-before
described, whether arranged singly in an open space in the dead wood, as here
shewn, or in duplicate with one on each side of the dead wood, or otherwise
placed more forward or more aft, or more or less deep in the water. And such
my Invention being, to the best of my knowledge and belief, entirely new, and
never before used within that part of His said Majesty's United Kingdom of
Great Britain and Ireland called England, His said Dominion of Wales, and
Town of Berwick-upon-Tweed, nor in any of His said Majesty's Colonies or
Plantations abroad, I do hereby declare this to be my Specification of the
same, and that I do verily believe this my said Specification doth comply in
all respects, fully and without reserve or disguise, with the proviso in the said
herein-before in part recited Letters Patent contained; wherefore I do hereby
claim to maintain exclusive right and privilege to my said Invention.
In witness whereof, I, the said Francis Pettit Smith, have hereunto set
my hand and seal, this Thirtieth day of November, One thousand eight
hundred and thirty-six.
FRANCIS PETTIT (L.s.) SMITH.
Signed, sealed, and delivered by the
within-named Francis Pettit Smith,

page_text: En the Matter of Letters Patent granted to Francis Pettit Smith, then
of Hendon, but now of No. 1, Wade's Terrace, East India Road, in
the County of Middlesex, Gentleman, for his Invention of "An
Improved Propeller for Steam and other Vessels," bearing date at
Westminster, the Thirty-first day of May, One thousand eight hun-
dred and thirty-six.
!
MEMORANDUM OF ALTERATION entered by the said Francis Pettit
Smith pursuant to the provisions of an Act passed in the fifth and
sixth years of the reign of His late Majesty King William the
Fourth, entituled "An Act to amend the Law touching Letters Patent
for Inventions."
I, the said Francis Pettit Smith, do hereby declare that I did, on the
Third day of November, One thousand eight hundred and thirty-six, duly
inroll a Specification of the above-mentioned Invention, and that in. such
Specification I did. declare the nature of my said Invention to consist in a sort
of screw or worm made to revolve rapidly under water in a recess or open
space formed in that part of the after part of the vessel commonly called the
dead rising or dead wood of the run; and after describing the manner in
which my said Invention was to be performed by the statement therein con-
tained with reference to the Drawing thereto annexed, I did state that the
propeller might be made of wood, sheet iron, or other suitable material, and
with a greater number of threads or worms, and set at various angles with the
central line of the screw, but that I claimed as my Invention the propeller
therein-before described, whether arranged singly in an open space, as there
shewn, or in duplicate with one on each side of the dead wood, or otherwise
placed more forward or more aft, or more or less deep in the water.
NOW WHEREAS I, the said Francis Pettit Smith, do hereby further declare
that since the inrollment of my said Specification, I find that the dead wood
or run of the vessel is the only place in which the said propeller can be
advantageously placed, and that a screw of one turn or two half turns as a
propeller will be sufficient for every purpose; and for this reason I, the said
Francis Pettit Smith, in order to limit my claim to Invention to such a screw
for a propeller as herein-before last mentioned, a Drawing of which is
annexed, and to the position last mentioned, namely, placed singly in the

page_text: centre of that part of the vessel called the dead wood or run of the vessel, do
hereby make the following Memorandum of Alteration in the claiming clause of
the said Specification, reference being had to the said Drawing annexed; that
is to say, after the words "I claim as my Invention the propeller," instead of
the words "herein-before described, whether arranged singly in an open space
"in the dead wood, as here shown, or in duplicate with one on each side of
"the dead wood, or otherwise placed more forward or more aft, or more or
"less deep in the water," I hereby insert the words "described in Figures 1,
"2, and 8 of the Drawing annexed to this Memorandum of Alteration, and
placed singly in the centre of the dead wood or run of the vessel, as shown
"in the Figures of the Drawing annexed to the original Specification."
In witness whereof, I, the said Francis Pettit Smith, have hereunto
set my hand and seal, this Thirtieth day of April, One thousand eight
hundred and thirty-nine.
JNO. ESPIN.
To the Clerk of the Patents of England.
This is to certify, that the above-named Francis Pettit Smith has applied
to me for leave to enter with you the above-written Memorandum of Alte-
ration of the Specification of a certain Invention for which Letters Patent
were duly granted to him under the Great Seal, dated at Westminster, the
Thirty-first day of May, One thousand eight hundred and thirty-six, and the
Specification of which was inrolled on the Third day of November, One
thousand eight hundred and thirty-six; and on considering of the said appli-
cation I directed him to advertize his said Alteration in the London Gazette,
and in the Times and Morning Chronicle newspapers; and such advertize-
ments have been duly made in the said Gazette and Times on the Nine-
teenth day of April, One thousand eight hundred and thirty-nine, and in the
"Morning Chronicle" on the eighteenth day of the same month of April;
and no objection having been made to the said application, I have
accordingly granted leave to the said Francis Pettit Smith to file his said
Alteration, pursuant to the Statute passed in the sixth year of the reign of
His late Majesty, intituled "An Act to amend the Laws touching Letters
Patent for Inventions."

page_text: AND BE IT REMEMBERED, that on the Twenty-fourth day of May, in
the year of our Lord 1839, the aforesaid Francis Pettit Smith came before
our said Lady the Queen in Her Chancery, and acknowledged the Disclaimer
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Disclaimer aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Inrolled the Twenty-eighth day of May, in the year of our Lord One