IMPROVEMENTS IN PROPELLING VESSELS
Year: 1867

page_text: LETTERS PATENT to Henry Clarke, of 53, Chancery Lane, in the County
of Middlesex, and of Grange Hill, Jamaica, Clerk, for the Invention of
"IMPROVEMENTS IN PROPELLING VESSELS."
Sealed the 22nd November 1867, and dated the 3rd July 1867.
PROVISIONAL SPECIFICATION left by the said Henry Clarke at the
Office of the Commissioners of Patents, with his Petition, on the
3rd July 1867.
I, HENRY CLARKE, of 53, Chancery Lane, in the County of Middlesex, and
of Grange Hill, Jamaica, Clerk, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PROPELLING VESSELS," to be as follows:-
My Invention relates to the propulsion of vessels by means of what I term
a rotary sail, that is to say, of a large surface extended to operate on the atmo-
sphere by which I effect the act of propulsion instead of operating on the water
in the usual manner. For this purpose I employ
For this purpose I employ what may be termed a
screw, which I form of two, three, or more surfaces or blades mounted
obliquely on a horizontal axis; these blades or surfaces may be all disposed in
the same transverse vertical plane across the vessel like an ordinary screw
propeller, or may be one behind the other on the same axis. The axis is
mounted in suitable bearings at the necessary height from the deck or gunwales
of the vessel, which height is considerable, as the rotary sail must be of large

page_text: diameter to present the necessary surface for resistance to the atmosphere for
the propulsion. The axis of the rotary sail is actuated by steam power in the
vessel, and is caused to rotate thereby at a rate suitable for the speed to be
obtained. The sail in rotating presents its oblique surfaces to the atmosphere,
against which they press and force the vessel onwards precisely in the manner
of an ordinary screw propeller, with the difference that it operates in air instead
of in water. I form the surface or surfaces of the sail of any light material
calculated to withstand the pressure required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Clarke in the Great Seal Patent Office on the
2nd January 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
CLARKE, of 53, Chancery Lane, in the County of Middlesex, and of Grange
Hill, Jamaica, Clerk, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by 'Her Letters
Patent, bearing date the Third day of July, in the year of our Lord One
thousand eight. hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Henry Clarke, Her special license that I, the said Henry Clarke,
my executors, administrators, and assigns, or such others as I, the said Henry
Clarke, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein 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 PROPELLING
VESSELS," upon the condition. (amongst others) that. I, the said Henry
Clarke, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, 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 immédiately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said. Henry Clarke, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in, and by the following
statement (that is to say) :-

page_text: My Invention relates to the propulsion of vessels by means of what I term
a rotary sail, that is to say, of a large surface extended to operate on the
atmosphere, by which I effect the act of propulsion instead of operating on the
water in the usual manner. For this purpose I employ what may be termed
a screw, which I form of two, three, or more surfaces or blades mounted
obliquely on a horizontal axis; these blades or surfaces may be all disposed in
the same transverse vertical plane across the vessel like an ordinary screw
propeller, or may be placed one behind the other on the same axis. The axis
is mounted in suitable bearings at the necessary height from the deck or
gunwale of the vessel, which height is considerable, as the rotary sale must be
of large diameter to present the necessary surface for resistance to the atmos-
phere for the propulsion. The axis of the rotary sail is actuated by steam
power in the vessel, and is caused to rotate thereby at a rate suitable for the
speed to be obtained. The sail in rotating presents its oblique surfaces to the
atmosphere, against which they press and force the vessel onwards, precisely.
in the manner of an ordinary screw propeller, with the difference that it
operates in air instead of in water. I form the surface or surfaces of the sail
of any light material calculated to withstand the pressure required.
Having described the nature of my Invention, and the manner of performing
the same, I declare that what I claim as my Invention to be protected by the
herein-before in part recited Letters Patent is, propelling vessels by means of
a surface or surfaces acting on the atmosphere, arranged and operated in the
manner and as herein-before described.
In witness whereof, I, the said Henry Clarke, have hereunto set my hand
and seal, this Thirty-first day of December, in the year of our Lord
One thousand eight hundred and sixty-seven.
HENRY CLARKE. (L.S.)