IMPROVEMENTS IN THE CONSTRUCTION OF SCREW PROPELLORS, AND OF THE FLOATS, PADDLES, OR BOARDS OR PADDLE WHEELS AND WATER WHEELS.
Year: 1875

page_text: LETTERS PATENT to Ridley Henderson, of Timsbury, in the County of
Somerset, Mining Engineer, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF SCREW PROPELLORS, AND OF THE FLOATS, PADDLES,
OR BOARDS OR PADDLE WHEELS AND WATER WHEELS.
دو
Scaled the 12th April 1876, and dated the 14th October 1875.
PROVISIONAL SPECIFICATION left by the said Ridley Henderson at
the Office of the Commissioners of Patents, with his Petition, on
the 14th October 1875.
"
I, RIDLEY HENDERSON, of Timsbury, in the County of Somerset,
Mining Engineer, do hereby declare the nature of the said Invention
for IMPROVEMENTS IN THE CONSTRUCTION OF SCREW PROPELLORS, AND OF THE
FLOATS, PADDLES, OR BOARDS OF PADDLE WHEELS AND WATER WHEELS," to be
as follows:-
This Invention consists in certain improvements in the construction
of screw propellors, and of the floats, paddles, or boards of paddle wheels
and water wheels, whereby a greatly increased superficial area is
obtained which is available for acting upon the water or resisting
medium during the process of rotation.

page_text: In the case of screw propellors the surfaces of the screw are raised in
ridges at an angle of about 40 degrees more or less on the forward pitch
of the blade, the ridges radiating from the centre of the propellor shaft,
a largely increased superficial area being thus obtained for acting upon
the resisting medium, and also for obtaining an increased grip upon the
water without in any way altering or increasing the length or breadth
or pitch of the propellor. Each ridge is tapered to an edge or point on
the forward or leading edges of the blades of the propellor in order to
facilitate the entrance into and the passage through the water of the
blades, and to decrease such resistance as does not contributo to their
propelling power, the loss of area thus ensured being compensated for
by continuing the ridges to the same extent beyond the back or rear
edges of the blades.
The ridges employed, as before mentioned, may either constitute
part of the same casting as the propellor itself, or may be attached
thereto in any suitable and well known manner.
In the application of this Invention to paddle wheels and water wheels
the floats, paddles, or boards instead of being plain or smooth as
hitherto, the same, (whether formed of iron or wood) are provided with
ridges having an angle of about 45 degrees running at right angles to
the shaft of the wheel. By means of this arrangement a greatly
increased superficial area of the floats, paddles, or boards is obtained
capable of acting or of being acted upon by the water or medium of
resistance, whilst the same length and breadth of the floats, paddles, or
boards as at present employed may be used.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Ridley Henderson in the Great Seal Patent Office
on the 13th April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RIDLEY
HENDERSON, of Timsbury, in the County of Somerset, Mining Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of October, in the
year of our Lord One thousand eight hundred and seventy-five, in the

page_text: thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Ridley Henderson, Her
special licence that I, the said Ridley Henderson, my executors, ad-
ministrators, and assigns, or such others as I, the said Ridley
Henderson, 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 THE CONSTRUCTION OF SCREW PROPELLORS, AND
OF THE FLOATS, PADDLES, OR BOARDS OF PADDLE WHEELS AND WATER WHEELS,"
upon the condition (amongst others) that I, the said Ridley Henderson,
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
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Ridley Henderson, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, that is to say :—
My said Invention consists in certain improvements in the con-
struction of screw propellors, and of the floats, paddles, or boards of
paddle wheels and water wheels, whereby a greatly increased superficial
area is obtained as compared with arrangements previously in use, and
which is available for acting upon the water or resisting medium during
the process of rotation.
In the case of screw propellors, upon the surfaces of the screw blades
are added or raised ridges or plates at an angle of about forty degrees,
more or less, in the forward pitch of the blade. Such ridges or plates
radiate from the centre of the propellor shaft, and thus a largely
increased area is obtained for acting upon the resisting medium, and
also for obtaining an increased grip upon the water without in any way
altering or increasing the length or breadth or pitch of the propellor.
Each ridge or plate is tapered to an edge or point on the forward or
leading edges of the blades of the propellor in order to facilitate the
entrance into and the passage through the water of the blades, and to

page_text: decrease such resistance as does not contribute to their propelling power,
the loss of area thus ensured being compensated for by continuing the
ridges or plates to the same extent beyond the back or rear edges of the
blades.
The ridges or plates employed, as before mentioned, may be made
either hollow or solid, and may either constitute part of the same casting
as the propellor itself, or may be attached to the latter in any suitable
and well known manner.
In the application of my said. Invention to paddle wheels and water
wheels, the floats, paddles, or boards instead of being plain or smooth as
hitherto constructed, the same (whether formed of iron or wood) are
provided with ridges having an angle of about 45 degrees running at
right angles to the shaft of the wheel. By means of this arrangement a
greatly increased superficial area of the floats, paddles, or boards is
obtained, the same being capable of acting upon or of being acted upon
by the water or medium of resistance, whilst the same length and
breadth of the floats, paddles, or boards as at present employed may be
used.
Having thus declared and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I would observe
in conclusion that what I consider novel and original and there-
fore claim as being the Invention secured to me by the said herein-
before in part recited Letters Patent is, the construction of screw
propellors, and of the floats, paddles, or boards of paddle wheels and
water wheels, substantially as and for the purposes herein-before
described and set forth.
In witness whereof, I, the said Ridley Henderson, have hereunto
set my hand and seal, this Twelfth day of April, in the year
RIDLEY HENDERSON. (L.S.)