AN IMPROVEMENT IN SCREW. PROPELLERS
Year: 1858

page_text: LETTERS PATENT to Abraham James Brooks, of Southsea, in the County
of Hants, Solicitor, for the Invention of "AN IMPROVEMENT IN SCREW.
PROPELLERS."
PROVISIONAL SPECIFICATION left by the said Abraham James Brooks
at the Office of the Commissioners of Patents, with his Petition, on
the 10th November 1858.
.I, ABRAHAM JAMES BROOKS, of Southsea, in the County of Hants, Solicitor,
do hereby declare the nature of the said Invention for "AN IMPROVEMENT IN
SCREW PROPELLERS," to be as follows:―
My Invention is intended to prevent "slip," and consequently to increase
the efficiency of screw propellers. It consists in adding or adapting to the
face of an ordinary screw propeller blade one or more vanes on each side of
the axis; one vane is fixed at the outer extremity of each blade, and is shaped
and fitted so as to prevent the water flying off by centrifugal action from the
ends of the blades.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Abraham James Brooks in the Great Seal Patent Office on
the 10th May 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ABRAHAM
JAMES BROOKS, of Southsea, in the County of Hants, Solicitor, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of November, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Abraham James Brooks, Her special licence that I, the said Abraham
James Brooks, my executors, administrators, and assigns, or such others as I,
the said Abraham James Brooks, 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 "AN
IMPROVEEMENT IN SCREW PROPELLERS," upon the condition (amongst others) that
I, the said Abraham James Brooks, 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 Abraham James Brooks, 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 thereof, reference being had to the Drawings here-
unto annexed, that is to say:-
My Invention is intended to prevent "slip," and consequently to increase
the efficiency of screw propellers. It consists in adding or adapting to the
face of an ordinary screw propeller blade one vane, or two or more vanes on
each side of the axis. One vane is fixed at the outer extremity of each blade,
and is shaped and fitted so as to prevent the water flying off by centrifugal
action from the ends of the blades.
I am aware that vanes somewhat analogous to mine have been heretofore
proposed, but the peculiar feature of my Invention consists in employing
vanes in the form of segments of cylinders concentric with the axis of the

page_text: propeller, and included between the propelling face of the blade and a plane
passing through the aftermost edge of the blade at right angles to the axis.
In the accompanying Drawings Figure 1 is an edge view, Figure 2 a front
view, and Figure 3 a back view of a propeller having three vanes; but I do
not limit myself to any particular number of vanes, nor to the distance
of the vanes from each other. A, A, A, are the vanes; B is the, boss;
C, C, blades of screw; D is a tie bar for supporting the upper edge of the
vanes.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim as my Invention,
the manufacture of screw propellers with vanes in manner and for the purpose
herein-before described.
In witness whereof, I, Abraham James Brooks, have hereunto set my
hand and seal, this Tenth day of May, One thousand eight hundred
and fifty-nine.