IMPROVEMENTS IN PROPELLING VESSELS
Year: 1855

page_text: LETTERS PATENT to Thomas Eyre Wyche, of Camberwell, in the County
of Surrey, Gentleman, for the Invention of "IMPROVEMENTS IN PROPELLING
VESSELS."
Sealed the 3rd November 1855, and dated the 23rd August 1855.
PROVISIONAL SPECIFICATION left by the said Thomas Eyre Wyche at
the Office of the Commissioners of Patents, with his Petition, on the
23rd August 1855.
I, THOMAS EYRE WYCHE, of Camberwell, in the County of Surrey, Gentle-
man, do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
PROPELLING VESSELS" to be as follows:-
My said improvements apply to peculiar arrangements of the blades of
screw propellers, and consist in employing four blades or half blades so
attached to the boss, that the circles which two of them cut when revolving in
the water would be crossed, or nearly so, by the circles which the two opposite
blades would describe.
This may be effected by dividing blades of the present construction into
two parts, setting the two half blades thus produced, the one a little 'to the
right and the other equally to the left of the line drawn across the boss for
the groove in which the blades are fixed or cast, leaving thereby a space.
for the passage of the water between the two half, or split blades, which
space enlarges as it recedes from the boss.

page_text: I prefer two half blades or two small whole blades, but my improvements
are applicable to various constructions of blades and half blades.
It should be observed, that if two entire blades are used in the upper aud.
two in the lower groove or line of the boss, or four on different but equi-
distant points, so as to give the duplicate or cross revolutions, it may be
necessary that the angles on the surfaces of the blades should not be drawn
from the same, but from opposite points of the blades or half blades, to prevent
the water from unnecessarily impinging on their surfaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Eyre Wyche in the Great Seal Patent Office on
the 23rd February 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
EYRE WYCHE, of Camberwell, in the County of Surrey, Gentleman, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of August, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Eyre Wyche, Her special licence that I, the said Thomas
Eyre Wyche, my executors, administrators, and assigns, or such others as I,
the said Thomas Eyre Wyche, my exccutors, 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 Thomas Eyre Wyche, 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 Thomas Eyre Wyche, 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 :-

page_text: My improvements consist in dividing the blade of the submarine propeller
for vessels into two equal parts from the periphery to the boss, and placing
one half of the blade a little to the right and the other equally to the left of
the diagonal or other line of the boss on which the base of the blade is
ordinarily set or cast in solid, so as to leave a considerable space for the water to
pass through, gradually diverging from the boss, and to give a violent impulse
to the outermost half of the blade. I prefer the blades to be formed of
concave and convex surfaces on each side, but blades of a different construc-
tion may be employed and similarly divided. There should be two half or
split blades on the upper part, and two half or split blades opposite on the
lower part to correspond. The action of each pair of half or split blades will
thus be of a duplicate character, the propulsion greatly increased and the
resistance of the impinging water diminished. The blades may be split into
two unequal parts, or into more parts than two, or small whole blades may be
employed, or half or split blades may be set on the same line, so as to leave a
considerable interstice between them, but I prefer two pairs of equal half
blades set equally on either side of the line, as before described. And I would
observe, that in some instances of half or split blades, it may be necessary to
arrange the angles on their surfaces to correspond with their position.
In witness whereof, I, the said Thomas Eyre Wyche, have hereunto set
my hand and seal, this Twenty-third day of February, in the
our Lord One thousand eight hundred and fifty-six.
year of
THOMAS EYRE WYCHE. (L.S.)