IMPROVEMENTS IN PRO- PELLERS FOR PROPELLING VESSELS
Year: 1874

page_text: LETTERS PATENT to John McGrigor Croft, of No. 15, Abbey Road,
Saint John's Wood, in the County of Middlesex, Physician and
Doctor of Medicine, for the Invention of "IMPROVEMENTS IN PRO-
PELLERS FOR PROPELLING VESSELS."
PROVISIONAL SPECIFICATION left by the said John M'Grigor Croft
at the Office of the Commissioners of Patents, with his Petition,
on the 11th July 1874.
I, JOHN MCGRIGOR CROFT, of No. 15, Abbey Road, Saint John's
Wood, in the County of Middlesex, Physician and Doctor of Medicine,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN PROPELLERS FOR PROPELLING VESSELS," to be as follows:-
My Invention consists in the adaptation and use of a wheel similar in
frame to an ordinary paddle wheel, but provided in lieu of the float
boards hitherto employed with two or more circles of curved wood or
metal spiral blades secured to the frame and arms aforesaid, whereby the

page_text: water is thrown obliquely outwards on either side of the vessel. A pair
of wheels of the character aforesaid can be used, one on each side of
the vessel, like the ordinary paddle wheels, or as a stern wheel, and may
be partially or wholly submerged, and more than one pair may be adopted
if thought requisite.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John M'Grigor Croft in the Great Seal. Patent
Office on the 8th January 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
McGRIGOR CROFT, of No. 15, Abbey Road, Saint John's Wood, in 1
the County of Middlesex, Physician and Doctor of Medicine, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of July, in the year
of our Lord One thousand eight hundred and seventy-four, in the 1
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John M'Grigor Croft,
Her special license that I, the said John McGrigor Croft, my
executors, administrators, and assigns, or such others as I, the
said John M'Grigor Croft, my executors, administrators, and a
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 PROPELLERS FOR PRO-
PELLING VESSELS," upon the condition (amongst others) that I, the said
John McGrigor Croft, 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 calender months¨
next and immediately after the date of the said Letters Patent.
:
NOW KNOW YE, that I, the said John McGrigor Croft, do hereby
declare the nature of the said Invention, and in what manner. the

page_text: Patent is, the arrangement and construction of propellers for propelling
vessels, substantially as herein-before described and illustrated.
•
particularly the combination with a propeller wheel of two or more
circles of curved wood or metal spiral blades secured to the frame and
arms of the wheel in such manner as to throw the water obliquely
outwards on either side of the vessel.
'
.
In witness whereof, I, the said John McGrigor Croft, have here-
unto set my hand and seal this Seventh day of January, in
the year of our Lord One thousand eight hundred and seventy-
five.
JOHN MCGRIGOR CROFT. (L.s.)