IMPROVEMENTS IN THE CONSTRUCTION OF SCREW STEAM SHIPS
Year: 1873

page_text: LETTERS PATENT to Archibald Thomson, of Liverpool, in the County
of Lancaster, Master Mariner, for the Invention of "IMPROVEMENTS
IN THE CONSTRUCTION OF SCREW STEAM SHIPS."
Sealed the 19th December 1873, and dated the 27th August 1873.
PROVISIONAL SPECIFICATION left by the said Archibald Thomson at
the Office of the Commissioners of Patents, with his Petition, on the
27th August 1873.
I, AROHIBALD THOMSON, of Liverpool, in the County of Lancaster,
Master Mariner, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF SCREW STEAM SHIPS," (to be as
follows:-
The object of this Invention is to provide ocean-going ships capable
of high speed with small consumption of fuel, and having great stability
and steadiness. For this purpose I construct the bottom of the ship
with two longitudinal grooves or channels therein, one along each side
of the keel. In the said keel formed of ribs and plates or otherwise I
form the screw shaft tunnel, and make an opening therethrough to
•

page_text: receive the screw. The screw works in the said opening at a distance
from the stern; I prefer that the screw should not project below the
bottom of the said keel.
In vessels constructed in this manner the screw works in solid water.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Archibald Thomson in the Great Seal Patent Office
on the 27th February 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARCHIBALD
THOMSON, of Liverpool, in the County of Lancaster, Master Mariner,.
send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of August, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Archibald Thomson, Her special licence
that I, the said Archibald Thomson, my executors, administrators, and
assigns, or such others as I, the said Archibald Thomson, 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 STEAM SHIPS," upon the condition (amongst others)
that I, the said Archibald Thomson, 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.

page_text: For strengthening a ship in accordance with my Invention I employ
iron girder, keelsons, and angle bars disposed, 'combined, and secured in
manner suitable for the size of ship and the carrying to be effected.
Having now described the nature of my said Invention, and par-
ticularized the same in such manner that others will be enabled to carry
my improvements into effect, I claim,―
⚫ First. Constructing screw steam ships with two longitudinal grooves
or channels alongside the keel or keel ridge when the screw shaft tunnel
and screw shaft are formed and placed over the keel or in the keel
ridge.
Second. Constructing screw steam ships with longitudinal grooves or
channels, alongside the keel or keel ridge when the propeller opening is
formed at a point between midship section and one-twelfth the length of
the ship from the stern.
Third. In ships with two longitudinal grooves or channels, the
employment of iron girder, keelsons, and angle plates.
In witness whereof, I, the said Archibald Thomson, have hereunto
set my hand and seal, the Seventeenth day of February, in the
year of our Lord One thousand eight hundred and seventy-
four.
-
In the presence of
JAMES JOHNSON,
The Patent Office,
Liverpool.
•
ARCH. THOMSON. (L.S.)