IMPROVEMENTS IN ASCERTAINING THE DRAUGHT OF WATER AND TRIM OF SHIPS OR VESSELS."
Year: 1856

page_text: LETTERS PATENT to Robert Walker, junior, of 62, Buchanan Street,
Glasgow, for the Invention of "IMPROVEMENTS IN ASCERTAINING THE
DRAUGHT OF WATER AND TRIM OF SHIPS OR VESSELS."
PROVISIONAL SPECIFICATION left by the said Robert Walker at the
Office of the Commissioners of Patents, with his Petition, on the 16th
September 1856.
I, ROBERT WALKER, junior, of 62, Buchanan Street, Glasgow, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN ASCERTAINING THE
DRAUGHT OF WATER AND TRIM OF SHIPS OR VESSELS," to be as follows:-
This Invention consists in ascertaining the draught of water of a ship or
vessel, by means of a glass tube communicating with the exterior water by a
pipe passing through the vessel, so that the water in the glass tube stands at
the same level as the water outside the vessel, and the draught is read on a
scale of feet and inches attached to the glass tube. In place of the glass
tube a pressure or vacuum gage may be used, communicating in a similar
manner with the exterior water; this instrument, being acted on by the greater
or less column of water outside the vessel, will indicate on a suitable scale
the draught of the vessel. It is preferred that this instrument should com-
municate with the water at some point near the middle of the ship, so that
it may always shew the average draught thereof; and there are indicators in

page_text: connection with the instrument, which are acted on by hanging weights, so as
to shew if the vessel is on an even keel, or the amount of deviation there-
from, also the amount of list the vessel may have on either side.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Walker in the Great Seal Patent Office on the
16th March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
WALKER, junior, of 62, Buchanan Street, Glasgow, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of September, in the year of our Lord
One thousand eight hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Robert Walker, Her special licence that I, the said Robert Walker, my
executors, administrators, and assigns, or such others as I, the said Robert
Walker, 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 ASCER-
TAINING THE DRAUGHT OF WATER AND TRIL OF SHIPS OR VESSELS," upon the
condition (amongst others) that I, the said Robert Walker, my executors or
administators, 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 Robert Walker, do hereby declare the
nature of the 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 thereof, that is to say: -
This Invention consists in ascertaining the draught of water of a ship or
vessel, by means of a vacuum guage communicating with the exterior water
by a
a pipe passing through the vessel, so that the instrument, being acted on by
the greater or less column of water outside the vessel, will indicate on a
suitable scale the draught of the vessel. It is preferred that this instrument
should communicate with the water at some point near the middle of the

page_text: ship, so that it may always shew the average draught thereof; and there are
indicators in connection with the instrument, which are acted on by hanging
weights, so as to shew if the vessel is on an even keel, or the amount of
deviation therefrom, also the amount of list the vessel may have on either
5 side.
And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawing hereunto
annexed.
DESCRIPTION OF THE DRAWING.
Figure 1 is a front elevation, partly in section, and Figure 2 is a longi-
tudinal section, of an apparatus arranged to my Invention. a is a pressure
or vacuum guage which may be of any ordinary construction, and placed in
any convenient part of the ship; b is a tube by which it communicates with
the water outside the ship; c is a rod to which the pressure or vacuum
guage a gives motion; this rod has at its upper end a rack c¹, which works
with the pinion d on the tube e, and so moves the pointer f, and causes it
to indicate on the dial the draught of the ship; or in place of forming the
rack c¹ on the rod c of the pressure or vacuum guage, the rod c may be con-
nected to a lever at or near one of its ends, such lever at its other end carrying
a curved rack to work with the pinion d. By this construction increased
facility of adjustment is obtained, as the amount of motion of the pointer
produced by a definite motion of the rod c may be varied by varying the
distance of the point at which the rod c is attached from the centre on which
the lever works. g is a pendulum capable of swinging in a direction across
the ship; it is fastened to the tube h carrying the pointer i, which thus receives
motion so as to indicate on the dial any list that the ship may have to
either side. k is another pendulum, placed at right angles to the pendulum g,
and mounted on the axis 7, which also carries the bevilled wheel m. This
wheel m drives the pinion n on the axis o, on which is also the pointer p; this
pointer thus receives the motion from the pendulum k, multiplied by the
wheels m and n, and it indicates on the dial the inclination of the keel of the
vessel.
By the instrument which I have described I am enabled also to measure
the speed of the ship. For this purpose I employ the graduated ring g, which
is capable of being turned round by the handles v, and so that its zero point
may be brought to correspond with any point of the other scale; and I arrange
the tube of the pressure or vaccuum guage so that it may be made to com-
municate with the exterior water by either one or other of the two mouths or
openings shown at Figure 3. When it is desired to ascertain the draught of

page_text: the ship, then the mouths is opened, which is simply a hole through the
bottom of the ship; and afterwards to ascertain the speed of the ship, the zero
point of the scale q is set to the indicated draught, and then the mouth s is
closed and the mouth t is opened. This mouth is formed by a tube which passes
through the bottom; this tube is closed at the end, and has a side opening
turned towards the bows of ships; the opening this mouth causes a further
movement of the indicator of the guage, and this further movement, measured
on the scale g, gives the speed of the vessels.
In witness whereof, I, the said Robert Walker, have hereunto set my
hand and seal, this Twelfth day of March, in the year of our Lord
One thousand eight hundred and fifty-seven.
Witness,
GEO. PITT.
ROBT WALKER, Jr. (L.S.)