Iм- PROVEMENTS IN APPARATUS FOR SOUNDING OR INDICATING THE DEPTH OF WATER
Year: 1875

page_text: LETTERS PATENT to William Kennedy, of Saltcoats, in the County
of Ayr, North Britain, for the Invention of "IMPROVEMENTS IN
PROVISIONAL SPECIFICATION left by the said William Kennedy at
the Office of the Commissioners of Patents, with his Petition, on
the 12th October 1875.
I, WILLIAM KENNEDY, of Saltcoats, in the County of Ayr, North
Britain, do hereby declare the nature of the said Invention for "Iм-
PROVEMENTS IN APPARATUS FOR SOUNDING OR INDICATING THE DEPTH OF WATER,"
to be as follows, that is to say:
:-
This Invention has for its object the application of improved and
extremely simple apparatus for sounding or indicating the depth of
water, and which acts continuously and is suitable not only for sounding
the water in which a ship or vessel floats but also for indicating depth
of water in the hold or compartment of a ship, or in any vessel or
space.

page_text: The Invention consists in arranging apparatus to indicate the pressure
at the bottom of the water which it is wished to sound so that the depth
may be inferred from such pressure; and for this purpose a tube of
small bore is connected at its upper end to a pressure gauge of any
convenient kind, such gauge being placed above the water or in any
convenient position whilst the other end of the tube is at the bottom of
the water, and is arranged so that the pressure there may take effect on
air or other gas, or mixture of gases, or on a liquid as much lighter than
water as possible. The bottom end of the tube may be open, and a
small air pump may be connected to any convenient part of the tube,
whereby to insure the tube's being filled with air when the gauge is
being observed; or the tube itself being incompressible, or as nearly so
as possible, may have attached to its bottom end a bag or diaphragm of
thin elastic material, through which the pressure may act on the air,
gas, or liquid inside the tube.
When the apparatus is used for sounding in a ship's course the tube
must be flexible or jointed, and there must be attached to the bottom
end of it a weight sufficient to sink it to the bottom of the water, or as
far as the length of tube will allow. A ship provided with such
apparatus will have a continuous indication at the pressure gauge
showing any variations of depth less than the extreme depth for which
the length of tube is adequate. An alarum apparatus actuated by
clockwork can be fitted in connection with the pressure gauge to attract
special attention on particular degrees of shallowness being indicated.
The clockwork might also be made to record the various indications of
the gauge.

page_text: of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said William Kennedy, Her special
licence, that I, the said William Kennedy, my executors, admini-
strators, and assigns, or such others as I, the said William Kennedy, 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 APPARATUS FOR SOUNDING OR INDICATING THE DEPTH OF
WATER," upon the condition (amongst others) that I, the said William
Kennedy, 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 William Kennedy, 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 in writing, reference being had to the accom-
panying Drawings, that is to say :—
This Invention has for its object the application of improved and
extremely simple apparatus for sounding or indicating the depth of
water, and which acts continuously, and is suitable not only for sounding
the water in which a ship or vessel floats, but also for indicating depth
of water in the bold or compartment of a ship, or in any vessel or
space.
My Invention consists in arranging improved and simple apparatus
to indicate in a direct and reliable manner the pressure at the bottom of
the water which it is wished to sound, so that the depth may be
inferred from such pressure; and for this purpose I employ a tube of
small bore which is connected at its upper end to a pressure gauge of
any convenient kind, such gauge being placed above the water or in
any convenient position, whilst the other end of the tube is at the
bottom of the water and is arranged so that the pressure there may

page_text: take effect on air or other gas or gaseous mixture. The bottom end of
the tube which should be enlarged may be open, and a small air force
pump may be connected to any convenient part of the tube, whereby to
insure the tube's being filled with air when the gauge is being observed;
or the tube itself being incompressible, or as nearly so as possible, may
have attached to its bottom end a bag or unstretched diaphragm of thin
elastic material, through which the pressure may act on the air or gas
inside the tube. Where a bag or diaphragm is employed it is important
to apply it so that any strain due to its clasticity cannot appreciably
alter the effective pressure communicated through it to the air or gas in
the tubc.
When the apparatus is used for sounding in a ship's course the tube
must be flexible or jointed, and there must be attached to the bottom
end of it a weight sufficient to sink it to the bottom of the water or as
far as the length of tube will allow.
And in order that my said Invention and the manner of performing
the same may be properly understood I hereunto append a Sheet of
explanatory Drawings, to be hercin-after referred to, and representing
some modifications of my sounding apparatus. In these Drawings the
same reference numerals are used to mark the same or like parts
wherever they are repeated.
access.
Figure 1 of the Drawings is a vertical section of a tank or vessel for
containing water, and having a simple modification of my apparatus to
be connected to a Bourdon or other suitable pressure gauge or indicator.
The said apparatus consists simply of a tube or pipe 1 dipping down to
the lower part of the tank and terminating in an enlargement 2 at tho
bottom, to the bottom of which enlargement the water in the tank has
The air in the pressure gauge, and in the tube 1, and enlarge-
ment 2 being confined therein becomes compressed by the water to a
degree corresponding with the depth of water in the tank, and the
pressure gauge in indicating the pressure to which the air is thus com-
pressed thereby virtually indicates the depth. A scale marked with
inches, fect, or fathoms may be put on the indicating face of the
pressure gauge so that the actual depth may be directly shown by the
pointer of the gauge. As the air is compressed in the gauge and tube 1
the water will rise in the enlargement 2, and the pressure shown will be
that corresponding to the depth down only to the level of the water in

page_text: the enlargement 2, but the scale may be corrected for this action; or if
an air force pump is fitted in connection with the tube 1 air may be
forced in to keep the water down to the bottom of the enlargement 2
notwithstanding the compression due to the water in the tank.
The modification shown in Figure 1 may be used for indicating depth
of water in the hold of a ship, and in cases where the depth of the water
to be indicated will never exceed a few feet a mercurial pressure gauge
may be used as the indicator.
Figure 2 is a vertical section of a modification suitable for continuous
sounding in a ship's course when the depths may reach 20 fathoms.
The tube 1 to be connected to the pressure gauge on shipboard is of
vulcanised rubber of considerable thickness as compared with its
bore, which may be only inch in diameter, or even less, whilst the
tube is of a length corresponding to the depth to be sounded. This
tube 1 is securely attached to a nozzle 3 fixed to a basin-shaped
casting which can be drawn with a little resistance along the bottom of
a channel without risk of catching, and which is made heavy enough to
sink with the air accompanying it; a cavity 5 is formed in the basin 4,
and is covered with a convex sheet 6 of vulcanised rubber fixed by
means of a ring 7 so as to hermetically enclose a quantity of air. The
cavity 5 communicates by a small passage with the nozzle 3 and tube 1,
and the pressure of the water acting on the rubber cover 6 compresses
the air in the cavity and is transmitted by the tube 1 to the gauge on
shipboard.
Figure 3 is a vertical section of a modification suitable for sounding
depths reaching as much as 50 fathoms. In this modification a hollow
cylindrical vessel of cast iron or other suitable metal has fixed on it a
cover 9 formed with the nozzle pipe 3 on which the rubber tube 1 is
secured; within the cylindrical vessel 8 there is placed a metal plunger
or long piston 10, having between it and the sides of the vessel S two
rings 11 of vulcanised rubber acting as what is known as rolling packing;
the water enters the bottom of the vessel 8 through a grating 12 and
compresses the air by forcing up the piston 10. The piston 10 should
be hollow and of such a weight as to displace as nearly as possible an
equal weight of water, whilst the vessel 8 should be made heavy enough
to sink to the extreme depth for which the apparatus is intended. A
nozzle 13 is formed in the cover 9, and is provided with a screw cap to

page_text: be opened at any time when about to use the apparatus for the
of insuring that it is properly full of air.
purpose
Figure 4 is a vertical section of a modification in which the piston 10
is attached to an external cylinder 14, shaped to work on the outside of
the vessel 8 with an interposed rolling packing ring 11 of vulcanised
rubber. This modification may be adopted in place of that shown in
Figure 3 if it should be found that sand or mud gets through the
grating 12 and interferes with the proper action of the apparatus.
When the tube 1 is flexible and of a length suitable for sounding in a
ship's course it may be coiled in a tub or open topped cylinder, slotted
discs being interposed at intervals to divide it into separate quantities,
cach of which is as much as can be conveniently lifted out at once on
the arm; or it may arranged like the rocket lines of the coastguard
life-saving apparatus; or it may be wound on a revolving barrel. In
the last-mentioned case the end may be connected to the axle of the
barrel, and the pressure gauge be fixed on the end of the barrel, the
barrel being weighted or otherwise arranged to always stop with ono
part uppermost.
The indication of depth does not depend on the length of tubing
immersed but simply on the pressure acting on the lower end of it, so
that it does not matter whether the ship is stationary and the tube
hanging vertically downwards, or is moving and the tube more or less
inclined. A ship provided with such apparatus will as long as the tube
and its bottom apparatus is overboard have a continuous indication at
the pressure gauge showing any variations of depth less than the extreme
depth for which the length of the tube is adequate. An alarm apparatus
actuated by clockwork can be fitted in connection with the pressure
gauge to attract special attention on particular degrees of shallowness
being indicated. The clockwork may also be made to record the various
indications of the gauge. In a similar way a depth indicator in con-
nection with a ship's hold may be arranged to set free the detent of
alarm apparatus on a predetermined depth of water having accumulated
in the hold.
Tidal movements can also be automatically indicated and recorded by
means of the apparatus, a tube of small bore and fitted with appliances
of the kind herein-before described for receiving and transmitting the
action of pressure due to the depth of water in a tideway being led to a

page_text: harbour office or other convenient place where the clockwork recording
appliances are situated.
Having thus particularly described my said Invention and the
manner of performing the same, I have to state that I do not restrict
myself to the precise details herein described and delineated, and that
I do not claim the indicating of the depth of a liquid by the position
vertically of a column of liquid supported in an uncertain manner partly
by an elastic diaphragm and partly by the liquid, the depth of which is
to be indicated; but that what I believe to be novel and original and
claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, the sounding or indicating of the depth of water by
means of a pressure gauge having connected to it one end of a tube, the
other end of which is arranged to receive the pressure due to the depth
of the water, substantially as herein-before described.
In witness whereof, I, the said William Kennedy, have here-
unto set my hand and seal, this Tenth day of April, in the year
of our Lord One thousand eight hundred and seventy-six.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
W. KENNEDY. (L.S.)