ROVEMENTS IN APPARATUS FOR MEASURING AND INDICATING THE LEAKAGE OF VESSELS
Year: 1856

page_text: LETTERS PATENT to George Davies, of the Office for Patents, 1, Serle
Street, Lincoln's Inn, in the County of Middlesex, Civil Engineer, for the
Invention of IMPROVEMENTS IN APPARATUS FOR MEASURING AND INDICATING
THE LEAKAGE OF VESSELS."-A communication from Reuben Shaler, of
Benton of America.
PROVISIONAL SPECIFICATION left by the said George Davies at the
Office of the Commissioners of Patents, with his Petition, on the
21st June 1856.
I, GEORGE DAVIES, of the Office for Patents, 1, Serle Street, Lincoln's Inn,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN APPARATUS FOR MEASURING AND IN-
DICATING THE LEAKAGE OF VESSELS," a communication to me from Reuben
Shaler, of Madison, Connecticut, in the United States of America, to be as
follows:-
This Invention (which it is proposed to call "the hydro-pneumatic leakage
meter,") is designed for the purpose of ascertaining and indicating the amount
of leakage or depth of water in the hold of a vessel. The principal feature of
novelty in the Invention consists in giving motion to an index for shewing the
depth of water in the hold by means of the compression of air within a tube
by the leakage water. The lower end of the said tube is immersed in the
water, and reaches down to nearly the bottom of the hold, and its upper end

page_text: extends to a convenient height in the cabin or other suitable part of the vessel.
At the upper end of the tube a chamber is formed, the upper part of which is
furnished with an air-tight elastic cover formed of india-rubber or other
suitable elastic material, and composed of a series of annular or diaphragm-
shaped plates, joined together alternately at their outer and inner circum-
ferences, so as to constitute an elastic spring of a circular bellows form, the
upper plate being made whole for the purpose of preventing the escape of air
through it. The number of sections required to form the spring will depend
upon the depth of the hold of the vessel, a shallow vessel requiring a smaller
number than a deep one. To the upper section of the spring a standard is
connected, the upper part of which is formed as a toothed rack, and gears with
a small toothed pinion, the spindle of which carries an index or pointer; this
index moves over the surface of a dial attached to a case fixed over the
upper end of the tube; the dial is divided into feet and inches, corresponding
with the depth of the vessel, the position of the divisions being ascertained by
experiment. As the water rises in the hold of the vessel, the compression of
the air in the tube will cause tho clastic bellows spring to elongate, and thus,
by means of the toothed rack and spur pinion, give motion to the index, and
cause it to point out the number of feet and inches of water in the hold of
the vessel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Davies in the Great Seal Patent Office on tho
. 19th December 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
DAVIES, of the Office for Patents, 1, Serle Street, Lincoln's Inn, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent bearing date the Twenty-first day of June, 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 George
Davies, Her special licence, that I, the said George Davies, my executors,
administrators, and assigns, or such others as I, the said George Davies, 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

page_text: United Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN APPARATUS FOR MEASURING AND
INDICATING THE LEAKAGE OP VESSELS," a communication from Reuben Shaler, of
Madison, Connecticut, in the United States of America, upon the condition
(amongst others) that I, the said George Davies, my executors or administra-
tors, 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 George Davies, do hereby declare the
nature of the 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, and on reference to the Drawings hereunto annexed, that is to
say:-
This Invention (which it is proposed to call "the hydro-pneumatic leakage
meter,") is designed for the purpose of ascertaining and indicating the amount
of leakage or depth of water in the hold of a vessel. The principal feature of
novelty in the Invention consists in giving motion to an index for shewing the
depth of water in the hold of a vessel by the compression of air within a tube
by the rising of the leakage water. The lower end of the said tube is immersed
in the water, and reaches down to nearly the bottom of the hold, and its upper
end extends to a convenient height in the cabin or other suitable part of the
vessel. At the upper end of the tube a chamber is formed, the upper part of
which is furnished with an elastic air-tight cover formed of india-rubber or
other suitable elastic material, and composed of a series of annular or dia-
phragm-shaped plates joined together alternately at their outer and inner cir-
cumferences, so as to constitute an elastic spring of a circular bellows form, the
upper plate being made entire for the purpose of preventing the escape of air
through it. The number of sections required to form the spring will depend
upon the depth of the hold of the vessel, a shallow vessel requiring a smaller
number than a deep one. To the upper section of the spring a standard is
connected, the upper part of which is formed as a toothed rack, and gears with
a small toothed pinion, the spindle of which carries an index or pointer; this
index moves over the surface of a dial attached to a case which is fixed over
the upper end of the tube; the dial is divided into feet and inches, correspond-
ing with the depth of the vessel, the position of the divisions being ascertained
by experiment. As the water rises in the hold of the vessel, the compression
of the air in the tube will cause the elastic bellows spring to clongate, and

page_text: thus, by means of the toothed rack and spur pinion, give motion to the index
and cause it to point out upon the dial the number of feet and inches of water
in the hold of the vessel.
The method of carrying this Invention into practical effect will be more
clearly understood upon referring to the annexed Sheet of Drawings, and to
the figures and letters of reference marked thereon. Figure 1 is a per-
spective view of the exterior of the apparatus, and Figure 2 is a vertical section
taken through about the middle of the same. A is a metallic tube, which
extends downwards to the bottom (or nearly so) of the hold of the vessel.
The upper part of this tube is formed into a chamber B, part of the exterior
surface of which at b is reduced in diameter, and has a screw thread cut upon
it to allow of the nut C being screwed down upon it. The nut C has an
interior flange c upon its upper edge, of about the same internal diameter as
the chamber B, and its exterior surface is made to coincido with the exterior
surface of the chamber B, so that the two, when screwed together, shall present
a plane surface on the outside. D is an india-rubber spring of a circular
bellows form composed of one or more sections of double diaphragm-shaped
plates, the lower plate d being of rather larger diameter than the other, so as
to allow of its outer edge being embraced and secured by the flange c of the
nut C, which also makes an air-tight joint. The top plate d* of the spring is
made entire to prevent the escape of the air. I would here remark that this
method of constructing the elastic spring allows of a greater amount of motion
than could be obtained by a spring made of a single plate of india-rubber,
without making the same inconveniently large. E is a standard secured in
an air-tight manner to the upper plate d* of the spring; the upper part e of
this standard is formed into a toothed rack, which gears with a spur pinion F,
and gives motion to it. The pinion F is keyed upon a shaft or arbor f, the
other end of which projects through the dial plate G, and carries an index or
pointer H. I is the exterior casing of the apparatus; and K is a bracket by
means of which it may be secured in its position in the cabin or other part of
the vessel as desired. Each instrument is tested by attaching to it the length
of tube required to reach the bottom of the hold of the vessel, and inserting the
same in a test pipe closed at the bottom, and furnished with apertures at each
foot of its height, which is then filled with water to the level of the extreme
height to be indicated on the dial. The compression of the air within the tube
A and chamber B by the rising of the water in the former, causes the spring D
to elongate, and raise the standard E, thus causing the pinion F and pointer H
to revolve; the indication is then marked on the dial, and the water let out of
the test pipe to the next foot in height, and the dial similarly marked, and so

page_text: on until the water reaches the bottom of the tube which gives the zero indi-
cation; or the operation may be reversed, commencing with zero and adding
a foot of water at a time until the desired height is indicated. A coiled spring
may be connected to the pinion shaft to assist the retrograde motion of the
index (a stop being placed on the dial to prevent the index from going back
beyond the zero indication), or a counter-weight may be attached to the
standard E for the same purpose if desired; but in practice they are found
unnecessary, as the elasticity of the india-rubber spring is amply sufficient for
the purpose.
The apparatus may be placed in the cabin or other convenient part of the
vessel as may be desired, where the indications may be plainly perceived by
every person inspecting it, and will at all times shew unerringly the depth of
leakage water in the hold of the vessel without the necessity for sounding the
pumps.
Having thus described the nature of the said Invention, together with the
manner of carrying the same into practical effect, I would remark in con-
clusion, that I claim as the Invention communicated to me,-
Firstly, employing the compression of the air in a tube caused by the rising
of the water therein, to give motion to an index for shewing the depth of water
contained in the hold of a vessel.
Secondly, the construction of the circular bellows-shaped elastic spring D.
And, thirdly, the combination of the tube A and chamber B with the
spring D, standard E, pinion F, and index H, substantially as and for the
purposes herein-before set forth.
In witness whereof, I, the said George Davies, have bereunto set my
hand and seal, this Eighteenth day of December, in the year of our
Lord One thousand eight hundred and fifty-six.
Signed and scaled in the presence of
BRISTOW HUNT,
Solicitor & Patent Agent,
GEORGE DAVIES. (L.B.)
1, Serle Street, Lincoln's Inn.