MEANS FOR INDICATING THE DEPTH OF WATER IN SHIPS AND VESSELS
Year: 1825

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
ASHWELL TABOR, of Jewin Street, Cripplegate, in the City of London,
Gentleman, send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fourteenth day of December, in the sixth year of His
reign, did, for Himself, His heirs and successors, give and grant unto me, the
said James Ashwell Tabor, His especial licence that I, the said James
Ashwell Tabor, my exors, adñors, and assigns, or such others as I, the said
James Ashwell Tabor, my exors, admors, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, usc, excrcise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, and
also in all His said Majesty's Colonies and Plantations abroad, my Invention
of "MEANS FOR INDICATING THE DEPTH OF WATER IN SHIPS AND VESSELS;"
in which said Letters Patent is contained a proviso obliging me, the said
James Ashwell Tabor, by an instrument in writing under my hand and scal,
particularly to describe and ascertain the naturo of my said Invention, and
in what manner the same is to be performed, and to cause the same to be
enrolled in His said Majesty's High Court of Chancery within two calendar
months next and immediately after the date of the said recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, 1, the said
James Ashwell Tabor, do hereby declare the nature of my said Invention
to consist in placing on the deck of a ship or vessel an index connected with
floats, which rise or fall according to the increase or decrease of water in the
said ship or vessel, in such manner as always to show on deck the depth of
water in the hold or well. And in further compliance with the said proviso, I,
the said James Ashwell Tabor, do hereby describe the manner in which
my said Invention is to be performed by the following description thereof,
reference being had to the Drawing annexed, and the figures and letters
marked thereon, that is to say:-
DESCRIPTION OF THE DRAWING.
Figure 1 represents the situation of my said means or apparatus as placed
on board a ship supposed to be heeling to the starboard side, with a portion of
water in her hold, and supposed to be viewed from the after part of the ship,
looking forwards. A is the upper deck; B, the main deck; and C, the
orlop deck. The dotted line D represents the line of the mainmast, which
shows the vessel to be heeling to the starboard side; E is the keelson, and F is
the keel. G represents the outer planking, it being thought quite unneces
sary to shew the framing of the ship for the purposes of my said Invention.
H is a dial plate with two indices, the shaft of one turning within and inde-
pendently of the other. This dial plate is supposed here to be placed just
abaft the mainmast, and may be set into any convenient kind of framework or
casing.
The mode of acting upon the indices of the dial will be more particu-
larly explained hereafter, so I will next proceed to describe the means used to
connect the indices with the floats. The line a, colored blue, represents a
small chain, led over and partly round, and fastened to a pulley or drum fixed
on the axis of the index marked L, as will be more particularly shown here-
after, and b, b, b, is a wire connected with the chain a, and leading down into
the hold of the ship, where its lower end is connected with another chain
marked C, and colored blue. This lower chain has a bob or float e attached to
it, with a swivel to prevent its fouling. K is a copper chamber or casing,
perforated with holes to admit the water from the surrounding places, and
formed in the limber, and , r, are two friction rollers to serve as guides for the
float chain c. It will of course be necessary that there should be a counterpoise
to the float e, and this is obtained as follows:- is a small chain passing over,
partly round, and fastened to a second pulley or drum on the shaft of the
index I., and leading downwards into the box M. At the lower end of the

page_text: chain f is a small weight i, and it will be seen that the box M is provided
with friction rollers similar to those before described, to serve as guides for the
chain f.
I have now described the means I use for communicating with the dial
from the hold of the ship or vessel on the larboard side of the keel, and it is
only necessary to observe of the remaining parts of this Figure that they
represent a similar arrangement for communicating from the starboard sido
with the index marked S.
It will now be necessary that I should describe the pulleys and axes of the two
indices by reference to Figure 2. I will then revert to Figure 1 to explain the
particular action of the apparatus. Figure 2 is a side view of the axis or
shafts of the indices; the shaft P passes through the shaft R, and P is the
shaft of the index marked L, and R is the shaft of the index marked S. On
cach shaft there is one large and one small pulley, the large one is connected
with the float and the small one with the weight or counterpoise; and the
object of the difference in size of the two pulleys is that the action of the
weights may be very small compared with the action of the floats, for the
convenience of having this part of the apparatus small. And I will here
observe, that springs may be used instead of the weights, but may be objcc-
tionable in consequence of the action of the salt water upon them.
I will now proceed to describe the general action of the apparatus, and for
this purpose must revert to Fig. 1. This Figure 1 represents a vessel heeling
to the starboard side; the water in the hold has raised the starboard float up a
considerable distance in the starboard float case, and a consequent depression
of the weight has taken place in the starboard weight box. The water having
receded from the larboard float case, the float e is lying at the bottom of the
case, and the weight i in the larboard weight box is consequently raised to its
greatest height, namely, up to the friction rollers. The elevation of the float
in the starboard float case, and consequent depression of the weight in the
starboard weight box, causes the index marked S, which is in fact the starboard
index, to indicate the number of inches or feet of water in the hold; for it
should here be observed, that there must be two indices, since when the vessel
heels the float on the windward side may not sometimes be acted upon, and
therefore it is that I call one the starboard index, and the other the larboard
index.
Now whereas my said means or apparatus for indicating the depth of water
in ships or vessels may be placed within the ordinary well case, or may have a
case appropriated to itself, and may be either generally cased in, or may have
cases fitted to each wire and chain, as may best suit the circumstances of its

page_text: particular application. But what I claim as my Invention is, the means or
apparatus for indicating the depth of water in ships or vessels, described in the
Drawing annexed, and placed in any suitable part of a ship or vessel; and
such means being, to the best of my knowledge and belief, entirely new, and
never before used within that part of His said Majesty's United Kingdom of
Great Britain and Ireland called England, His said Dominion of Wales, or
Town of Berwick-upon-Tweed, nor in any of His said Majesty's Colonies or
Plantations abroad, I do hereby declare this to be my Specification of my said
Invention, and that I do verily believe this my said Specification doth comply
in all respects, fully and without reserve or disguise, with the proviso in the
said herein-before in part recited Letters Patent contained; wherefore I do
hereby claim to maintain exclusive right and privilege to my said Invention.
In witness whereof, I, the said James Ashwell Tabor, have hereunto
set my hand and seal, this Tenth day of February, in the year of our
Lord One thousand eight hundred and twenty ci