IMPROVEMENTS IN SOUNDING INSTRUMENTS
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of the firm of J. C. Robertson & Co., of No. 166,
Fleet Street, in the City of London, Patent Agents, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminsters, the Nineteenth day of
December, One thousand eight hundred and fity-one, in the fifteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Richard Archibald Brooman, my exors, adññiors, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said Richard
Archibald Brooman, my exors, adñiors, and assigns, or such others as I, the
said Richard Archibald Brooman, my exors, adññiors, 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, use, exer-
cise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, in the Islands of Guernsey, Jersey, Alderney, Sark, and Man, and
also in all Her said Majesty's Colonies and Plantations abroad, the Invention
of "IMPROVEMENTS IN SOUNDING INSTRUMENTS," communicated to me from
abroad, in which said Letters Patent is contained a proviso, that 1, the said
Richard Archibald Brooman, shall cause a particular description of the nature
of the said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be enrolled in Her said
Majesty's High Court of Chancery within six calendar months next and

page_text: immediately after the date of the said in part recited Letters Patent, as in
and by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Richard Archibald Brooman, hereby declare that the nature of the said
Invention, and the manner in which the same is to be performed, are fully
described and ascertained in and by the present Specification thereof, reference
being bad to the Drawings hereunto annexed (that is to say):-
Figure 1 of the annexed Drawings exhibits an external elevation of a
sounding instrument embracing the said improvements in its complete state,
but detached from an outer casing in which it is enclosed for the sake of pro-
tection, and also of giving additional weight; Figure 2 is a front longitudinal
section of the instrument as enclosed in its outer casing; and Figure 3, a
transverse section on the line a, y, or a top view of the instrument, supposing
the cap E removed; B and A are two tubes (which may be of any relative
diameter, though in practice it is preferred that B should be about double
that of A), one (A) is of glass, and the other (13) of metal, and both are
enclosed in a larger tube of metal W. The glass tube A has a separate
casing F, within which it is eccentrically fixed by means of a packing of
plaister of Paris, so that it may at one side come up against and be seen
through a long slit s left in the side of the tube W, and a corresponding one
in the casing F; E, E', are caps which screw on to the tube W at top and
bottom. The portions of W exterior to B and F are filled up with lead or
some other like solid material; A and B communicate with one another at
top through a spiral channel d formed by the insertion of two small buttons
d', d', at the top of B, there being a stop in the channel which causes the
water to make a complete revolution before it enters into or is discharged
from the tube B, thereby preventing the escape of air when the instrument is
in a horizontal position, or even when inverted, but the tubes A and B have
no communication with the outside except through an aperture 6 at the
bottom of B, and occasionally through a passage tapped in the cap E, when
the same is opened (by means of the stop-cock C), for the purpose of obtaining
access to the interior of the glass tube A; H, I, is a strong iron case or
frame. within which the whole is enclosed, having openings I, I, at the side
through which the water may have access to the aperture 6 in the bottom of
the tube B; K is a scale of numbers affixed alongside of the slot s to indicate
the height to which the water ascends in the tube A, and which height
becomes the measure of th depth of water outside on the principle to be next
herein-after explained. The instrument being attached to the end of the deep

page_text: sea line and lowered overboard, the water enters through the aperture 6 in the
bottom of the tube B, forces up and compresses the air in the inter-communi-
cating tubes A and B with a force exactly proportionate to the depth to which
the instrument descends. Now, the amount of the atmospheric resistance
being a fixed and known quantity, and the weight of a column of sea water
being also a fixed and known quantity, it follows that the height of the column
of water in the glass tube A must always be an exact proportion to the depth
of water outside. Thus assuming the pressure of the atmosphere to be in
round numbers fifteen lbs. per square inch, and that to be equivalent to thirty-
two feet of sea water, then a pressure of one atmosphere would indicate a
depth of five and one-third fathoms, a pressure of two atmospheres a depth of
ten and two-thirds fathoms; a pressure of three atmospheres, a depth of
sixteen fathoms, and so on progressively. I therefore first ascertain by ex-
periment the exact pressure required to make the water begin to overflow
from B to A, and adopt that point at the commencement of the scale.
Suppose it to be 45lbs. to the square inch, this would give sixteen fathoms on
the scale, then another atmosphere or 60lbs. would give 21, and so on pro-
gressively. However, it must be observed in practice, that as no two glass
tubes are ever found precisely alike in diameter, it is impossible to form
beforehand a scale of numbers suitable for all tubes, and such a scale there-
fore can only be arrived at in each and every case by actual experiment. I find
it convenient for this purpose to gauge a number of these instruments at a
time, say twenty or thirty, enclosing them in a strong cylinder filled with
water, the top of which is firmly screwed down and applying the hydraulic
pressure at the bottom. No average result obtained in this way can pretend
to literal or theoretical exactness, but it will be found sufficiently near the
truth to exclude any serious amount of practical error.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that what I claim is the con-
struction of sounding instruments in such a manner that the pressure of the
water into which they are made to descend, shall cause an indicator or register
tube enclosed therein to be filled with water (or other fluid) to a height
exactly proportionate to the depth of the lescent or sounding, as also the
graduated scale K, the spiral channel d and the outer casing H, H.
In witness whereof, I, the said Richard Archibald Brooman, have
hereunto set my hand and seal, this Eighth day of May, in the year
of our Lord One thousand eight hundred and fifty-two.
R. A. (L.S.) BROOMAN.

page_text: AND BE IT REMEMBERED, that on the Eighth day of May, in the
year of our Lord 1852, the aforesaid Richard Archibald Brooman came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Enrolled the Eleventh day of June, in the year of our Lord One
thousand eight hundred and fifty-two.