Sounding Apparatus for Purposes of Navigation.
Year: 1899

page_text: Date of Application, 10th Jan., 1899-Accepted, 11th Feb., 1899
COMPLETE SPECIFICATION.
Sounding Apparatus for Purposes of Navigation.
We, ZERA LUTHER TANNER, care of the Navy Department, Washington,
D.C., U.S.A., Commander, retired, U.S.N., and JOHN BELL BLISH, care of the
Navy Department, Washington, D.C., U.S.A., Lieutenant, U.S.N., do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
A sounding apparatus invented by Sir William Thomson, (Lord Kelvin) has
been much in use, in which a glass tube, coated with a chemical on its inner
surface, is used to indicate or register the depth to which the tube may be
immersed. This device is very effective and satisfactory, but as the chemically
prepared tube can seldom be used more than once, a ship on a long voyage, or a
cruiser on duty must carry a large number of such tubes in order to be fairly
equipped. The object of the present invention is to produce tubes which will
indicate the depth of water to which they have been submerged for a length of
time sufficient to effect measurement, and which tubes may be used repeatedly.
Referring to the drawings:
Fig. 1 represents a tube, in broken section, according to this invention;
Fig. 2 represents the measuring scale;
Fig. 3 is a broken sectional view of a hollow sounding lead with the registering
tube inclosed;
Fig. 4 is an elevation, partly sectioned, of a light casing of metal with the
registering tube inclosed;.
The glass tubes A, for convenient use are preferably say 20 to 28 inches in
length, and about one-eighth inch in internal diameter, being uniform as near
as may be.
The inner surface of the glass tube A is ground, either by actual abrasion of
sand and a rubber, or by the chemical action of fluoric acid.
We have been able to grind such tubes effectively by the use of a rod provided
with a rubber carrying emery or other abradant. The grinding can best be
done when the tuhe is open at both ends.
One end of the tube A is closed by a cap, which for convenience may be a
metal cap B. We have used brass caps, cemented to the tubes. A screw plug C
makes an air tight stopper for the cap. In use the upper end of the tube must
be closed "air tight," and should a test show any leakage the joint must bo
closed by wax, or a gasket.
As in using the Thomson tube, well known in this art, the tube A is let
down into the water attached to any usual sounding line or apparatus. So long
as the closed end of the tube is higher than the open end, the pressure of water
will compress the air in the tube, and the water will enter the tubo to a distance
proportioned to the submersion, and to practically the same distance whether the
tube he in perpendicular position or not.
When water enters the ground glass tube A, it changes the opaque appearance
of the hore of the tube, and renders the tube transparent. When the inside of
the tube has been thus wet and rendered transparent, it will so remain for some
FD 077

page_text: time, say from half an hour to an hour under ordinary conditions, giving ample
time for measurement.
While the tube A might be graduated, we find it less expensive to use a
graduated scale, such as D, against which the tube is placed to measure the
submersion. A trough-like instrument with the scale marked thereon, can
receive the tube after sounding, and the line dividing the transparent and
opaque portions of the tube will indicate on the scale the depth of immersion.
The scale can be made from measurements, in the first instance, and then if the
tubes are made with care, the tubes and scales may be duplicated with sufficient
accuracy for ordinary soundings say of five to fifty or one hundred fathoms. If
great accuracy is desirable, the tubes can be tested separately, or in groups,
and any
aberration of any tube noted. Tubes may be numbered and notes of
aberration retained.
To dry the tuhe the plug C may be removed, and by suction, air may be
drawn through the tube, and the tube thus dried in a minute or less, when the
bore will resume the usual opaque appearance of ground glass, and the tube
is ready for further use. Air may be blown through the tube to dry it, but
it dries more quickly by suction. There is no limit to the number of times the
tube may be used.
To protect the tube A while in use we have found it convenient to inclose it
in a tubular box E, either packed with rubber or cork rings, such as F, er
without such packing. Box E may be a brass tube, a little longer than the tube A,
and sufficiently large to receive such tube loosely. A cover E' is attached to
the box by a bayonet fastening. Chain G prevents loss of the cover. Loops H
serve for attachinment to the lead line. Preferably the box E is open for the
free admission of water, so that the water forms a cushion about the glass tube.
In any case the box E should be open at the bottom, so that the sea water
may enter and compress the air in tube A. A cross wire E prevents tube A
passing out at the bottom of box E.
A sounding lead K may be made hollow to receive tube A. In such case it
is well to stiffen the lead by a hard metal tube E inclosed therein, such tube E
being more rigid than lead."
The lead K preferably has a bail K¹ for attachment of the lead line, and this
bail can be swung aside to permit the opening of cover E.
An opening, as K³, permits the entrance of water to the tube within the
hollow sounding lead.
Other forms of protecting boxes or inclosures might be used to protect tube A.
Those above described have been found very satisfactory in actual use, and the
tubes A have been found reliable and economical.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:—
1. A glass tube of small diameter and ground on its inner surface practically
throughout its length, and sealed at one end, for the purpose set forth.
2. The ground glass tube of small diameter, ground on its inner surface, and
having a metallic end piece and a removable plug therein, so that air may be
forced through the tube, to dry the same.
3. The hollow sounding lead stiffened by an inclosed tube of hard metal, and
having means for the ready introduction of the glass registering tube A, and
provision for protecting said tube A and for admitting water to the said tube.
Dated this 9th day of January 1899.
CRUIKSHANK. & FAIRWEATHER,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow, Agents for the Applicants.