IMPROVEMENTE IN CERTAIN NAUTICAL AND SURVEYING IN- STRUMENTS
Year: 1853

page_text: LETTERS PATENT to George Gowland, of No. 76, South Castle
Street, Liverpool, in the County of Lancaster, Chronometer and
Nautical Instrument Maker, for the Invention of "IMPROVEMENTS
"
PROVISIONAL SPECIFICATION left by the said Richard Gowland
at the Office of the Commissioners of Patents, with his Petition,
on the 15th July 1853.
T, GEORGE GOWLAND, do hereby declare the nature of the said
Invention for "IMPROVEMENTE IN CERTAIN NAUTICAL AND SURVEYING IN-
STRUMENTS" to be as follows:-
The Invention relates to nautical and surveying instruments capable
of measuring or indicating angles, and more particularly to sextants
and compasses, and it consists in certain arrangements for facilitating
the reading off of the angles or indications of such instruments. I
construct sextants and theodolites, and similar instruments, with one
or more dials, having a hand or hands which receive an increased or
multiplied motion from the motion of the instrument. This motion
being much greater than that of the instrument itself, enables the

page_text: degrees or graduations of the instrument to be read off with great
facility. The compass is made with a spherical graduated zone instead
of a flat card; and the graduations are placed on the exterior of this
zone; in proximity to which I place a hand or point. By this arrange-
ment the graduations of a ship's compass are rendered much more
conspicuous, and the compass may be raised to the level of the eye of
the stcersman, or even higher; and thus the local attraction of the iron
in the hull of the ship may be diminished. This cannot be done with
the ordinary compass without removing it out of sight of the steersman.
The compass so constructed may be used in a theodolite, in combina-
tion with the hands and dials first mentioned.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Gowland in the Great Seal Patent Office,
on the 11th January 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
GEORGE GOWLAND, of No. 76, South Castle Street, Liverpool, in the
County of Lancaster, Chronometer and Nautical Instrument Maker,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of July, in the year
of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said George Gowland,
Her special licence that I, the said George Gowland, my execu-
tors, administrators, and assigns, or such others as I, the said
George Gowland, 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 niake, 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 CERTAIN NAUTICAL AND SURVEYING
INSTRUMENTS," upon the condition, amongst others, that I, the said
George Gowland, by an instrument in writing under my hand and seal,

page_text: should particularly describe and ascertain the nature of the said Inven-
tion, 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 Gowland, do hereby de-
clare 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 thereof, reference being had to the accom-
panying Drawing, and to the figures and letters marked thereon, that
is to say:
Figure 1, is a front view of a mariner's compass constructed accord-
ing to my Invention; Figure 2, is a plan, and Figure 3, is a vertical
section of the same. The same letters refer to similar parts in each
Figure. A, is an arched bar of brass, supporting the gimbal ring B,
which carries the hemispherical brass cup C. D, is a hemispherical
glass, which is fitted into a brass ring E, by which it is attached to the
cup C. The parts C, and D, thus form a spherical box, which contains
the compass card F, and magnetic needles G. The card F, is made
of thin sheet copper or brass or other suitable material, and is of the
form of a zone of a sphere, with.the points of the compass painted on
its exterior. G, G, are the magnetic needles, which are fixed in the
interior of. the card, and may be either straight or curved. H, is a
cross bar, fixed to the card, and having a pin I, which rests in an
agate cup J. The agate cup is fixed in the upper part of the brass
bell K, which is supported by the pin L, the point of
hollow or cavity in the under side of the agate cup J.
which enters a
The pin I., is
fixed to the box C, which is loaded with a weight at M, to cause it to
assume the position shewn in the Drawing with the pin I, in a vertical
position. N, is a curved wire or a line marked on the glass, which
serves as the usual "lubber's line," and the compass is fixed in such
a position that this line or wire and the centre of the card may be
in a plane coincident with or parallel to a vertical plane passing through
the head and stern of the ship or vessel to which the compass is fitted
when such ship or vessel is in still water.
By constructing the compass in this manner, with the .points or
graduations. marked on the exterior periphery of the zone-shaped card

page_text: instead of upon the upper surface of a flat card, I am enabled to raise
the compass to a considerable height above the deck of the vessel, and
thus to diminish the effect of the local attraction of the iron work of the
vessel, and at the same time the indications are rendered very distinct,
and the steersman is enabled to sec both the head of the vessel and the
compass with a much less movement of his eye.
Figure 4, is a vertical section, shewing a box for containing spirits
of wine or other suitable liquid which may be employed for checking
the vibrations of the needles and card, particularly in stormy weather.
O, is the box, which is made of brass or other suitable material, and
suspended by gimbals I, on the stem Q, which is fixed in the compass
box in the place of the pin T. R, is a pin fixed in the, box O, and
carrying on its point the bell K, on which the card and needles are
supported as before. S, is a dished cover to the box O, having
central aperture of sufficient diameter to allow the upper part or neck
of the bell K, to pass freely through it. The liquid in the box O,
serves to check the violent oscillations of the bell K.
Figure 5, is an elevation of a theodolite with a compass constructed
according to my Invention. The compass card F, is a narrow zone
of a sphere, and the box D, is made of glass of a similar shape, or
it may be cylindrical, as shewn in the Figure. N, is the curved wire
or "lubber's line." The observer who looks through the telescope T,
at any distant object can readily cast his eye upon the compass card,
and note the bearing of the object. The horizontal and vertical angles
can be measured and read off in the usual manner, or the size of the
graduations may be increased by the application of a toothed wheel
and pinion, and a dial and index. Thus U, is a toothed wheel fixed to
or constituting the lower plate of the instrument. V, is a pinion, whose
spindle turns in a bracket W, fixed to the upper plate X, of the instru-
ment. Y, is an index attached to the spindle of the pinion V, and
working upon a graduated dial Z.
The vertical limb u, of the instrument is also toothed, and gears into
a pinion whose spindle turns in a bracket w, fixed on the horizontal
plate X. y, is an index attached to the spindle of the pinion, and
working upon the graduated dial z. The bracket w, has a single
line or a vernier at a. The indices may also be furnished with ver-

page_text: niers. The pinions may be so proportioned that each revolution of
the pinion may be equal to ten degrees or any other convenient
portion of the circumference of the horizontal or vertical limbs. The
indications are thus increased in dimensions, and may be subdivided as
required. The teeth of the wheels and pinions should be accurately
shaped and fitted to each other. The compass box D, is fixed upon
the plate X, and no gimbals are required, as the plate is levelled in the
ordinary manner before taking an observation. If, however, the
instrument be only roughly levelled, the card is capable of adjusting
itself a little on its pin so as to admit of its indications being read off.
This construction of compass may also be employed in lieu of the
ordinary compass in the different sorts of levels and other similar
instruments used in surveying as well as in theodolites.
Having new described the nature of my said Invention, and in what
manner the same is to be performed, I wish it to be understood that
I do not confine myself to the precise materials hercin-before men-
tioned as being employed in the construction of different parts of the
instruments, as the same may be varied, care being taken to avoid the
use of iron or steel where the same would injuriously affect the action
of the magnetic needles; but what I claim is,-
The constructing the cards of mariners' compasses, and the cards of
compasses used in surveying instruments, in manner herein-before
described.
In witness whereof, I, the said George Gowland, have hereunto
set my hand and seal, this Tenth day of January, in the year of
our Lord One thousand eight hundred and fifty-four.
Witness,
GEORGE GOWLAND. (L.S.)
GEO. P. KIRBY,
No. 3, Belmont Road,
West Derby Road,
Liverpool.