IMPROVEMENTS IN MARINE AND SURVEYING COM- PASSES.
Year: 1853

page_text: LETTERS PATENT to Paul Cameron, of Glasgow, in the County of
Lanark, North Britain, Nautical Instrument Maker, for the
Invention of "IMPROVEMENTS IN MARINE AND SURVEYING COM-
PASSES.
Sealed the 15th September 1853, and dated the 18th March 1853.
the said Invention for "IMPROVEMENTS IN MARINE AND SURVEYING COM-
PASSES" to be as follows:-
This Invention relates to various improved arrangements connected
with the mariner's and surveyor's compass, and refers, first, to the
compensation for the vibrating motion of the compass card, by attach-
ing a brass rod, having a ball attached at each end; one ball being
fitted into a socket in the bottom of the compass case, whilst the other,
which is larger, swings upon the rod, as suspended on the upper ball

page_text: as a centre, and thus compensates for the oscillations. Again, one half
of the compass card is divided into a series of triangles, the edge of the
needles being graduated, so that, as the needle works round over the
triangles, the mariner may at once see his actual route on comparison
with the distance run. To the centre of the compass card or needle
is attached is attached a small vertical style, so that the shadow of such
style, being compared with the dial table, furnishes a a means for at
once ascertaining the variation. To the north pole of the compass-
box is fixed a brass case, containing a slip of brass divided into degrees
of the tangent, and one of the sides is divided into a line of numbers
to give the altitude, corresponding to a base line of 100, which may
be increased by multiplying or dividing according to the proportion of
the numbers. To the south pole of the compass-box is fixed a small
telescope, with cross sights for reading off degrees of altitude and
heights of objects, so that the compass may be applied in azimuths and
altitudes of objects, and for the ordinary purposes of surveying. For
the purpose of rectifying, the compass is suspended within a brass ring,
the exterior of which is grooved, and has a tangent screw working
in it; so that, by this screw, the compass may be set to the magnetic
meridian at any time. And to ascertain and adjust the proper dimen-
sion of the copper correcting ring for the oscillations, a solid ring is
first taken, and fine copper wire is wound upon it, until its section is
increased sufficiently for the intended purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Paul Cameron, in the Great Seal Patent Office,
on the 17th September 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
PAUL CAMERON, of Glasgow, in the County of Lanark, North Britain,
Nautical Instrument Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of March, in the year
of our Lord One thousand eight hundred and fifty-three, in the six-
teenth year of Her reign, did, for Herself, Her heirs and successors,

page_text: give and grant unto me, the said Paul Cameron, Her special licence
that I, the said Paul Cameron, my executors, administrators, and
assigns, or such others as the said Paul Cameron, my executors,
administrators, or 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 United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN MARINE.
AND SURVEYING COMPASSES," upon the condition (amongst others) that I,
the said Paul Cameron, by an instrument in writing under my hand
and seal, 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 Paul Cameron, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying draw-
ings, and to the letters and figures marked thereon, that is to say:
My said Invention relates to various improved arrangements con-
nected with the mariner's and surveyor's compass; and refers, first,
to the compensation for the vibrating motion of the compass card, by
attaching a brass rod, having a ball at each end; one ball being fitted
into a socket in the bottom of the compass case, whilst the other,
which is larger, swings upon the rod, as suspended from the upper ball
as a centre, and thus compensates for the oscillations. Again, one
half of the compass card is divided into a series of triangles, the edge
of the needle being graduated, so that, as the needle works over the
triangles, the mariner may at once see his actual route on comparison
with the distance run. To the centre of the compass card or needle
is attached a small vertical stile; the shadow of such stile, being com-
pared with the dial tables, furnishes a means for at once ascertaining
the variation and deviation. To the north pole of the compass box
is fixed a brass case, containing a slip of glass divided into degrees of

page_text: the tangent; and one of the sides is divided into a line of numbers, to
give the altitude corresponding to a base line of 100, which may be
increased by multiplying ог dividing according to the proportion of the
numbers. To the south pole of the compass box is fixed a small
telescope, with cross sights, for reading off degrees of altitude and
heights of objects, so that the compass may be applied in azimuths
and altitudes of objects, and for the ordinary purposes of surveying.
For the purpose of rectifying, the compass is suspended within a brass
ring, the exterior of which is grooved, and has a tangent screw working
in it; so that, by this screw, the compass may be set to the magnetic
meridian at any time; and to ascertain and adjust the proper dimension
of the copper correcting ring for the oscillations, a solid ring is first
taken, and fine copper wire is wound upon it, until its density is suffi-
cient for the purpose.
Figure 1, on my sheet of drawings, is a vertical section of my im-
proved compass, as suited for marine purposes. Figure 2, is a plan
of the compass corresponding; but with telescope, and its collateral
details, removed. Figure 3, is a full size plan of the improved com-
pass card, with the magnetic needle in position, shewing the action of
the triangular divisions on the face. Figure 4, is a vertical section of
the compass frame, with the compass in external elevation within it,
as arranged when the attached telescope is not in use; and Figure 5,
is a side elevation of a separate graduated sight frame, for adjustment
to the compass at pleasure. The compass is contained in a case A,
as usual; the needle case B, being freely suspended from the upper
portion of the case A, by the universal joint ring arrangement C, of
the common kind. It is for the purpose of preventing the too great
oscillation or vibratory action of the needle and index card case B,
that the first part of my Invention is employed. This consists of a
short brass rod D, formed with a small ball or spherical piece E, at
its upper end, which spherical piece fits into a corresponding concavity
in the bottom of the needle case. This forms a ball or universal joint
for the free movement of the rod D, upon it as a centre of suspension.
The lower end of the rod D, has fast upon it a second, but larger, ball
or weight F, of iron or lead, and the action of this contrivance is to

page_text: check the oscillation of the compass card vibrations, by means of the
reverse counteracting vibratory movement of the weight F. As the
needle case moves, the ball moves also; but as the latter is loosely
jointed to the case, it follows that the vibrations of the weight F, being
from a different centre, act in opposition to those of the case B, and
speedily check its movement. The iron ball is to be used in stormy
weather, and the lead one at other times. As pointed out in Figure 3,
of my drawings, one half of the compass card-the lower half in the
present instance-is divided off into a series of triangles G, the needle
H, being suspended over the card. This modification is intended both
for surveyors and mariners; the edge of the needle H, being graduated
to suit the triangles G, so that, as the needle works round over the
triangles, the mariner may at once see his course by comparing the
difference between his latitude at any given time and that of his
original point of departure, with the actual distance which his ship
has run similarly the surveyor ashore can thus easily ascertain the
distance between two points. The mariner's compass needle I,
Figure 1, is suspended from its centre, in the ordinary manner; and
on the needle, directly above the centre of motion, is attached a vertical
stile or gnomon J, standing up exactly at right angles with the line of
the needle. In reference to this stile, I have arranged a series of
tables to be used in connection with the points of the stile shadow at
any determined time of observation; that is to say, the mariner notes
the line of the stile shadow, and, comparing this with the proper table,
he at once ascertains from these data what is the magnetic variation
both local and terrestrial. These dial tables are so constructed that
the shadow of the stile shall correspond to the apparent time of day;
hence, on taking an observation of this kind, if the shadow is before
or after the true point, the difference is the amount of variation east
or west, as the case may be. Again, if the sun or stars are not visible,
the variation and deviation may be found by placing an artificial light
on the azimuth ring K, to correspond with the arrangement of the
tables. In the upper part of the interior of the containing case A, is
a graduated brass ring K, one half of which is divided into 180 degrees,
and within this is the gimbal ring L, suspended by its centres at zero,

page_text: and at 180 degrees of the ring K. In some cases, the bizel, or outer
ring of the compass bowl, is divided in a similar manner. To the
north and south poles of the graduated ring K, are attached the two.
studs M, N, for holding a telescope or telescopic quadrant O, and
base P, respectively; these details being intended for taking altitudes
and distances; and the base P, also carries a sliding brass rod Q, to aid
the observer in reading off the indications, as well as a spirit level for
the requisite adjustment. The telescope O, has upon it a line of num-
bers, and a line of natural sines R, corresponding to the similarly
divided line on the base P. The exterior of the K, in the com-
pass box A, has a worm or screw thread cut round it, and into this
thread is fitted the worm or tangential screw S. In this way, by
turning round the worm S, the ring K, is caused to revolve until the
cross sight of the telescope cuts the intended object; the azimuth
thereof is given on the ring, whilst the altitude is given on the quadrant
or upright piece Q. To the south pole of the ring K, is attached a
brass frame piece T, fitted with a slip of glass U, which is divided into
degrees of the tangent. Thus, when the cross sight of the telescope
intersects the object viewed through the glass, the altitude of the object
is given on the glass instead of upon the quadrant. For the purpose
of rectifying, the compass bowl V, has fitted in it an inner copper
ring W, lined with layers of copper wire, so as to have the effect of
soothing the needle oscillations; more or less copper wire being applied
until the required density of metal is obtained.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I may observe, in conclusion, that I do not
confine or restrict myself to the precise details or arrangements which
I have had occasion to describe or refer to, as many variations may be
made therefrom without deviating from the principles or main features
of my Invention; but what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent, is,-
First, the general arrangement and construction of marine and sur-
veying compasses, as herein-before described.

page_text: Second, the application and use of a pendulous or swinging link or
rod, weighted at its lower end, and suspended from the bottom of the
compass bowl, for diminishing or compensating for the oscillation of
the latter.
Third, the system or mode of neutralising the needle oscillations in
stormy or heavy weather, by attaching an iron ball to the swinging
link, in place of the lead one ordinarily used.
Fourth, the system or mode of indicating courses or distances run,
by means of a graduated needle, working over a triangulated card or
index face.
Fifth, the system or mode of ascertaining the precise amount of
magnetic variation and deviation, by the use of a stile or needle attached
to the compass needle centre.
Sixth, the system or mode of ascertaining the precise amount of
magnetic variation and deviation in foggy or cloudy weather, by the use
of a stile or needle, attached to the compass needle's centre, in com-
bination with an artificial light placed on the azimuth ring.
Seventh, the application and use, in compasses, of a telescope and
base, for ascertaining the altitude of the sun, moon, and stars.
Eighth, the system or mode of finding the altitudes of objects, by
means of a separate attachable telescope and glass, or transparent
graduated slip.
In witness whereof, I, the said Paul Cameron, have hereunto set
my hand and seal, this Fifteenth day of September, in the
year of our Lord One thousand eight hundred and fifty-three.
PAUL CAMERUN. (L.S.)