Improvements in Ships' Compasses and in the Means for Adjusting the same.
Year: 1890

page_text: Date of Application, 27th Mar., 1890
Complete Specification Left, 29th Dec., 1890-Accepted, 14th Mar., 1891
PROVISIONAL SPECIFICATION.
Improvements in Ships' Compasses and in the Means for Adjusting
the same.
FREDERICK SMITH, 23, Oxford Street, Southampton, Optician, and GEORGE
WILSON HEATH, Crayford, Kent, Optician, do hereby declare the nature of this
invention to be as follows:-
According to this invention we greatly improve the present compasses and the
mode of adjusting them to meet the errors caused by local attraction in iron ships
and otherwise.
We provide a compass after the ordinary or Admiralty patterns preferably with
short needles, but varying in length according to the varying size of the compass.
We also preferably use liquid in the compass bowls either attached to the bezel
ring of the compass itself or upon a separate metal ring which can be fixed to the
bezel we place upon two three or more sides thereof as may be required a cage with
a screw or rack motion to this is attached a tubular case which can be raised or
lowered at pleasure in any convenient manner within this case we place magnets of
any required size. The position in relation to the bezel and compass needles
dependent from the compass card can be regulated by the screw or rack motion with
case to correct the errors of the compass.
We also use spring journals or springs resting upon a platform to carry the
compass to meet any vibration.
We place the compass preferably in a binnacle with healing error central magnet
and flinders bar with horizontal cylinders at either side containing one or more iron
tubes as correctors.
We provide a moveable cap to the top of the binnacle and we make a specially
arranged gimbal to fit within this cap top upon this gimbal we mount a dial or
dunb card with ships head pointers and sight vanes so that by these means the
correct magnetic bearings may be ascertained and by the aid of the aforementioned
adjustable magnets the compass within the binnacle may be corrected to these
ascertained bearings. When the top of the binnacle cannot be used we provide a
tripod to carry the dumb card the tripod has adjustable legs and can be fixed on the
bowl of binnacle.
Dated this 27th day of March 1890.
FREDERICK SMITH.
GEORGE WILSON HEATH.
COMPLETE SPECIFICATION.
Improvements in Ships' Compasses and in the Means for Adjusting
the same.
We, FREDERICK SMITH, 23, Oxford Street, Southampton, Optician, and
GEORGE WILSON HEATH, Crayford, Kent, Optician, 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 :--
According to this invention we greatly improve the present compasses and the
mode of adjusting them to meet the cardinal and other errors caused by local
attraction in iron ships and otherwise.
We make the compass after the ordinary or Admiralty patterns preferably with
short needles but varying in length according to the varying size of the compass.
We also preferably use liquid in the compass bowl.

page_text: Figure 1 of the accompanying drawings is a vertical section and Figure. 2 a plan
of a compass bowl with needles, card and correctors. Upon the bezel ring A or as
here shewn upon a separate metal ring B fixed to the bezel we place upon each of
three sides thereof (or upon two sides or all four sides) a cage consisting say of an
upper member C a lower member C' and two studs C which unite them. To this
cage is adjustably attached by a screw D (or it might be an endless screw and a
toothrack or other suitable adjusting gear) a tubular case E. Within each case E
we place one or more magnets F (four are shewn as an example), of any convenient.
size for correcting the cardinal error. The screws D serving to raise or lower the
cases E, the magnets F therein can thus be brought in the desired position relatively
to the bezel and compass needle G. HH are springs for supporting the compass
bowl K in the gimbal ring I.
In the vertical section Figure 3 and plan view Figure 4 the compass bowl K is
shewn provided with brackets having conical pegs L each resting in a cup I' which
is supported on a volute spring 12 that is contained in a small cage I³ fixed or formed
on the interior of the gimbal ring 1.
We place the compass preferably in a binnacle with heeling error central magnet
and flinders bar with horizontal cylinders at each side containing one or more tubes
as correctors. a a are cases which by means of brackets or in any other suitable
manner are attached to the binnacle e and contain each a tubular iron cylinder
serving as corrector.
We provide a removable cap to the top rim M¹ of the binnacle M as shewn in
the vertical section Figure 5 and form the said rim with two notches wherein can
rest the two pivots N of a specially arranged gimbal ring N' to work within this
cap top rim M. Upon this gimbal ring N¹ we mount a dial or dumb card O with
ships head pointer l' and sights Q for ascertaining the correct magnetic, bearing
and then correcting the compass within the binnacle by the means above described.
Another tripod arrangement applicable where the top of the binnacle cannot be
used is shewn in Figure 6. The three legs W are hinged to the ring R to which
the azimuth instrument X is gimballed. The legs W have inner telescopic bars W
which can be made to clamp the rim of the bowl of the binnacle and are made fast
to the upper part by means of the set screws W. The azimuth instrument shewn
is the improved Heath's London Polaris ships course corrector described in Heath s
Patent Specification No. 2559 of 1889, but any other corrector may be mounted
and fixed to the same tripod appliance.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. One or more cardinal error correctors consisting each of a cage to which
is adjustably attached by means of screw gear a case holding one or more magnets,
and applied to the bezel or bezel ring of a compass, substantially as described and
shewn.
Second. The means substantially as described and shewn for elastic suspension of
the compass bowl.
Third. The means for attaching an azimuth instrument to the binnacle substan-
tially as described with reference to Figures 5 and 6.
Fourth. The cases a attached to the binnacle c and containing tubular
correctors.
Dated this 29th day of December 1890.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.