An Improved Artificial Horizon.
Year: 1894

page_text: Date of Application, 10th July, 1894
Complete Specification Left, 10th Apr., 1895-Accepted, 24th May, 1895
An Improved Artificial Horizon.
I, HENRY ARTHUR GADSDEN, of St. George's Club, Hanover Square, in the
County of London, Gentleman, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to an improved artificial horizon of the kind
described in the Specification of former Letters Patent granted to me No. 8150
of 1889 and which comprises a pin, rod or arm in combination with means for
supporting balancing and adjusting it in front of or behind the horizon glass of a
sextant, octant, quadrant or similar instrument in such a manner that the said pin,
rod or arm is adapted to serve as a substitute for or in lieu of the natural
horizon.
According to my present invention the beam carrying the pin that serves as the
artificial horizon, and which beam may be a balance beam or not as preferred, also
carries a sighting device such as a pair of connected parallel pins or a slotted pin or
it may be a plain pin arranged parallel with the first mentioned pin and it may be
with another pin that is co-axial with the centre about which the beam turns, the
arrangement being such as to facilitate the determination of the altitude of a
heavenly body or a distant object.
The first mentioned pin and the sighting device (or pin) may be placed on
opposite sides of the horizon glass of a sextant, quadrant or similar instrument.
For adjusting the exact position and speed of movement of the pin that serves
as the artificial horizon the beam is provided with a projection or arm that suitably
connects the beam with a pendulum whose axis of oscillation is preferably located
above the fulcrum of the beam and is provided with screw adjustments for raising
and lowering the axis of oscillation and for adjusting its position laterally. In one
arrangement the connection of the beam with the pendulum is effected by means of
a pin or arm that projects from the beam and extends through a hole in an arm
that projects laterally from the pendulum.
The adjustable pendulum may advantageously be used in connection with a beam
baving only one pin rod or arm.
D
י
1004
COMPLETE SPECIFICATION.
An Improved Artificial Horizon.
I, HENRY ARTHUR GADSDEN, of St. George's Club, Hanover Square, in the
County of London, Gentleman, 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 :-
This invention has reference to an improved artificial horizon of the kind

page_text: '
described in the Specification of former Letters Patent granted to ine
No. 8150 of 1889, and which comprises a pin, rod or arm in combination with
means for supporting balancing and adjusting it in front of or behind the
horizon glass of a sextant, octant, quadrant or similar instrument in such a manner
that the said pin, rod or arm is adapted to serve as a substitute for or in lieu
of the natural horizon.
According to my present invention, the bean carrying the pin that serves as
the artificial horizon, and which beam may be a balance beam, or not, as
preferred, also carries a sighting device such as a pair of connected parallel
pins, or a slotted pin, or it may be a plain pin, arranged parallel with the first
mentioned pin, and, it may be, with another pin that is co-axial with the centre
about which the beam turns, the arrangement being such as to facilitate the
determination of the altitude of a heavenly body or a distant object.
The first mentioned pin and the sighting device (or pin) may be placed on
opposite sides of the horizon glass of a sextant, quadrant or similar instrument,
hereinafter referred to as a sextant.
For adjusting the exact position and speed of movement of the pin that serves
as the artificial horizon the beam is provided with a projection or arm that
suitably connects the beam with a pendulum whose axis of oscillation is preferably
located above the fulcrum of the beam and is provided with screw adjustments
for raising and lowering the axis of oscillation and for adjusting its position
laterally.
In the accompanying drawings,
Figs. 1, 2 and 3 show respectively in side elevation, end elevation, and plan, an
artificial horizon constructed according to this invention, the outline of the box or
casing therefor being indicated by dotted lines.
1 is a balance bean pivoted on a pin 2 carried by a bearing 3 secured to the
main or rear plate 4 of a box or casing that is adapted to be fixed to a sextant
so as to be vertical when the sextant is in use. 5 is a pin that serves as the
artificial horizon, and 6 is a slotted pin that serves as a sighting device. These
pins 5 and 6 are secured to the beam i so as to project horizontally and at right
angles therefrom, and are arranged parallel with each other and with the outwardly
projecting end 2 of the pivot pin 2, as for the purpose hereinbefore stated. They
are arranged to work in curved slots 5 and 6 respectively in the plate 4 and
extend on opposite sides of the horizon glass of the sextant to which the casing is
attached. 7 is a pin or arm that projects downward at right angles from the
beam 1 and extends through a hole in an arm or bracket 8 that projects laterally
from a pendulum 9, the arrangement being such that a given relative movement of
the pendulum will cause a quicker movement of that end of the beam 1 carrying
the pins 5 and 6. The pendulum is pivoted at 10 to a block 11 that is capable of
being raised and lowered and also of being moved laterally for the purpose of
adjusting the position of the axis of oscillation of the pendulum when setting the
artificial horizon for use. For raising the axis of oscillation, the block Il is
suspended by a vertical screw 12 which works in it and rests upon the top of the
casing. For moving the axis laterally, the said block is arranged to slide vertically
in a stirrup-shaped guide piece 13 the upper end of which works in a slot in the
top of the casing, and through the sides of which works a horizontal screw'14,
the head 14 and a nut 14 on which, are screwed up against opposite sides of the
casing, so that upon rotating the said screw, the guide piece 13, block 11, and
screw 12 will be inoved horizontally to the right or left according to the direction
in which the screw 14 is turned.
A friction device may advantageously be combined with the pendulum to
prevent or reduce tremor thereof. A suitable device for this purpose consists
of a bar 15 pivoted to the pendulum at 16, and arranged to slide on a part 4*
of the casing that is horizontal when the artificial horizon is in use. To increase
the action of this friction bar, it may be forced against the pin or arm 7, with
more or less pressure, by a screw, not shown, but which is arranged to work

page_text: through the front plate of the casing and to act against the side of the said bar.
To facilitate the sextant carrying the artificial horizon being held in a truly
vertical position, as is necessary when measuring altitudes, there may be pivoted
to the plate 4, as shown, or to the sextant, a short pendulum 17 arranged to
swing in a plane at right angles to the said plate and having fixed at right
angles thereto, a needle 18 so arranged, that when the sextant is vertical, the
needle will be in the line of sight and parallel with the pins 2*, 5 and 6.
The adjustable pendulum 9 may advantageously be used in connection with a
beam 1 having only one pin, rod or aran, preferably the slotted pin 6, which then
serves as the artificial horizon.
I consider it advantageous to make the distance or height between the two sides
or legs of the slotted pin such that the said sides or legs will be tangential to
the highest and lowest points of the image of the sun as seen reflected in the
horizon glass.
By the use of two pins or appliances, the one in front and the other behind the
horizon glass brought in line of sight, greater accuracy in measuring is obtainable.
In lieu of using the slotted pin 6 in conjunction with the plain pin, there may,
as before indicated, be substituted a second plain pin like pin 5 in lieu of the
slotted pin 6.
or tastes.
•
As will be obvious, I do not confine myself to the shape of the casing, or to
the shape of the working parts, as the saine may be varied to suit requirements
Also the adjustment screws for the pendulum 9 may be placed elsewhere-
than shown in the drawings, for instance, they may be placed at the lower instead
of the upper part of the pendulum, or, providing great accuracy in workmanship
is observed, the adjustment screws may be partially or wholly dispensed with, but
in the absence of such accuracy, I prefer to provide screws arranged as shown!,
because adjustments are then more easily made than when they are arranged in
other positions.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed 1 declare that what I.
claim is :-
1. An artificial horizon of the kind herein referred to, in which the beam carrying
the pin that serves as the artificial horizon, also carries a sighting device such as a
pair of connected parallel pins, or a slotted pin, or a plain pin, arranged parallel with
the first mentioned pin, and it may be with another pin that is co-axial with the
centre about which the beam turns, substantially as herein described.
2. An artificial horizon of the kind herein referred to, in which the beam
carrying the pin or device that serves as the artificial horizon is provided with a
pin projection or arm through which and an arm, projection or bracket on the
pendulum, the beam and pendulum are connected as set forth, and in which the
pendulum is provided with screw adjustments whereby its axis of oscillation cau
be raised and lowered and moved laterally, substantially as herein described for
the purpose specified.
3. My improved artificial horizon constructed arranged and operating substantially
as described and shown, whether the beam 1 be provided with both pins 5 and 6, or
with either, or with two plain pins, and whether the apparatus be used with or
without the friction device 15 and the supplementary pendulum 17 with its pin 18
for the purposes mentioned.
Dated this 10th dor of Anil 1905
HENRY A. GADSDEN.
W. Lloyd Wise,
46, Lincoln's Inn Fields, W.C., Patent Agent for the Applicant.