Improved Apparatus for Use in Determining a Ship's Bearings and Distance from given Bodies, and for like purposes.
Year: 1893

page_text: Date of Application, 13th July, 1893
Complete Specification Left, 2nd Apr., 1894-Accepted, 5th May, 1894
PROVISIONAL SPECIFICATION.
Improved Apparatus for Use in Determining a Ship's Bearings and
Distance from given Bodies, and for like purposes.
THOMAS D'OYLY BULKELEY Carlton Villa Klea Avenue Clapham Common
London S. W. Master Mariner do hereby declare the nature of this invention to be
as follows:-
To permit one or more bearings of a fixed or movable object or objects to be
taken by day or night, and with use of the distance run between the bearings or
known distance or distance between two objects to find the distance an observer is
or was off the objects or object at first second or other bearing, my invention may
consist of a suitable base or platform, on the centre line of which a dumb card
marked like an ordinary compass card revolves round a boss and is moved round
by a tangent screw, from the centre boss a metal arm graduated to equal parts
radiates, of a suitable length, for the present twelve inches, and upon this arm a
dumb card similar to the former one, slides, from the centre of each of these dumb
cards, a metal arm radiates, graduated to equal parts, and each of these arms may
be fitted with sight vanes, for taking bearings, and connected where they cross by
a slide, that the said two arms may be placed at any angle or compass point of
their respective cards, and the slide may have an upright object pin, to assist in
taking bearings. This apparatus may be clamped to a standard or tripod, fitted
with a lamp suspended over the centre by an arch or bow, for illumination at night
time the bow or arch, to move round the standard in azimuth if required. With
an instrument so constructed I may take bearings or angles of a distant object and
with the distance run between the bearings, find the distance off at either bearing,
also by difference of bearing, determine the distance of a moving object it solves
plane triangles, and may be used for finding the "danger angle" and for setting
the course of the ship to pass any distance off an object, and may be used as an
ordinary dumb card, on ship board.
Dated this 12th day of July 1893.
THOMAS D'OYLY BULKELEY.
COMPLETE SPECIFICATION.
.
Improved Apparatus for Use in Determining a Ship's Bearings and.
Distance from given Bodies, and for like purposes.
I, THOMAS D'OYLY BULKELEY, Carlton Villa, Klea Avenue, Clapham Common,
London S.W. Master Mariner, 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 :-
My invention has for its object to provide an instrument or apparatus whereby
one or more bearings of a fixed or movable object or objects can be taken by day
or night, and whereby by noting the distance run between the times of taking the
bearings, or knowing the distance between the places where the bearings are taken
or distance between two objects, the distance an observer is or was off the objects
or object at the time of taking the first second or other bearing may be readily
ascertained. According to my invention I provide a suitable base or platform,
ID01

page_text: having a stud or pivot on which a dumb card marked like an ordinary compass card
is mounted so as to be capable of being rotated thereon by hand or otherwise.
Fitted to turn on this stud or pivot is an arm of any suitable length, graduated or
.divided to equal parts, and upon this arm is fitted to slide a dumb card similar
to that herein before referred to. From the centre of each of these dumb cards,
an arm radiates the said arms being graduated or divided to equal parts, and each
of these arms is fitted with a sight vane, for taking bearings. Where thèse bars
cross each other they pass through a compound slide, that is two slides pivotted
one to the other so that the two arms may be placed at any angle or compass
point of their respective cards. The pivot on which the slides turn may extend
upwards so as to form an object pin, to assist in taking bearings. The apparatus
may be clamped to a standard or tripod, and may be fitted with a lamp supported
above the table in any suitable manner so as to cast a light onto the apparatus to
enable it to be used at night time, the lamp support being preferably adjustable in
position horizontally and vertically.
An instrument constructed according to my invention may be used at sea to take
bearings or angles of a distant object, and with the distance run between the times
of taking the bearings known, the distance of the object off at either bearing may
be readily ascertained; also by difference of bearing, the distance of a moving
object may be determined; it may also be used to solve plane triangles, and for
finding the "danger angle" so that the course of the ship may be set to pass at
any desired distance off an object. It may also be used as an ordinary dumb card,
on board ship.
In order that my invention may be well understood I will further describe the
same with reference to the accompanying drawings,
Figure 1 of which is an elevation and Figure 2 a plan of an apparatus constructed
according to my invention.
Figures 14 13 and 1° are diagrams explanatory of the use of the apparatus.
A is a table or platform which may be supported on a tripod stand or otherwise
so as to be removable when required, or if desired it may be fixed in any suitable
position. Mounted so as to turn on a stud or pivot B on the table A is a bar or
arm C marked with divisions to indicate distances, such as feet, yards, chains,
fathoms, miles or the like. On this bar is adjustably fitted a veruier or slide D
to which is pivotted at an arm E, a similar arm F being mounted above the
arm C on the stud or pivot B. These arms E and F which may be any desired
length are each marked with divisions similar to those on the bar or arm C and
pass through a compound slide or vernier that is two slides or verniers G G²
pivotted one on top of the other, the edges M of the slides D, G G2 being used for
indicating, on their respective arms, the distances.
Fitted to turn on the stud or pivot B beneath the bar or arm C is a dumb card H
marked like an ordinary compass card and provided with a milled edge to facilitate
turning the card on its pivot, a similar dumb card H2 being fitted to-turn on the
pivot h on which the arm E turns. The pivot g by which the slides or verniers G G
are connected together, projects some distance above the said slides or verniers GG'
and serves as an object pin for use in combination with sight vanes I and K on the
bare F and E for taking bearings. L is a lamp which may be of any suitable
construction provided with a shade to shield the light from the observers eyes and
with a reflector to cast the light onto the graduated bars and dumb cards to enable
the observer to read them at night time. This lamp may be carried on a post m
as shewn or on any other suitable support but preferably so as to be capable of
being adjusted in position in a horizontal plane and also vertically.
The table or platform A is marked wtth a line (which I call a "lubbers" line)
which passes through the axis on which the dumb card H and the bars or arms C
and F turn.
The apparatus when in use on board ship is placed in position so that
this "lubbers" line is parallel to or in line with the "fore" and "aft" centre line
of the vessel.
I will now explain with reference to diagrams 1A 1B an example of using the

page_text: apparatus on board ship to find, by change in the ships course and extent of run
of the ship between the times of taking bearings, the distance off of an object.
First, place the dumb card H in position to indicate the true course of the ship
and place the edge N of the bar or arm C on the lubbers line marked on the
table A and fix the arm in this position by means of the screw clamp c. Figure 1 ;.
then looking through the sight vane I at the object, move the bar or arm on its.
pivot B so as to bring the sight pin g in line with the object and the sight vane as.
shewn in diagram Figure 1A and clamp the bar or arm F in this position by
screwing down the nut 6 on the pivot B.
When the ship has run a sufficient distance to alter its bearing on the object,.
move the slide D which carries the dumb card H2 along the bar or arm C until the:
edge M of the slide reaches the mark on the bar or arm corresponding to the
distance travelled by the ship since taking the first bearing, as shewn for example in.
diagram Figure 1B. Now take a bearing of the object by looking through the sight
vane K and moving the bar or arm E on its pivot h so as to bring the sight ping
in line with the object, care being taken not to move the bar or arm F from its
position in which it had been fixed. The compound slides or verniers G G' will
thus have been moved along the bars E and F and the triangle formed by the three
bars CEF will be a reduced representation of the triangle having for its base.
the ships course, and for its sides, lines from the object to the points in the
ships course where the two bearings were taken. At the point where the bars or
arms E and F cross each other the edges M of the slides G G2 will indicate on the
arm or bar F the distance of the object when the first bearing was taken and on the
arm or bar E the distance of the said object when the second bearing was taken
In this manner bearings may be made at any desired intervals and the distance
from the object at all times be readily ascertained.
If the true course of the ship has not been maintained during the intervals of
taking the bearings the arm or bar C must be placed to correspond to the course
made good before the second bearing is taken.
Another example of the use of the apparatus will be understood by reference to.
Diagram 1° wherein let 1 and 2 represent two objects the distance between which
is known to the observer and it is required to ascertain the distance of the objects.
from the observer. First place the dumb card H in position to indicate the ships
true course and place the bar or arm C parallel to the course from one of the objects to.
the other object, which may be ascertained by reference to the chart. Next place
the edge M of the vernier or slide D on the bar or arm C to the mark on the said
arm corresponding to the distance between the objects and take bearing of the
objects 1 and 2 by means of the sight pin g and the sight vanes I and K respectively
on the arms F and E then where these arms cross each other the marks on them at.
the point of intersection as read off by the edges M of the slides G G2 will give the
distances respectively of the objects 1 and 2, and also the true bearing of each.
object from the observer obtained respectively by the cards H H³.
These examples will be sufficient to explain the use of the apparatus without the
necessity for describing all the purposes for which it may be employed for instance
it may be used on board ship when stationary or at anchor or it may be used on:
land to ascertain the distance of objects whether they be stationary or moving.
When the apparatus is set to take bearings on one side of the ships course (say
for example on the right hand side as in Figures 1 and 2) and bearings are required
to be taken of objects on the opposite side (for example on the left hand side as in
Figures 14 1B and 1") the arms F and E may be unclamped from their pivots B.
and h and without disconnecting them from the slides G G be placed on the
opposite side of the arm C the arm F being then placed on the pivot h and the
arm E on the pivot B and clamped as before. Or if the table or platform A be
sufficiently long the arms E F and C may be turned on the pivot B to the opposite
side of the "lubbers" line without detaching any of the parts. Only the edges M
of the slides or verniers D G and G' can be used for indicating on their respective.

page_text: arms the distances, the distances of these edges from the centres h and g being
allowed for in marking the scales on the arms.
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 :-
1. The combination and arrangement of parts constituting an apparatus or instru-
ment for ascertaining distances of objects and for determining ships courses and like
purposes by day or by night substantially as hereinbefore described and illustrated
by the accompanying drawings.
2. In apparatus for ascertaining distances of objects from an observer the com-
bination of three bars C E and F marked with scales of distances and carrying
sighting vanes (IK) and a sighting pin (9) the bars or arms being connected
together so as to be capable of being moved to form triangles of any required shape
substantially as and for the purpose hereinbefore described and illustrated by the
accompanying drawings.
3. In apparatus for determining ships bearings and distances from given objects
or for like purposes the combination with the arms C E and F and parts connected
therewith of dumb cards H and H2 substantially as and for the purpose hereinbefore
described and illustrated by the accompanying drawings.
Dated the 27th day of March 1894.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, Agents.