An Improved Instrument for Ascertaining and Marking Courses and Positions on a Chart.
Year: 1892

page_text: Date of Application, 24th Mar., 1892
Complete Specification Left, 21st Dec., 1892-Accepted, 18th Mar., 1893
PROVISIONAL SPECIFICATION.
An Improved Instrument for Ascertaining and Marking Courses
and Positions on a Chart.
JOHN WILSON GILLIE, Nautical Instrument Maker, of the New Quay, North
Shields in the County of Northumberland do hereby declare the nature of this
invention to be as follows:
A rectangular piece of thin sheet metal bent upon itself to form a clip capable of
holding firmly between its two surfaces, a horn or brass protractor, or a piece of
paper, cardboard, ivorine or other substance, mounted upon a spindle of suitable
length which is firmly attached at each end to a roller. The two rollers are exactly
the same size and milled on their edges, to avoid any liability to slip over the
surface of the chart or plan. A handle to move the instrument over the chart is
provided mounted on a spindle, like the handle of a winch, coffee machine or drill
brace, so as to prevent any accidental circular motion being given by the hand to
the instrument, which might move it out of its parallel course. In use as a course
projector, the edge of a protractor, or a piece of paper, cardboard &c. is laid on the
track on the chart, the direction of which has to be ascertained and whilst it is
firmly held with one hand, the opposite edge is inserted in the clip; the protractor
or piece of paper now held in the clip is raised slightly and rolled over the nearest
compass printed on the chart, so enabling the direction of the track to be read off.
Or the protractor may be laid with its zero line over a meridian or parallel of
latitude, then raised and rolled over the track, when the course may be read off
from the protractor.
As a position projector, a piece of paper, cardboard or ivorine is held in the
clip, on the edge of which a small dot is made with a pencil, this dot is then placed
over the exact latitude or longitude (found by observation or otherwise) at the
side of the chart, while the axis of the parallel rolling clip is placed either parallel
with or at right angles to the meridian line, depending upon whether it is latitude
or longitude which is to be set off, the paper is then raised and rolled until the
dot is opposite the corresponding longitude or latitude, when the dot will indicate
the position of the vessel, lighthouse &c.
Dd this 09-1 ton of March 1902
JOHN WILSON GILLIE.
COMPLETE SPECIFICATION.
An Improved Instrument for Ascertaining and Marking Courses and
Positions on a Chart.
I, JOHN WILSON GILLIE, Nautical Instrument Maker of the New Quay,
North Shields, in the County of Northumberland do hereby declare the nature.
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement :-
A rectangular piece of thin sheet metal is bent into such a form as that shown
in side view in Fig. 1 of the accompanying drawings, so that a straight edge or
protractor made of horn, xylonite, thin brass or other similar material, or a sheet
of paper or cardboard is held firmly between the two inner surfaces shown at A.
This clip so bent is then mounted upon a spindle B', by means of the bearings B³
Fig. 2, which are soldered securely to both surfaces of the clip as shown at A'
Fig. 1. The rollers Be carefully turned to exactly the same size and milled on
their circumferences so as to grip the surface of the chart are tightly and truly
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page_text: fitted one on each end of the spindle B₁. To facilitate the insertion or withdrawal
of any article in or from the clip, I prefer to use an opening lever A³, which may
be fitted into a hole B³ in which it is held by a small pin A', so that when the
upper part of the lever is pulled backwards, the lower end A' presses against the
lower inside surface of the clip, permitting a protractor or other article to be
easily removed from or inserted in the opening A. To move the instrument over
the chart, I provide a handle A2 which is held in its place by a screw which
passes through the hole B2. The screw may be made with a short neck, so that
when it is screwed home, it does not bind the handle fast to the clip, but allows
of it moving round its own axis, in order to prevent any accidental circular motion
being imparted by the hand to the instrument, which might move it out of its
parallel course. For use in ascertaining courses, the edge of a protractor or
straight edge or a piece of paper, cardboard &c. is laid on the track on the chart,
the direction of which has to be ascertained, and whilst it is firmly held with one
hand, the opposite edge is inserted in the clip; the protractor or piece of paper &c.
now held in clip is raised slightly and rolled over the nearest compass printed on
the chart, so enabling the direction of the track to be read off. Or the protractor
may be laid with its zero line over a meridian or parallel of latitude, then raised
and rolled over the track, when the course may be read off from the protractor.
Of course if the course had to be marked or laid off, the operation would just be
reversed.
For use in ascertaining or marking positions, a piece of paper, cardboard or
ivorine is held in the clip, on the edge of the paper a small dot is made with a
pencil, this dot is then placed over the exact latitude or longitude (found by
observation or otherwise) at the side of the chart, while the spindle of the parallel
roller clip is placed either parallel with or at right angles to the meridian line,
depending upon whether it is latitude or longitude which is to be set off, the piece
of paper or cardboard &c. is then raised and rolled until the dot is opposite the
corresponding longitude or latitude, when the dot will indicate the position of the
vessel, lighthouse &c.
There are other ways in which the instrument may be used.
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-
1st. For ascertaining and marking courses and positions on a chart, the combi-
nation of a clip, parallel rollers and protractor fully described herein and illustrated
in Figures 1 & 2 of the accompanying drawings.
2nd. For ascertaining and marking courses and positions on a chart, the particular
arrangement and construction of clip herein described and illustrated.
3rd. For ascertaining and marking courses and positions on a chart, the particular
arrangement and construction of parallel rollers herein described and illustrated.
Dated this 20th day of December 1892.
JOHN WILSON GILLIE.