A New or Improved Apparatus for Use in Determining the Position of a Ship, upon the Chart, by Means of Soundings.
Year: 1898

page_text: Date of Application, 25th Aug., 1898
Complete Specification Left, 25th May, 1899-Accepted, 1st July, 1899
A New or Improved Apparatus for Use in Determining the Position
of a Ship, upon the Chart, by Means of Soundings.
I, JOHN GEORGE CALDER FLAWSE, presently of 206, Watt Street, South Side,
Glasgow, Master Mariner, do hereby declare the nature of this invention to be as
follows:-
This invention relates to an apparatus for use in determining the position of a
ship, upon the chart, by means of the soundings.
To enable the apparatus to be used with any certainty in locating the position
of the ship upon the chart it is necessary to know, (1) the course steered, (2) the
distance between each sounding, and (3) the depths given by the soundings.
The apparatus consists of a frame provided with a roller and a cross bar or wire
upon which a slide is fitted. The roller, which may have rubber upon it to pre-
vent it slipping, is capable of being traversed over the chart in the same manner
as a parallel ruler. A flat cross bar with a straight edge may be fitted between the
sides of the frame and just in advance of the roller. This cross bar may be gradu-
ated with degrees or have scales cut upon it if so desired. The slide, which is
capable of being slid along the wire from side to side and of being turned there-
upon has preferably four sides. There may be jointed to the slide one, two, or
more extensions so connected together that they can be set at different angles
to one another and when set, be locked in position by means of thumb screws or
such like. The joints are such as to allow free movement of the different parts.
For large scale charts additional strips or pieces may be provided which can be
clamped to the sliding scale.
If so desired the wire upon which the scale slides can be tightened up by means
of a screw or such like device.
A radiograph consisting of a disc with angles or radial lines thereon may be
used in conjunction with the apparatus.
Strips of paper are provided upon which the soundings can be marked by means,
preferably, of a rubber or other stamp. Instead of paper strips celluloid or other
strips may be used.
If desired the device may be provided with double rollers.
With this apparatus five or other suitable number of soundings are taken at
certain distances apart, ascertained in the usual way, and these soundings are
marked upon a paper strip which latter is then secured upon the slide. The in-
strument is now laid upon the chart with its straight edge lying in the same
direction as the course of the ship. The course of the ship being known it is easy
to apply the instrument to the compass on the chart so that its straight edge will
lie in the direction in which the ship is sailing. The instrument is now moved
over the chart and the soundings given on the strip of paper compared with the
soundings on the chart. If the soundings are found to
agree with the
soundings on the chart at a certain place then it may be assumed that such place
is the location of the ship. To increase the accuracy of the instrument inter-
mediate soundings may he noted on separate strips which can be secured to the

page_text: other sides of the slide. As the instrument works on the parallel ruler principle,
when once set to the direction of the ship's course, it can be traversed over the
chart without losing that direction. The extensions of the slide are useful when
the ship is pursuing a more or less zig-zag course as the soundings can be marked
upon such extensions, which, when set to the course of the ship, can be traversed
over the chart and the soundings compared as before.
Dated this 24th day of A 1800
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.
A New or Improved Apparatus for Use in Determining the Position
of a Ship, upon the Chart, by Means of Soundings.
I, JOHN GEORGE CALDER FLAWSE, presently of 206, Watt Street, South Side,
Glasgow, 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 ascer
tained in and by the following statement:
This invention relates to an apparatus for use in determining the position of a
ship, upon the chart, by means of the soundings.
To enable the apparatus to be used with any certainty in locating the position
of the ship upon the chart it is necessary to know, (1) the course steered, (2) the
distance between each sounding and (3) the depths given by the soundings.
Referring to the drawing annexed, whereon,
Fig. 1 is a plan view of the apparatus and Figs. 2 to 6 detail views.
bar a.
The apparatus consists of a frame or a flat solid bar a, similar to a parallel ruler
and provided with rollers b, c, and a bar d upon which a slide e is fitted. The
bar d is cut away slightly near each end to a rectangular section, as shown at
Fig. 2, so as to lock firmly into place in the jaws f (see Figs. 1 to 3) attached to the
The rollers b, c, may be ribbed, as shown, or be covered with rubber in
order to prevent them slipping. The bar a is made with a straight edge a'. The
slide e has holes through which the bar passes and it is provided with a handle e¹
and bent up prongs e², e², upon which a cross bar h rests and is held in place by
means of a flat spring screwed, at h', to the slide. The cross bar h is, by prefer-
ence, as shown in section at Fig. 4, made of a trough or channel' shape and into
the trough or channel a strip o of celluloid or waterproof paper or such like is
inserted. The bar h can be adjusted in position relatively with the slide whilst
the latter can be freely moved along the bar d from side to side and can be turned
thereon to a certain extent.
Secured removably to the bar h by means of a joint i (see plan and side views Figs. 5
and 6) is an extension j to which again a second extension can be removably
secured by means of a similar joint i. Each extension is made with a segmental
plate to which a movable jaw 22 is secured by means of a thumb screw 3. By
slipping the jaw of, say, the extension j upon the bar h said extension will be
slidably connected to said bar, and, by manipulating the thumb screw, the
extension can, after being adjusted to any desired angle relatively to the bar h,
be clamped in position. The same remarks apply to the extension & which can
be slid along and adjustably secured at any desired angle to the extension j. Both
extensions j, k, are made in the same manner as the bar h.
The device is capable of being traversed over the chart in the same manner as
a parallel ruler,

page_text: If desired, instead of having two extensions, one, or more than two can be used.
They can be easily fitted together or taken apart as desired..
A radiograph consisting of a disc with angles or radial lines thereon may be
used in conjunction with the apparatus.
With this apparatus five or other suitable number of soundings are taken at
certain distances apart, ascertained in the usual way, and these soundings are marked
(say in pencil) upon the strip o (see Fig. 1) of the bar h which latter is then secured
upon the slide e.
The instrument is now laid upon the chart with its straight
edge a lying in the same direction as the course of the ship. The course of the
ship being known it is easy to apply the instrument to the compass on the chart
so that its straight edge will lie in the direction in which the ship is sailing. The
instrument is now moved over the chart and the soundings given on the strip o
compared with the soundings on the chart. If the soundings are found to agree
with the soundings on the chart at a certain place then it may be assumed that
such place is the location of the ship. To increase the accuracy of the instrument
intermediate soundings may be noted on separate strips of paper which can be
secured to the sides of the bar h if necessary. As the instrument works on the
parallel ruler principle, when once set to the direction of the ship's course, it can
be traversed over the chart without losing that direction. The extensions of the
slide are useful when the ship is pursuing a more or less zig-zag course as the
soundings can be marked upon such extensions which, when set to the course of
the ship, can be traversed over the chart and the soundings compared as before.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I consider novel and desire to claim is:-
An apparatus for use in determining the position of a ship, upon the chart, by
means of soundings, constructed and used substantially as hereinbefore described
with reference to the drawing annexed.
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.