Improvements in or relating to Apparatus for Recording the Course of Ships or Vessels
Year: 1896

page_text: Date of Application, 27th Aug., 1896
Complete Specification Left, 21st May, 1897- Accepted, 14th Aug., 1897
PROVISIONAL SPECIFICATION.
Improvements in or relating to Apparatus for Recording the Course
of Ships or Vessels.
A communication from EDOUARD BECH, Chief Professor of the School for Navi-
ution in 43 Rue Stephanie, Antwerp, in the Kingdom of Belgium.
I, ALFRED JULIUS BOULT of 111 Hatton Garden in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
The apparatus, the subject of the present invention, has for its object to ascer-
tain the exactitude with which a ship follows a given point of the compass, the
deviations from the course prescribed being registered by the apparatus in a con-
tinuous manner. Let us assume for example that the captain of a ship has
decided in order to get from one place to another to steer a N.N.E. course. The
quartermaster is told to keep this course without deviations, that is to say, so that
the line of the keel exactly coincides with the line N.N.E. of the compass; if tho
quartermaster does not steer exactly this course, the line of the keel will not be
in the direction of the point of the compass, and the devintion will be registered
by the apparatus.
The course-recording apparatus consists of two dark chambers, the first ono
being provided with three openings.
1st a round opening in the middle of the upper wall;
2nd a large rectangular opening in one end wall provided with a hermetic
3rd a small rectangular opening in the opposite wall dividing the two chambers.
cover;
Through the round opening passes a brass tube provided at its lower end with a
lens which is arranged over the centre of the compass which is suspended in the
dark chamber by means of a universal joint and at such a distance from the lens
that the lens is focussed exactly on the centre of the compass-card.
In order to enable the lens to be adjusted to the exact position, it is fixed to a
tubo sliding in a second tube, such as used in telescopes.
On the compass-card is placed a light alidade made, say, of aluminium. This
alidade is provided with a round opening which enables it to surround the casing
of the compass-card and to turn freely in such manner that any desired point of
the compass-card can be indicated. This alidade carries on one of its ends a small
lens and in the middle a mirror placed at an angle of 45° and of about one milli-
metro in width.
The small rectangular opening is arranged so that a vertical line passing through
its centre is exactly opposite to the line of the keel drawn on the casing of the
compass and so that its centre is in a horizontal line which passes ou the alidade
from the centre of the mirror to the lens, the alidude being supposed to coincide
with the compass-point which coincides with the line of the keel.
The second dark chamber contains a registering hollow cylinder preferably of

page_text: brass, which is driven by clockwork mechanism and makes a complete revolution
round its horizontal axis in four hours. The cylinder is so arranged that a point
of its periphery which is the nearest to the division wall of the chambers is on the
continuation of the straight line of the alidade and in the focus of the lens.
At first the alidade is adjusted to the point of the compass corresponding to the
course to be steered. In a chamber converted into a darkroom or even in the
space in which the apparatus is placed a strip of gelatino-bromide of silver paper,
sensitive to light (on which the axial line has been beforehand traced in pencil),
is wound round the cylindrical drum in such manner that the said pencil line
coincides with the middle line of the drum. Then the second dark chamber is
placed against the first chamber the light, which is above the lens tube is lighted
and the end cover removed after which the clock work of the drum is set in motion.
The source of light sends its rays through the tube which strike the mirror and
are reflected and produce a luminous point, on the middle of the sensitive
paper
strip. As long as the course does not change, the luminous point remains in the
same relative position and as the drum rotates the luminous point produces a
peripheral line on the paper strip which forms a straight line when the paper strip
is unwound. But if the line of the keel deviates to the right or to the left the
luminous point is thrown to the left or to the right from the axial line of the
strip and the more the actual course deviates from the course to be kept the greater
will be the distance of this luminous point to the right or to the left of the axial
line. The combined movement of the ship and of the drum produces a curve,
which enables the differences between the actual and the prescribed course to be
measured, the direction of these differences or deviations to be determined, and the
time at which these deviations were made to be found.
It is sufficient for this purpose.
paper
1st to divide the paper strip into equal lengths which correspond to equal
periods of time; if we assume that the periphery of the drum is 0.48 metres and
that it makes one revolution in four hours then it turns through 12 centimetres
in one hour or through 1 centimetre in each five minutes. If therefore the paper
strip is divided into forty-eight equal parts of one centimetre each, each part will
correspond to a period of time of five minutes.
2nd to determine a scale for the deviations in the following manner :-
The apparatus is placed on a model of a ship in an instrument such as is used
in the schools of navigation for studying the regulation and compensation of the
compass.
The alidade is placed in the direction of the course to be steered on the compass-
card and une line of the keel of the ship is brought to coincide with the end point
of the alidade then the apparatus is set in motion for a few minutes. The luminous
point then describes a straight line along the pencil line in the middle of the
paper strip. Then the dark chamber containing the registering drum is closed,
the alidade is placed ten degrees to the right or to the left of the course. The
cover of the dark chamber containing the registering cylinder again removed and
the apparatus again set in motion for a few minutes whereby another straight line
parallel to the previous one is obtained.
The same operation is performed the alidade being set to five degrees from the
course whereby a straight line is obtained. In such manner it is very easy to
produce a scale for measuring the deviations.
A quick sudden alteration of the course gives a curve at right angles to the
middle line of the sensitive paper strip and not so distinctly traced as the rest of
the curve.
Thus the time when the deviation from the course took place can be
easily determined and also whether the deviation was to the port or starboard side.
Dated this 27th day of August 1896.
BOULT & WADE,
Agents for the Applicaut.

page_text: Improvements in or relating to Apparatus for Recording the Course
of Ships or Vessels.
A communication from EDGUARD BECH, Chief Professor of the School for Navi-
gation in 43 Rue Stephanie, Antwerp, in the Kingdom of Belgium.
I, ALFRED JULIUS BOULT of 111 Hatton Garden in the County of Middlesex,
Chartered Patent Agent 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:- -
The apparatus the subject of the present invention has for its object to ascer-
tain the exactitude with which a ship follows a given point of the compass, the
deviations from the course prescribed being registered by the apparatus in a con-
tinuous manner. Let us assume for example that the captain of a
ship has
decided in order to get from one place to another to steer a N.N.E. course. The
quartermaster is told to keep this course without deviations that is to say so that
the line of the keel exactly coincides with the line N.N.E. of the compass; if the
quartermaster does not steer exactly this course, the line of the keel will not be
in the direction of the point of the compass, and the deviation will be registered
by the apparatus. As the compass card must be left absolutely free, it can at no
time be brought in contact with the recording apparatus which moves round this
card at the same time as the vessel and which would cause said card to participate
in its rotation.
The course recording apparatus consists of two dark chambers ABCDEFGH
and BCEGNILK Figure 1 placed side by side. These two dark chambers
together form a box shown in Figure 7 (a be d) and suspended by means of
gimbals. The base y h of the support is secured to a pivot ef say of copper which
can turn in a casing m secured to the ship. The first chamber is provided with
three openings.
First, a circular opening M in the upper wall ABG H.
Second, a large rectangular opening e f g h in the end wall A H D F pro-
vided with a hermetically closing cover.
Third a small rectangular opening pqrs in the opposite wall B G E C dividing
the two chambers.
Through the circular opening M passes a brass tube provided at its lower end
with a leus n which is arranged over the centre of the compass which is suspended
iu the dark chamber by means of a universal joint and at such a distance from the
lens that the lens is focussed exactly on the centre of the compass card.
In order to enable the lens to be adjusted to the exact position, it is attached to
a tube sliding in the tube n such as used in telescopes.
On the compass-card is placed a light alidade made say of aluminium see
Figures 2 and 24. This alidade is provided with a circular opening which enables
it to surround the central casing of the compass card and to turn freely in such
manner that any desired point of the compass-card can be indicated. This alidade
carries on one of its ends a small lens band in the middle a mirror c d¹ placed at
an angle of 45° (Figures 1 and 2*).
The small rectangular opening 9s is arranged so that a vertical line y z
passing through its centre is exactly opposite the line of the keel drawn on the
casing of the compass and so that it intersects a horizontal line which passes on
the alidade from the centre of the mirror e' through the lens b' the alidade being

page_text: IS 10 Shy With the nine of the кcel.
The second dark chamber B G ICE KL see Figure 1 contains a hollow regis-
tering cylinder V preferably of brass which is driven by clockwork mechanism and
makes a complete revolution round its horizontal axis T T in say four hours.
A continuous registering system may be arranged on it so as not to have to
replace the sensitive paper band every few hours. The cylinder is so arranged that
a point X of its periphery which is the nearest to the division wull of the cham-
bers BGC is on the continuation of the straight line et b of the alidade and in
the focus of the lens b'.
To use the
apparatus.
WORKING OF THE APPARATUS.
1. Start the clockwork mechanisın.
2. Remove the registering cylinder.
3. Wind on the cylinder a strip of sensitized gelatine bromide of silver paper.
4. Replace the cylinder and close the dark chamber containing it.
5. Light the lamp above the tube n.
6. Steer an exnet course and during this time bring the luminous point exactly
on the keel line of the apparatus by causing it to turn on its pivot f
7. Then fix the apparatus by means say of a set screw thus preventing the pivot f
from turning in the casing . The apparatus is then rigidly secured to the ship.
8. Open the casing pqrs by drawing up the shutter POS so as to open
communication between the two chambers.
The luminous beam from the source of light will pass through the tuben and
strike the mirror e and will be deflected in the direction eb and will produce a
luminous point at X in the focus of the lens band in the centre of the sensitive
strip.
As long as the line of the keel does not change this luminous point will remain
in the same place, and as the cylinder turns, the luminous point will trace ou the
sensitive paper a line which when the band is unwound will be a straight line.
If the line of the keel moves to the right or to the left the luminous point will be
projected to the right or to the left hand side from the centre of the strip, the
deviation being the greater, the greater the deviation of the actual course from the
course steered.
The combined movement of the ship and of the cylinder will produce a curve
which will cuable,
1. The deviation from the course to be measured.
2. The direction of the deviations and the time at which they took place to be
known.
Having now particularly described and ascertained the nature of the suid in-
vention as communicated to me by my foreign correspondent, and in what manner
the same is to be performed I declare that what I claim is:--
An apparatus for recording the course of ships or vessels whereby the deviations
of the vessel from the course steered are registered substantially as described.
Duted this 21st day of May 1897
BOULT & WADE,
Agents for the Applicant.