Improvements in and relating to Tidal Stream Indicators.
Year: 1899

page_text: Date of Application, 15th June, 1899-Accepted, 4th Nov., 1899
COMPLETE SPECIFICATION.
Improvements in and relating to Tidal Stream Indicators.
We, STEPHEN PENNEY, of 64, Darnley Road, Gravesend, in the County of
Kent, Trinity Pilot, and EDWARD OCTAVIUS POTTER, DAVID ALEXANDER POTTER,
and BRUCE HERSEE POTTER, trading as J. D. Potter, of 31, Poultry, in the City
of London, Admiralty Chart Agent, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
66
In the navigation of vessels around the coast of Great Britain, it is very
desirable that the masters in charge of the vessels, should have a reliable and
convenient means of quickly ascertaining the condition or set" of the tidal
stream at a certain part or parts of the coast, at a particular time. It is further
desirable that past conditions of the tide at a certain part of the coast at a
given time, should also be ascertained readily, in case of inquiries into collisions
between vessels, shipwrecks, and for other purposes. Our improvements in and
relating to tidal stream indicators are designed to supply the required informa
tion.
In carrying our invention into effect, we employ a clock of any convenient
construction, but preferably provided with a special dial, to be described here-
inafter. We also provide a series of cards which have a central perforation,
adapted to fit over the case of the clock, as if it were an outward extension of the
clock dial, with information relating to the tides and localities printed on the
cards.
One hand only, the hour hand, is required for the clock, with a convenient
means of setting the said hand to any required point on the clock dial, and this
being set in the manner described hereinafter, the condition and set of the tidal
stream, at the locality indicated by the hand, is read off upon the card at that
part in line with the hand. As the hand travels over the face of the dial, point-
ing to the information upon the card, so does it indicate the condition of the
tidal stream, which can thus be read off with great facility. Each card has a
certain range of coast, and the cards are changed to suit the various localities.
The accompanying drawings, Figs. 1 to 12 inclusive (including Fig. 8°), are
on thirteen separate cards, each showing three circles thereon. Between the
two inner circles Roman numerals are shown, spaced equally apart, the upper
one being O, and the lower one VI: with the characters I, II, III, IIII, V,
between them on each side, reading from the top. The dial of the clock is
similarly and correspondingly marked, as shown in Fig. 8 and Fig. 8*, but
with equal divisions between the several Roman numerals indicating minutes,
and each card is made capable of being placed upon the clock by means of the
central hole (as above stated) the 0 or zero character on the clock dial coinciding
with the like character on the card, as shown in Fig. 8. Sometimes we provide
for a small projecting pin or stud on the clock and a corresponding hole in the
card to facilitate and ensure the card being placed in its proper position, or
.....מr

page_text: *6
‘register,” upon the clock, and when the proper card for the required locality
is thus placed, the indicator is ready for use. Before proceeding, however, to
describe its application, the several cards are referred to as follows.
Card No. 1, (Fig. 1), is headed "Tidal Streams between Peterhead and Flam-
borough Head," with particulars of the several streams at the localities named,
generally arranged in a radial manner from the several numerals. In addition to
this, information is given in the two top corners of the time of high water full
and change, and hours and minutes, indicated by initials and abbreviations
of spring and neap tides, at the several places named. In the lower corners of
the card the greatest rate of the stream at spring tides are also given at the
localities named; but it is to be noted that while these corner references are
given for convenience in using the indicator, they are not essential to the
invention. This card is used when it is required to know the condition of the
tidal stream at any of the points of the coast between Peter Head and Flam-
borough Head.
"
Card No. 2, (Fig. 2), is similarly used for the tidal streams off points of the
coast between Flamborough Head and Orfordness," as stated in the heading;
and similar information is given to that on the card Fig. 1.
Card No. 3, (Fig. 3), is headed "Tidal Streams between lines joining Lemau
and Ower and River Texel, North Foreland and Dunkirque," with the like
information of the streams radiating from the numerals, as before.
Card No. 4, (Fig. 4), is headed Tidal Streams from Orfordness and North
Foreland and London Bridge," and therefore embraces the river Thames below
London Bridge. This card likewise gives the condition of the flood and ebb
streams at the points named in a radial manner from the numerals.
Card No. 5, (Fig. 5), refers to Tidal Streams between lines joining Beachy
Head and Point d'Ailly, and North Foreland and Dunkirque." From this it
will be seen that the tidal streams separate upon certain lines between the
localities named in the instructions radiating from the numerals, and these
streams flow towards each other from each of the stated localities to the adjoining
radiating instructions, except at the numerals I, on the right hand side of the
card, and V, on the left hand side, where the instructions state "both streams
setting away from line of separation after high water," in the former case; and
in the latter case, "both streams setting toward line of meeting before high
water," these instructions being arranged in a circumferential instead of in the
radial manner aforesaid. In the upper corners of this card are given the time
and rise of high water full and change of spring and neap tides, at the localities
named on the English and French sides of the English channel; and at the lower
corners the greatest rate of the spring tide streams on the respective sides of the
Channel.
Fig. No. 6, (Fig. 6), refers to the "Tidal Streams at the six Light Vessels in
the Straits of Dover," and it gives the compass directions of the several streams
at the vessels named, together with their rates of flow in knots, approximately
radiating as before-from the numerals.
But in Card No. 7, (Fig. 7), the "Tidal Streams between Beachy Head and
Start Point" are given in a circumferential manner in the direction of the
arrows; the stream setting to the westward away from Dover (at the rates
stated), as shown on the right hand side of the card from Beachy Head to Start
l'oint, between the numerals () to VI, while the stream sets to the castward
towards Dover, (at the rates stated), from Start Point to Beachy Head, between
the numerals VI to O.
On card No. 8, (Fig. 8), the directions of the "Tidal Streams between Owers,
Nab, Spithead, Solent and Needles and South of the Isle of Wight," are again
arranged in a radiating manner from the several numerals, together with tables
of the time and depths of high water, and greatest rate at spring tides, at the
localities named, which tables are arranged in the corners of the card, as before
described. In this figure, the dial face of the clock is shown, with the hand

page_text: pointing to II which refers to an example of the working of the tide indicator to
be given hereinafter.
Card No. 9, (Fig. 8), shows the face of a clock within a card that is blank of
instructions, but bearing on its face the three circles, and the numerals between
the two inner circles, as mentioned above. All the cards used are cut through on
the light line marked b, so as to fit over the case of the clock c.
Card No. 10 (Fig. 9), refers to the tidal streams between what is known as
Start Point and Longships, in which the direction of the tidal streams is indi-
cated as westerly at all the numerals on the upper portion of the card, and
easterly at all the lower numerals on the card. Midway, however, at the
numerals 111 on both the right and left hand sides of the card, the tide is indi-
cated in the condition of "turning."
Card No. 11, (Fig. 10), refers to the "Tidal Streams 10 miles West of Ushant
to Eddystone Light or Start," and to the direction and condition of the stream
It also contains in the corners the time
radiating from the several numerals.
and depth of high water full and change on both sides of the Channel, with the
rate of the spring tide.
The
Card No. 12, (Fig. 11), is headed "Tidal Streams Eastward of a direct line
joining Scilly, Tuskar, and Smalls," and shows the direction of the tidal streams
by compass at the several light vessels named at the several numerals.
time and depth of high water full and change, together with the spring rate is
given at the corners of the card for the localities named; but in addition to this
the general direction of the tidal stream is indicated in a circumferential manner,
on both sides of the card, between the numerals I and V.
Card No. 13, (Fig. 12), indicates in a similar manner to the previous card the
Tidal Streams in the St. George's Channel, Irish Sea, and North Channel,"
part of the directions being given in a radial manner from the numerals, and
part in a circumferential manner between the numerals I and V, on both sides.
of the card. In the corners, the time, depths, and rates are given as before, for
the localities named.
In all the cards shown in the figures, the numerals O to VI represent hours, and
likewise on the clock dial shown in Fig. 8, the numerals on the right hand side
of the card or dial denoting the hours after high water, while the numerals on the
left hand side of the card denote the hours before high water, high water being
denoted by O, as zero, at the top. Furthermore, the Admiralty tide tables for
British and Irish ports must be used in conjunction with our tidal stream
indicator. In using these tables, the time of high water at Dover is taken
therefrom as the standard for all the localities previously referred to, except in
the St. George's Channel and Irish Sea, (Fig. 12), in which case the time of high
water must be taken from the Liverpool tide table.
The following method and examples are given as illustrations of the manner
of using our tidal stream indicator:-
First, refer to the Admiralty tide tables, as above stated, finding the time of
high water therefrom at Liverpool, if the locality is comprised within St.
George's Channel and the Irish Sea, (Card No. 13, Fig. 12); or at Dover, for all
the localities stated on the other cards. Then wind up the clock, and set the hand
or pointer (which revolves as an hour hand only) at that part of the dial corre-
sponding to the time or hour of the tide before or after high water, to be ascer-
tained as in the following example. Then place the particular card, having the
required locality named thereon, over the face of the clock; the O or zero on the
dial, coinciding with the same 0 or zero on the card.
Supposing it is required to find the set of the tidal stream in the Solent, on
December 25th, 1898. From the Admiralty tide tables it is found that the time
of high water at Dover on that day was 9.2 a.m.
The corrected time at the ship was …..
6.0 a.m.
Qo

page_text: ence 18
2.5
and this being 2 hours after high water the pointer is set accordingly, and on
placing the card No. 8 over the case of the clock, the hand of the clock, placed
at the point named, would indicate the set of the stream at the locality pointed
to.
It will be seen that the condition of the tidal stream at a given locality can be
readily ascertained for any particular time, in the past, or in the future, and
therefore our invention is useful not only for the ordinary purposes of navigation,
but also in inquiries as to wrecks, fixtures and arrangements as to yachting and
other regattas, salvage and harbour operations, and the like. Also that
the names of other localities, or sea marks such as light vessels, light-houses,
buoys, and the like, may be used instead of or in addition to those given on the
respective cards shown in the figures.
Furthermore, any convenient kind of clock may be used, or the clock may be
dispensed with in some cases, but it is desirable that the clock should be adapted
for regulating the position of the hand or pointer readily. It is also to be
understood that we do not claim absolutely the combination of a clock with
a navigational card, as we are aware that it has been proposed to combine a
clock with a compass card, but this is beyond the limits of our invention.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
1. The herein described improvements in and relating to tidal stream indi-
cators, consisting of a series of cards, each containing information relating to
the direction of the tidal stream or streams at or adjoining specified points of
the coast of Great Britain and Ireland, or of light ships or other marks in the
adjacent seas, substantially as and for the purpose specified and shown by the
drawings.
2. A navigational card containing information relating to the direction of the
tidal stream or streams at, before, and after high water, or at adjoining specified

page_text: points of the coast of Great Britain and Ireland, or of light ships or other marks
in the adjacent seas, substantially as and for the purpose specified and shown by
the drawings, Figs. 1 to 12 inclusive.
3. A navigational card containing information relating to the direction of the
tidal stream or streams at, before, or after high water at or adjoining specified
points of the coast of Great Britain and Ireland, or of light ships or other marks
in the adjacent seas, the said information being combined with numerals
arranged at equal divisions around a circle to denote the hours before and after
high water, substantially as and for the purpose specified and shown by the draw-
ings, Figs. 1 to 12 inclusive.
4. The combination of a clock, provided with a dial marked to represent six
hours before and after high water and an hour hand adapted to be set to any
desired point on the face of the dial, with a card containing information relating
to the direction of the tidal stream or streams at or adjoining specified points
of the coast of Great Britain and Ireland or of light ships or other marks in the
adjacent seas, the said card being adapted to fit over the case of the clock, and
to present the said information in sequence of localities and time to show the
direction or state of the tide by the indication of the hand of the clock while
running, substantially as and for the purpose specified and shown by the
drawings.
5. The herein described improvements in and relating to tidal stream indicators
for specified points of the coast of Great Britain and Ireland and marks in the
adjacent seas, comprising the combination of one or more navigational cards
containing information relating to the tidal stream or streams in sequence of
localities and time, a running clock with an hour hand adapted to point to the
condition of the tidal stream at a required locality, and tidal tables by means of
which the said clock hand is properly set, substantially in the manner and for the
purpose specified and shown by the drawings.
FAIRFAX & WETTER,
37 & 39, Essex Street, Strand, London, Agents for the Applicants.