AN IMPROVED INSTRUMENT OR APPARATUS FOR INDICATING PROVISIONAL SPECIFICATION OCEAN AND OTHER CURRENTS
Year: 1873

page_text: LETTERS PATENT to John Barlcay Leslie, of 27, Great George Street,
Westminster, in the County of Middlesex, Gentleman, for the
Invention of "AN IMPROVED INSTRUMENT OR APPARATUS FOR INDICATING
PROVISIONAL SPECIFICATION left by the said John Barclay Leslie at
the Office of the Commissioners of Patents, with his Petition, on
the 16th October 1873.
I, JOHN BARCLAY LESLIE, of 27, Great George Street, Westminster,
in the County of Middlesex, Gentleman, do hereby declare the nature
of the said Invention for "AN IMPROVED INSTRUMENT OR APPARATUS FOR
INDICATING THE DIRECTION OF OCEAN AND OTHER CURRENTS," to be as follows:
My Invention has for its object the indication of the direction or set of
a current or tide, and consists of an instrument or apparatus composed of
a vertical brass rod carrying an indicator and compass with the means of

page_text: locking or fixing them as herein-after described, which instrument or
apparatus is intended to be lowered from a ship to the depth required, and
the indicator and compass fixed so as to indicate the set of the current
or tide at such depth.
On the said rod is mounted a moveable indicator which is capable of
turning freely on the rod in any direction as impelled by a current, and
at the bottom of the rod is fixed a compass heavily weighted. Inside of
the said vertical rod is an inner rod connected with the said compass,
which inner rod works with a spring in such a manner that when the
spring is relieved from pressure the compass is free.
At the top of the rod is a moveable weight which is suspended by
means of a catch and line, but when liberated slides down the rod and
simultaneously fixes the compass and indicator. This weight is provided
at the bottom with a toothed clutch, which, when the weight is dropped
on to an india-rubber ring fixed on the indicator, completely locks the
indicator at any angle.
By liberating the weight after the instrument or apparatus has been
lowered to the required depth the indicator and the compass are simul-
taneously locked by means of the said clutch and ring or other suitable
locking arrangement, when the instrument can be drawn up from the
water, and the set of the current or tide is shown by the position of the
indicator and the compass.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Barclay Leslie in the Great Seal Patent
Office on the 16th April 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
BARCLAY LESLIE, of No. 27, Great George Street, Westminster, in the
County of Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of October, in the year of our
Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,

page_text: give and grant unto me, the said John Barclay Leslie, Her special licence
that I, the said John Barclay Leslie, my executors, administrators, and
assigns, or such others as I, the said John Barclay Leslie, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend; within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
INSTRUMENT OR APPARATUS FOR INDICATING THE DIRECTION OF OCEAN AND OTHER
CURRENTS," upon the condition (amongst others) that I, the said John
Barclay Leslie, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Barclay Leslie, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawings here-
untò annexed and to the letters and figures marked thereon (that is to
say):
My Invention of "An Improved Instrument or Apparatus for Indi-
cating the Direction of Ocean and other Currents," has for its object the
indication of the direction or set of a current or tide, and consists of an
instrument or apparatus composed of a vertical brass rod carrying an
indicator and compass with the means of locking or fixing them
as herein-after described, which instrument or apparatus is intended
to be lowered from a ship to the depth required (below the keel of
the vessel) and the indicator and compass fixed so as to indicate the set
of the current or tide at such depth.
On the said rod is mounted a moveable indicator which is capable of
turning freely on the rod in any direction as impelled by a current, and
at the bottom of the rod is fixed a compass heavily weighted. Inside of
the said vertical rod is an inner rod connected with the said compass,
which inner rod works with a spring in such a manner that when the
spring is relieved from pressure the compass is free.

page_text: and serving with a groove inside the weight to guide the weight in its
descent. H is an inner vertical rod to the bottom of which is connected
the compass card I. To this rod H is fitted a spring K of sufficent
strength to hold up the compass card and the indicator B when the
spring is relieved from pressure. This spring is protected from the
water by its being encased in an india-rubber tube. The top of the
vertical rod H⚫terminates in a disc which when pressed downwards com-
presses the spring; L is a slide moving in slots formed in each side
of the hollow part of the vertical rod A, which slide rests on the said
disc at the top of the inner rod, and on which slide the indicator B
rests and is supported while the weight E is kept suspended by the catch
F. By means of this arragement when the pressure is applied to the
indicator B by the falling of the weight E, the indicator and the slide L
are carried downwards to the extent allowed by the slots in the hollow
rod A, and the spring being compressed allows the inner vertical rod H
to descend and lock the compass; M is a heavy weight at the bottom of
the compass to sink the instrument in the water as required; and N is a
line fixed to the top of the instrument by means of which it is lowered
into the water from the ship.
From the foregoing description it will be evident that in order to
ascertain and indicate the direction of a current or tide, the instrument
is lowered to the required depth below the keel of the vessel by means
of the line N, when by pulling the line G the weight E is liberated and
allowed to slide down the rod A and simultaneously lock the indicator
B and compass I, in such a manner as to indicate the direction of the
current or tide at the time when the weight was liberated. The instru-
ment is then hauled up again into the ship.
The catch or apparatus for suspending the weight may be varied
from that shewn in the Drawing and so may also the locking apparatus.
Having thus described the nature of the said Invention and in what
manner the same is to be performed, I hereby declare that I do not
claim as of my Invention any of the parts of the instrument separately
considered, but what I do claim as of my Invention is, the combination
of the several parts so as to form an instrument or apparatus in which an
indicator is mounted on a vertical rod so as to be capable of taking its
direction in relation thereto, as impelled by current or tide, and of being

page_text: locked simultaneously with the compass by means of a falling weight
for the purpose of indicating the direction of such current or tide as
herein-before described.
In witness whereof, I, the said John Barclay Leslie, have here-
unto set my hand and seal, the Fifteenth day of April, in the
year of our Lord One thousand eight hundred and seventy-
four.
JOHN BARCLAY LESLIE. (L.S.)