A NEW OR IMPROVED SYSTEM OF MARINE LOG, TO BE CALLED 'SOUNDING LOG.
Year: 1854

page_text: LETTERS PATENT to Adolphe Pécoul, Master Mariner, of Marseilles, in the
Département of Bouches-du-Rhône, Empire of France, and of 16, Castle
Street, Holborn (City), London, for the Invention of "A NEW OR IMPROVED
SYSTEM OF MARINE LOG, TO BE CALLED 'SOUNDING LOG.'
Sealed the 16th January 1855, and dated the 14th November 1854.
PROVISIONAL SPECIFICATION left by the said Adolphe Pécoul at
the Office of the Commissioners of Patents, with his Petition, on the
14th November 1854.
I, ADOLPHE PÉCOUL, Master Mariner, of Marseilles, in the Département. of
Bouches-du-Rhône, Empire of France, and of 16, Castle Street, Holborn
(City), London, do hereby declare the nature of the said Invention for "A NEW,
OR IMPROVED SYSTEM OF MARINE LOG, TO BE CALLED ; SOUNDING LOG," " to be as
follows:-
The object of this Invention is the construction of an instrument which may
be used. both for measuring the distances travelled over by ships and vessels
of any description, and for sounding without stopping the ship's progress or
heaving-to. For this purpose I use a log of a pyramidal or conoidal shape,
the vertex of the pyramid or conoid pointing downwards, and carrying a pulley,

page_text: over which the sounding line is made to pass; this latter has suitable marks to
read off the fathoming by, instead of the usual knots. A spring is so adapted
to the lower part of the log that it lets the line slip downwards, but upon the
line being drawn the other way, the spring holds or catches the line, and thus
the relative position of the line and log is preserved, and the fathoming may be
read off. The log is kept in its vertical position by means of a suitable weight
hung at the end of the sounding line. When it is desired to use this log for
sounding, the log is heaved and the line paid out from the reel whilst the
ship sails on, until the above-mentioned weight rests on the bottom of the sea,
and thus causes the line to be stopped, and the pyramidal or conoidal log to
lie flat on the water's surface; the log is then hauled on board, and the
fathoming read off. If it be desired to use this instrument for logging only, an
additional floater is used between the pulley and ship; this floater is secured
to the line and to the base of the conoidal or pyramidal log. In this case
there is also a pin, to prevent the line from being drawn down by the
weight..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Adolphe Pécoul in the Great Seal Patent Office on the
2nd May 1855...
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ADOLPHE
PÉCOUL, Master Mariner, of Marseilles, in the Department of Bouches-du-
Rhône, Empire of France, and of 16, Castle Street, Holborn (City), London,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of. November, in the year of our Lord
One thousand eight hundred and fifty-four, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
-Adolphe-Pécoul,-Her_special_licence_that_I, the said Adolphe Pécoul, my
executors, administrators, and assigns, or such others as I, the said Adolphe
Pécoul, 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 "A NEW OR IMPROVED SYSTEM OF
MARINE LOG, TO BE CALLED SOUNDING LOG,"" upon the condition (amongst
!

page_text: others) that I; the said Adolphe Pécoul, by an instrument in writing under
my hand and seal, should particularly 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 Adolphe Pécoul, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement :-
The object of this Invention is the construction of an instrument which may
be used both for measuring the distances travelled over by vessels or ships of
any description, and also for sounding without stopping the ship's progress or
heaving-to..
And in order that this Invention may be fully and clearly understood,
I have on the annexed Sheet of Drawings represented or illustrated the way in
which the same is or may be carried into effect and used.
Figs: 1, 2, 3, & 4 shew the sounding log in different positions, and as
applied to different uses. Figs. 5 & 6 are a front and end view respectively
of the pulley block. The same letters of reference stand for like parts in the
different Figures.
This sounding log consists of a small buoy of brass, copper, or any other
suitable material, and which is capable of sustaining a weight of about six
pounds, nine and three-quarter ounces, avoir-du-poids. This buoy, which
is shewn a little inclined in the Drawings, has the shape of an inverted
triangular pyramid, whose base a, b, c, is an equilateral triangle, the
three sides being isosceles triangles. At the vertex d 'I fix a pulley, over
which passes the log line, having a weight e at its end. The length of
line between the buoy and the weight is variable, that is to say, it can be
increased or diminished, according to the degree of accuracy with which the
ship's course is to be estimated, or according to the depth of the water which
it is desired to sound. This length having been determined upon, a pin fis
inserted between the strands of the line, thus stopping the weight froni sinking
further. From this pin backwards at a suitable distance, I fasten to the line a
floater or cork h, which receives the point or pin g, attached to the two corners
b, c, of the pyramid's base, by means of a piece of line, in such manner that
the buoy a, b, c, d, being placed perpendicular, as at Fig. 1, the three line ends
draw the buoy equally. When, after the operation of measuring or sounding,
the log is hauled on board, the point g leaves the cork h, the weight e rises up

page_text: till it touches the buoy, and this latter assumes a horizontal position, as shewn
at Fig. 2, so as to offer the least resistance. The sounding weight e, offering
very little surface hold, is intended to render more stable the buoy, and to
-diminish its liability to being carried away by currents; hence the difference
of drift in this and in the common log may be applied to ascertaining the
approximate velocity of the current. But the main object of this addition is to
-afford 'the means of sounding whenever required, and. without stopping or
heaving-to, which will be found a great commodity, especially when nearing
the land. For this purpose I fix at the vertex of the buoy the apparatus
shewn in side and end view, Figs. 5 & 6. This apparatus. consists of a
pulley i, capable of turning in a block k, k, suitably secured to the buoy. I is a
spring box, containing the spring m, which bears against the line in such
manner as to allow it to slip between the spring and the pulley as long as the
weight e draws the line, and to stop it as soon as tlie weight touches the sea's
.bottom, when the buoy assumes the position shewn in dotted lines at Fig. 3
The spring box is mounted on á pin n, which allows it to be turned aside,
and also to be fixed farther from or. nearer to the block, by means of a set
screw o, for the purpose of stiffening the spring. p. is a screw pin, which passes
through the two cheeks k, k, of the block, and prevents the line from coming
off. When the log is hauled on board, the buoy assuming a horizontal
position, the sounding line forms a very acute angle with the spring m, so as
to prevent the line from slipping back. In order that the line may pass
between the spring and pulley, it. must not have knots, as usual, to mark off
the lengths; but I replace these knots by marks, painted or fixed in any other
suitable manner to the line, so that it may not be prevented from slipping.
When the log is to be used for sounding, the most suitable way of working it
is as follows: After having passed the line over the pulley, fixed and adjusted
the spring box k, and inserted the pin p, the weight is taken to the vessel's
stern, and thrown overboard. I also find it convenient to fix some tallow on
the bottom of the weight. As soon as the weight is taken to the vessel's
stern; the buoy is thrown overboard-from-the stern; -and-the-line-is-paid-
out until the weight may be supposed to have touched the sea's bottom.
This latter precaution is only necessary at night; for in the day-time it is
easily perceived when the weight touches the ground, by the buoy floating in a
horizontal position. In order to facilitate the operation and prevent the line
from curling, it is coiled crosswise on the log reel; also, in order not to strain it
unduly, the line has to be paid out quickly.
Having thus described the nature of my Invention, and the manner in which

page_text: the same is or may be carried into effect, I wish it to be understood that what
I claim as the novel principle secured to me by the herein-before in part recited
Letters Patent is, the system of sounding logs for measuring the speed of the
vessel, and taking soundings without stopping or heaving-to, substantially as
described above, and illustrated on the annexed Drawings, or any mere
modification of the modes shewn.
In witness whereof, I, the said Adolphe Pécoul, have hereunto set my
hand and seal, this Seventh day of April, in the year of our Lord