IMPROVE- MENTS IN APPARATUS FOR PREVENTING COLLISIONS AT SEA
Year: 1857

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN APPARATUS FOR PREVENTING COLLISIONS AT SEA."-A commu-
nication from Messieurs Trève and Felix Pitel, both of Brest, in the
Empire of France.
Sealed the 23rd October 1857, and dated the 1st May 1857.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on the
1st May 1857.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN APPARATUS FOR PREVENTING COLLISIONS AT SEA," a com-
munication from Messieurs Trève and Felix Pitel, both of Brest, in the Empire
of France, to be as follows:-
This Invention relates to an improved alarum sounding signal applicable
indiscriminately to sailing or steam vessels, and consists in the application
and use of a whistle similar to a locomotive whistle; but in place of this
whistle being in connection with a steam. engine boiler; and sounded by the
action of the steam, it is placed in communication with a compressed air'

page_text: reservoir, and is sounded by the action of the compressed air therein. A
force pump is fitted to the air vessel for the purpose of keeping up the
pressure.
By using compressed air in place of steam the whistle may be applied to
sailing vessels in lieu of being confined to steamers, and the power of the 5
blast and consequent degree of sound may be regulated to any extent;
whereas in the cases where steam boilers are used the sound will depend on
pressure of steam, which cannot readily or economically be, increased.
the
SPECIFICATION in pursuance of the conditions, of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 31st October 1857.
TO ALL TO, WHOM THESE PRESENTS SHALL COME, I,, JoпN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the, County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North. Britain,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of May, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and. successors, give and grant unto me,
the said John Henry Johnson, Her special license that I, the said John
Henry Johnson, my executors, administrators, and assigns, or such others as I,
the said John Henry Johnson, my executors, administrators, or 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
"IMPROVEMENTS IN APPARATUS FOR PREVENTING COLLISIONS, AT SEA," a commu-
nication from Messieurs Trève and. Felix Pitel, both of Brest, in the Empire
of France, upon the condition (amongst others) that I, the said. John
Henry Johnson, 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 tho date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby,
declare the nature of the said Invention, and. in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and by the
following statement, that is to say :—
The said Invention relates to the application and use of a peculiar alarum
apparatus on board ships, whereby collisions at sea in foggy dark weather may
be prevented.
This apparatus is applicable to all ships, but more especially to sailing
vessels, or ships fitted with auxiliary propellers.
Hitherto, as is well known, steam whistles have been adopted on a large
number of steam ships, whereby alarum signals can be given at great distances;
but as this, instrument is placed on the boiler and sounded by the steam
thereof, it is only applicablo to vessels propelled constantly by steam power,
or having a constant supply of steam in their boilers. The action of such an
apparatus and the volume of sound emitted therefrom is necessarily limited
by the maximum pressure of the steam in the boiler.
By employing the apparatus herein-after described, and which constitutes
the main feature of this Invention, these objections are obviated.
According to this Invention compressed air or wind is substituted for steam,
which is dispensed with, and consequently the alarum apparatus is equally.
applicable to sailing vessels and steamers, whilst it is capable of being worked
at variable pressures so as to augment or diminish its sound, as may be found
necessary, according to the distance is required to be heard.
The improved apparatus consists simply of a whistle similar to those
employed on locomotive engines; but its pipe, in place of being fitted into a
steam boiler, is inserted into a strong compressed air chamber or vessel of
sufficient capacity to contain a convenient quantity of compressed air, such
vessel being composed of sheet or cast iron, and of sufficient strength to
contain air at a pressure of several atmospheres. A small lever is placed
within easy reach of the man on the watch, for the purpose of opening. a
communication with the air vessel and producing a loud whistle as often
as may be found desirable. In order to be able to renew the pressure of
the air, when requisite, a small air-forcing pump is fitted to the air vessel.
A manometer or pressure guage, with which the air vessel is also furnished,
serves to indicate the pressure of the air therein, whilst a safety valve, if found
desirable, may also be fitted to the apparatus. It will be thus readily under-.
stood that the whole may be combined so as to form one portable apparatus,
occupying only a very small space, and capable of being easily carried to any
part of the ship where it may be required for use. In using this apparatus
during the night or in foggy weather, the man of the watch in charge of it
will simply require to place his hand from time to time on the small lever, for

page_text: the purpose of opening and closing the air cock, and thereby producing one
or more loud whistles so as to give an alarum to any neighbouring vessels
within hearing. As the sound will carry an immense distance, sufficient time
will be given for a neighbouring vessel to reply in a similar manner, and use
every precaution against accident.
The apparatus can be equally heard in a strong or head wind. for by in-
creasing the pressure of the air by means of the force pump; the power of the
whistle can be also proportionately increased.
Although I have more especially mentioned whistles similar to those in use
on locomotive engines as being used in conjunction with the compressed air
vessels, yet I would here observe that I do not confine or restrict myself to
sounding instruments of that kind, as any description of apparatus or instru-
inent capable of producing sound by the aid of compressed air or wind is
equally applicable.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe, in conclusion, that I do not confine or restrict myself
to the precise details or arrangements which I have had occasion to describe
or refer to, as variations may be made therefrom without deviating from
the principles or main features of the said Invention; but what I consider to
be novel and original, and therefore claim as the Invention secured to me by
the herein-before in part recited Letters Patent, is,―
First, the general construction and arrangement of alarum apparatus for
nautical purposes, as herein-before described.
Second, the application and use of compressed air or wind for sounding an
alarum whistle or other wind instrument, whereby alarum signals can be
sounded on sailing and other vessels without the aid of steam, as hercin-before
described.
In witness whereof, I, the said John Henry Johnson, havo hereunto
set my hand and seal, this Thirty-first day of October, One thousand
J. HENRY JOHNSON. (L.S.)