A NEW AND IMPROVED INSTRUMENT TO BE USED IN WAR TO MEASURE THE DISTANCE OF AN ENEMY BY OBSERVING THE SHOOTING, AND NOTING THE TIME BETWEEN THE APPEARANCE OF THE SMOKE OF THE GUN AND HEARING THE REPORT
Year: 1874

page_text: LETTERS PATENT to Henri Adrien Bonneville, of the British and
Foreign Patent Offices, 18, Rue de la Chaussée d'Antin, Paris,
France, and 6, Piccadilly, in the County of Middlesex, Patent
Agent, for the Invention of "A NEW AND IMPROVED INSTRUMENT TO
BE USED IN WAR TO MEASURE THE DISTANCE OF AN ENEMY BY OBSERVING THE
SHOOTING, AND NOTING THE TIME BETWEEN THE APPEARANCE OF THE SMOKE
OF THE GUN AND HEARING THE REPORT."-A communication from Paul
Emile Le Boulengé, residing at Liege, in the Kingdom of Belgium,
Captain-Commander in Belgian Artillery.
.
PROVISIONAL SPECIFICATION left by the said Henri Adrien Bonne..
ville at the Office of the Commissioners of Patents, with his
Petition, on the 23rd March 1874.
I, HENRI ADRIEN BONNEVILLE, of the British and Foreign Patent
Offices, 18, Rue de la Chaussée d'Antin, Paris, France, and 6, Piccadilly,
in the County of Middlesex, Patent Agent, do hereby declare the nature
of the said Invention for "A NEW AND IMPROVED INSTRUMENT TO BE USED'

page_text: IN WAR TO MEASURE THE DISTANCE OF AN ENEMY BY OBSERVING THE SHOOTING,
AND NOTING THE TIME BETWEEN THE APPEARANCE OF THE SMOKE OF THE GUN and
HEARING THE REPORT," communicated to me by Paul Emile Le Boulengó,
a person resident at Liege, in the Kingdom of Belgium, Captain-Com-
mander in Belgian Artillery.
The Invention relates to an instrument to be used in war to measure
the distance of an enemy by observing his shooting and noting the
time between the appearance of the smoke of a gun and the hearing of
its report. It consists of a tube of glass, the length of which is divided
in degrees representing the distances. This tube closed at both extre-
mities is filled with a liquid, and contains a metallic cursor formed of two
disks connected by a central rod. The diameter of the disks is a little
less than the diameter of the tube, and when the tube is held vertically
the cursor descends slowly and with an uniform movement.
To use the instrument hold it horizontally in the hand, the cursor
being at that end of the tube which corresponds to the zero of the
graduation. When at the observed hostile position you see the smoke of
a gun or of a small arm turn the hand rapidly to place the tube vertically
and the cursor immediately begins to come down. When you hear the
report of the gun turn the tube in the contrary way, the cursor stops,
and by reading the corresponding division you have the requested
distance.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henri Adrien Bonneville in the Great Seal Patent
Office on the 21st September 1874,
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRI
ADRIEN BONNEVILLE, of the British and Foreign Patent Offices, 18, Rue
de la Chaussée d'Antin, Paris, France, and 6, Piccadilly, in the County
of Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Hera
Letters Patent, bearing date the Twenty-third day of March, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give & grant unto me, the said Henri Adrien Bonneville,

page_text: Her special licence, that I, the said Henri Adrien Bonneville, my
executors, administrators, and assigns, or such others as I, the said
Henri Adrien Bonneville,. 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 AND IMPROVED INSTRUMENT TO BE USED.
IN WAR TO MEASURE THE DISTANCE OF AN ENEMY BY OBSERVING THE SHOOTING, AND
NOTING THE TIME BETWEEN THE APPEARANCE OF THE SMOKE OF THE GUN AND
HEARING THE REPORT," communicated to me by Paul Emile Le Boulengé,
a person resident at Liége, in the. Kingdon of Belgium; Captain-Com-
mander of Belgian Artillery, upon the condition (amongst others) that
I, the said Henri Adrien Bonneville, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and scals, 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

page_text: smoke of a gun or small arm turn the hand rapidly to place the tube
vertically, and the cursor will immediately begin to descend. When you
hear the report of the gun turn the tube in the contrary direction, the
cursor stops, and by reading the corresponding position you have the
required distance.
Regard has been taken in the construction of the instrument of the
variations occasioned by the temperature in the rapidity of the sound.
The volume and density of the cursor, the density and dilatability of the
liquid are so combined that the temperature exerts the same effect on
the rapidity of the cursor as on the rapidity of the sound.
The glass tube is enclosed in a copper casing with a longitudinal.
opening to read the graduation. This instrument is simple, practicable,
portable, and very accurate; anyone can use it.
All telemeters invented to this day are more or less simple methods of
triangulation, the instrument just described is consequently quite new,
both as a tellemetric method and as a mechanical combination. These
two points support the claim of the Inventor to a Patent for Invention.
Having thus described the nature of the said Invention and the manner
of carrying it into effect, I claim and wish to secure by Letters Patent an
instrument to be used in war to measure the distance of an enemy, con-
structed according to the tellemetric method and combination above.
described and represented.
In witness whereof, I, the said Henri Adrien Bonneville, have here-
unto set my hand and seal, this Seventeenth day of September,
in the year of our Lord One thousand eight hundred and seventy-
four.