APPARATUS SERVING TO MEASURE UPON A LARGE SCALE THE SMALLEST PRESSIONS OF ANY FLUID MATTERS
Year: 1858

page_text: LETTERS PATENT to Eugène Francois Sans, Engineer, residing at Epernay
(Marne), in the Empire of France, for the Invention of "APPARATUS
SERVING TO MEASURE UPON A LARGE SCALE THE SMALLEST PRESSIONS OF ANY
FLUID MATTERS."
Sealed the 10th September 1858, and dated the 17th April 1858..
PROVISIONAL SPECIFICATION left by the said Eugène Francois Sans
at the Office of the Commissioners of Patents, with his Petition, on the
.17th April 1858.
I, EUGÈNE FRANCOIS SANS, Engineer, residing at Epernay (Marne), in the
Empire of France, do hereby declare the nature of the said Invention for
"APPARATUS SERVING TO MESURE UPON A LARGE SCALE THE SMALLEST PRESSIONS
OF ANY FLUID MATTERS," to be as follows:-.
For the purpose of measuring the pressure of fluids contained in reservoirs,
pipes, &c., a glass monometer is used provided with two vertical branches,
joined at their lower extremities by means of a syphon; one of these branches
communicates with the fluid, the tension of which is to be measured, the
other one with the atmosphere. The syphon formed by the two branches is
half filled with any liquid whatever, and the difference of level in the two
branches indicates the measure of the tension.

page_text: try a longer description. The graduation is experimentally registered with
the aid of an usual manometer.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Engène Francois Sans in the Great Seal Patent Office
on the 6th October 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EUGÈNE
FRANCOIS SANS, Engineer, residing at Epernay (Marne), in the Empire of
France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of April, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Eugène Francois Sans, Her special licence that I, the said Eugène
Francois Sans, my executors, administrators, and assigns, or such others as I,
the said Eugène Francois Sans, 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
"APPARATUS SERVING TO MEASURE UPON A LARGE SCALE THE SMALLEST PRESSURE
OF ANY FLUID MATTERS," upon the condition (amongst others) that I, the
said Eugène Francois Sans, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Eugène Francois Sans, 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 and accompanying Drawings, (that is to say:-
For the purpose of measuring the pressure of fluids contained in reservoirs,
pipes, &c., a glass manometer is used provided with two vertical branches,
joined at their lower extremities by means of a syphon; one of these branches
communicates with the fluid, the tension of which is to be measured, the other

page_text: one with the atmosphere. The syphon formed by the two branches is half
filled with any sort of liquid, and the difference of level in the two branches
indicates the measure of pressure.
Such a disposition only produces erroneus indications, and the examiner is
incorrectly informed, besides, many errors result from the capillary attraction
in pipes generally too small, and the use of the above described manometer does
not allow an exact distribution of the gas used for light. Instead of this
apparatus generally used, a manometer with a dial, denominated "the dial
manometer," has been tried, but unsuccessfully. Pressure is shown on a pretty
large scale, but the variations, if not strong, leave the hand unmoved, as the
pieces acting upon it can be put in motion only by an excess of pressure
sufficient to overcome their inertness. This apparatus is not sensitive enough,
and does not answer the purpose.
The manometer, the description of which is as follows, offers the following
advantages:-
1st, a very perceptible sensibility, so that it may be compared only to the
air bubble in a water level, the indications being registered by the liquid itself
upon which the pressure of the gas is acting.
2nd, the interior diameter of the registering tube, its inclined position, and
the shape of the vessel preventing almost entirely the capillary attraction.
3rd, the vertical heights of the registering liquid are measured upon an
inclined plane, so that they are made twenty, thirty, and even forty times
more appreciable.
DESCRIPTION OF THE DRAWINGS.
A, Metal or glass vessel fastened to a stand T; B, crystal pipe of the same
size in all its length, and fastened to the vessel by screws; the part of the
junction which is fastened to the vessel is bent so that it may reach the
bottom; C, scale upon which the divisions are marked; R, cock leading
the gas into the vessel; S, cock stopping the end of the crystal tube; over
this cock is another small tube through which water may be admitted at the
same time; it is of use for the motion of the air in the tube. This cock is
disposed in such a way that the interior part of the box may be put in com-
munication with the atmosphere, the gas being not admitted, or the gas alone
may be admitted if required. The vessel A is filled with the gas as far as the
point upon the scale, it is admitted through the small tube of the cock S.
As soon as the gas comes in the compartment A its tension is acting upon the
surface of the liquid which is forced into the pipe until the vertical height of
the water overbalances it.

page_text: The working of this apparatus is easily understood, and it is therefore
unnecessary to give a longer description. The graduation is experimentally.
registered with the aid of the usual manometer.
In witness whereof, I, the said Eugène Francois Sans, have hereunto
set my hand and seal, this Sixth day of October, in the year of our
Lord One thousand eight hundred and fifty-eight.
FRANÇOIS SANS. (L.S.)