AN IMPROVED MODE OF AND APPARATUS FOR ASCERTAINING THE PRESENCE OF EXPLOSIVE GASES
Year: 1865

page_text: LETTERS PATENT to George Frederick Ansell, of Bernard Street, Russell
Square, in the County of Middlesex, Analytical Chemist, for the Inven-
tion of "AN IMPROVED MODE OF AND APPARATUS FOR ASCERTAINING AND
Scaled the 29th August 1865, and dated the 9th March 1865.
PROVISIONAL SPECIFICATION left by the said George Frederick Ansell
at the Office of the Commissioners of Patents, with his Petition, on
the 9th March 1865.
1. GEORGE FREDERICK ANSELL, of Bernard Street, Russell Square, in the
County of Middlesex, Analytical Chemist, do hereby declare the nature of the
said Invention for "AN IMPROVED MODE OF AND APPARATUS FOR ASCERTAINING
AND INDICATING THE PRESENCE OF EXPLOSIVE GASES," to be as follows:-
The object of this Invention is to provide a certain means of indicating the
presence of inflammable or explosive gases in mines, in buildings, and in the
holds of ships. To this end I avail myself of the natural law known as
the diffusion of gases, and rely upon the endosmosis action of the gas whose
presence it is desired to make known.
The manner of carrying out this Invention or of obtaining an audible or visible
indication of the presence of carburetted hydrogen gas in amine or elsewhere
inay be greatly varied, but in all cases the same principle of action will obtain.
Thus I may inflate an india-rubber ball or bladder with common air, and
place it in a box, and cause it to support a lever jointed to the upper part of

page_text: the box. This lever being arranged to keep while in its normal position an
alarum apparatus quiescent, will when forced up set the alarum apparatus
free, and thus an audible signal will be communicated of the presence of
danger. This effect will be obtained when the inflated ball is surrounded by
an atmosphere of hydrogen gas, for the gas will on the endosmosis principle
enter and further expand the ball or bladder, and thereby lift the lever and
set the alarum in action. A inore rapid indication will be obtained by using
an inverted porous jar or vessel closed at bottom by a flexible cover, through
which the end of a bent tube projects. In the bend of the tube mercury is
poured, and upon the open end of the tube a plug of ivory is floated. The
porous vessel being filled with air will, if presented to an atmosphere of
carburetted hydrogen gas, absorb a portion thereof, which by increasing the
pressure within the vessel will cause a displacement of mercury, and raise the
ivory plug, which may strike a bell, or otherwise produce an indication that
will arrest the attention of miners or others intended to be warned of the
danger. Either of these arrangements, by making metallic contact and thus
closing a battery circuit, may, through electro-magnetism, set an alarum in
action at one or more places where the danger signal is required to be given.
As the principle on which the Invention is based requires only the use of
automatic machinery for its application, it will be obvious that it may be used
in all cases where the danger of an accumulation of explosive mixtures of
gases is to be apprehended.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Frederick Ansell in the Great Seal Patent Office on
the 9th September 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
FREDERICK ANSELL, of 27, Bernard Street, Russell Square, in the County of
Middlesex, Analytical Chemist, send greeting.
WHEREAS Her Most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of March, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Frederick Ansell, Her special licence that I, the said George
Frederick Ansell, my executors, administrators, and assigns, or such others as
I, the said George Frederick Ansell, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and

page_text: .
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 MODE OF AND APPARATUS FOR ASCERTAINING AND INDICATING THE
PRESENCE OF EXPLOSIVE GASES," upon the condition (amongst others) that I, the
said George Frederick Ansell, 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 George Frederick Ansell, 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 hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
:-
The object of this Invention is to provide a certain means of indicating the
presence of inflammable or explosive gases in mines, in buildings, and in the
holds of ships. To this end I avail myself of the natural law known as the
diffusion of gases, and rely upon the endosmosis action of the gas whose
presence it is desired to make known to give a visible or audible indication of
its presence, and, when desired, of indicating the per-centage of the, gas that
is present in the atmosphere.
The manner of rendering the principle of the diffusion of gases available for
the above-named purposes I will now proceed to explain, reference being had
to the accompanying Drawings, which shew several arrangements of appa-
ratus which may be set in action by being exposed to an atmosphere of
carburetted hydrogen gas.
Fig. 1 shews in elevation an instrument for giving an audible signal of the
presence of an admixture of carburetted hydrogen with the atmosphere of a
coal mine or other confined space. This instrument consists of a frame A, or
preferably a compound metal standard, to allow for differences of temperature,
from the bed of which rises an adjustable cup B; upon this cup is placed an
india-rubber balloon or ball C inflated with air, and bound round the middle
by an inelastic band to prevent it from expanding laterally. On the top of
the balloon is laid a cap D, to which a crank lever D¹, carried by a cross
bar A¹, is jointed. The upper end of the lever D' is cranked to enter between
the teeth of a crown wheel E, which is mounted loosely on a spindle F
pendent from the cross bar A2 of the framing, and thus serves as a stop to

page_text: that wheel. The under face of the crown wheel is provided with ratchet teeth
which are intended to operate on the tail of a hammer G, and cause it to
strike a bell H set on the top of the frame A, the propulsion of the hammer
against the bell being effected by a spring placed under the tail of the
hammer. Mounted loosely on the spindle which carries the crown wheel E,
and set immediately above it, is a bobbin I, upon which is wound a weighted
cord, having its pendent end laid over a guide pulley K. This bobbin carries
a ring of ratchet teeth, into which a click carried by the crown wheel takes
for the purpose of coupling the wheel and bobbin together. When this
instrument, arranged as shewn in the Drawing, is exposed to carburetted
hydrogen gas, the tendency of that gas will be (acting according to the law of
the diffusion of gases) for it to pass through the pores of the inflated ball C,
and mingle with the air contained therein, and in doing so the ball will
expand by reason of an increased internal pressure to which it is subjected.
The effect will then be to force up the cap D, and thereby release the crank
lever from the teeth of the crown wheel. The wheel being now free the
weighted cord will immediately commence to rotate the bobbin I, and with it
the wheel E, which through its ratchet teeth will set the hammer in rapid
vibration, and cause through the hammer spring a succession of blows to be
struck upon the bell, thereby indicating the presence of danger. I would
here remark that that the manner of obtaining an audible or visible indication
of the presence of carburetted hydrogen gas in a mine or elsewhere may be
greatly varied, but in all cases the same principle of action will obtain.
Fig. 2 shews in sectional elevation an instrument for indicating a sudden
irruption of gas in a mine, and transmitting an audible or other signal to a
distant part by the aid of electricity. In this instance I use an inverted
porous jar or vessel A, composed of porous earthenware, like the cells of an
ordinary galvanic battery, or of graphite, in lieu of the india-rubber ball for
containing atmospheric air; this jar A I place upon the wooden bed B of
the instrument. Within this jar I place a bent mercury tube C, the upper
end of which projects through the top of the vessel, and is open to the
atmosphere. The tube is filled to a suitable height with mercury, and upon
the surface of the mercury in the projecting limb of the tube a float of metal
rests, its weight being counterbalanced by means of a weighted cord to which
it is attached. This cord is wound round a barometer wheel D, the axle of
which may be fitted with a pointer for shewing on a graduated metal disc E
when danger is approaching. Keyed to the axle of the wheel D is an
excentric F, upon which rests a rocking tube G, containing a loose ball, which
is free to roll from one end to the other for that purpose, and yet serves to

page_text: retain the tube when not disturbed in its elevated position. There is metallic
contact with this tube and the disc E, produced through the bracket
bearing. A covered wire H, soldered to the disc E, leads down to a metallic
coupling H on the bed of the instrument, and secured to a metal plate I
(which serves as a rest for the rocking tube G when depressed) is a covered
wire I, which leads down to a metallic coupling 12 on the bed B. The
metallic couplings Hand I are intended to receive the electric wires from a
battery in connection with an electro-magnetic alarum apparatus situate at
come distant part of the mine, or it may be above ground. Supposing now
the instrument to be properly coupled, and a sudden irruption of gas to occur,
the porous vessel will absorb a portion thereof, and the consequent increase of
the pressure within the vessel will cause a displacement of the mercury. The
float will thus be raised and the wheel D turned, and with it the excentric F.
As the larger diameter of the excentric comes, round the tube G will be tipped
over into the dotted position, and the electric circuit will be immediately
completed in the instrument. The alarum apparatus within the battery
circuit will then be set in action, and the attention of the attendant will be
directed to the point of danger. The electro-magnetic alarum apparatus may
be of any approved construction.
I would here remark that the instrument shewn at Fig. 1 may readily be
brought within a battery circuit; the apparatus shewn in red in that Figure,
or any other well-known arrangement, being introduced into the instrument
for the purpose of setting an electro-magnetic alarum in action.
For indicating in a very simple and efficient way the per-centage of
carburetted hydrogen gas niixed with the air, the instrument shewn at Fig. 3
may be used. It consists merely of a bent glass tube A mounted on a
pedestal B, and one limb of this tube is graduated and the other is expanded
at its upper end into a cup C. Cemented into this cup is a porous disc D,
and the bend of the tube is filled with mercury or other suitable fluid to the
graduation O, at which it will ordinarily stand. When the instrument is.
presented to an atmosphere containing carburetted hydrogen it will indicate
the per-centage of gas present by entering the cup C, and causing the mercury
to rise (under the increasing pressure to which it is exposed) up the graduated
limb of the bent tube.
In order to adapt the Invention to the use of mine inspectors I modify the
ordinary aneroid barometer, as shewn at Figures 4 and 5, by inserting in the
back thereof a porous disc A (see the cross section Fig. 5), which when
exposed to the atmosphere of a fiery mine by the removal of a metal cap B,
Fig. 6, will allow the atmosphere to enter the instrument and act upon the

page_text: corrugated chamber C, and thereby indicate the presence of fire damp. To
the graduated face of the instrument I fit a vernier D, adjustable by a central
button E, which will facilitate the reading off of the changes in the indicator
to a great nicety, and thereby shew the per-centage of carburetted hydrogen
gas present in the mine.
From the foregoing explanation it will be understood that the principle of
the Invention admits of ready application to all cases where the danger of an
accumulation of explosive mixtures of gases is to be apprehended.
Having now set forth the nature of my Invention of an improved mode
of and apparatus for ascertaining and indicating the presence of explosive
gases, I claim applying the principle of the diffusion of gases to indicate the
presence of inflammable or explosive gases by adapting to suitable indicating
apparatus a porous air vessel or chamber, in which the volume of the inclosed
air may be increased in the manner and for the purpose above described;
In witness whereof, I, the said George Frederick Ansell, have hereunto
set my hand and seal, the Ninth day of September, in the year of our
Lord One thousand eight hundred and sixty-five.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
GEO. F. ANSELL. (L.S.)