IMPROVEMENTS IN APPARATUS FOR FACILITATING THE ASCER- TAINING AT THE SURFACE OF MINES THE COMPOSITION OF THE ATMOSPHERE IN THE SUBTERRANEAN WORKINGS OR GALLERIES, AND THE PROPORTION OF FIRE-DAMP OR OTHER MEPHYTIC GAS CONTAINED IN SUCH ATMOSPHERE
Year: 1876

page_text: LETTERS PATENT to Edwin Powley Alexander, of 14, Southampton Buildings,
in the County of Middlesex, Consulting Engineer and Patent Agent, for the
Invention of "IMPROVEMENTS IN APPARATUS FOR FACILITATING THE ASCER-
TAINING AT THE SURFACE OF MINES THE COMPOSITION OF THE ATMOSPHERE
IN THE SUBTERRANEAN WORKINGS OR GALLERIES, AND THE PROPORTION OF
FIRE-DAMP OR OTHER MEPHYTIC GAS CONTAINED IN SUCH ATMOSPHERE."
A communication from abroad by Alexandre Lemaire-Douchy, of Paris, in the
Republic of France.
Scaled the 7th November 1870, and dated the 18th May 1876.
PROVISIONAL SPECIFICATION left by the said Edwin Powley Alexander at
the Office of the Commissioners of Patents on the 18th May 1876.
EDWIN POWLEY ALEXANDER, of 14, Southampton Buildings, in the County of
Middlesex, Consulting Engineer and Patent Agent: "IMPROVEMENTS IN APPARATUS
FOR FACILITATING THE ASCERTAINING AT THE SURFACE OF MINES THE COMPOSITION
OF THE ATMOSPHERE IN THE SUBTERRANEAN WORKINGS OR GALLERIES, AND THE
PROPORTION OF FIRE-DAMP OR OTHER MEPHYTIC GAS CONTAINED IN SUCH ATMO-
SPHERE." A communication from abroad by Alexandre Lemaire-Douchy, of Paris,
in the Republic of France.
This Invention relates to a peculiar arrangement of apparatus for facilitating
the ascertaining at any moment at the surface of mines the composition of the
atmosphere in the subterranean workings or galleries, the proportion of fire-damp
or other incphytic gas contained in such atmosphere, and the precise inoment at
which the mixture of air and gas is about to become dangerous. The essential
feature of the said Invention consists in the automatic and continuous withdrawal,
outside of or to the surface of a mine, of samples of the atmosphere contained in
any of the underground workings or galleries thereof, and in supplying such samples
to analysing apparatus for the purpose of their being analysed on the spot at any
moment by any of the known methods or processes.
In carrying out this Invention a continuous air exhauster is employed, which
consists by preference of two closed vessels supported on the opposite ends of a
lever capable of oscillating vertically upon a fixed centre. The first of these
vessels is connected at its top by a flexible tube with a water supply pipe, and at
its bottom by another flexible tube with the top of the second vessel. A third
Darine cll

page_text: flexible tube is attached to the bottom of the second vessel for the exit of the
water after it has accomplished its object of expelling the air and forming a vacuum
in each vessel alternately, the water on escaping from the first vessel flowing into
the second vessel. These tubes are all provided with stop-cocks, which are opened
and closed by tappets brought into action by the rising and falling motions of the
vessels. The descent of each vessel is checked (until it has been filled with water)
by the action of a counterweighted lever and trigger catch. On the tops of both
vessels there are provided three cocks, one of which communicates by tubing with
the subterranean workings or galleries of the mino, so that when the vessel is
being exhausted a portion or sample of the atmosphere in the workings will be
drawn into it. The other two cocks on each vessel communicate with analysers
arranged for testing the air or mixture of air and gas by any of the well-known
methods. As the water rises in each vessel the sample of air contained therein will
be expelled through the last-mentioned tubes into the analysers, and when filled
with water the vessel will descend by its extra gravity, and produce the requisite
opening and closing of the cocks. The tube or tubes which descend into the mine
are connected by branch tubes to a series of cocks situate inside the mine (one for
each gallery or working), and from each of these cocks there is led a separate pipe
to each gallery. Any one of the said cocks is capable of being opened and closed
from the surface either by the aid of a battery or magnets, electric apparatus, and
electro-magnets, or by compressed air, or otherwise. In the case of using electricity
the wires from the coils of the electro-magnets of the cocks are carried up to a
commutator outside the mine, which indicates the several corresponding cocks
below, so that on establishing a circuit through any particular electro-magnet_the
corresponding cock will be opened and the air drawn from the gallery or working
in connection with the said cock.
Facility is thus afforded for testing at any moment the composition of the air
contained in any particular part of the mine. If desired an electric bell or other
alarm apparatus may be connected with the analysers, so as to give due notice
to the attendant before the mixture of air and gas reaches the point of absolute
danger.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edwin Powley Alexander in the Great Seal Patent Office on the
13th November 1876.
EDWIN POWLEY ALEXANDER, of 14, Southampton Buildings, in the County of
Middlesex, Consulting Engineer and Patent Agent. "IMPROVEMENTS IN APPARATUS
FOR FACILITATING THE ASCERTAINING AT THE SURFACE OF MINES THE COMPOSITION
OF THE ATMOSPHERE IN THE SUBTERRANEAN WORKINGS OR GALLERIES, AND THE
PROPORTION OF FIRE-DAMP OR OTHER MEPHYTIC GAS CONTAINED IN SUCH ATMO-
SPHERE." A communication from abroad by Alexandre Lemaire-Douchy, of Paris,
in the Republic of France.
"
The said Invention relates to a peculiar arrangement of apparatus for facilitating
the ascertaining at any moment at the surface of mines the composition of the
atmosphere in the subterranean workings or galleries, the proportion of "fire-damp
or other mephytic gas contained in such atmosphere, and the precise moment at
which the mixture of air and gas is about to become dangerous. The essential
feature of the said Invention consists in the automatic and continuous withdrawal
(by means of the apparatus herein-after described) to the outside of or to the
surface of a mine of samples of the atmosphere contained in any of the underground
workings or galleries thereof, and in supplying such samples to analysing apparatus
for the purpose of their being analysed on the spot at any moment by any of the
known methods or processes.
The said apparatus is situate outside the mine, is protected from all accidents

page_text: and causes of perturbation, is easily superintended, and, moreover, by the aid of a
signal bell, or other similar means of attracting attention, it signals the danger
to the attendant or others, and indicates in which of the workings the deleterious
gas is being disengaged.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer
to the annexed explanatory Sheet of Drawings, which represents a side elevation of
the said apparatus having an analyser connected therewith.
The said apparatus consists of two vessels A & B provided with water-level
indicators N, N¹, which vessels are connected the one with the other by a cock R¹
attached to the lower part of the vessel B and to the upper part of the vessel A. by
a branch pipe and short length of india-rubber tubing sufficient to allow for the
change in position of the two vessels, as herein-after explained.
The same
arrangement is fitted to the cock R₁ which regulates the supply of water. At the
lower part of the vessel A there is fitted a cock R for allowing of the escape of
the water after it has effected the working of the apparatus. On the top of cach
vessel there are fitted the smaller cocks a, h, r, and a², h¹, r¹, the cocks and
serving to afford free passage of the gas from the mine into the respective vessels,
whilst the other cocks a, h, and a¹, h¹, serve to direct the said gas to the analyser J.
The two vessels A and B are supported on plates provided with central spindles
K and L, carrying rams in contact with weighted catch levers 7, 1, so arranged
as not to permit of the oscillating movements of the vessels until they are
completely filled with water. The spindles K, L, rest upon the ends of a vibrating
lever E, F, which oscillates on a fulcrum c. It is this oscillating movement that
places the vessels A and B alternately in communication with the gas in the
inine, as will be herein-after explained.
The apparatus being constructed as described, and arranged as shown in the
Drawing, its working will be readily understood. Water being supplied by the
pipe D from any convenient source fills the vessel B and drives out the air therefrom
through the cocks a¹, h¹. When the vessel is full it counterbalances the weight on
the catch lever, this latter yielding, the vessel is impelled by gravity, and effects
its movement of oscillation round the fulcrum c by means of the vibrating balance
lever E, F. In its descent the vessel B has caused the cocks ¹, R¹, and R¹¹, to be
opened by being brought in contact with the stops or tappets M, m, and m³, carried
by the rods T, T", and also causes the vessel A. to ascend. This vessel in
its ascent brings the levers of the cocks a, h, in contact with the stop Q, fixed on
the rod T¹, thereby opening the said cocks. The water contained in the vessel B
flows into the vessel A at the same time, producing a vacuum in the vessel B. The
gas from the mine consequently enters the said vessel through the cock ², which
is placed in communication with the mine by a tube, as shown in the Drawing.
When the vessel A is filled with water the same movement and results are
obtained as with the filling of the vessel B, and this latter on rising opens the
cocks a¹, h, communicating with the gas analyser J, and so on, the movements
being repeated on the influx of the water from the pipe D.
I shall now proceed to explain the mode of application of this apparatus to the
discovery of "fire-damp" or other noxious gases in mines, but as regards the
accessory apparatus employed, I lay no claim to such as part of this Invention,
neither do I confine or restrict myself to any special form of such accessory
apparatus, reserving to myself the right of using such form or arrangement as may
best conform to the circumstances of each case. The Drawing hereunto annexed
illustrates clearly the method of using the said improved apparatus constituting
the present Invention.
The tubes which proceed from the vessels A, B, into the mine are united so as to
form one conduit, which opens out into a series of branches at V conveniently
situate inside the mine. From this point lead other tubes corresponding in number
to that of the galleries or workings in the mine, such tubes being laid along the
said galleries and extended as the work progresses. Each of these tubes before

page_text: reaching the vessels A, B, is connected with a cock H actuated by an electro-
magnet.
The wires which conduct the electricity to the electro-magnets pass
outside the mine to a commutator I which indicates each cock corresponding to a
given gallery. By this means any part of the mine may be selected at pleasure
for the purpose of having the nature of its atmosphere ascertained.
The tubes employed may consist either of caoutchouc or metal, and form a
species of canalization which is extended in proportion as the work progresses.
The air expelled from the vessels A and B is directed into an indicating or
analysing apparatus at J, which gives at each instant its particular composition
and consequently is enabled to give warning before the mixture of air and gas
becomes explosive. It is not necessary to illustrate or describe any particular
form of analysing apparatus as any well-known arrangement or system of testing
may be employed, such, for example, as plates of fusible metal, spongy platinum,
pumice stone, the electric spark, chemical reactions, and the like, provided that
means be afforded for introducing into the analyser or tester a mixture of air
and gas which will render the air drawn from the mine more readily explosive,
so as to be forewarned and enabled to take the necessary measures before the
atmosphere of the galleries contains sufficient fire-damp to produce an explosion.
An electric bell or other alarm may be combined with the analyser so as to intimate
to all concerned when the composition of the air in the mine has become dangerous.
The various parts of the said apparatus may be more or less modified, for example,
the cocks in lieu of being actuated by electro-magnets as described may be
Moreover,
worked either by compressed air or by any other suitable means.
although the apparatus such as I have described for drawing in the gas possesses
the advantage of economising the water employed, since it admits of its being used
twice, and answers its purpose perfectly well, this apparatus may in some cases in
actual practice be modified, for example, by dispensing with one of the cylindrical
vessels and substituting a rotary pump or other contrivance for producing a vacuum
in a continuous manner whilst still preserving the essential features of the said
Invention, namely, the automatic and continuous withdrawal from a mine of the
air contained in the subterranean galleries or workings. It is obvious that the
dimensions of the said apparatus should be adapted to the depth of the mine, and
to the length of the galleries over which it is intended to have control; it is neces-
sary in fact that each complete aspiration of one of the vessels should draw to the
exterior over and above the air contained within the pipes or conduits, a portion
of the air contained in the gallery submitted to investigation, and if this be not
accomplished at the first aspiration (as in the case of a mine of considerable depth),
it is at least necessary that the changes in the composition of the atmosphere of
the workings should be indicated within a period of a few minutes of such changes
taking place. It will, therefore, be necessary to calculate the capacity of the vessels
A and B, and the diameter of the conduit pipes. In like manner the weights P, P¹
will be regulated so that the extra charge which causes them to tilt shall represent
a given force sufficient to insure the regular working of the cocks, and to produce a
powerful aspiration capable of overcoming the resistance due to the friction of the
air in the conduit pipes. The vertical downward motion produced by this force
follows the ordinary laws of gravity, it is in no way impeded by the resistance of
the weights P, P¹ since thic levers 7, l' are so arranged as to effect the release or
disengagement at the commencement of the descent. The amount of force due to
the extra charge of water may thus be augmented at will and be employed, if found
desirable, for other purposes, such, for example, as the working of the cocks H by
the compression of the air, or by the action of electro-motors or magneto-electric
machines of the Graham or other type answering the same purpose.
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 what I consider to be novel and original and therefore
claim as the Invention secured to me by the herein-before in part recited Lettors
Patent is, the manufacture and use of a self-acting apparatus constructed and

page_text: arranged to operate substantially in the manner herein-before described and
illustrated by the Drawing hereunto annexed for the purpose of ascertaining at
any moment at the surface or outside of a mine the composition of the atmosphere
in the subterranean workings or galleries of the said mine, the proportion of fire-
damp or other dangerous gas contained in such atmosphere, and the precise moment
at which the mixture of air and gas is about to become dangerous.
In witness whereof, I, the said Edwin Powley Alexander, have hereunto set
my hand and seal, this Thirteenth day of November, in the year of our Lord
One thousand eight hundred and seventy-(6)six.
EDWIN P. ALEXANDER. (L.S.)