CERTAIN NEW AND IMPROVED GAS- LIGHT APPARATUS's, PROCESSES, AND PHILOSOPHICAL INSTRUMENTS
Year: 1817

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DANIEL
WILSON, of Dublin, Gentleman, send greeting.
WHEREAS His most Excellent Majesty King George the Third did,
by His Letters Patent under the Great Seal of His United Kingdom,
bearing date at Westminster, the First day of March, in the fifty-seventh
year of His reign, grant unto me, the said Daniel Wilson, my exors,
adiñors, and assigns, His especial licence, full power, sole privilege and
authority, that I, the said Daniel Wilson, my exors, adñññors, and assigns,
should and lawfully might, during the term of years therein mentioned,
make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, my Invention of "CERTAIN NEW AND IMPROVED GAS-
LIGHT APPARATUS's, PROCESSES, AND PHILOSOPHICAL INSTRUMENTS;" in which said
Letters Patent there is contained a proviso that if I, the said Daniel Wilson,
shall not particularly describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, by an instrument in
writing under my hand and seal, and cause the same to be inrolled in His
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said Letters Patent, that then the said
Letters Patent, and all liberties and advantages whatsoever thereby granted,
shall utterly cease, determine, and become void, as in and by the same,
relation being thereunto had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Daniel Wilson, do hereby declare that the nature of my said Inventions,
and the manner in which the same are to performed, are particularly
described and ascertained in and by the Drawings hereunto annexed, and
the following description thereof (that is to say):-
In order to render the gas procured by the distillation of coal proper for
illumination, it is necessary to free it from the sulphuretted hydrogen gas

page_text: which it contains. This is usually done by forcing it through a mixture of lime
and water, but from the difficulty of mixing a gas and a liquid the purification
is generally incomplete. My method consists in generating ammoniacal gas
which meets the air procured from the coal in its. passage.to.the gasometer
mixes compleatly with it, and by combining with the sulphuretted hydrogen
gas renders it soluble in water, which the whole is made to pass through.
The ammoniacal gas is procured by the distillation of the ammoniacal liquor
(one of the products of coal) with lime.
Fig. 1 is a section of the apparatus. A is the vessel in which the ammo-
niacal gas is generated; it is set in brickwork, with a fireplace under it.
B, the pipe for admitting the coal gas, which is conducted below a per-
forated shelf C by branch pipes D, D. An agitator E passes through
the pipe B, which is worked by a wheel and pinion in the usual manner.
F is a cannister for charging and discharging the lime. G, a small pipe
communicating with a cistern of ammoniacal liquor. In order to work the
apparatus, a mixture of lime and water is introduced by the cannister F so
high as to cover the perforated shelf C; a moderate fire is then applied,
and a small current of of ammoniacal liquor allowed to flow in by the pipe G.
The coal gas passing in by B meets the ammoniacal gas as it is generated, and
is then conducted by the pipe H into the vessel I, which contains water, a few
inches higher than the perforated shelf K, under which the gas is spread, and
the sulphuretted hydrogen, rendered soluble by combining with the ammonia,
is wholly dissolved in the water, and the gas for illumination proceeds in a state
of purity to the gasometer by the pipe L. The current of ammoniacal liquor
introduced by G must be regulated by the quantity of gas to be purified.
The
gas as it
passes from L should be occasionally tested by a solution of lead,
and when it occasions a precipitate the lime in A should be changed. The
water in I, when saturated with the combination of ammonia and sulphuretted
hydrogen, may be employed for reproducing the ammonia, so that the same
ammonia may be worked over many times.
Secondly, in order to prevent an improper consumption of gas, it is necessary
to restrict the aperture which conveys it to the burners, but, from the tar
and other impurities deposited in the restriction, it very soon closes up.
My improvement consists in having the restricted aperture in a stopcock,
which has a small crank attached to its stopper, and the end of this crank, by
the opening and shutting of the stopcock, is made to enter and recede from the
restricted aperture, so as always to keep it at the same size.
Fig. 2 is a section of the stopcock and apparatus. A is the stopper which
is notched as at B; C is a small crank with a joint at D; it passes through a

page_text: of it, and is inserted in a
The wire is represented by
guide hole at E, and enters the restricted aperture F when the stopcock is
shut, and. recedes from it when it is opened. The crank is attached to the
stopper by a.wire which passes through the end
drilled hole parallel to the surface of the stopper.
the dotted line. The aperture F must be made in proportion to the size of
the burner and the pressure under which the gas burns, and I do not claim
the whole stopcock as my Invention, but only that part which relates to the
keeping the restriction clear.
Thirdly, in order to ascertain the pressure under which gasses exist, and the
changes of the weight of the atmosphere, for various purposes of science and
the arts, a column of mercury oscillating in a tube is employed, which is well
known as the common barometer. But this instrument is in many cases
inconvenient from its want of portability. My Invention consists in forming
an instrument fit for all the purposes of the barometer by placing. .a portion
of an elastic fluid in an air-tight vessel in such a manner that, by an increase
or diminution of the pressure under which it exists, it will, by its contraction or
expansion, act upon and occasion the fall or rise of a column of mercury.
Fig. 3 is a section of the instrument. A is a cylindrical vessel of iron,
about one inch in diameter, and one inch and an half deep. It is closed at
top and bottom; a glass tube B, open at both ends, is inserted through the top,
and made to project inside to the centre of the cylinder. C is a thermometer,
which is likewise inserted thro' the top, so that its bulb be inside; both are
cemented in air-tightly. A quantity of mercury is then introduced thro' the.
tube B until its extremity be covered a quarter of an inch by it. This may be
ascertained by drilling a small hole thro' the side of the cistern at the proper
height, which may again be cemented when the mercury is at that level, and
a small quantity of mercury added until it stands in the tube B a little above
the cistern. The space above the mercury being filled with air, it will contract
or expand in proportion as the external pressure encreases or diminishes,
and a corresponding rise or fall of the mercury will take place in the tube B;
but I prefer filling the space above the mercury with hydrogen or nitrogen
instead of atmospherical air to prevent any oxidation of the mercury. In
order to graduate the instrument, the end of the tube B is attached to an air-
pump or condenser which have a barometer guage. The air in the cistern A
is now condensed until the barometer guage indicates 32 inches, when the
height of mercury in the tube B is marked. The included air is afterwards
dilated by the air pump until the guage indicates 20 inches, when the height
of the mercury is again marked, and this space is divided into twelve equal
parts, which represent barometrical inches, and are engraved on the scale with

page_text: a vernier in the usual manner. During the graduation the cistern is kept at a
fixed temperature. When the instrument is to be used it may be brought
to this temperature by holding it in the hand, otherwise a correction for heat
is necessary. The amount of this is ascertained by dipping the cistern in
water at different temperatures,,and obtaining the rate of expansion in the
tube B, which is afterwards marked on the scale of the instrument. A poreus
piece of wood is inserted in the end of the tube B, which will allow a free
passage of air, but prevent the mercury from escaping, and a stopcock is
comented over it, which should be closed when the instrument is carried.
The whole is surrounded by a brass tube.
Fourthly, for many purposes it becomes desirable to ascertain the quantity
of moisture dissolved in airs, my Invention for accomplishing which consists
in attaching the bladder of a small animal to a glass tube, and filling it with
mercury, which will rise or fall with variations of moisture in the air to which
it is exposed. I prefer the urine bladder of a rat, but all animal bladders
possess this property. When the instrument is filled with mercury, in order
to graduate it, it is dipped in water at the temperature of sixty degrees of
Fahrenheit, and the point to which the mercury sinks is marked; it is then
inclosed in air exposed to the absorbing power of sulphuric acid of the
specific gravity of 1.85 degrees, and the point to which the mercury rises is
marked. This space is divided into one hundred equal parts, and engraved on
a scale which is attached to it; 0 degrees indicates extreme moisture, and one
hundred degrees extreme dryness.
In witness whereof, I, the said Daniel Wilson, have hereunto set my
hand and scal, this Twenty-ninth day of August, in the year of our
Lord One thousand eight hundred and seventeen.