IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR LIGHTING STREET AND OTHER GAS LAMPS
Year: 1877

page_text: LETTERS PATENT to James Longshaw, of the Firm of Longshaw & Sons, of
Warrington, in the County of Lancaster, for the Invention of "IMPROVEMENTS
IN THE METHOD OF AND APPARATUS FOR LIGHTING STREET AND OTHER GAS
LAMPS."
Sealed the 26th March 1878, and dated the 27th September 1877.
PROVISIONAL SPECIFICATION left by the said James Longshaw at the
Office of the Commissioners of Patents on the 27th September 1877.
JAMES LONGSHAW, of the Firm of Longshaw & Sons, of Warrington, in the County
of Lancaster. "IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR LIGHTING
STREET AND OTHER GAS LAMPS."
The object of this Invention is to effect the simultaneous lighting of all the street
lamps in a town or city, or all the gaslights in a theatre or other building or place, at
one time by means of a current of electricity.
Each gas tap is provided with a small electro-magnet, and by exciting all these
electro-magnets at once by a current of electricity, all the taps can be opened or closed
simultaneously.
The electro-magnets are all provided with wires, by means of which they are all
connected to a battery or series of batteries at a distant point, or to any other known
means of producing a strong electric current.
The lighting of the gas is effected as follows by means of platinum wire or foil,
or spongy platinum assisted by an electric current produced as before, and conveyed
either by the same wires, or by separate wires as may be found most expedient:-
The platinum being so placed in connection with each tap that when the tap is
opened, the gas will impinge thereupon, a current of electricity is first caused to pass
through the platinum, such current not being sufficiently strong to heat the platinum
to any very great extent, but sufficient to impart a certain amount of warmth and
thoroughly dry the saine, and drive off all moisture. The platinum wire, foil, or
sponge, now possesses this peculiar property, that if a current of coal gas is allowed
to impinge upon it whilst in this warm and thoroughly dry state, it becomes heated
IDin 37

page_text: to such an extent that it lights the gas All that is required therefore is, first, to
thoroughly dry and warm all the platinum wires, foils, or sponges, by passing a
current of electricity through them; and, secondly, to open the taps by the same or
another electric current, and allow the gas to impinge upon the platinum in this
dried and warm state.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Longshaw in the Great Seal Patent Office on the 26th March
1878.
JAMES LONGSHAW, of the Firm of Longshaw & Sons, of Warrington, in the County
"IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR LIGHTING
of Lancaster.
STREET AND OTHER GAS LAMPS."
The object of this Invention is to effect the simultaneous lighting of all street
lamps in a town or city, or all the gaslights in a theatre or other building or place,
at one time by means of a current of electricity.
Each gas tap (which I prefer to be of the peculiar construction herein-after
described) is provided with a small electro-magnet, and by exciting all the
electro-magnets at once by a current of electricity, all the taps can be opened or
closed simultaneously.
The electro-magnets (which may in some cases be assisted by auxiliary permanent
magnets) are all provided with wires, by means of which they are jointly connected
to a battery, or series of batteries, at a distant point, or to any other known means of
producing a strong electric current.
The lighting of the gas is effected as follows by means of platinum wire, or foil,
or spongy platinum, assisted by an electric current produced as before, and conveyed
either by the same wires, or by separate wires as may be found most expedient :-
The platinum being so placed in connection with each tap that when the tap is
opened, the gas will impinge thereupon, a current of electricity is first caused to pass
through the platinum, such current not being sufficiently strong to heat the platinum
to any very great extent, but sufficient to impart a certain amount of warmth and
thoroughly dry the same and drive off all moisture. The platinum wire, foil, or
sponge, now posseses this peculiar property, that if a current of coal gas is allowed
to impinge upon it whilst in this warin and thoroughly dry state, it becomes heated
to such an extent that it lights all the gas. All that is required therefore is first to
thoroughly dry and warm all the platinum wires, foils, or sponges, by passing a
current of electricity through them; and, secondly, to open the taps by the same, or
another electric current, and allow the gas to impinge upon the platinum in this
dried and warın state; or, if preferred, the taps may be opened first, and the gas
be ignited by means of an electric spark, as well understood by electricians.
Such being the nature and object of my said Invention, I will now proceed to
describe in detail the manner in which the same is to be or may be performed or
carried into practical effect, and in order that the same may be clearly understood,
I have annexed hereunto a Sheet of Drawings illustrative thereof, and have marked
the same with figures and letters of reference corresponding with those in the
following explanation thereof.

page_text: Fig. 1 in the annexed Drawing illustrates in section the construction of tap which
I propose using for my improved method of lighting street lamps by electricity.
It may be described as a cylinder containing three separate compartments divided
by partitions a, b, c, as shown on the Drawing; a forms part of outside case of tap;
c is made longer than b, and in about the same proportion as shown in the Drawing.
The gas chambers d and e can be from one sixteenth of an inch in diameter to any
size, according to the quantity of gas required. The chamber fought to be two or
three times the size in diameter of d and e together; g is entrance for the gas, and
is connected with a pipe from the main; h is the exit, and is connected by a pipe to
the burner.
At the bottom of the chambers d, e, and f, where the whole are united together
in one at i, i, is a quantity of metallic mercury. On this stands, in the chamber f,
the column k, which floats on the surface of the mercury, and is perfectly free in its
action, being separated by a small air cavity. The level of the mercury being one-
eighth or one-sixteenth of an inch (more or less as the case requires) below the
partition marked b, any gas now entering at g would pass into the chamber e, e,
and thence by h to the burner.
By exerting the slightest pressure on the movable column k, the mercury i, i, rises
according to the extent of the pressure, and fills the chamber d and e up to the
line x, or to such an extent that it overcomes the pressure of the gas, and thus shuts
it off from the burner. The column of mercury in the cavity ff, under all circumstances
prevents any escape of gas into the air.
By relieving the pressure on the column k, k, the mercury falls to its original
position at 2, and the gas as before escapes to the burner. This tap can be made
of metals, glass, ebonite, or porcelaine, as the case may require, and the column k, k,
can be made partially hollow, in order to place in it small weights, such as shot, to
regulate the level of the mercury at z. If metal is employed for the tap where the
mercury touches, the metal of the tap will have to be coated with some hard varnish;
or the surface of the metal so oxidized to prevent the mercury forming an amalgum
with the metal used.
Fig. 2 represents in elevation the electro-magnet which I purpose to employ in
connection with the tap just described, or with any other suitable tap; 1, 7, is the
soft iron core, over which is a wooden or other cover m, m, in the form of a bobbin,
the space round the cover being filled or partially filled, as the case requires, with
coiled insulated copper wire mx; the amount of wire varies according to work
required. The end of the soft iron core at l, l, projects slightly above the woodwork
and has a faced surface, also at 1x the end projects, but is rounded, as shown in the
Drawing. At n, supported from the woodwork, is a pin or axle on which the
permanent magnet o, o, is suspended, having perfect freedom of action between the
points o and ox, the latter position being marked in dotted lines. At p is a brass
pin projecting from the woodwork, and preventing magnet from getting opposite the
centre of the core l, l*.
The ends of the permanent magnet o are turned at right angles, as represented in.
Fig. 3, so that when this magnet o is touching the pin p in Fig. 2, the north pole
nearly touches the core at 1x with one end, and the other rests on the lever q, q,
which is made of brass, and on the side facing the core is a soft piece of iron 7, 1,
the same size as surface of 1, 1, fastened to the brass lever, the lever q, q, supported
on a pin 8 on which it works with perfect ease, and so balanced by a weight that
when left to itself is just touching the upper surface of the brass lever q, q.
The action of the whole is as follows:-By passing through the wire coil a current
of electricity to make the la south pole and * a north pole, first, the soft iron r, r,
is at once attracted to the surface 1, and the lever q, q, assumes the position shown
in dotted lines. At the same instant the permanent magnet o is repulsed, and
occupies the position shown by the dotted lines o* in the Drawing, thus locking or
holding down the brass lever in the position shown after the electricity in the wire
coil ceases. The surfaces 1, 1, and r, r, are not allowed to touch, but to close as near
as possible without doing so.

page_text: If necessary when the permanent magnet o, o, is holding down the brass lever q, q,
to prevent any tendency of working back to its original position by vibrations or
otherwise, there is on the upper side of the lever q, q, a very small extra thickness of
metal; or a very small cavity can be formed in which one of the edges of the
permanent magnet will catch.
The whole is made so that when the end of the core is made into a north pole,
and 1* into a south pole, the face, r, is attracted slightly, just relieving entirely the
permanent magnet from the metal lever q, and the permanent magnet at once strikes
the pin o, so that when the current ceases the brass lever q, q, assumes its original
position.
Each lamp is provided with one of these electros, and the wires from one magnet
fastened to the wires of the other, and so on until a large number are so connected.
It will be seen that by placing the free end of the brass lever q, q, over the
column k, k, in Fig. 1, and working with the electric current as before described, the
gas can be shut off or allowed to escape as required. The size of the tap and electro-
magnets will depend on the amount of gas used, but for ordinary burners the magnets
will be from one inch in length to two inches, and the remainder in about the pro-
portion of the Drawings. All the working parts to be as light as consistent with the
works to be done.
The whole apparatus should be placed in a box to keep dust from the working
parts and fixed in a convenient place on the lamp post.
The lighting of the gas can be effected by the electric spark from a large Rumkorff's
coil. This spark is made to pass by means of wires from one lamp to the other
over the burner by means of points connected with the wires conveying the spark;
or by means of platinum partially or fully heated with the electric current (as before
described) suspended at a proper distance over the burner; or by means of an
induced current of electricity to be obtained from each of the electro-magnets used
to open and shut the tap, by providing on each of the electro-magnets a secondary
coil, as known on the common induction coils. By this means a separate spark is
obtained for each burner when charged by a large quantity of electricity from a
Rumkorff's coil, with slight alteration in the above-described magnet the column k, k,
can be pressed and relieved. By a toothed wheel the magnet being placed hori-
zontally, and the lever q, q, being fastened with a spring, so that when the magnet
acts the whole would be attracted, and on the action ceasing it will spring back to
its original position, this lever is caused to pull a wheel forward by means of ratchet
teeth, so that by making contact with the battery so many times the tap could be
opened and shut by inclined planes on the back of the wheel
Each magnet may be strengthened if required by placing an iron tube over the
copper coil.
Having now described the nature and object of my said Invention, together with
the manner in which the same is to be or may be performed or carried into practical
effect, I wish it to be understood that I claim as my Invention the novel apparatus
herein-before described for lighting gas lamps by electricity, or any mere
modification or imitation thereof, constructed and operating in substantially the
same manner.
In witness whereof, I, the said James Longshaw, have hereunto set my
hand and seal, this Twenty-third day of March, in the year of our Lord
One thousand eight hundred and seventy-eight.
JAMES LONGSHAW. (LS)