IMPROVEMENTS IN ILLUMINATING CLOCKS
Year: 1876

page_text: LETTERS PATENT to John Alfred Langston, of Tavistock Street, Bedford Square,
in the County of Middlesex, Architect, for the Invention of "IMPROVEMENTS IN
ILLUMINATING CLOCKS."
Scaled the 19th January 1877, and dated the 20th July 1876.
PROVISIONAL SPECIFICATION left by the said John Alfred Langston at the
Office of the Commissioners of Patents on the 20th July 1876.
JOHN ALFRED LANGSTON, of Tavistock Street, Bedford Square, in the County of
Middlesex, Architect. IMPROVEMENTS IN ILLUMINATING CLOCKS."
"
The object of this Invention is to illuminate clocks. in such a manner that
observers may ascertain the time at night when the face of the clock could not
under ordinary circumstances be seen.
This object has hitherto been obtained in different ways, viz., either by throwing
or projecting a light on to the dial or face of the clock from a lamp or burner placed
outside the clock, or by constructing the dial or face of the clock of some trans-
parent or translucnt substance, such as glass, and then placing lights behind such
transluent dial without the figures thereon, and the position of the movable hands
may be clearly seen.
The light required for these purposes is obtained either from a number of lamps
or gas burners placed behind the transluent dial, or from an electric light or lime
light, which is usually placed in front so as to throw the light on to an opaque dial
or face. All these plans are open to objections, not the least of which is the cost of
the gas or of the apparatus required for producing the light.
By means of my improvements I am enabled to effect the desired object in a
most economical manner, and to do this without the necessity of having a glass or
transluent dial or face.
The Invention consists in making the movable hands of the clock either partly or
wholly tubular, and perforating them along their faces and at their extreme ends
so as to form lines of gas jets with roses at the ends. The hands are secured at
their inner ends to hollow key tubing or sockets, which are supplied with gas.
When dark and the gas is turned on it issues from the burners or perforations made
along the faces of the hands, the latter will then present the appearance of two lines
Price 6d1

page_text: of flame representing the hands, which will pass over or in front of the face or dial
of the clock, and by their position will serve to indicate the true time or hour.
In order to prevent the gas from being blown out by the wind the burners or
perforations (from which the gas issues) may be protected by means of lateral or
other guards or shields.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Alfred Langston in the Great Seal Patent Office on the 20th
January 1877.
JOHN ALFRED LANGSTON, of Tavistock Street, Bedford Square, in the County of
Middlesex, Architect. IMPROVEMENTS IN ILLUMINATING CLOCKS."
ct
The object of this Invention is to illuminate clocks in such a manner that
observers may ascertain the time at night when the face of the clock could not
under ordinary circumstances be seen.
This object has hitherto been obtained in different ways, vizt, either by throwing
or projecting a light on to the dial or face of the clock from a lamp or burner placed
outside the clock, or by constructing the dial or face of the clock of some trans-
parent or translucent substance, such as glass, and then placing lights behind such
translucent dial with the figures thereon, and the position of the moveable hands
may be clearly seen.
The light required for these purposes is obtained either from a number of lamps
or gas burners placed behind the translucent dial or from an electric light or line
light, which is usually placed in front so as to throw the light on to an opaque dial
or face.
All these plans are open to objectious, not the least of which is the cost of
the gas or of the apparatus required for producing the light.
By means of my improvements I am enabled to effect the desired object in a
most economical and safe manner, and to do this without the necessity of having a
glass or translucent dial or face.
The Invention consists in making the movable hands of the clock tubular and
either perforating them along their faces and at their extreme ends so as to form a
line of gas jets with a rose at the end, or the hand may be made to carry a gas
tube which is perforated with a line of holes throughout its length. The hands of
the clock are secured at their inner ends to hollow or tubular sockets, which are
supplied with gas. When dark and the gas is turned on it issues froin the holes or
jets made along the tubular lands or from the jets in the gas tubes carried by the
latter. The hands will then present the appearance of two lines of flame, one short
representing the hour hand, and the other long representing the minute hand.
These flaming hands will travel over or in front of the face or dial of the clock, and
by their position will serve to indicate the true time or hour.
In order to prevent the gas from being blown out by the wind the perforations
or jets in the tubular hands or travelling pipes from which the gas issues may be
protected by means of lateral or other guards or shields.
It will readily be understood that these tubular hands may be constructed in
various ways without departing from the nature and object of my Invention, I have
therefore, in the accompanying Drawing, shown various ways in which the object
of my Invention may be effected.
Fig. 1 is a front elevation of part of a large clock face, showing the tubular hour
and minute hands adapted thereto..
Fig. 2 is a vertical section of the same, showing also the tubular connections of
the hands with the gas supply pipes, and also a portion of the clock movement for
actuating the hands.
The clock face or dial a, a, may be cast in one piece with the figures for the
hours cast therewith or thereon. The hour hand b is fixed on the end of a tube b¹,
Fig. 2, which is actuated by the gearing in the ordinary manner, and is provided

page_text: with a weighted lever b³ to counterbalance the hand b. The minute hand c is
mounted at the outer end of a tubular arbor or shaft c¹ (Fig. 2), which passes
through the tube which carries the hour hand, and is actuated in the ordinary
manner by the toothed gearing c². The weight of the hand c is counterbalanced by
the weighted lever c³, and the tubular shaft c¹ is supported in fixed bearings at each
end. Each end of this shaft is made conical, and is accurately ground to fit
perfectly gas tight in the conical sockets c, d, one of which is connected to the
gas supply pipe c, Fig. 2.
At Figures 3 and 4 I have shown these parts of the fittings drawn in longitudinal
section, on an enlarged scale, in order that their construction may be clearly seen
and understood. A semi-circular annular groove is turned in the conical end of
the tubular shaft c¹ for the purpose of enabling the gas to pass from the supply
pipe e into the interior of the tubular shaft c¹, and to pass out at the other end
either to the tubular minute hand c or to the hour hand b, the conical boss b
Fig. 4, of which is perforated to allow the gas to pass through to the gas pipe of
the hour hand.
Fig. 5 is a transverse vertical section of the hour and minute hands, drawn upon
an enlarged scale.
It will be seen in this instance that the hands are constructed of angle iron or
other metal bent up or forged into the required form to give strength. The
hands are open at their central parts, as at f, Figures 1 and 5, for the purpose of
allowing the flame of the gas to be seen in the space. The gas from the tubular
shaft c passes through the perforation in the conical outer end and enters the
tubes 5, Figures 4 and 5, which are perforated throughout their length so as to
form jets or burners through which the gas issues, as shewn at Fig. 5.
At Figs. 6 I have shown a modification in plan and section, and drawn upon
an enlarged scale. In this instance there is a longitudinal opening extending along
the face of the hands, but it is not open, as in Fig. 5, but is covered in with a piece
of glass or tale so as to protect the gas jets from the action of the wind, this object
being more perfectly effected by the use of projecting guards g, J.
Figs. 7 represent sectional and plan views of another modification in which,
instead of the continuous longitudinal opening f of Figures 5 and 6, a number of
circular holes are made in the face of the hand and are covered in or protected by
discs of talc, glass, or other suitable material, or if preferred these holes may be left
open and uncovered. The other parts are the same as in the other Figures.
Fig. 8 represents in plan, side clevation, and section another modification in
which in place of adapting perforated gas tubes to the hands the latter are made
hollow and act as the gas tube. Perforations for the escape and ignition of the gas
are made in one of the faces of the hand, and the jets of gas issuing therefrom are
partially protected from the wind by means of circular guards h, h. In the Figures
I have shewn two different modes of protecting the jets from the wind, namely,
first, the circular guards h, just described, which will protect the jets from side
currents, and, second, tale or metal discs i which are placed above the jets and will
protect them from direct currents which strike the face or dial at right angles.
It will be found convenient to use these two plans in combination, as shown at
Fig. 8, so that if the jets, which are protected from the side currents by the circular
guards h, h, are extinguished by a current blowing directly on or against the face,
they will be again ignited by those jets which, being protected from such direct
currents by the discs i, will remain alight, and if the latter are extinguished by a
side wind they will be again ignited by the jets which are protected from such
currents by the circular guards h. It will be evident that these gas jets may, if
preferred, be adapted to the under side of the hand, in which event they would
illuminate that part of the clock face over which the hands are passing, the hands
themselves appearing as black opaque parts moving over an illuminated ground.
Fig. 9 represents another modification in which the gas jets are used to illuminate
the dial or clock face, and to show the hands as opaque parts passing over the
illuminated part of the dial. Lateral guards j, j, are used to protect the jets from

page_text: currents of wind. The gas is supplied to the. minute hand c along the tubular
shaft c¹ direct to the gas tubes which are adapted to the hand in the manner shown
in the Drawing.
Having now described my Invention of "Improvements in Illuminating Clocks,"
and having explained the manner of carrying the same into effect, I claim as the
Invention secured to me by Letters Patent, as aforesaid :-Constructing the hour
and minute hands of a clock in such a manner that gas may be supplied thereto,
and when allowed to issue from jets or perforations made in the hands for the
purpose, and properly ignited, the flames will be carried round by the moving
hands so as either to illuminate a portion of the face of the clock, or by their flaming
appearance they will indicate the relative positions of the hands, as and for the
purpose herein set forth.
In witness whereof, I, the said John Alfred Langston, have hereunto set my
hand and seal, the Twentieth day of January, in the year of our Lord One
thousand eight hundred and seventy-seven.
JOHN ALFRED LANGSTON. (L.S.)