IMPROVEMENTS IN LAMPS
Year: 1872

page_text: LETTERS PATENT to George Grainger Tandy, of Anerley Road, Penge,
in the County of Surrey, Gentleman, and William Stroudley, of
Brighton, in the County of Sussex, Engineer, for the Invention of
"IMPROVEMENTS IN LAMPS."
Sealed the 21st January 1878, and dated the 25th November 1872.
PROVISIONAL SPECIFICATION left by the said George Grainger Tandy
and William Stroudley at the Office of the Commissioners of Patents,
with their Petition, on the 25th November 1872.
1
We, GEORGE GRAINGER TANDY, of Anerley Road, Penge, in the
County of Surrey, Gentleman, and WILLIAM STROUDLEY, of Brighton,
in the County of Sussex, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN LAMPS," to be as follows:-
The object of this Invention is principally to construct a railway
carriage roof lamp for burning with safety hydrocarbon oils, either alone
or blended, and in such a manner that the reservoir containing the oil
may be kept cool by causing a current of air to be continually playing

page_text: over its surface, so as to carry off any heat that may be imparted thereto
by the flame of the burner. Attempts have been made to effect this
object by placing the oil reservoir outside the lamp casing, so that as the
train passes rapidly through the air the reservoir may be said to be bathed
in or surrounded by air in rapid motion. Lamps so constructed are i
however liable to damage owing to the oil reservoir being thus exposed.
With the present Invention we prefer to use the burner for which a
Patent was obtained by Messrs. Tandy, Dryden, and Perkins, dated
January 7, 1870, No. 63.
In constructing a lamp according to this Invention we employ a casing of:
the ordinary form, and perforate one or more rows of holes in the upper part
to allow of the passage of the air into and out of the casing. The interior
of the lamp consists of two cylinders placed concentrically one within
the other, and connected at their lower ends by an annular plate or
disc, the under side of which forms part of the reflector. The outer
edges of this disc are made to extend beyond the outer cylinder, so as to
fit into the outer casing of the lamp and rest on the upper edge of the
glass globe or dish. The reservoir is attached to the upper end of and
outside the outer cylinder. A metal flange or lip is fixed on to the top
of the reservoir, and is made to fit above or between the row or rows
of holes in the outer casing. Within the inner cylinder is placed a
metal chimney, to the lower end of which is attached the central part
of the reflector. It will thus be seen that the inner cylinder will act
as a shield to prevent the heat from the metal chimney heating the oil
reservoir by radiation. There will therefore be an annular space
between the outer casing and the oil reservoir, and another annular
space between the oil reservoir and the inner cylinder.
The operation of the several parts will be as follows:-The external air
will pass through the row of holes in the casing into the annular space out-
side the oil reservoir; from thence it will descend to the lower part of the
annular space, and will pass through a row of holes below the oil reservoir
into the annular space between the reservoir and the inner cylinder; it it
will then rise up in close contact with the sides of the reservoir, and will
pass over the top thereof and issue through the upper row of holes, if there
be two rows in the casing, or through the neck of the lamp, and thence pass
into the external atmosphere. By causing the air to circulate in this manner
any heat that the reservoir may acquire from being placed inside the casing
will be carried off by the rapid current of air that will pass through the

page_text: lamp, and over or in contact with the entire external surface of the
reservoir.
As a modification of the above, and when a burner to be used with
a glass chimney is employed, the amount of air desired to support
combustion may be obtained by perforating the annular reflector between
the casing and the outer cylinder with small holes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Grainger Tandy and William Stroudley in
the Great Seal Patent Office on the 24th May 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, GEORGE
GRAINGER TANDY, of Anerley Road, Penge, in the County of Surrey,
Gentleman, and WILLIAM STROUDLEY, of Brighton, in the County of
Sussex, Engineer, send greeting.
L
"
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of November, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto us, the said George Grainger Tandy and William
Stroudley, Her special licence that we, the said George Grainger Tandy
and William Stroudley, our executors; administrators, and assigns, or
such others ǎs we, the said George Grainger Tandy and William
Stroudley, our executors, administrators, and assigns, should at any thi
vitimie
agree with, and no-others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use, -
exercises and vend, within the United Kingdom of Great Britain and
Ireland the Channel Islands, and Isle of Man, an Invention for "In-
PROVEMENTS IN LAMPS," upon the condition (amongst others) that we, the
said George Grainger Tandy and William Stroudley, our executors.or
administrators, by an instrument in writing under our, 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 immediately after the date of the
said Letters Patent.
"
a

page_text: NOW KNOW YE, that I, the said George Grainger Tandy, on behalf of
myself and the said William Stroudley, do hereby declare the nature of
our 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 Drawing hereunto annexed, and
to the letters and figures marked thereon (that is to say) :—
.
The object of this Invention is principally to construct a railway
carriage roof lamp for burning with safety hydrocarbon oils, either alone
or blended, and in such a manner that the reservoir containing the oil
may be kept cool by causing a current of air to be continually playing
over its surface, so as to carry off any heat that may be imparted thereto
by the flame of the burner. Attempts have been made to effect this
object by placing the oil reservoir outside the lamp casing, so that as
the train passes rapidly through the air the reservoir may be said to be
bathed in or surrounded by air in rapid motion, and which air will-carry
off any heat that may radiate from the heated oil reservoir. Lamps so
constructed are however liable to damage owing to the oil reservoir
being thus exposed outside the lamp casing, and it is one of the
advantages of our present Invention that such external reservoir may be
dispensed with.
With the present Invention we prefer to use the burner for which a
Patent was obtained by Messrs. Tandy (one of the present Patentees) and
John Andrews Dryden, dated First March, One thousand eight hundred
and seventy-two, No. 648. [In our Provisional Specification this Patent
was erroneously stated to bear date January Seventh, One thousand
eight hundred and seventy.]
Our Invention is more particularly applicable to railway carriage roof
lamps, but can be adapted to other lamps such as street lamps, ships'
lamps, swinging lamps, or other lamps or lanterns. In our improved
railway carriage roof lamps the burner consists of an oil cup or chamber
to hold the wick, and is provided with a metal dome which encloses the
wick. This burner is placed at the bottom of the enveloping glass dish,
on the upper edge of which is carefully fitted the reflector, so as to
prevent ingress of air to the flame except through the proper channels
provided for the purpose as hereafter described. In the space above the
reflector is placed a metal cylinder which divides such space into two
annular chambers; one of which communicates with the external
atmosphere by means of a series of holes made in the outer casing. Two

page_text: .
tubes conduct the air from the inner annular chamber to the interior of.
the burner in order to support combustion and access of air to the burner,
except through these channels, is carefully prevented. The upper.or
outer orifices of these tubes are protected by means of wire gauze or
perforated metal from the effects of external currents of air, so that the
supply of air to the burner may be uniform and steady. The oil is.
contained in a reservoir placed inside the body of the lamp and is kept
cool by the current. of cold air that is continually passing from the
outside through holes in the outer casing into the outer annular
chamber, which is formed by a cylinder attached to the bottom of the oil
reservoir. Two tubes lead down from the oil reservoir and conduct the
oil to the burner; the reflector has a piece cut out of the centre, and to
this detachable part of the reflector is attached a metal chimney for.
creating sufficient draught through the burner below as in our former
.Patent. In order to increase the up draught, we make this metal
chimney rather longer than usual, and surround its upper end with
a short tube so as to leave a narrow annular space around the upper
end of the chimney.
-
hereafter
In the accompanying Drawings, Fig. 1 is a sectional elevation of our
improved lamp applicable for the roofs of railway carriages; a, a, is an
enveloping glass in which the burner of the lamp is placed. Its under
side is made with three or more projecting knobs or feet, on which the
lamp will rest when placed on the ground, and such knobs will not
obstruct the light. At the top of this enveloping glass is placed a
reflector o, e¹, made of bright metal or other suitable material-;- it is
formed of two-parts o and of The outer part-e of the reflector is made
of an annular form-and-is-fixed to the oil and air pipes and
described, and fits closely on the top edge of the glass envelope-a-a.
The-central-parto of the reflector-carries a metal chimney, and rests
on. a ledge formed round the inner edge of the annular part. c, so
that it may be lifted out without disturbing the other part. The oil
reservoir-d, d, is made of a curved-or semicircular form; and is placed
within-an annular space formed by the metal case e, e, of the lamp,-and
the metal cylinder b, b, which is attached to the part c of the reflector.
This reservoir d-carries at its lower end a short cylinder which extends
down to the reflector and divides the annular space into two parts, A
and A¹, and it communicates with the burner below by means of the two
tubes ff; and as the oil passes down one tube to the burner air will

page_text: pass up the other tube into the oil reservoir. All the air to support
combustion is drawn in from outside the lamp into the outer annular
space A¹ through holes made in the casing as at g¹, and passes down the
narrow space between the reservoir and outer casing, and from the
space A¹ through holes in the short cylinder (attached to the bottom of
the reservoir) into the inner annular space A, and from thence down the
tubes 9, 9, and is conveyed thereby to the spaces i, i, (inside the burner)
on each side of the wick holder. The air then rises up to the space
between the wick holder and the dome or reflector h, whereby it is
thrown on to the flame near the point of ignition. The oil supply
pipes f, f, are placed behind the air tubes g, g, so as to protect them
from the direct radiation of heat from the flame. The open ends of the
air tubes are protected from sudden (gusts of air by wire gauze or per-
forated metal shields. As the burner, the oil reservoir, and oil and air
tubes, and the annular part c of the reflector are all connected together
they may all be lifted at once from the envelope or case e. As the
cylinder b, b, is placed at some distance from but concentrically with
the metal chimney c³, a third annular chamber B will be formed and
will prevent the heat from the chimney c³ from heating the oil
reservoir d. The two annular chambers A and B communicate at the
upper part and the space at this point forms a fourth chamber C, which
is carried by a plate h perforated with a number of holes to allow the
air to pass out as indicated by the arrows. This plate also carries a
short tube which extends a little above the top of the chimney. A
conical tube is placed outside the short tube 7, and conducts the hot air
out at the top.
The operation of the several parts is as follows:-The oil from the
reservoir & will flow down the pipes finto the oil well of the burner,
and will saturate the wick. When the wick is ignited and the metal
chimney c³ is put in its proper place (as shewn in the Drawing) air
from outside the lamp will pass through the holes g¹ in the outer casing,
then down between the casing and oil reservoir into the annular
chamber A³, thence through the holes in the reservoir cylinder into the
space A, and in so doing will pass in close contact with the surface of
the oil reservoir d as indicated by the arrows. A portion of this air will
pass through the perforated metal covers of the air tubes 9, 9, and will
be conducted by the latter to the interior of the burner, and be caused
(by the inclined sides of the deflector or dome h) to impinge on the

page_text: flame just above the point of ignition and will thus produce perfect
combustion. A portion of the air which enters the chamber A will pass
upwards through a series of holes in the horizontal plate k, and another
portion will pass up the narrow annular space between the short tube / and
the upper end of the chimney, and thus assist in creating a draught
through the lamp and up the chimney... By this combination arrange-
ment and construction of parts we are enabled to burn hydrocarbon oils
without danger or risk of overheating the reservoir or other parts of the
lamp, and we can produce a light of great steadiness and brilliancy.
Instead of admitting the air at g' we sometimes find it convenient to
admit it into the interior of the lamp at some point above the oil
reservoir. For this purpose we make a series of small holes in the
casing just above the top of the reservoir as at g³, Fig. 2, which is a
sectional elevation of a railway carriage roof lamp made in this way.
The holes communicating from the outer annular space A' (under the oil
reservoir) with the inner annular space A, must of course be closed, and
the oil reservoir and parts attached thereto will rest upon a ring or wire
fixed on the upper edge of the outer casing. This being the case it will
not be necessary that the lamp or reflector should fit air-tight on the
upper edge of the glass globe which is necessary in the former instance.
If preferred the oil tubes may be placed inside the air tubes, and the
wick holder arranged in the same vertical plane as the air and oil tubes
as shewn at Fig. 2. This arrangement of parts will be found convenient
for use in third-class carriages or other carriages where the light is
required to be thrown across several adjoining compartments.
Although in the foregoing description we have only explained our
Invention as adapted to railway carriage-roof lamps it will be evident
that the same principle of construction is equally applicable to ships'
lamps, signal lamps, carriage lamps, and street and other stationary
lamps in which hydrocarbon oils can be consumed. The essential
features of the Invention will be the same in all cases, but the form
and construction of the envelope or casing must be varied according to
the circumstances of the case for which the lamp is to be usēd.
In the street lamp shewn in sectional elevation at Fig. 3 the hori-
zontal perforated plate / and short tube 2 of the roof lamp are dispensed
with, and an additional short chimney ♬ (fixed on a horizontal plate ³) is
used for the purpose of assisting the draught through the lamp.

page_text: Having now described our Invention, and having explained the manner
of carrying the same into effect, we claim as the Invention secured to
us by Letters Patent as aforesaid admitting air from the outside into the
interior of the lamp in the manner or manners herein set forth, and also
dividing the air space above the reflector into two or more annular spaces,
as at A, A¹, and B, and communicating with each other and with a
common air chamber O above formed by the perforated metal plate k
and short tube 1, all arranged and operating as and for the purposes
G. GRAINGER TANDY. (L.S.)