IMPROVEMENTS IN OIL LAMPS FOR RAILWAY CARRIAGE AND OTHER PURPOSES
Year: 1880

page_text: .
LETTERS PATENT to William Phillips Thompson, of the Firm of Wm. P.
Thompson & Co., Patent Agents, of 6, Lord Street, Liverpool, in the
County of Lancaster, and of 323, High Holborn, in the County of Middlesex,
Civil Engineer, for an Invention of IMPROVEMENTS IN OIL LAMPS FOR
RAILWAY CARRIAGE AND OTHER PURPOSES." A communication from abroad
by Joseph Scrafton. of Labore, in the Empire of India.
"
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 22nd September 1880.
WILLIAM PHILLIPS THOMPSON, of the Firm of Wm. P. Thompson & Co., Patent
Agents, of 6, Lord Street, Liverpool, in the County of Lancaster, and of 323, High
"IMPROVEMENTS IN OIL
Holborn, in the County of Middlesex, Civil Engineer.
LAMPS FOR RAILWAY CARRIAGE AND OTHER PURPOSES." A communication from
abroad by Joseph Scrafton, of Lahore, in the Empire of India.
The said Joseph Scrafton has invented this lamp with a view especially to the
burning of vegetable oils, though it is also applicable to some mineral oils. The
Invention consists mainly in placing in the centre of the reservoir a V shaped or
conical aperture so as to allow the light from the wick to fall and be reflected
downward through the glass bottom of the lamp, thus eliminating the shadow
vertically beneath so annoying in the usual constructions of lamps. This passage of
the rays through the reservoir is also advantageous in that it warms the oil and
keeps it from freezing in cold weather while the lamp is burning, enabling too
inferior oils to be burnt, specially such as in ordinary course would be too viscid
or thick to ascend the wick.
The following is a description of his lamp in the words of the said Joseph
Scrafton, as communicated to me with orders to file.
First. The lamp reservoir outside is made of tin, and can be made any shape.
The centre of the reservoir or internal tube from top to bottom is made of copper
silvered over, and conical shape. On top of the reservoir a brass washer is fitted
round the hollow tube; in this the burners are held and the light is reflected
down through the reservoir. By this arrangement the shade of the reservoir is
removed and the light down the inner tube or reflector is brilliant.

page_text: Second. The internal shape of the single burner is the saine, and in centre of
the tube a partition is connected to each side of reservoir. The partition is closed
at the bottom and open at the top. Into this partition the burner is fixed.
Recesses are cut in each side of the partition to admit the oil into the partition
where trimming rests. The light is by this means reflected down the opening cach
side of the wick.
Third. The reservoir at bottom has four recesses cut in it about a quarter of an
inch deep to allow a current of air up the centre of reservoir. By this means the
smoke is burnt, and hence a brilliant white light is obtained.
Fourth. The centre of the reservoir being hollow the flame is reflected downwards
and heats the oil, and it remains hot so long as the lamp burns, and by this means
the worst class of vegetable oils, and also oils that have a tendency to solidify,
burn exceedingly well in the coldest climate, and by allowing a current of air up
the centre the wick does not become charred over so quickly, and the lamp will
burn till all the oil in the reservoir is consumed. This lamp will burn all night
without re-trimming, hence for railway signal lamps and all other classes of
railway lamps it is invaluable, for it does not smoke the glasses. This lamp has
been designed specially for railway carriage roof lamps, and is made to fit in all the
lamp cases, and does not require a chimney.
Fifth. In any other class of railway lamps, where it is not necessary-to-have-the-
light reflected downwards, the reservoir could have a straight tube in the centre,
across the centre-of-this-tube-a-partition_to_hold_the_trimming, and recesses at
-bottom-same-as-the_other_lamps. The advantage of this would be that the flame
heats the oil, and air coming up the tube round the wick-burns-the-smoke-For-
signal lamps in particular this would be invaluable, as it would not smoke the glasses.
Sixth. The guides each side on top of reservoir are hollow, and air is by this
means admitted into the reservoir, and a hole is cut in the guide to admit air
into the globe. The burner plate handle is also hollow and admits air into the
reservoir.
In ordinary cases the chimney preferably ascends in a slightly conical form from
the reflector, and there is preferably a tube or guard surrounding the chimney for
four or five inches, but open at the top to the air chamber.
The lamp can be lit by raising the interior or lamp proper out of the case. When
lit it is let down onto the glass bottom, and the continuation of the reflector
standing on the rim preventing the ingress of draughts. The air from the air a
chamber descends the air tubes, passes in part direct to the wick, and in part round
and beneath the reservoir, and up through the V chamber to the wick. The
products of combustion pass up the chimney and help to warm the air in the air
chamber before escaping. The light from the wick reflected from the reflector
spreads all round the apartment except to that part nearly vertically beneath the 4
lamp. The light however of the flame shining on the reflecting side of the ✓ shaped
chamber is reflected vortically and nearly vertically downward, supplying this
deficiency.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Phillips Thompson in the Great Seal Patent Office on the
21st March 1881.
WILLIAM PHILLIPS THOMPSON, of the Firm of Wm. P. Thompson and Co., Patont
Agents, of 6, Lord Street, Liverpool, in the County of Lancaster, and of 323, High
Holborn, in the County of Middlesex, Civil Engineer. "IMPROVEMENTS IN OIL
LAMPS FOR RAILWAY CARRIAGE AND OTHER PURPOSES." A communication from
abroad by Joseph Scrafton, of Lahore, in the Empire of India.
The principal object aimed at in this Invention is the production of a lamp that
shall cast no downward or lateral shade.
This is accomplished by placing in the centre of the reservoir a conical or other
aperture widening out below, so us to allow the light from the wick to fall and be
reflected downward through the glass bottom of the lamp, thus eliminating that
shadow beneath the lamp so annoying in ordinary railway carriage lamps. This
passage of the rays through the reservoir is also advantageous in that it warms the
oil and keeps it from freezing in cold weather while the lamp is burning, and also
in that it enables oils to be burned that would otherwise be too thick or viscid to
ascend the wick.
The Invention is best described by aid of the accompanying Drawings of a lamp
arranged for railway carriage use, in which Fig. 1 is a vertical section of the entiro
lamp in position in carriage roof; and Fig. 2, another section at right angles thereto
showing the lamp alone; Fig. 3, four views of the reservoir arranged for only one
wick tube; Fig. 4, the same arranged for two wick tubes. Like letters refer to
like parts in all the views. In these A is the reservoir fitted with two burners;
B, same when only one. wick tube is required; C, wick tubo plate; D, internal
reflector, preferably of copper silvered over; E, F, wick tubes; G, top reflector; H, air
pipes; I, knob for fastening, putting in, and taking out the wick tube plate; J, J, holes
for supplying air to the burners; K, glass bottom or cover for lamp; L, ceiling of
carriage; M, top roof of carriage; N, ordinary perforated permanent lamp box;
P, perforated sides and top of lamp of ordinary construction; Q, rim for lifting
lamp in and out by ; R, funnel.
The mode of action is as follows:-The top P being removed, and the internal
parts lifted out of the glass bottom K, the reservoir A or B is filled with oil, the
tube plate refixed in position by knob or catch I, the wicks lighted, and the whole
placed in position as shown in Fig. 1. The heat of the flame causes the air and
products of combustion to rise through funnel R and escape round and through
perforations in cover P' and lid N¹. This causes a partial vacuum, and air rushes
in through perforations in the sides of N and P down the tubes H, and out through
holes J into chamber K. The holes J being in the side of the tube furthest from
the flame cause the air to be projected out towards the sides of K, and thus the
force of the current is broken up; part of the air goes direct to the wick, and
another part goes round through apertures S left all round below reservoir D
(which rests on legs, as shown), and rising up, as shown by the arrows (Fig. 1),
feeds the inner sides of the wicks. Parts of the lower portion of the compartment
not lit by the direct rays of the flame get those reflected from G, while rays from
the interior sides of the flames strike reflector D and pass straight downward,
lighting up the circular part not illuminated by reflector G. The rays are shown
as they would fall if there were no glass; they will however be refracted by the
glass out of the straight line somewhat.
With a single wick (Fig. 3) the same action with slight modification happens,
except that there is a diaphragm in aperture D, dividing it into two as shown,

page_text: which together take the part of single conical aperture 1 of Figs. 1 and 4. The
upper portion of the lamp above reflector G being similar to those in general use it
is needless to describe here. The various metallic parts, though for the purposes of
drawing they are shown slightly clear of each other, are brazed together in the
usual manner, except, of course, that the wick tube plate and the two lids P¹, N, 5
are made to lift, and the part N is loose from the lifting rim Q and lower portion
upon which the glass K rests.
The centre of the reservoir being hollow the flame is reflected downwards and
heats the oil, which remains hot so long as the lamp burns. By this means the
worst class of vegetable oils, and also oils that have a tendency to solidify, will, I 1
am confident, burn exceedingly well in the coldest climate. By allowing a current of
air up the centre the wick does not become charred over so quickly, and the lamp
will burn until all the oil in the reservoir is consumed.
This lamp will burn all night without re-trimming, hence for railway signal
lamps and all other classes of railway lamps it is invaluable, for it does not smoke 1
the glasses. This lamp has been designed specially for railway carriage roof lamps,
and is made to fit in all the lamp cases, and does not require a chimney.
In any other class of railway lamps, where it is not necessary to have the light
=reflected-downwards, the reservoir-could-have-a-straight-tube-in-the-centre, across
the centre of this tube a partition to hold the trimming, and recesses at bottom same 2
as the other lamps. The advantage of this would be that the flame heats the oil,
and air coming up the tube round the wick burns the smoke. For signal lamps in
particular-this-would-be-invaluable, as-it-would-not-smoke-the-glasses.
It will be seen at once that other modifications too could be used. Thus, it is
not necessary that D should be either conical or cylindrical; it can have other than 2
a circular coutour, though I find a circular contour is best. Again, I have shown
only two arrangements, both for straight wicks; the wick tubes could however be
curved so as to form a circle or two arcs of a circle, and thus form a burner similar
to an argand. But all these and other kindred modifications I consider equally as
infringements of my Invention.
The chimney can be made of circular or elliptic horizontal section to suit shape
and grouping of the wick.
In cases where the oil is fed from above I still use the conical reflector, merely
eliminating the oil box, and where mineral oils are used and mica draught arresters,
I place a second conical reflecting screen round the conical hole in the lamp to shield 3
the oil vessel from the beating rays; in fact, make the reflecting surface distinct from
the oil reservoir walls. To prevent the oil box dashing about in the glass basin, I
sometimes place light steadying springs or other stays between the oil box and the
glass attached to the former.
Having now described my Invention, and the best mode known to me of carrying
it into effect, I wish it to be understood that what I believe to be new and desire
to claim is,-
First. The manufacture of an oil lamp having a passage or passages through the
reservoir near or between the wick or wicks formed with reflecting surfaces, and so
arranged as to reflect the light or light and heat upon those portions of the
apartment below the lamp not lighted by rays direct from the top reflector,
substantially as described.
Second. The arrangement herein described for keeping the oil warm in lamps,
namely, forming the lamps with deep apertures, pockets, or passages near the wick,
into which the downward rays from the lamp can enter, and thus warm the sides
of said pockets or apertures and the adjacent oil.
Third. The conical reflecting surface (D), placed substantially as shown in relation
to the wick, and provided with air admission space below, so as to reflect the rays
of the wick or wicks downwards, whether the said surface form an actual part of
the oil chamber, be a cover or lining to the oil chamber, or stand alone, the oil being
fed to the wick from above.

page_text: Fourth. The general arrangement of reservoir and its appurtenances, substantially
as and for the purposes described, and especially the arrangement by which air
passes under and through the reservoir to feed the flame.
In witness whereof, I, the said William Phillips Thompson, have hereunto set
my hand and seal, this Eighteenth day of March, in the year of our Lord One
thousand eight hundred and eighty one.
W. P. THOMPSON. (L.S.)