IMPROVEMENTS IN LAMPS
Year: 1869

page_text: LETTERS PATENT to Francis William Hastings Medhurst, Lieu-
tenant Royal Artillery, of No. 53, Chancery Lane, in the County of
Middlesex, for the Invention of "IMPROVEMENTS IN LAMPS."-A com-
munication from abroad by Lasslo Chandor, of St. Petersburg,
in the Empire of Russia.
Sealed the 14th September 1869, and dated the 3rd April 1869.
PROVISIONAL SPECIFICATION left by the said Francis William
Hastings Medhurst at the Office of the Commissioners of Patents,
with his Petition, on the 3rd April 1869.
I, FRANCIS WILLIAM HASTINGS MEDHURST, Lieutenant Royal
Artillery, of 53, Chancery Lane, in the County of Middlesex, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN LAMPS,"
to be as follows:-
This Invention relates to improvements in lamps for burning the
vapors of hydrocarbon oils and other combustible liquids. By means
of these improvements perfect combustion, economy, cleanliness, and

page_text: safety are obtained without any smell, and without the use of a
chimney.
According to this Invention I enclose the wick in a tube of suitable
length, the lower end of which screws into the usual reservoir containing
the liquid to be consumed, in which the lower end of the wick is im-
mersed. The upper end of the wick is flush with the top of the tube,
which is enclosed in a second tube capable of sliding thereon. The upper
end of this outer tube rises above the wick tube, and at its upper end is
placed a plug or nipple of copper or other suitable material, which may
be solid, but is preferably made hollow and closed at the top, said plug
being filled with cotton, asbestos, or other absorbent material; this plug
or nipple rests on the top of the inner tube and wick, and is provided with
two or more grooves, corresponding grooves being also formed in the
outer tube before referred to, serving as channels for the exit of the
vapor generated at the plug or nipple. As this plug is open at the lower
end and rests on the wick the liquid by capillary attraction rises into
the nipple, and is there evaporated on a match being applied for igniting
the same.
The vapor escaping at the orifices before mentioned burns
without odour or smoke, the heat from the flame continuing to evaporate
the liquid as it rises into the nipple by the aid of the wick. As the
nipple is interposed between the wick and the flame the wick is very
slightly carbonized, thus avoiding the necessity of frequently trimming
and replacing it.
I prefer to enclose the tubes before mentioned in a porcelain or other
cone-topped tube formed to imitate a candle, and provided at its upper
part with several air holes for supplying the necessary oxygen for com-
bustion, which is caused to impinge on the flame, thus obviating the
use of a draught chimney. The ascending current of air also serves to
cool the tube and renders the lamp perfectly safe for use. The gas or
vapor being generated only in the same proportion as it is consumed
does not accumulate in the reservoir, which further never becomes
heated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Francis William Hastings Medhurst in the Great
Seal Patent Office on the 2nd October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
WILLIAM HASTINGS MEDHURST, Lieutenant Royal Artillery, of 53,
Chancery Lane, in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of April, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Francis William Hastings Med-
hurst, Her special licence that I, the said Francis William Hastings
Medhurst, my executors, administrators, and assigns, or such others
as I, the said Francis William Hastings Medhurst, my executors,
administrators, and assigns, should at any time 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, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
LAMPS," a communication to me from abroad by Lasslo Chandor, of St.
Petersburg, in the Empire of Russia, upon the condition (amongst
others) that I, the said Francis William Hastings Medhurst, my exe-
cutors or administrators, by an instrument in writing under my, 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.
NOW KNOW YE, that I, the said Francis William Hastings Medhurst
do hereby declare the nature of the 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 Sheet of
Drawings hereunto annexed, and to the letters and Figures marked
thereon (that is to say) :-
This Invention relates to improvements in lamps for burning the
vapors of hydrocarbon oils and other combustible liquids. By means of

page_text: these improvements perfect combustion, economy, cleanliness, and safety
are obtained without any smell, and without the use of a chimney.
According to this Invention I enclose the wick in a tube of suitable
length, the lower end of which screws into the usual reservoir contain-
ing the liquid to be consumed, in which the lower end of the wick is
immersed. The upper end of the wick is flush with the top of the tube,
which is enclosed in a second tube capable of sliding thereon. The
upper end of this outer tube rises above the wick tube, and at its upper
end is placed a plug or nipple of copper or other suitable material,
which may be solid, but is preferably made hollow and closed at the top,
said plug being filled with cotton, asbestos, or other absorbent material.
This plug or nipple rests on the top of the inner tube and wick, and
is provided with two or more grooves, corresponding grooves being also
formed in the outer tube before referred to serving as channels for the
exit of the vapor generated at the plug or nipple. As this plug is open
at the lower end and rests on the wick the liquid by capillary attraction
rises into the nipple, and is there evaporated on a match being applied
for igniting the same. The vapor escaping at the orifices before-
mentioned burns without odour or smoke, the heat from the flame
continuing to evaporate the liquid as it rises into the nipple by the aid
of the wick. As the nipple is interposed between the wick and the
flame the wick is very slightly carbonised, thus avoiding the necessity
of frequently trimming and replacing it.
I prefer to enclose the tubes before mentioned in a porcelain or other
cone topped tube formed to imitate a candle, and provided at its upper
part with air holes for supplying the necessary oxygen for combustion,
which is caused to impinge on the flame, thus obviating the use of a
draught chimney. The ascending current of air also serves to cool the
tube and render the lamp perfectly safe for use. The gas or vapor being
generated only in the same proportion as it is consumed does not
accumulate in the reservoir, which further never becomes heated.
The above improvements are applicable to lamps and chandeliers
generally.
Figure 1 is an elevation of a lamp constructed according to this 3
Invention, and Figure 2 a central vertical section of same showing the
the internal arrangement.

page_text: a is an ordinary wick which I enclose in a wick tube b, the upper
end of the wick a being flush with the top of said wick tube b. This
tube 6 (seen detached in vertical section Figure 3) I enclose in a second
tube c, rising above tube b, and fitting into the usual oil reservoir d, into
which the wick a and tube b also pass, as seen. In the upper end of
tube c (shown also detached in vertical section and plan Figure 4) I place
a plug or nipple e which rests on the top of wick a and tube b, and
entirely closes the outer tube c, with the exception of the passages f, for
the escape of the vapor to be consumed. In Figure 2, as well as in the
detached sectional elevation and plan, Figure 6, I have shown a hollow
plug or nipple closed at the top and filled with asbestos or cotton, but
said nipple e may be solid, as shown in central section and plan, Figure 5,
and in the sectional plan, Figure 7, taken on line 1, 2, Figure 2. I have
shown a hollow plug and tube c as both provided with grooves. This
plug or nipple e is provided with two or more grooves f, which together
with the corresponding grooves f, provided in the upper part of tube c,
form passages for the escape of the vapor generated at the nipple e,
or the grooves may be in the plug or tube only if desired. As this
nipple when hollow is open at the lower end, and rests on the wick a,
the liquid is absorbed by the material contained in said nipple, and is
there evaporated on a match being applied to ignite the vapor escaping
through channels f; g is a screwed cap or flange fitted or formed on the
outer tube c, and screwing into the oil reservoir d, which it completely
closes with the exception of the passage through the wick and tube.
The reservoir d may be mounted on a suitable pedestal, or it may be
applied to chandeliers or candelabra generally. With this view I prefer
to enclose tube c in a porcelain or other tube h formed to resemble a
candle, and pierced at its upper part with several air holes i for supplying
air for combustion and keeping the lamp cool; k, aperture in reservoir d
for the admission of air to replace the liquid exhausted by vaporization.
A modification of the above arrangement consists in dispensing with
the inner wick tube 6 by employing a woven wick of sufficient stiffness.
In this case the nipple e instead of being formed as before described
would simply consist of a wire gauze cap enclosing the end of the wick,
as shown in Figure 8. This wire gauze cap or nipple protects the wick
from being charred or carbonized by the flame, and thus obviates the
necessity of trimming the wick.

page_text: Having described the nature of this Invention and the manner of
performing the same, I declare that what I claim as the Invention of
improvements in lamps to be protected by the herein-before in part
recited Letters Patent is,―
1st. The nipple or plug e, made either solid or hollow and grooved or
not for maintaining the evaporation of the liquid supplied by the wick,
together with the modified arrangement of nipple, Figure 8, as herein-
before deseribed.
2ndly. I claim the tube c provided with grooves f for the escape of
the vapor generated at nipple or plug e, as herein-before described.
3rdly. I claim in combination with the above part cand e the
porcelain or other non-conducting tube h, having perforations i, through
which the air is supplied for combustion and for keeping the lamp
cool.
Lastly. I claim the general construction of lamp shown in the
Drawings and herein-before described.
In witness whereof, I, the said Francis William Hastings Med-
hurst, have hereunto set my hand and seal, this Twenty-ninth
day of September, in the year of our Lord One thousand eight
hundred and sixty-nine.
Witness,
A. M. CLARK,
Patent Agent,
53, Chancery Lane,
London.
F. W. H. MEDHURST. (L.S.)