IMPROVEMENTS IN LAMPS FOR BURNING PARAFFIN OB PETROLEUM OILS, OR OTHER LIKE HYDROCARBON FLUIDS
Year: 1871

page_text: LETTERS PATENT to Thomas Rowatt, the younger, of Edinburgh,
in the County of Mid Lothian, Lamp and Oil Manufacturer, for
the Invention of "IMPROVEMENTS IN LAMPS FOR BURNING PARAFFIN OB
PETROLEUM OILS, OR OTHER LIKE HYDROCARBON FLUIDS."
Sealed the 14th July 1871, and dated the 3rd March 1871.
PROVISIONAL SPECIFICATION left by the said Thomas Rowatt at the
Office of the Commissioners of Patents, with his Petition, on the
3rd March 1871.
I, THOMAS ROWATT, the younger, of Edinburgh, in the County of
Mid Lothian, Lamp and Oil Manufacturer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN LAMPS FOR BURNING PARAFFIN
OR PETROLEUM OILS, OR OTHER LIKE HYDROCARBON FLUIDS," to be as follows:-
My Invention applies principally to lamps having wicks producing a
circular flame; such lamps have hitherto been constructed to produce
combustion, 1st, by means of what is known in the trade as a “cut in”
chimney, that is, a glass chimney descending below the top of the

page_text: wick tube, contracted suddenly just above the surface of the wick to
about the diameter of the wick tube, and then rising perpendicularly
to same height; and 2nd, by means of an ordinary bell-shaped chimney
used in connection with a button or deflector held just above the flame
by a wire. It will be seen that both these methods necessitate the use
of a glass chimney liable to be frequently broken, and thus causing
annoyance and expense.
To avoid this I use, first, a brass dome surrounding the wick tube
having a circular opening in its summit, this causes tho outside current
of air to impinge on the flame.
Second. I use a tube fixed to the inside of the wick tube to carry the
inside current of air clear of the flame a little way before being impinged
upon it.
1
Another method of obtaining the same result is to make the inside
wick tube a little higher than the outside tube, but I prefer the former 1
arrangement. By this means also when the wick is turned up to bo
burned, part of it is exposed to the action of the outside current of air,
and superior combustion is effected.
Thirdly. I use two circular deflectors one above the other, the upper
one being slightly hollowed on the under surface and tapered upwards 2
at the edges. These deflectors are held above the flame by a wire
resting on the body of the burner.
By my Invention perfect combustion is obtained without the aid of
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Thomas Rowatt in the Great Seal Patent Office
on tho 2nd September 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
ROWATT, the younger, of Edinburgh, in the County of Mid Lothian,
Lamp and Oil Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of March, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
3

page_text: fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, tho said Thomas Rowatt, the younger, Her special
licence that I, the said Thomas Rowatt, the younger, my executors,
administrators, and assigns, or such others as I, the said Thomas
Rowatt, the younger, 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 FOR BURNING Paraffin OR PETROLEUM
OILS, OR OTHER LIKE HYDROCARBON FLUIDS," upon the condition (amongst
others) that I, the said Thomas Rowatt, the younger, my executors 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 bo
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.
KNOW NOW YE, that I, the said Thomas Rowatt, the younger, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement (that is to say) :-
:-
This Invention applies principally to lamps having wicks producing
a circular flame, which lamps have hitherto been constructed to produce
combustion, first, by means of what is known in the trade as a "cut-in"
chimney, that is, a glass chimney descending below the top of the wick
tube contracted suddenly just above the surface of the wick to about
the diameter of the wick tube, and then rising perpendicularly to some
height; and secondly, by means of an ordinary bell-shaped chimney
used in connection with a button or deflector held just above the
flame by a wire. It will be seen that both these methods necessitate
the use of a glass chimney liable to be frequently broken, and thus
causing annoyance and expense; and to avoid this is the object of my
improvements.
The manner in which this Invention is to be performed will be clearly
understood by the following particular description thereof, reference
being had to the figures and letters on the accompanying Sheet of

page_text: Drawings, in which Fig. 1 is an elevation, and Fig. 2 a vertical section,
of the burner and upper part of a lamp constructed according to my
improvements; and Figs. 3, 4, and 5 are views of detached parts, Fig. 4
being a plan of Fig. 3 at the line S, T.
First, I use a brass dome a surrounding the wick tube b, and having
a circular opening c in its summit, and this causes the outside current
of air to impinge on the flame; and to the inside of this dome I attach
a smaller dome d with a circular opening at the top and having the
flange e by which it is connected with the outsido domo perforated with
air holes ſ, and thus I divide the current of air passing upwards outsido
of the wick tube, one portion of the current passing up between the
domes and the other passing up through the inner dome. In order still
further to increase the draught I attach a metal tube to the insido
of the outer dome just below its junction with the inner dome, which
tube extends downwards to nearly the bottom of the wick tube, the
diameter of the bottom end of the tube being considerably less than
that of the inlet air chamber g.
Secondly. I use a short tube or nozzlo i fixed in the inside of the
wick tube and projecting above it in order to carry the inside current
of air clear of the flame a little way before being impinged upon it; and
another method for obtaining the same result is to make the inside wick
tube a little higher than the outside tube, but I prefer the former
arrangement. By this means also when the wick is turned up to be
burned part of it is exposed to the action of the outside current of air,
and superior combustion is effected.
2
Thirdly. I uso two circular deflectors k, l, one above the other, the
upper one being slightly hollowed at the under surface and tapered
upwards at the edges, the deflectors being held above the flame by a
central wire m fixed to the body of the burner. I find that three
mechanical contrivances arranged proportionately to each other as a
regards size, distances, and other requirements and surrounded with an
oval or globular glass produce perfect combustion without the aid of
a chimney.
Having now described the nature and particulars of my said In-
vention, and the manner in which the same is to be performed, I desiro 3
it to be understood that I claimı,—

page_text: Secondly. The tube or nozzlo fixed to the inside of the wick tube
and its equivalent, the raising of the inside wick tube a little higher
than the outside tube.
Thirdly. The two buttons or deflectors.
And, fourthly. These several parts in combination with an oval or
globular glass, as all such improvements aro hercin described and
illustrated in the accompanying Sheet of Drawings.
In witness whereof, I, the said Thomas Rowatt, the younger, have
hereunto set my hand and seal, this Thirtieth day of August, in
the year of our Lord One thousand eight hundred and seventy-
one.