A NEW OR PECULIAR METHOD OF RAISING OIL IN LAMPS, TO SUPPLY THE WICK
Year: 1787

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HARVEY STOKES, of Holywell Row, Shoredith, in the County of Middlesex,
Turner of Metal, do send greeting.
WHEREAS His most Excellent Majesty King George the Third did, by
His Royal Letters Patent under the Great Seal of Great Britain, bearing
date at Westminster, the Sixth day of November, in the twenty-eighth year of
His reign, give and grant unto me, the said Thomas Harvey Stokes, His
especial licence, ful power, sole privilege and authority, that I, the said
Thomas Harvey Stokes, during the term of fourteen years therein expressed,
should and lawfully might make, use, exercise, and vend, within that part of
the Kingdom of Great Britain called England, the Dominion of Wales, and
Town of Berwick-upon-Tweed, my Invention of "A NEW OR PECULIAR METHOD
OF RAISING OIL IN LAMPS, TO SUPPLY THE WICK;" in which said Letters
Patent there is contained a provisoe obliging me, the said Thomas Harvey
Stokes, by an instrument under my hand and seal, particularly to describe
and ascertain the nature of my said Invention, and in what manner the same
is to be performed, and cause the same to be inrolled in His Majestie's High

page_text: Court of Chancery within one calendar month next and immediately after
the date of the said Letters Patent, as by the said Letters Patent, reference
being thereunto had, may more fully and at large appear.
NOW KNOW YE, that in compliance with the said provisoe, I, the said
Thomas Harvey Stokes, do hereby declare that the nature of my said Inven-
tion, and the manner in which the same is to be performed, is particularly
described and ascertained as follows (that is to say :-
My method of raising oil in lamps, or any other illuminating instrument
or thing, consists as follows, viz:-First, by making a vessel of tin, brass, or
any other metal, cylindrical, or any other form, as the artist thinks proper, to
contain the oil. The depth and diameter of this vessel is not material, so that
another vessel be made to act in the inside of that first described as a piston,
to work freely or loosely in its inside. These two vessels are made fast
together at the tops of them by means of a piece of bladder, oil silk, or any
other flexible material, provided it is properly air-tight, and must be of such a
depth when fastened as to admit one vessel to fall down one inch or one inch
and an half within the other, and when the inside vessel is down as far as the
bladder, &c. will admit, the bottoms must not touch each other. The inside
vessel must have a hole in the centre of the bottom, in which a tube is to be
soldered, to be elevated as high as the oil is required to be raised. The height
and diameter of this tube is also not material, so that the following spring is
adapted and adjusted to the heighth required. This spring is of a spiral form,
and made of flat brass wire, iron wire, or any other elastic body, and the force
of this spring, as to action, is and must be equal, or nearly so, to the column
of oil that is to be raised. This spring is fastened to the bottom center of the
outside vessel, and ascends up the elevated tube, and is fastened to the inside
thereof, so that these two vessels, when put together by means of the bladder,
&c., before described, by pulling the elevated tube, the whole acts like a pair
of bellows, and if the oil is poured in at the top of the elevated tube, all the
air betwixt the two vessels in the inside is in some measure condensed, and
the bladder, or oil silk, or such flexible material used, will be expanded, and
the spring, by the weight of the oil so poured in, will be compressed. The
consequent effect will be that the oil will keep up in the elevated tube to the
heighth required, sufficient to feed the wicks. The oil and spring being in a
state of equilibrium, viz, the column of oil being the same weight as the pull
or power of the spring, so that as the oil burns away the said column of oil
consequently becomes shorter and lighter, so likewise the spring becomes more
expanded, consequently weaker, restores the cquibrium, and keeps the oil

page_text: always at a height sufficient to feed the wicks, and which will be the case as
ong as any oil is between the vessels to be raised.
In witness whereof, I, the said Thomas Harvey Stokes, have hereunto
set my hand and seal, the Twenty-eighth day of November, in year of
our Lord One thousand seven hundred and eighty-seven.
Inrolled the Twenty-eighth day of November, in the year last above
written.