IMPROVEMENTS IN PRESSURE GAUGES
Year: 1853

page_text: LETTERS PATENT to James Webster, of Leicester, for the Inven-
tion of IMPROVEMENTS IN PRESSURE GAUGES."
PROVISIONAL SPECIFICATION left by the said Janics Webster
at the Office of the Commissioners of Patents, with his Petition,
on the 23rd August 1853.
I, JAMES WEBSTER, of Leicester, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN PRESSURE GUAGES" to be as
follows:-
This Invention consists of a combination of apparatus for indicating
the pressure of steam and other fluids by a column of mercury. For
this purpose a glass tube and graduated dial are employed similar to
those heretofore used in pressure guages, whether they be employed
for indicating the pressure of steam or other fluid in a boiler or other
vessel, or for indicating a vacuum when pressed on by air. The glass
tube is fixed in a globular or other suitably formed vessel, which has a
thin metal (by preference steel) partition across it. Mercury is on one
side, and water, or it might be other fluid, is placed on the other side
of the partition. The globular formed vessel is fixed on a cylinder,
S

page_text: which is closed at bottom, but has a pipe rising up through the closed
end, over which pipe is fixed an inverted vessel or tube. In use the
steam or other fluid presses on the water, and by its pressure against
the partition the inercury is caused to rise up the glass tube, and to
indicate the pressure.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Webster in the Great Seal Patent
Office on the 23rd February 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JAMES WEBSTER, of Leicester, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of August, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James Webster, Her special licence
that I, the said James Webster, my executors, administrators, and
assigns, or such others as I, the said Jamies Webster, 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 PRESSURE GUAGES," upon the condition (amongst others) that I, the
said James Webster, by an instrument in writing under my hand and
seal, 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 James Webster, 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 thereof (that is to say):

page_text: This Invention consists of a combination of apparatus for indicating
the pressure of steam and other fluids by a column of mercury. For
this purpose a glass tube and graduated dial are employed similar to
those heretofore used in pressure guages, whether they be employed
for indicating the pressure of steam or other fluid in a boiler or other
vessel, or for indicating a vacuum when pressed on by air. The glass
tube is fixed in a globular or other suitably formed vessel, which has
a thin metal (by preference steel) partition across it. Mercury is on
one side, and water, or it might be other fluid, is placed on the other
side of the partition. The globular formed vessel is fixed on a cylinder,
which is closed at bottom, but has a pipe rising up through the closed
end, over, which pipe is fixed an inverted vessel or tube. In use the
steam or other fluid presses on the water, and by its pressure against
the partition the mercury is caused to rise up the glass tube, and to
indicate the pressure.
Having thus stated the nature of my said Invention, I will proceed
to describe the manner of performing the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1, shows a vertical section, and Figure 2, a front elevation
of a steam pressure guage constructed according to my Invention.
Figure 3, shows a vertical section, and Figure. 4, a front clevation of
an air pressure guage, the only difference being that in the one case
(Figures 1, and 2,) the pressure of steam acts on the under side of a
flexible partition, and raises a column of mercury into the glass tube of
the guage, by which the pressure will be indicated by the graduated
scale, and in the other case (Figures 3, and 4,) the atmosphere presses
on the mercury in the glass tube of the gauge, and causes it to 'lescend
into the vessel, and the respective scales are graduated accordingly.
The zero point of one instrument being at the lower part of the scale,
the zero point of the other being at the upper part of the scale. a, is
the vessel to which the glass tube b, is fitted. This vessel is in two
parts, and is divided by a partition c, which I prefer to be of thin sheet
steel, having on either side a piece of waterproof fabric. b, is the glass
tube, which is open to the atmosphere at top. e, is the graduated

page_text: scale. f, is a tube, which in Figures 1, and 2, I fill up to the bend
(and also the lower compartment of the vessel a,) with water, so that
the steam is kept from contact with the partition in the vessel a. The
tube f, in Figures 3, and 4, is to be connected with the cylinder or
vessel which is vacuous, and the extent of vacuum will be indicated
by the extent to which the column of mercury falls.
Having thus described the nature of my Invention, and the manner
of performing the same, I would have it understood that I make no
claim to the parts separately. But what I claim is, the combination of
the parts shewn and described.
In witness whereof, I, the said James Webster, have hereunto
set my hand and scal, this Twenty-third day of February, in
the year of our Lord One thousand eight hundred and fifty-
four.
Witness,
S. CARPMAEL.
JAMES WEBSTER. (L.S.