IMPROVEMENTS IN THERMOMETERS AND OTHER LIKE INDICATORS
Year: 1853

page_text: LETTERS PATENT to William I.ittell Tizard, of Aldgate, in the City
of London, Brewers' Engineer, for the Invention of "IMPROVE-
PROVISIONAL SPECIFICATION left by the said William Littel!
Tizard at the Office of the Commissioners of Patents, with his
Petition, on the 5th October 1853.
I, WILLIAM LITTELL TIZARD, of Aldgate, in the City of London,
Brewers' Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THERMOMETERS AND OTHER LIKE INDICATORS" to be
as follows:-
The Invention consists in attaching iron or electro-plated or glazed
bulbs or cylinders to glass tubes and embedding the tubes in india-
rubber or other suitable material in metal and wooden cases.
Secondly, in substituting sheet tale for glass tubes, and firmly
screwing or otherwise fixing that material on a metal frame, rendering
the metal and joints air-tight by tinning and electro-plating.
Thirdly, in attaching or applying buffers of india-rubber or other
elastic material.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Littell Tizard in the Great Scal Patent
Office on the 5th April 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM LITTELL TIZARD, of Aldgate, in the City of London, Brewers
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of October, in the year of
our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Littell Tizard, Her special
licence that I, the said William Littell Tizard, my executors, adminis--
trators, and assigns, or such others as I, the said William Littell Tizard,
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 THERMOMETERS AND OTHER LIKE INDICATORS," upon the
condition (amongst others) that I, the said William Littell Tizard, 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 William Littell Tizard, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, reference being had
to the Drawings hereunto annexed, that is to say:
My Invention consists in substituting sheet tale for glass tubes in
the construction of thermometers, barometers, steam pressure gauges,
and other like mercurial indicators. I am aware that sheet talc has
been employed as a substitute for glass in making water gauges, and

page_text: my Invention is confined to using that material in those indicators only
where mercury is employed.
Figure 1, of the Drawings annexed is a front elevation, and Figure 2,
a vertical section of a thermometer constructed according to my
Invention. A, A, is a frame of cast iron which forms the body of the
instrument; B, is the mercury chamber; and C, the indicator groove
which communicates with the mercury chamber by the aperture a.
The face of the frame A, is planed true to receive the sheet of talc D;
which is screwed firmly up against it by means of screws E, E, passing
through the brass plate F, a portion of which is slotted out so as to
expose the tale covering the groove C, and allow the height of the
mercury in it to be seen. The brass plate is graduated according to
any of the common scales used for indicating degrees of temperature.
The indicator groove terminates at the upper part of the frame in a
conical passage b, through which the mercury chamber is filled in the
ordinary manner. When this has been done the instrument is held
over a spirit lamp, or otherwise exposed to such a degree of temperature
as to cause the mercury to rise to the top of the indicator groove, and
up the conical passage b, an iron plug c, is then inserted, a small
quantity of melted solder dropped on top of the plug, and the instru-
ment removed from the spirit lamp. The contraction of the mercury
at once takes place, and the atmospheric pressure exerted on the melted
solder causes it to penetrate into and fill up any space that may be left
between the sides of the plug c, and the passage b, and thus produce a
hermetical joint. The operation of filling in the mercury and sealing
the passage must be performed as quickly as possible.
Figure 3, is a front elevation, Figure 4, a vertical section, and
Figure 5, a transverse section of a steam pressure gauge constructed
according to my Invention. A, A, is the cast iron frame of the instru-
ment; B, the mercury chamber; and C, the indicator groove which
communicates with the mercury chamber at a. D, is a sheet of talc
which comes up against the face of the frame A, and is secured in
position by screws E, E, passing through the graduated brass plate F,
which is slotted out so as to expose the talc covering the groove, and
allow the height of the mercury in it to be seen. The plate F, is

page_text: graduated from zero to any required degree of pressure. G, is a
tubular passage formed in the metal of the frame A, and communicating
at one end with the mercury chamber B, while the other end is in
connection at b, with a pipe from the steam boiler or apparatus con-
taining the fluid whose pressure is to be indicated, the steam or other
fluid thus having free access to the mercury chamber, and raising the
mercury in the indicator groove to a height proportioned to its
pressure.
From the foregoing description a maker of such instruments will
easily see the manner of applying my improvements in the construction
of barometers, vacuum gauges, and other mercurial indicators. I do
not confine myself to the exact details herein-before given, as the
same may admit of considerable variation without departing from my
Invention. In some cases I propose to tin or electro-plate the joints
of the talc and metal in order to render the same more effectually air-
tight.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that what I claim
as my Invention is, the substitution of sheet tale for glass tubes in
the construction of thermometers, steam pressure gauges, and other like
mercurial indicators.
In witness whereof, I, the said William Littell Tizard, have
hereunto set my hand and seal, this Fifth day of April, One
thousand eight hundred and fifty-four.
W. L. IIZARD. (L.S.)