IMPROVEMENTS IN. THE CONSTRUCTION OR THERMOMETERS
Year: 1862

page_text: LETTERS PATENT to Nathaniel Richard Hall, of Rosherville, Northfleet,
in the County of Kent, and Michael Leopold Parnell, of the Strand, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN. THE
CONSTRUCTION OR THERMOMETERS
"
Sealed the 27th Mareh 1863, and dated the 20th October 1862.
PROVISIONAL SPECIFICATION left by the said Nathaniel Richard Hall
and Michael Leopold Parnell at the Office of the Commissioners of
Patents, with their Petition, on the 20th October 1862.
We, NATHANIEL RICHARD HALL, of Rosherville, Northfleet, in the County
of Kent, and MICHAEL LEOPOLD PARNELL, of the Strand, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE CONSTRUCTION OF THERMOMETERS," to be as follows:-
This Invention consists in stretching between two pins suitably affixed to a
wall or otherwise, a length of metallic wire, to. which wire is connected a
spiral spring, the wire being so adjusted that the spring shall be drawn out.
The change of temperature causes the said wire to expand and contract; the
spring will give or take by this arrangement. Near the spring is suspended
a lever by means of a pin or otherwise attached to the said wire, and by.
means of a second pin forming a fulcrum, the lower end of the lever by the
expansion and contraction of the wire is moved both ways, and by a line
connected to the lower end of the lever, and carried round a roller, causes the

page_text: roller to turn; the line is kept in this position by means of a weight, and upon
the spindle of the roller a hand is placed, which moves before a dial, upon
which is shewn the scale in use for thermometers.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Nathaniel Richard Hall and Michael Leopold Parnell in the
Great Seal Patent Office on the 17th April 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, NATHANIEL
RICHARD HALL, of Rosherville, Northfleet, in the County of Kent, and
MICHAEL LEOPOLD PARNELL, of the Strand, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of October, in the year of our
Lord One thousand eight hundred and sixty-two, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
us, the said Nathaniel Richard Hall and Michael Leopold Parnell, Her special
licence that we, the said Nathaniel Richard Hall and Michael Leopold Parnell,
our executors, administrators, and assigns, or such others as we, the said
Nathaniel Richard Hall and Michael Leopold Parnell, our executors, adminis-
trators, 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 THE CONSTRUCTION OF THERMOMETERS," upon the
condition (amongst others) that we, the said Nathaniel Richard Hall and
Michael Leopold Parnell, our executors or administrators, by an instrument in
writing under our, or one of our, 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 imme-
diately after the date of the said Letters Patent:
NOW KNOW YE, that we, the said Nathaniel Richard Hall and Michael
Leopold Parnell, do hereby declare the nature of our 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 and accompanying Drawings, that
is to say:-
This Invention consists in stretching between two. fixed pins or stationary

page_text: points (which said pins or points) can be fastened in a wall. or elsewhere, or
in a portable frame), a suitable length of wire, to which is connected a spring,
and is so adjusted that the spring shall be drawn out or wound, which will
keep the wire in a strained position, and the changes of temperature causing
the wire to expand and contract, the spring will give or take by this arrange-
ment, and form the working part of this thermometer.
Figure 1 in the Drawing shews the working principle of this thermometer.
A, A, are two fixed pins, between which is stretched the wire E, kept strained
by the spring B, by the expansion and contraction of the wire E, the end of
it nearest the spring will have a small movement, and by a plate C, with a pin
in it is connected the mechanical parts, described and set forth in the other
Figures of the Drawing. Figure 2 shews the thermometer fixed to a wall or
stationary. A, A, are two fixed pins, between which is stretched the wire E, kept
strained by the spring B, near the spring is the pin C on which to suspend
the lever F. The plate D has a pin in it and is so adjusted that it may be
in contact with the lever F, and form a fulcrum for it to act upon, then by
the expansion and contraction of the wire, the point of the lever at C, will
be moved both ways, and the lever acting upon the fixed fulcrum at D, the
other end of the lever at M will also be moved both ways. To the end of
the lever M is attached the line G, which is carried round the roller H, and
then fastened to the small spring at I. On the spindle or axis of the roller
the hand K is fixed, which moves before the dial L, which dial can be
graduated with any of the scales used for thermometers. Figure 8 is the
ornamental case, dial, and have of the arrangements described in Figure 2,
with the wire E left exposed to receive the various changes of temperature
fastened to the fixed point at A. Figure 4 shews an alteration of the mechanical
arrangement, and also shews a strip of metal instead of a wire stretched or
strained by a spring of different construction to that in the other Drawings,
thereby setting forth that the principle of this thermometer is not changed by
using a strip of metal or any suitable material that expands and contracts
(instead of a wire) kept strained by a spring of any suitable form, as follows:-
The fulcrum of the lever F is at one end D, and the pin C acts upon the
lever between its ends D and M. The spring B is capable of being raised or
lowered at the screw G, that the pin C in the strip of metal E may be brought
to its right position upon the lever. A is a fixed rod, on which the strip
of metal may be also raised or lowered for the same purpose by the
sliding ring N. Figure 5 is a portable arrangement of this thermometer.
The fixed rods A, A, are fastened in the frame P, P, P, P. Upon the
rods A, A, are the sliding rings N, N, to bring the pin C to its right position

page_text: in the short arm of the lever F, which short arm of the lever is at right
angles with the long arm, that the lever may be in a parallel position with
the wire E. The fixed point D is the fulcrum upon. which the lever acts,
the line G is attached to, the end of the lever at M, and carried round the
roller H, and then fastened to the small spring at I; on the spindle or axis
of the roller the hand K is fixed, which moves before the dial L, and indicates
the variations of temperature. Figure 6 is the ornamental case, dial, and
hand of Figure 5.
The parts claimed in this Invention are the principle of shewing (upon a
dial by a hand) the degrees of temperature by means of metal of any suitable
kind, which said metal is used in the form of wire or flexible strip of any
sufficient length, that the expansion and contraction may vary enough to work
the mechanical parts that give motion to the hand. A length of wire or strip
of flexible metal of any kind is therefore claimed as the motive agency (in
conjunction with the mechanical arrangements set forth in the Drawings)
for working a hand to indicate the degrees of temperature exhibited upon a
dial, and the application of a spring to keep the wire or flexible strip constantly
strained, that the expansion and contraction shall not take place without
moving the hand (through the medium of the other parts) is also claimed as
new in construction of thermometers.
In witness whereof, I, the said Michael Leopold Parnell, on behalf of
myself and of the said Nathaniel Richard Hall, have hereunto set my
hand and seal, this Seventeenth day of April, in the year of our Lord
One thousand eight hundred and sixty-three.
M. L. PARNELL. (L.S.)