IMPROVEMENTS ENTS IN PRESSURE AND VACUUM GAUGES AND OTHER GAUGES PROVIDED WITH DIALS
Year: 1871

page_text: LETTERS PATENT to Edward Rau, of No. 75, Ruc d'Arlon, Brussels,
FT
in the Kingdom of Belgium, Mechanical Engineer; for the Invention
of " IMPROVEMENTS
ENTS IN PRESSURE AND VACUUM GAUGES AND OTHER
GAUGES PROVIDED WITH DIALS."
LIKE
L
Sealed the 1st December 1871, and dated the 9th September 1871.
PROVISIONAL SPECIFICATION left by the said Edward Rau at the
Office of the Commissioners of Patents, with his Petition, on the
9th September 1871.
I, EDWARD RAU, of No. 75, Rue d'Arlon, Brussels, in the Kingdom
of, Belgium, Mechanical Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN; PRESSURE AND VACUUM, Gauges
AND OTHER LIKE GAUGES PROVIDED WITH DIALS," to be as follows:-
:
• T
This Invention consists in constructing pressure and vaccuum gauges
and other like gauges with dials capable of being illuminated by means
of a lamp or other source of light placed behind the dial, thus
rendering such dials as easy of inspection at night as in the day time..

page_text: In order that the manner in which I propose to carry out my
Invention may be fully understood I have in the Drawing hereunto
annexed shewn a pressure gauge provided according to my Invention
with a luminous dial.
.
In order that the manner in which I propose to carry out my
Invention may be fully understood I have in the Drawing hereunto
annexed shewn a pressure gauge provided according to my Invention
with a luminous dial.
Figure 1 is a vertical section of the gauge; a is the lamp; b, luminous
dial; c, front glass; d, holes for the passage of air; e, caoutchouc ring
at the side.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward Rau in the Great Seal Patent Office on
the 8th March 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
RAU, of No. 75, Rue d'Arlon, Brussels, in the Kingdom of Belgium,
Mechanical Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of September in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Edward Rau, Her special license that I,
the said Edward Rau, my executors, administrators, and assigns, or such
others as I, the said Edward Rau, 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 AND
VACUUM GAUGES AND OTHER LIKE GAUGES PROVIDED WITH DIALS," upon the
condition (amongst others) that I, the said Edward Rau, 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
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 Edward Rau, do hereby declare
the nature of the said Invention. and in what manner the same is to

page_text: be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention consists in constructing pressure and vacuum gauges
and other like gauges with dials capable of being' illuminated by means
of a lamp or other source of light placed behind the dial, thus rendering
such dials as casy of inspection at night as in the day time.
In order that the manner in which I propose to carry out my
Invention may be fully understood I have in the Drawing hereunto
annexed shewn a gauge provided according to my Invention with a
luminous dial.
Figure 1 is a vertical section, and Figure 2 a face view of the gauge
with its dial capable of being illuminated. The working parts of the
gauge may be of any ordinary construction, and are not shewn in the
Drawings.
a is the dial face, which may be of ground or opaque glass; 6 is a
transparent glass in front of the dial and held in place by the copper
ring ; c is the index or pointer situated between the two glasses and
fixed on an axis d connected with the revolving axis of the gauge; e is
the lamp placed behind the dial; f, f, are holes for the passage of air
to the lamp; g is the outlet for heated air; h is a packing ring of
caoutchouc; k, a door in the side of the casing through which the lamp
can be taken in or out.
Having thus described the nature of my Invention, and the manner
of performing the same, I would have it understood that I do not
confine myself to the precise details of construction herein described,
but that what I claim is, the construction of pressure and vacuum
gauges and other like gauges with dials capable of being illuminated by
a lamp placed behind them, substantially as described.
In witness whereof, I, the said Edward Rau have hereunto set
my hand and seal, this Twentieth day of February, in the
year of our Lord One thousand eight hundred and seventy-two.,