IMPROVEMENTS IN STEAM AND VACUUM GAUGES
Year: 1859

page_text: LETTERS PATENT to John Blake, of Accrington, in the County of
Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN STEAM AND
VACUUM GAUGES."
Sealed the 17th February 1860, and dated the 24th August 1859.
PROVISIONAL SPECIFICATION left by the said John Blake at the
Office of the Commissioners of Patents, with his Petition, on the 24th
August 1859.
I, JOHN BLAKE, of Accrington, in the County of Lancaster, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN STEAM
AND VACUUM GAUGES," to be as follows:-
One end of a pipe, of any required length, is attached to the condenser,
boiler, or other vessel where the degree or quality of the vacuum or pressure
is required to be known, and the other end of the pipe connected to the vessel
which holds the mercury, which vessel is of any desired external shape, but
made internally with a rectangular or other formed recess or chamber, having
seatings, upon which a plate or segment of glass is jointed and fixed with
putty or other suitable cement, which glass thus forms one of the sides or

page_text: surfaces of a rectangular or other formed recess or chamber open at the top,
in which chamber the mercury is placed, and communicates with the bore of
the pipe connected with the condenser, boiler, or other vessel of which the
internal vacuum or pressure is to be indicated. The space which holds the
mercury is of larger area than that of the communicating pipe, and the move-
ment of the mercury in the pipe and chamber is in corresponding proportion,
so that a short vessel may be employed for indicating a high pressure or
extreme vacuum. The outside of the vessel is graduated, and the rising and
falling of the mercury can be seen through the plate or segment of glass, thus
forming an efficient and simple indicating chamber. The vacuum gauge and
steam gauge are separate instruments, and each indicating chamber can be
graduated to measure up or down according to the position of the com-
municating pipe.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Blake in the Great Seal Patent Office on the
23rd February 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
BLAKE, of Accrington, in the County of Lancaster, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of August, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said John Blake, Her special licence that I, the said John
Blake, my executors, administrators, and assigns, or such others as I,
the said John Blake, 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 STEAM AND VACUUM GAUGES," upon the condition (amongst
others) that 1, the said John Blake, 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,

page_text: NOW KNOW YE, that I, the said John Blake, do hereby declare the
nature of my said Invention, and the manner in which the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say) :-
I attach one end of a pipe of any required length to the condenser, boiler,
or other vessel where the degree or quality of the vacuum or pressure is
required to be known, the other end of the pipe being connected to the vessel
which holds the mercury, which vessel is of any desired external shape, but
made internally with a rectangular or other formed recess or chamber having
seatings upon which a plate or segment of glass is jointed and fixed with
putty or other suitable cement, which glass thus forms one of the sides or
surfaces of a rectangular or other formed recess or chamber open at the top,
in which chamber the mercury is placed, and communicates with the bore of
the pipe connected with the condenser, boiler, or other vessel of which the
internal vacuum or pressure is to be indicated. The space which holds the
mercury is of larger area than that of the communicating pipe, and the move-
ment of the mercury in the pipe and chamber is in corresponding proportion,
so that a short vessel may be employed for indicating a high pressure or
extreme vacuum. The outside of the vessel is graduated, and the rising and
falling of the mercury can be seen through the plate or segment glass, thus
forming an efficient and simple indicating chamber. The vacuum and stean
gauge are separate instruments, and each indicating chamber can be graduated
to measure up or down according to the position of the communicating pipe.
These improvements will be clearly understood by referring to the figures
and letters on the accompanying Sheet of Drawings, in which Figure 1
represents a front elevation, and Figure 2 a transverse section of a steam
gauge; and Figure 3 a similar section at about its full dimensions; Figure 4
is a front elevation, and Figure 5 a transverse section of a vacuum gauge.
The chamber for the mercury is shewn at a, and is made of a rectangular
shape, three of the sides b being formed of iron, and the fourth side by the
sheet of glass c, which is jointed and fixed with putty or other suitable cement,
as shewn at d.
Having thus fully described the nature and particulars of my said Inven-
tion, and the manner in which the same is to be performed, I desire it to be
distinctly understood that I do not confine myself to the precise details herein
set forth, as such may be varied or modified without departing from the
principle thereof; but I claim as my Invention, and which, to the best of my
knowledge and belief has not been hitherto used within the realm, the
employment of a flat sheet or segment of glass for forming one of the sides of

page_text: the chamber which holds the mercury in steam and vacuum gauges, as herein
described and illustrated in the accompanying Sheet of Drawings.
In witness whereof, I, the said John Blake, have hereunto set my
hand and seal, this Twenty-first day of February, in the year of our
Lord One thousand eight hundred and sixty.
Signed, sealed, and delivered by the
within-named John Blake, in the
presence of
E. J. HUGHES, Patent Agent,
Manchester.
JOHN BLAKE. (L.S.)