CERTAIN IMPROVEMENTS IN THE CONSTRUCTION OF GUAGES FOR INDICATING OR MEASURING THE EXPANSIVE PRESSURE OF STEAM OR OTHER ELASTIC VAPOURS OR GASES USED EXPANSIVELY AS A MEDIUM OF POWER
Year: 1835

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
RADLEY, of Oldham, in the County Palatine of Lancaster, Gentleman, send
greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent, under the Great Seal of Great Britain, bearing date at
Westminster, the Fourth day of December, in the sixth year of His reign,
did, for Himself, His heirs, and successors, give and grant unto me, the said
James Radley, His especial licence, full power, sole privilege, and authority,
that I, the said James Radley, my executors, administrators, and assigns, and
such others as I, the said James Radley, my executors, administrators, and
assigns, should at any time agree with, and no other, from time to time and
at all times during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend within England, Wales, and the Town
of Berwick-upon-Tweed, my Invention of "CERTAIN IMPROVEMENTS IN THE
CONSTRUCTION OF GUAGES FOR INDICATING OR MEASURING THE EXPANSIVE PRESSURE
OF STEAM OR OTHER ELASTIC VAPOURS OR GASES USED EXPANSIVELY AS A MEDIUM
OF POWER;" in which said Letters Patent is contained a proviso, that I, the
said James Radley, shall cause a particular description of the nature of my
said Invention, and in what manner the same is to be performed, to be
enrolled in His Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and as

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
James Radley, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, is particularly described
and ascertained in the Drawings hereunto annexed, and to the following
explanation thereof, that is to say :-
My improvements in the construction of guages for indicating or measuring
the expansive pressure of steam or elastic vapour or gases used expansively
as a medium of power, are principally designed for what are termed high-
pressure boilers or generators, and consist in the peculiar construction and
novel arrangement of the guage or apparatus for ascertaining the pressure
of the steam or other clastic force, and particularly in the adaptation thereto
of an atmosphere or volume of common air or any other vapour or gas capable
of being compressed or reduced in volume for the purpose of indicating by
such compression the expansive force of the steam acting upon it, the medium
of communicating such elastic force being an intervening column of mercury
or quicksilver.
In ordinary high-pressure boilers or generators, where the regulation of
the pressure of the steam or other vapour is left intirely to the safety
valve, the incapability of ascertaining the precise pressure is well known,
the object therefore of my present Invention is to obviate that difficulty,
and to indicate the pressure of the steam or other vapour or gasses to
almost any extent, and thereby enable the attendant to prevent the acci-
dental explosions which have hitherto arisen in consequence of this defect.
In order to illustrate my Invention, and shew the apparatus more clearly, I
have attached hereto a Drawing of one construction of my improved guage
adapted for a steam boiler.
Figure 1 is a front elevation thereof, and Figure 2 a vertical section
taken through the middle, the same letters of reference indicating corre-
sponding parts in both the Figures. a and a* are two circular chambers
or small cylinders formed of iron or other suitable material screwed into
or otherwise securely fastened on to a base or foot piece b, b, through
which a channel or passage c, c, is made for the purpose of forming a
communication between the two cylinders; into the centre of the base a
small tube or socket d is screwed for the purpose of supporting the glass
tube e, and under this tube another channel 9, 9, is made, communicating
with the passage c. In the base the lower parts of all these vessels and
passages are occupied with mercury up to the level marked m, m. Near the
top of the cylinder a a cock f is inserted, by which steam is to be admitted
from the boiler or generator into the cylinder when the pressure is required

page_text: to be ascertained. On the upper end of the other cylinder a, there is a
chamber h, with a cap screwed thereon supporting a glass tube i, properly
secured into the upper end of the chamber and rendered perfectly air-tight;
the top of the tube i has a spherical air chamber o. The chamber his
furnished with a small valve for the admission of air into the chamber, and
opposite to it there is a socket which receives the upper end of the glass
tube e.
The chamber a and a with the communicating passages are charged
with mercury as said, by removing the screw cap from the socket 7, and
pouring the mercury into the glass tube c, which by descending into the
chambers a and a*, will flow to about the level shewn. There is a small tube
or cylindrical piece, screwed into the foot piece immediately under the
chamber a, in order to conduct the mercury to the passage c, from the
centre of the column, and thereby prevent the passage of any condensation of
steam which might pass down the sides of the column. On the admission of
steam through the cock f, the mercury will be forced down in the chamber a,
and rise up into the chamber h, and glass tube i, i, and there, indicate the
pressure of the steam within the boiler. The scale n, n, placed behind the
tube, or the tube itself being graduated, will shew the amount of pressure
of the steam upon every square inch. The spherical air vessel o has a screw
plug p, for the purpose of increasing or diminishing the capacity of the air
chambers, by means of which plug the volume of air to be compressed may
be adjusted to the graduated scale. The valve is simply employed for the
purpose of regulating the air contained in the spaces h, i, o, to the pressure of
the external atmosphere,, which is done by raising the plug and thereby
opening a small lateral air channel 7, and the equilibrium being thus effected,
the plug is then screwed down again, previously to which the steam is to be cut
off from the guage by closing the cock f. It will be seen by this arrangement
the instrument is perfectly under command, for, as often as it may be thought
desirable to regulate the guage, the air occupying the spaces may be adjusted
to the proper or atmospheric density, and should it be found, on removing the
pressure of the steam; that the mercury does not descend or stand at its
former level in the glass tube e, (previously marked) it will be perceived that
the air within has varied in density, which may be corrected and adjusted to
an equilibrium with the external atmosphere by opening the valve k. The
glass tube i is made conical or tapering towards the top, for the purpose of
diminishing its capacity, as shewn in the Drawing, by which arrangement the
graduations on the scale may be made equal, whereas, if the tube is cylindrical,
the degrees must be decreasing in space towards the top, in proportion to the
increasing density of the air.

page_text: In conclusion, I would remark that it will be evident when any other
clastic vapour than atmospheric air is employed as the volume to be com-
pressed in density by the pressure of the steam, that a reservoir of such
gas or vapour must be connected to the valve or passage , to adjust its
density, and restore it to its proper equilibrium as before described with
reference to atmospheric air.
Having now explained the nature of my Invention, and the manner of
carrying the same into effect, I wish it to be understood that I claim as the
subject of my Invention the peculiar construction and novel arrangement of
the steam guage above described, and particularly the application of a volume
of atmospheric air or other elastic vapour under any modified variation capable
of being compressed into a smaller volume or greater density by the pressure
or force of the steam or other elastic vapour or gases contained in the boiler
or generator for the purpose of ascertaining and indicating the pressure or
force of such steam or vapour.
In witness whereof, I, the said James Radley, have hereunto set my
hand and seal, the Second day of June, in the year of our Lord One
thousand eight hundred and thirty-six.