CERTAIN IMPROVEMENTS IN THE CONSTRUC- TION OF WATER GUAGES POR STEAM BOILERS
Year: 1858

page_text: LETTERS PATENT to Thomas Charles Medwin, of No. 10, Clayton Place,
Kennington Road, in the Parish of Lambeth, in the County of Surrey,
Engineer, for the Invention of "CERTAIN IMPROVEMENTS IN THE CONSTRUC-
TION OF WATER GUAGES POR STEAM BOILERS."
Sealed the 4th June 1858, and dated the 19th March 1858.
PROVISIONAL SPECIFICATION left by the said Thomas Charles Medwin
at the Office of the Commissioners of Patents, with his Petition, on the
19th March 1858.
I, THOMAS CHARLES MEDWIN, of 10, Clayton Place, Kennington Road,
in the Parish of Lambeth, in the County of Surrey, Engineer, do hereby
declare the nature of the said Invention for "CERTAIN IMPROVEMENTS IN THE
CONSTRUCTION OF WATER GUAGES FOR STEAM BOILERS," to be improvements on a
former Patent of mine, in which the float in the boiler was suspended from
a balanced lever within the boiler, from which lever a rod passed out of the
top of the boiler through a vertical pipe into a slide valve box; the slide
covering a hole or steam passage communicating with a steam whistle, whilst
the water in the boiler is kept at the proper height, but whenever it is either
too high or too low, the steam passage is uncovered, allowing. the steam to

page_text: escape to the whistle. The rod from the float passing out of the valve box
through a stuffing box has on the top an index pointer, which shews the
height of the water in the boiler.
My present Invention is that of attaching the float immediately to the
vertical rod, and making a direct action from the float to the valve whistle 5
& pointer; the length of the valve box & run of the valve being equal to
the greatest variation in the height of the water.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Charles Medwin in the Great Seal Patent Office on
the 31st July 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
CHARLES MEDWIN, of No. 10, Clayton Place, Kennington Road, in the Parish
of Lambeth, in the County of Surrey, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of March, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Charles Medwin, Her special licence that I, the said Thomas
Charles Medwin, my executors, administrators, and assigns, or such others
as I, the said Thomas Charles Medwin, 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 "CERTAIN IMPROVEMENTS IN THE CONSTRUCTION OF WATER GUAGES
FOR STEAM BOILERS," upon the condition (amongst others) that I, the said
Thomas Charles Medwin, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Charles Medwin, do hereby
declare the nature of my said Invention, and in what manner the same is

page_text: to be performed, to be particularly described and ascertained in and by
the following statement, which is further illustrated by the accompanying
Drawing.
.
Fig. 1 represents a transverse section of part of a steam boiler with a steam
whistle, and a water guage fixed on its upper part. A is a hollow float, which
may be made of any shape or suitable material, and of such a weight or
specific gravity as to float with one-half of its bulk in the water and the other
half above, and of such a size or bulk as to insure a power of floatation
sufficient at all times to overcome the resistance of friction of the slide valve
within the box, and also the rod passing out at the stuffing box. B is a
tubular or solid rod, fastened to the float by a collar above and a screw nut
below, and passes loosely through the pillar C into the valve box D, where it
is connected to the slide valve i, and varying in length to suit the water space,
and then through the stuffing box to the index pointer G. When a tubular-
rod is used the bottom end is closed, and there is a hole as at O opening the
interior of the float to the atmosphere. The inner face d, d, of this valve box
is faced true and smooth, with an outlet e leading into the branch E, on the
top of which is fixed an ordinary steam whistle F. The outlet e is shewn
covered with a slide valve or shutter i, before mentioned, which will continue
to cover the outlet as long as the water in the boiler remains at a proper working
height; but should the evaporation be less than the pump supplies until the
float be lifted up to the situation denoted by the dotted lines a, a, the valve
will also be pushed up, allowing the steam to escape to the whistle by which a
signal will be given, when by looking at the pointer it will be seen that the
water is above the working height. On the other hand, should the consump-
tion be greater than the supply from the pump until the float falls to the lower
dotted lines b, b, the steam will escape to the whistle and give notice, and the
index will point out in the guage plate that the water is too low or below the
proper height.
The Figure 2 represents an outline side view of this whistle and float, in
which the same letters are used to denote the same parts.
Fig. 3 represents a water gunge only, without a whistle; K is a pillar pipe
with a stuffing box L at the top, to which is attached the guage plate M
within this pipe K; the float rod N, which is either hollow or solid, passes
up from the float m, n, to the pointer o, showing the variation in the height of
the water.
The originality claimed in this Invention is for the simple direct-acting rod

page_text: from the float to the slide valve and pointer, and the general arrangements of
parts as herein described.
In witness whereof, I, the said Thomas Charles Medwin, have hereunto
set my hand and seal, this Twelfth day of July, in the year of our Lord
One thousand eight hundred and fifty-eight.
Witnessed by
J. R. HILL,
Civil Engineer and Patent Agent,
7, Duke Street, Adelphi.
THOS. CHAS. MEDWIN.