A Low-WATER INDICATOR OR ALARM FOR BOILERS
Year: 1869

page_text: LETTERS PATENT to Benjamin Joseph Barnard Mills, of 35, South-
ampton Buildings, in the County of Middlesex, Patent Agent,
for the Invention of "A Low-WATER INDICATOR OR ALARM FOR
BOILERS." A communication from abroad by Hiram Kimball, of
Randolph, in the County of Orange, and State of Vermont, United
States of America, Engineer.
PROVISIONAL SPECIFICATION left by the said Benjamin Joseph
Barnard Mills at the Office of the Commissioners of Patents, with
his Petition, on the 2nd June 1869.
I, BENJAMIN JOSEPH BARNARD MILLS, of 35, Southampton Buildings,
in the County of Middlesex, Patent Agent, do hereby declare the
nature of the said Invention for "A LOW-WATER INDICATOR OR ALARM
POB BOILERS," a communication to me from abroad by Hiram Kimball,
of Randolph, in the County of Orange, and State of Vermont, United
States of America, Engineer, to be as follows:-
The Invention consists of a water chamber or reservoir located
externally of the boiler above the water line, and communicating with

page_text: the interior of the boiler through a pipe at the lowest level to which the
water in the boiler can properly be allowed to descend. The clevated
chamber contains a buoyant cylinder, to the upper part of which is
attached a valve closing a port which communicates with the atmosphere,
so that so long as the water in the boiler is at a proper height the pressure
of steam keeping the elevated reservoir full or partially full of water will
cause the valve to be pressed against its scat, but the instant the water
descends below a proper level the water will run from the elevated
reservoir and its place will be supplied by steam, permitting the cylinder
to descend by its gravity, so that the port will be opened and steam
discharged therethrough, sounding a whistle or any other alarm which
may be provided. As the interior of the reservoir is inaccessible to the
engineer the alarm will continue until a proper quantity of water is
again supplied to the boiler, but as soon as the surface of the water rises
above the mouth of the connecting pipe water will be forced up into the
chamber, taking the place of the steam therein, and causing the discharge
aperture to be closed as before. The reservoir can be made of any
capacity to receive a buoy or float of necessary size and power, and can
readily be connected to any boiler by tapping a hole through the end or
side thereof for the reception of the connecting pipe. The buoyant
cylinder differs in effect from an ordinary float in that it is wholly
submerged, so that the entire force of its floatation or displacement
may be used.
It is proposed to use two of the attachments connecting with the
boiler at different heights, ouc to serve as an indicator for ordinary
pumping, the other to indicate if the water is dangerously low.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Benjamin Joseph Barnard Mills in the Great Seal
Patent Office on the 2nd December 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
JOSEPH BARNARD MILLS, of 35, Southampton Buildings, in the County
of Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of June, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-

page_text: second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Benjamin Joseph Barnard Mills, Her
special licence that I, the said Benjamin Joseph Barnard Mills, my
executors, administrators, and assigns, or such others as I, the said
Benjamin Joseph Barnard Mills, 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 "A Low-WATER INDICATOR OR ALARM
FOR BOILERS," a communication to me from abroad by Hiram Kimball,
of Randolph, in the County of Orange, and State of Vermout,
United States of America, Engineer, upon the condition (amongst
others) that I, the said Benjamin Joseph Barnard Mills, 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 Benjamin Joseph Barnard Mills,
do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, that is to
say:
This apparatus is provided with a water chamber or reservoir located
externally of the boiler above the water line, and communicating with
the interior of the boiler through a pipe at the lowest level to which the
water in the boiler can properly be allowed to descend. The elevated
chamber contains a buoyant cylinder, to the upper part of which is
attached a valve closing a port which communicates with the atmo-
sphere, so that so long as the water in the boiler is at a proper height
the pressure of steam keeping the elevated reservoir full or partially full
of water will cause the valve to be pressed against its seat, but the
instant the water descends below a proper level the water will run from
the elevated reservoir and its place will be supplied by steam, permitting
the buoyant cylinder to descend by its gravity, so that the port will be
opened and steam discharged therethrough, sounding a whistle or other

page_text: alarm, which cannot be stopped until the boiler receives a proper supply
of water. The apparatus may be attached to a boiler of any description
any convenient and proper position to effect the purposes stated.
in
And in order that the Invention may be more clearly understood and
readily carried into effect I will proceed, aided by the accompanying
Drawings, more fully to describe the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1 represents a vertical section of the apparatus, illustrating its
application to the side of a horizontal boiler; Figure 2 is an clevation
shewing it in its application to the side of a vertical boiler; and Figure 3
is an elevation shewing its application to the end of a horizontal boiler,
the boiler in each case being represented in section to show the height
of water. Similar letters of reference indicate corresponding parts in the
several views.
A may represent a boiler of any construction, to which an external
chamber or reservoir B is connected by a pipe P communicating with
the interior of the boiler at the lowest level to which it is deemed safe or
proper for the surface of the water to descend. Within the reservoir B
is a buoyant cylinder F from the top of which projects a rod fcarrying a
valve G, which when the buoyant cylinder F is clevated, by being sur-
rounded with water in the reservoir B, will be pressed upward against
its scat. II so as to close the port or aperture h therein. K, K, may
represent guides for the rod, and La stop to limit its descent. It will
be apparent that so long as the water within the boiler is maintained at
a proper level, that is to say, above the opening of the pipe P, the steam
pressure will keep the reservoir B constantly full of water and the
aperture closed; but if the surface of water within the boiler descends
below the opening of the pipe P the water within the reservoir will
instantly descend into the boiler, and steam taking its place will permit
the buoyant cylinder F to fall, the effect of which is to withdraw the
valve G from its scat H and cause a discharge of steam through the
aperture , so as to sound a whistle I or any other suitable alarm which
may be provided. As the interior of the reservoir is inaccessible to the
engineer the alarm will continue until a proper quantity of water is
again supplied to the boiler, but as soon as the surface of the water rises
above the mouth of the connecting pipe water will be forced up into the
chamber, taking the place of the steam therein, and causing the discharge

page_text: aperture to be closed as before. The reservoir can be made of any
capacity to receive a buoy or float of necessary size and power, and can
readily be connected to any boiler by tapping a hole through the end or
side thereof for the reception of the connecting pipe. The buoyant
cylinder differs in effect from an ordinary float in that it is wholly sub-
merged, so that the entire force of its floatation or displacement may be
employed. It is proposed to use two of the attachments connecting with
the boiler at different heights, one to serve as an indicator for ordinary
pumping, the other to indicate if the water is dangerously low. The
apparatus cannot be tampered with or controlled by the engineer. While
the boiler is under pressure the alarm must continue until water is
supplied to a proper level. It is simple and cheap of construction and
certain in its operations, and in the event of leaking of the buoy or float,
or any other derangement, the effect will be to open the discharge orifice
and thus indicate that attention is required, instead of leaving it closed
as is the effect of some apparatuses devised for the same general purpose.
In practice the buoyant cylinder should be made of as large size as the
capacity of the reservoir will properly permit.
It is not desired to restrict the Invention to the precise construction
and arrangement of parts herein represented, as the same may be
modified without departing from the essential principles involved.
Having thus described the nature of the said Invention, and the mode
in which the same is carried into effect, I would have it understood that
what I claim is, the elevated chamber B, buoyant cylinder F, valve G,
and connecting pipe P, when combined and arranged to operate sub-
stantially as set forth.
In witness whereof, I, the said Benjamin Joseph Barnard Mills,
have hereunto set my hand and scal, this Thirtieth day of
November, in the year of our Lord One thousand eight hundred
and sixty-nine.