IMPROVEMENTS IN GLASS GUAGES
Year: 1876

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
GLASS GUAGES." A communication from abroad by Louis Ingermann, of
Minden, Prussia, in the Empire of Germany.
ealed the 24th April 1877, and dated the 31st October 1876.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 31st October 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN GLASS GUAGES." A communication from abroad.
by Louis Ingermann, of Minden, Prussia, in the Empire of Germany.
This Invention relates to improvements in the construction of glass gauges, and
it consists in substituting for the glass tube ordinarily employed a chamber of metal
or other suitable material provided with apertures which are closed by flat panes of
glass or other transparent media, by means of which the level of the liquid in the
chamber may be readily ascertained.
In carrying out this Invention as applied to a steam boiler, for example, the metal
chamber is attached to and communicates with the boiler in the ordinary manner.
It is provided on two sides with a series of circular openings closed by glass discs or
panes, which are placed between rings or washers of india-rubber or other suitable
material, and are secured in position by suitable glands or screwed rings.
A plug is provided at the lower part of the chamber to enable access to be
obtained to the interior for the purpose of cleaning the same.
Gauges constructed according to this Invention are not liable to be cracked by
sudden changes of temperature, whilst the increased section of the water channel
greatly diminishes the danger of bursting from the internal pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 24th
April 1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN GLASS GAUGES." A communication from abroad
by Louis Ingermann, of Minden, Prussia, in the Empire of Germany.
The said Invention, relating to improvements in glass guages, consists in substi-
tuting for the glass tube ordinarily employed a body of metal or other suitable
material provided with apertures which are closed by flat circular panes of glass or
other transparent medium, by means of which the level of the liquid in the guage
may be readily ascertained.
By the use of the said Invention there are obtained greater security against
accidents and increased facilities for observing the water line.
Explosions of the ordinary cylindrical glass tubes take place principally on loco-
motives by reason of the change of the temperature, the guages being frequently
exposed to violent cold breezes. The glass tube of the water gauge therefore being
heated by the steam, frequently explodes when the cold wind from one side cools
the glass unequally, especially if the latter is not filled completely with water.
The bursting of the glass tubes is attended with danger to the engineman and
fireman, in addition to entailing the expenses of renewal. By the use of the
improved glass gauge however, a complete immunity from explosions from this cause
is obtained.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents an elevation of the improved
gauge; Figure 2 is a vertical section of the same taken along the line c, d, Figure 1;
and Figure 3 is a horizontal section, and Figure 4 a sectional plan, the sections being
taken respectively along the lines e, f, and a, b, Figure 1.
In the example shown in the Drawing, which illustrates a mode of carrying out
the said Invention, A is a metal body provided with flanges a for attachment to the
boiler in the ordinary manner; this body, which by the rectangular channel is in
communication above with the steam space, and below with the water space, is on
two sides provided with round holes B, placed as close together as practicable, those
on one side being exactly opposite those of the other side, so as to admit of a free
view through the holes. These holes are closed by flat circular panes or discs of
glass g, g, which are fixed steam-tight by means of the glands or screwed rings h, h,
and by two rings or washers i, of india-rubber or other suitable material. The
channel k of rectangular section, Figure 3, extends through the whole length of the
body, and connects the steam space with the water space of the boiler. The water
line will be readily observed through the glass panes.
The steam channel and the water channel & may be provided with cocks in
the ordinary manner, or with conically pointed screw plugs m, m³, as shewn in the
Drawing.
In general the improved gauge may be fitted with all usual accessories, such, for
example, as gauge cocks or plugs for the facility of cleaning, and the like.
Having now described and particularly ascertained the nature of the said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I consider to be novel and original and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is, a glass gauge having flat circular glasses or panes of a transparent

page_text: medium, substantially as and for the purpose herein-before described, and as illus-
trated by the accompanying Drawings.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, this Twentieth day of April, One thousand
eight hundred and seventy-seven.
J. HENRY JOHNSON. (L.S.)