THE ADAPTATION OF MICA OR TALC TO WATER GAUGES TO STEAM AND OTHER BOILERS
Year: 1872

page_text: LETTERS PATENT to Thomas Bear, of No. 9, Richmond Terrace,
Brighton, in the County of Sussex, Gentleman, for the Invention of
"THE ADAPTATION OF MICA OR TALC TO WATER GAUGES TO STEAM AND
OTHER BOILERS."
Sealed the 3rd April 1872, and dated the 14th February 1872.
PROVISIONAL SPECIFICATION left by the said Thomas Bear at the
Office of the Commissioners of Patents, with his Petition, on the
14th February 1872.
I, THOMAS BEAR, of No. 9, Richmond Terrace, Brighton, in the County
of Sussex, Gentleman, do hereby declare the nature of the said Invention
for "THE ADAPTATION OF MICA OR TALC TO WATER GAUGES TO STEAM AND OTHER
BOILERS," to be as follows:-
I take mica (sometimes called talc) and laminate the mica or talc into
sheets of a substance best suited for the purpose, the mica or tale so

page_text: laminated I then place either on the outside or inside of a metal frame-
work, the whole properly secured and rendered steam and water tight
by means of bolts or screws or any other method best suited for the
purpose, forming when finished a kind of elongated or other shaped box
or tube open at each end to allow of the free ingress or egress of water
and steam. The mica or tale being transparent the rise and fall of the
water in the boiler can be clearly distinguished and thereby forming an
indestruotable water gauge.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Bear in the Great Seal Patent Office on
the 14th August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
BEAR, of No. 9, Richmond Terrace, Brighton, in the County of Sussex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of February, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas Bear, Her special license
that I, the said Thomas Bear, my executors, administrators, and assigns,
or such others as I, the said Thomas Bear, my executors, adminis-
trators, 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 "THE ADAPTATION OF MICA OR TALC TO WATER
GAUGES TO STEAM AND OTHER BOLLERS," upon the condition (amongst others)
that I, the said Thomas Bear, 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.

page_text: NOW KNOW YE, that I, the said Thomas Bear, 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 Invention consists in the employment of mica, sometimes called
talc, in the construction of water gauges for steam boilers. For this
purpose the mica or talc is laminated into sheets of the required thickness
and is used for closing in the front and back of a metal chamber, the
top and bottom of which are connected by pipes with the steam boiler.
i
In the Drawings hereunto annexed I have shewn a water gauge
constructed in the manner I prefer for carrying out my Invention.
Figure 1 shews a face view, Figure 2 an edge view, and Figure 3 a
transverse section of the gauge.
a, a, is an elongated slotted plate cast with pipes b, b, projecting from
it at top and bottom, the pipes which are to connect the gauge with
the boiler may be attached to these pipes & in any suitable manner; c, c,
are thin sheets of mica placed across the front and back of the slot in
the plate a; d, d, are slotted plates of metal, which by bolts e, e, and
nuts e¹, e¹, are caused to clamp the edges of the sheets of mica between
themselves and the plate a; the front and back of the slot in the plate
a are thus closed over by the sheets of mica and the slot is formed
into a close chamber with the pipes b, b, leading out from it at top and
bottom; ff, are thin washers of vulcanized india-rubber interposed
between the sheets of mica and the plate a to make a steam and water
tight joint between them. Or other means may be adopted for making
the joint steam and water tight. The thin sheets of mica thus firmly
held around their edges are not only capable of supporting very high
pressures but also they are indestructible and not liable to crack or
'fly" when exposed to cold currents of air as is the case with glass
tubes when employed as water gauges for steam boilers.
"
Having thus described the nature of my Invention, and the manner
in which I prefer to carry the same into effect, I would have it under-
stood that what I claim is,-
1. The employment of mica, sometimes called talc, in the construction
of water gauges for steam and other boilers.

page_text: 2. The construction of water gauges for steam and other boilers,
substantially as herein described and shewn by the Drawings annexed.
In witness whereof, I, the said Thomas Bear, have hereunto set
my hand and seal, this Thirteenth day of August, in the year of
our Lord One thousand eight hundred and seventy-two.