An Improved Barometer.
Year: 1894

page_text: KIU * IIUNAI DI BOLT VALIUM,
An Improved Barometer.
I, ALEXANDER M' KAY of 2 Stockwood Crescent, Luton, Bedfordshire,
Gardener, do hereby declare the nature of this invention to be as follows:-
:―
In this invention a column of fluid in a tube open at top communicates through
a bend at us lower end with the underside of a vertical chamber, closed on all sides
except where it is connected at its base with the tube.
The said chamber is preferably in the form of a bulb and contains an air cushion,
that is air confined under pressure from the column of water first referred to, which
16 free to enter it from beneath.
As the pressure of the atmosphere on the column of water incienses or decreases
it causes the air in the chamber to contract or expand, and this contraction or
expansion necessarily affects the height of the column of water first inentioned.
The tabular scale is placed at the side of this changing column, and shows by its
figures the variations in the column a se in the column of water indicating a
diminution of atmospheric pressure, while a fall indicates an increase.
Instead of water, spirit or oil or mercury may be employed, but water is
preferable being quick in action and mexpensive
To prevent the entry of dust or foreign matter the mouth of the open tube may
be covered by fine gauze or an air filter of some suitable kind, but this must not
check the atmospheric pressure. To prevent evaporation the surface of the water
may carry a small float, or may be covered with oil of some slow drying kind or
both these expedients may be employed.
It will be understood that no vacuum is employed also that any suitable materials
may be used. The tube and its an-chamber may be affixed to a small board or
backing for protection, or may be arranged to stand on a base or stand of wood,
glass, metal or other suitable substance.
Dated this 22nd day of December 1894.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Agent for Applicant.
I, ALEXANDER MCKAY of 2 Stockwood Crescent, Luton, Bedfordshire,
Gardener do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention is the outcome of long practical experience and is designed to
supply a simple, effective and inexpensive instrument for indicating the pressure of
the atmosphere.
It consists of a column of fluid in an open tube communicating through a bend at
its lower end with the underside of a vertical chamber closed on all sides except
where it is connected at its base with the tube.

page_text: The said chamber is preferably in the form of a bulb or cylinder and contains an
air cushion, that is an confined under pressure from the column of water first referred
to, which is free to enter it from beneath.
As the pressure of the atmosphere on the column of water increases or decreases
it causes the air in the chamber to contract or expand, and this contraction of
expansion necessarily affects the height of the column of water first mentioned.
will now describe the invention with reference to the accompanying drawings
in which Figures 1, 2, 3 and 4 show different forms of glass tubes adapted for
carrying out my invention. In each case the end a, is closed and the end b, left
open. c, 18 the compressed an chamber. d, is the fluid. e, is the graduated scale
or table.
The tabular scale e, is placed at the side of each column, and shows by its figues
the variations in the column, a rise in the column of water indicating a diminution
of atmospheric pressure, corresponding to rainy or stormy weather, while a fall
indicates an increase of pressure or fine weather
Instead of water, spuit or oil or mercury may be employed, but water is preferable
being quick in action and expensive.
The instrument can be made in various sizes but from experience I find that the
internal diameter of the tube b, if made about one eighth of an inch in diameter is
quicker in action
To prevent the entry of dust or foreign matter the mouth of the tube may be
covered by fine gauze oi an air filter of some suitable kind, but this must not check
the atmospheric pressure.
To prevent evaporation the surface of the water may carry a small float, on
inay be covered with oil of some slow drying kind of both these expedients may be
employed
It will be understood that no vacuum is employed also that any suitable materials
may be used. The tube and its air chamber may be affixed to a small board or
backing for protection, or may be arranged to stand on a base or stand of wood,
glass, netal or other suitable substance.
Having now particularly described and ascertained the nature of my said inven-
tion and in what mannei the same is to be performed, I declare that what I
claim is
A barometer not containing a vacuum, consisting of an open tube communicating
at one end with an inverted air chamber formed by a closed tube or reservoir of any
shape, said open tube being of any suitable length or dimensions, but preferably as
high or higher than the air chamber, as herein described and set forth.
Dated this 15th day of Febranty 1896.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent
OCOL
190 105 10
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