Year: 1897

page_text: I, JOHN NORMAN COLLIE, of The Pharmaceutical Society of Great Britain,
17 Bloomsbury Square, London, W.C., Fellow of the Royal Society, do hereby
declare the nature of this invention to be as follows:-
-
This Invention relates to a portable mercurial barometer capable of being packed
within the compass of a small hand or pocket case and free from the liability to
breakage in travelling to which an ordinary standard mercurial barometer is
exposed.
The barometer is constructed of glass terminal chambers connected by a tube of
caoutchouc so as to admit of being coiled or folded in a small compass, and in
combination therewith a graduated standard which may be rigid (or may be
jointed, so as to fold) the standard having fitted to slide upon it adjustable carriers
provided with clamping rings in which the terminal chambers of the barometer
tube are secured. Each carrier is adapted to be clamped in suitable position upon
the standard so that the mercury level in the lower chamber or cistern may be
made to coincide with the zero point of the standard scale or be otherwise adjusted
with reference thereto according to requirements whilst the height of the upper
chamber may be adjusted to suit the height of the mercurial column at the
altitude where the instrument is to be used, each carrier being furthermore pro-
vided with a vernier scale and index adjustable by rack and pinion and reading
off on the scale of the standard. The upper chamber is provided with an internal
dip tube forming a trap to intercept any air which might accidentally enter the
bore and prevent it rising into the chamber and impairing the vacuum. The
lower chamber or cistern is provided with a stop-cock (which may be of glass or
other material unattacked by mercury) for preventing the mercury running out
when the instrument is packed.
In the manufacture of the instrument a portion of the mercury is boiled in the
upper chamber in the usual way to expel air, after which the rubber tube is
attached to the two chambers and the whole is then filled with mercury (previously
boiled) any air imprisoned in the tube being extracted by the air pump.
Dated this 24th day of February, 1897.
A. M. & WM. CLARK,
Chartered Patent Agents, 53 Chancery Lane, London.

page_text: tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement:-
This Invention relates to a portable mercurial barometer capable of being
packed within the compass of a small rand or pocket case and free from the
liability to breakage in travelling to which an ordinary standard mercurial
barometer is exposed. The barometer is constructed of glass terminal chambers
connected by a tube or caoutchouc so as to admit of being coiled or folded into a
small compass, and in combination therewith a graduated standard which may
be rigid (or may be jointed so as to fold) the standard having fitted to slide upon
it, adjustable carriers provided with clamping rings in which the terminal
chambers of the barometer tube are secured. Each carrier is adapted to be
clamped in suitable position upon the standard so that the mercury level in tho
lower chamber or cistern may be made to coincide with the zero point of the
standard scale or be otherwise adjusted with reference thereto according to
requirements whilst the height of the upper chamber may be adjusted to suit the
height of the mercurial column at the altitude where the instrument is to be used,
each carrier being furthermore provided with a vernier scale and index adjustable
by rack and pinion and reading off on the scale of the standard. The upper
chamber is provided with an internal dip tube forming a trap to intercept any
air which might accidentally enter the bore and prevent it rising into the chamber
and impairing the vacuum. The lower chamber or cistern is provided with a stop-
cock (which may be of glass or other material unattacked by mercury) for prevent-
ing the mercury running out when the instrument is packed.
In the manufacture of the instrument a portion of the mercury is boiled in the
upper chamber in the usual way to expel air, after which the rubber tube is
attached to the two chambers and the whole is then filled with mercury (previously
boiled) any air imprisoned in the tube being extracted by the air pump.
The invention is illustrated in the accompanying drawings forming part of this
Specification in which Figure 1 is a face view of the upper carrier and Figure 2
a similar view of the lower carrier in their respective relative positions, on the
standard except that they are brought close together owing to the middle portion
of the standard and of the connecting rubber tube being broken away.
A is the standard preferably of 1 section graduated along one edge of its face.
B is the upper or vacuum chamber and C the lower chamber or cistern respectively
supported by clamps D mounted upon upper and lower carriers E F. Each carrier
is adapted to slide upon the standard being provided on the rear side with lugs
which embrace the edges and back of the standard as will be readily understood
and each is provided with a clamping screw G by which it may be securely fixed in
position on the standard. Each carrier is also provided with a vernier H adjust-
able by means of a rack and pinion motion I in relation to the scale of the
standard, which is visible through an aperture on the carrier alongside of which
the vernier works each vernier carrying an index ring h which slides over the
adjacent mercury chamber for adjustment by the vernier to the mercury level.
The upper chamber B is provided with the internal dip tube b forming an air
intercepting trap, and it is connected to the lower chamber by the indiarubber
tube K whose ends are attached by wire-bound joints to the necks of the
chambers B and C.
It is these joints which are supported in the clamps D the two parts of each
clamp being secured by a tightening screw / so as to admit of the tube and
chamber being readily mounted and dismounted as required.
The lower chamber C is provided with the stop-cock L for the purpose above
mentioned.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In a portable barometer the combination of glass terminal chambers con-

page_text: nected by a tube of caoutchouc and of a graduated standard as and for the purpose
specified.
2. The herein described portable barometer consisting of terminal chambers
connected by a tube of caoutchouc, in combination with carriers adjustable upon
a graduated standard substantially as specified.
Dated this 24th day of November, 1897.
A. M. & WM. CLARK,
Chartered Patent Agents, 53 Chancery Lane, London.