Year: 1888

page_text: .
* Date of Application, 10th. Dec., 1888
Complete Specification Left, 9th Jan., 1889
⚫ Complete Specification, Accepted, 16th Feb., 188
I, GEORGE CHARLES LILLEY of 10 London Street in the City of London
Compass Maker do hereby declare the nature of my said invention to be as follows:—
My Invention relates to what are known as spirit or liquid compasses and has for
its objects to provide means whereby such compasses may be readily taken apart
to obtain access to the interior and whereby also the liquid used is. prevented from
becoming discoloured by contact with the packing for the glass and an improved
construction is provided whereby the appearance of air bubbles beneath the glass is
prevented so that if a lifter screw be used to raise the card from the pivot or the
pivot be made capable of withdrawal any air which may be admitted makes its way
to a part where it will not be seen.
According to my Invention I use a bevelled glass or one which will leave a
space between its edge and the casing and I construct the upper part or ring
carrying the glass so that it and the glass can be removed together without disturbing
the setting of the glass in the said upper part or ring.
I prefer to make the said upper part or ring in two portions between which the
glass is held the lower edge of one portion bearing on the top of the glass and the
other portion being secured to the first portion by screws or by screwing the one
in the other or otherwise in such manner as to retain the glass in position in
the upper part or ring which is then screwed or otherwise fastened as a whole to the
top edge or rim of the compass bowl which contains the liquid. The edge of the
glass or its setting and the opposite upper part of the interior of the compass
bowl are so shaped or relatively situated that they afford between them an open
annular chamber with a free passage thereto from the compass bowl which chamber
cannot be seen from the outside of the compass and into the space afforded by this
chainber any air bubbles "freely rise and are concealed from view. The packing of
india rubber or the like if used between the upper part or ring and the bowl to
make good the joint between the two can be out of contact with the liquid so that
it is not discoloured thereby.

page_text: In order to enable the compass bowl to be filled completely with liquid and yet
prevent danger of bursting due to the expansion of the liquid I provide an opening
communicating from the interior to the exterior of the compass bowl and provided
with a valve or closure normally kept closed by a spring or otherwise but capable
of yielding to relieve the bowl under excessive pressure.
Datad this 10th day of December 1888
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fiolds, London,
Agents.
I GEORGE CHARLES LILLEY of 10 London Street in the City of London Compass
Maker 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 :-
My Invention relates to what are known as spirit or liquid compasses and has
for its objects to provide means whereby such compasses may be readily taken apart-to
obtain access to the interior and whereby also the liquid used is prevented from
becoming discoloured by contact with the packing for the glass and an improved
construction is provided whereby the appearance of air bubbles beneath the glass is
prevented so that if a lifter screw be used to raise the card from the pivot or the
pivot be made capable of withdrawal any air which may be admitted makes its way
to a part where it will not be seen. There is also provided a safety or relief device
for relieving the compass bowl of pressure due to expansion of the liquid therein
and avoiding the necessity for compressing the liquid. This device consists of a
relief valve or closure which is normally kept closed by a spring or otherwise but
which opens when undue pressure of the liquid arises.
I will describe the way in which my Invention may be carried into effect reference
being had to the accompanying drawing which shews a vertical section of a compass
constructed according to my Invention.
According to my Invention I use a bevelled glass A or one which will leave a space
at a between its edge and the casing and I construct the upper part or ring carrying
the glass so that it and the glass can be removed together without disturbing the
setting of the glass in the said upper part or ring.
I prefer to make the said upper part or ring in two portions between which the
glass is held the lower edge of one portion 6 bearing on the top of the glass A and

page_text: the other portion c being secured to the first portion b by screws or by screwing the one
into the other as illustrated or otherwise in such manner as to retain the glass A in
position in the upper part or ring which is then screwed as shewn or otherwise
fastened as a whole to the top edge or rim of the compass bowl D which contains the
liquid. The edge of the glass A or its setting and the opposite upper part of the
interior of the compass bowl and ring are so shaped (as will be seen clearly in
the drawing) or relatively situated that they afford between them the open annular
chamber a with an entirely free passage thereto all the way round from the interior of
the compass bowl which chamber a cannot be seen from the outside of the compass.
and into the space afforded by this chamber any air bubbles freely rise and are
concealed from view. The packing of india rubber or the like if used (at d) between
the upper part or ring and the bowl to make good the joint between the two can be
out of contact with the liquid so that it is not discolored thereby. The glass A although
shewn flat on its underside may be made slightly convex if so desired.
In order to enable the compass bowl to be filled completely with liquid and yet
prevent danger of bursting due to the expansion of the liquid I provide an opening
at E communicating from the interior to the exterior of the compass bowl D and
provided with a valve for closure normally kept closed by a spring g or otherwise but
capable of yielding to relieve the bowl under excessive pressure. As illustrated the
valve fis kept closed by the spring g which is shown as being connected to the stem
of the valve and to the post or "point stem" of the compass and a special bushing is
provided by the tube e as a valve seating. When excessive pressure of the liquid
occurs it passes through the opening E and acts on the valve f so as to open it
whereby the pressure is relieved and danger of injury to the instrument prevented.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is
1. In spirit or liquid compasses the use of a glass with a bevelled or inclined edge so
arranged and combined with the compass bowl and securing or containing ring as to
leave a space a entirely free all round to the interior of the compass bowl substantially
as and for the purpose herein before described.
2. In spirit or liquid compasses the combination of the bevelled edge glass and
securing rings b and c substantially as herein before described.
3. In spirit or liquid compasses a passage provided with a relief valve or closure
which opens under undue pressure substantially as herein before described.
Dated this 24th day of December 1888.
GEORGE CHARLES LILLEY.