An Improved Level.
Year: 1891

page_text: Date of Application, 20th Mar., 1891
Complete Specification Left, 18th Dec., 1891-Accepted, 6th Feb., 1892
PROVISIONAL SPECIFICATION.
An Improved Level.
HERBERT SPURRELL 2, Hartfield Rise Eastbourne Sussex Architect do hereby
declare the nature of this invention to be as follows:-
An apparatus to be called an Improved Level for use by architects engineers
mechanics & others, consisting of a flexible tube filled with fluid the two extremities
or terminals of the tube being enclosed in metal boxes or reservoirs fitted with
valves to prevent escape of fluid. At a point about 5 feet from one end of the
tube a glass gauge shews the fluid divided by an air space into two columns side
by side which so long as the terminals are on a level surface will be seen in
equilibrium. Any difference of level in the position of terminals is at once com-
municated to the gauge through the syphon action which takes place when one
terminal is lower than the other. Thus by means of this apparatus the level of
nny two points distant from one another within the length of the tube can be
quickly & easily ascertained.
Dated this 19th day of March 1891
COMPLETE
SPECIFICATION.
An Improved Level.
1, HERBERT SPURRELL, of 2 Hartfield Rise, Eastbourne, Sussex, Architect,
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 has for its object an improved level.
This level is suitable for use by builders, masons, architects, engineers, mechanics
and others who may require to ascertain the difference of level between two
surfaces or points not very distant the one from the other. The instrument may
be described as consisting of two tubes in part flexible terminating in boxes or
reservoirs and containing two columns of water or liquid.
Above the tops of the liquid columns the tubes are connected so that the vertical
height of one column is always the same as the vertical height of the other column
above the liquid level in its respective box, although the height of both will vary
with the position of the boxes or reservoirs. The boxes being portable can be
placed wherever required. The boxes are similar and the water or liquid is made
to stand when adjusted for taking a level to the same depth in each so that the
indication given is also the difference in level of the surfaces on which the boxes
stand.
The apparatus is arranged so that it may be closed for transport and means for
adjustment are provided.
In order that my said invention may be fully understood and readily carried into
effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.

page_text: Figure 4 is similar to a portion of Figure 1 but with the parts in another position,
shewing the plug to be in a position for adjusting the instrument previous to
commencing to take a level.
Figures 5, 6 and 7 are sections on the lines A A, B B and C C of Figure 2
respectively.
Figure 8 is a plan and Figure 9 is a section of one of the boxes or reservoirs.
a a are two flat bottomed metal boxes: when in use these boxes contain water
which preferably is coloured. bare covers, they screw on and close the boxes
liquid tight. In each cover a tube is fixed dipping down some distance into
the liquid contents of the box and projecting upward to serve as a nozzle to receive
a flexible pipe of vulcanised india rubber. Each cover is also provided with a
vent passage fitted with a screw stopper e When the stopper is screwed home
the vent is closed but the vent can be opened by slacking the screw. dd are two
similar india rubber pipes of small diameter and convenient length, say one of five
feet and the other fifteen feet: they are connected with the tubes 4. e is a hollow
or tubular metal handle; the pipes d d pass up within it. is the shell or body
of a stop cock of peculiar construction and are nozzles on the shell which
receive the ends of the india rubber tubes d d. g is the plug of the cock. hare
glass tubes cemented air tight into sockets in the shell are passages through
the shell and plug which when the plug is in the position shewn in Figure 1 are
continuous with the india rubber pipes d and glass tubes h. are other passages
in the plug. At their upper ends the glass tubes are cemented into sockets in
a cap piece, there is a passage in the cap piece which establishes a
connection between the tubes h-k² is a screw plug which in adjusting the
instrument may be slackened to permit the entrance or the exit of air. 7 is a
guard screwed on to the shell to protect the glass tubes; it has windows
and slots cut in it on opposite sides so that the tubes may be seen side by
side through the windows. m is an outer metal tube also with slots in it;
this tube can be turned partly around the guard 7; it serves as a shutter to open
and close the windows for protection of glass tubes when the instrument is not
in use it also carries a moveable scale m'.
The apparatus is prepared for use in the following manner :-
The plug of the cock is turned to the position shewn in Figure 4. One of the
boxes a is then immersed in the liquid with which the apparatus is to be filled and
the other is placed at a lower level.
The vent stopper c are both slackened and by sucking with the lips at the
vent in the lower box the liquid is caused to siphon over. When the boxes are
full or nearly full they are placed close together on a level surface. The water
level in the two boxes then soon equalises. Next the gauge of the instrument
Figure is held upright with the lower ends of the glass tubes below the level
surface. The screw plug is slackened and the stop cock is turned to the position
indicated in Figure 1. The liquid now rises in both glass tubes to the level of
the water in the boxes which already has been equalised by the siphon action.
When the water or liquid level is in a convenient position and the liquid columns
equal in height the plug is screwed up tight and the apparatus is ready.
The heights of the columns in the glass tubes above the liquid levels in their
respective boxes a a are equal and will remain so if one of the boxes be raised
above the other.
For carrying the instrument from place to place the vent stoppers are screwed
in and the stop cock is turned to the position indicated in Figure 3 so that all the
passages in the plug are closed.
To ascertain the difference of level of two surfaces a box a is placed on each;
the vent stoppers are slackened and the top cock is turned to the position of
Figure 1 the difference of level of the liquid in the two glass tubes is then read
by the scale m counting the graduations of inches and 1th of an inch between
the heads of liquid columns which difference will be equal to the difference in level
between the surfaces on which the boxes stand.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed declare that what I
claim is :-
1. A level substantially as described consisting of two columns of liquid con-
tained in two tubes or channels connected at their upper ends and at their lower
ends terminating in two similar and separately moveable boxes or vessels; the
whole so arranged that difference of liquid level within the boxes or vessel may
be read from the upper surfaces of the liquid columns.
2. A level in accordance with the preceding claim and with means for adjustment
and for closing the instrument for transport substantially as described.
Dated this 12th day of December 1891.
HERBERT SPURRELL.