IMPROVEMENTS IN SPIRIT LEVELS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said Robert Sutcliffe at the
Office of the Commissioners of Patents on the 2nd December 1880.
ROBERT SUTCLIFFE, of Castle Mills, Idle, in the County of York, Spinner.
"IMPROVEMENTS IN SPIRIT LEVELS."
This Invention has for its object the construction of spirit levels which will
indicate the degree of inclination of surface being graduated, and having screw
adjustment whereby the degree of inclination may be compensated for and
recorded.
Levels constructed according to this my said Invention consist of a tube or
spirit receptacle, the ends of which are turned upwards or at right angles to the
main tube; the vertical parts are graduated with a "scale," so that on the level
being applied to a surface not horizontal the spirit in the vertical tube at one end
will sink and rise in the vertical tube at the other end, and by the scale shew the
degree of inclination. Under the level are adjusting screws by means of which
the level may be set "true," the screw recording the degree of fall within the
length of the level.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Sutcliffe in the Great Seal Patent Office on the 1st June
1881.
ROBERT SUTCLIFFE, of Castle Mills, Idle, in the County of York, Spinner.
"IMPROVEMENTS IN SPIRIT LEVELS."
This Invention has for its object the construction of spirit levels which will
indicate the degree of inclination of surface being graduated.
Levels constructed according to this my said Invention consist of a tube or
spirit receptacle, the ends of which are turned upwards or at right angles to the
main tube; the vertical parts are graduated with a "scale," so that on the level
being applied to a surface not horizontal the spirit in the vertical tube at one end
will sink and rise in the vertical tube at the other end, and by the scale shew the
degree of inclination. Under the level are adjusting screws by means of which
the level may be set "true," the screw recording the degree of fall within the
length of the level.
Such being the nature and object of this my said Invention I will now proceed
to describe the same in detail, and in order that the same may be fully understood
I have hereunto annexed a Sheet of Drawings illustrative thereof, and have marked
the same with Figures and letters of reference in which
Fig. 1 is a longitudinal section of a level constructed according to this my said
Invention; Fig. 2 is an end elevation, and Fig. 3 a plan view; A is the case or
wooden box in which the lower part of the rectangular fluid tube B is embedded
and held; the vertical parts of the tube C have marked thereon the datum lines
D, D, which lines are truly parallel to the base A of the level; the upper part of
the tube B form the air space, secures equilibrium of air pressure with the air
space and the two vertical columns, whilst the cover or rounded form of air space
prevents any lodgment of spirit when the level has been overturned. It will be
understood that the recording columns need not of necessity to be vertical but by
preference.
Having thus fully described the nature and object of this my said Invention,
together with the manner in which the same is to be or may be performed or
carried into practical effect, I would have it understood that I claim as my
Invention,―
The construction of spirit level, as herein described and illustrated by Drawings.
In witness whereof, I, the said Robert Sutcliffe, have hereunto set my hand
and seal, this Twenty-seventh day of May, in the year of our Lord One
thousand eight hundred and eighty one.
PAR
CHAT THIN