AN IMPROVED INSTRUMENT FOR ASCERTAINING AND DENOTING THE ANGLE, INCLINATION, OR DIP OF MINERAL STRATA, THE GRADIENTS OF RAILWAYS, OF ROADS, AND THE SLOPE OF PLANES GENERALLY
Year: 1878

page_text: LETTERS PATENT to William Fairley, of Chester-le-Street, in the County of
Durham, Mining Engineer, for the Invention of "AN IMPROVED INSTRUMENT
FOR ASCERTAINING AND DENOTING THE ANGLE, INCLINATION, OR DIP OF
MINERAL STRATA, THE GRADIENTS OF RAILWAYS, OF ROADS, AND THE SLOPE
OF PLANES GENERALLY."
Sealed the 20th September 1878, and dated the 29th March 1878.
PROVISIONAL SPECIFICATION left by the said William Fairley at the
Office of the Commissioners of Patents on the 29th March 1878.
WILLIAM FAIRLEY, of Chester-le-Street, in the County of Durham, Mining
Engineer. "AN IMPROVED INSTRUMENT FOR ASCERTAINING AND DENOTING THE
ANGLE, INCLINATION, OR DIP OF MINERAL STRATA, THE GRADIENTS OF RAILWAYS,
OF ROADS, AND THE SLOPE OF PLANES GENERALLY."
The object of my Invention is to simplify and improve the means employed for
ascertaining and denoting the angle, inclination, or dip of mineral strata, the
gradients of railways, of roads, and the slope of planes generally.
My Invention consists of a rule or straight edge properly graduated and made
to receive "snug" one or more slides, also graduated.
The top edge of the rule carries a spirit level, and near one end there is a narrow
aperture, through which is pushed, when the instrument is in operation, one of the
aforesaid slides.
To use the instrument the bottom edge of the rule is placed upon the sloping
plane, whose angle or inclination it is desired to ascertain. One of the slides is
withdrawn from its recess and thrust through the aforesaid aperture. That end of
the rule (the other end being held upon the inclined plane) is now raised up the
slide until the spirit level shows the rule to be level, the slide being perpendicular
and supporting the rule in a horizontal position upon the sloping plane, which latter
represents the secant, the perpendicular slide, the tangent, and the rule, the radius

page_text: of the angle the inclined plane forms with the horizon. This angle may be read
on the graduated slide in degrees and minutes, or in ratios, at the discretion of the
observer.
To ascertain obtuse angles a second slide is employed in combination with the
former.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Fairley in the Great Seal Patent Office on the 28th September
1878.
WILLIAM FAIRLEY, of Chester-le-Street, in the County of Durham, Mining
Engineer. "AN IMPROVED INSTRUMENT FOR ASCERTAINING AND DENOTING THE
ANGLE, INCLINATION, OR DIP OF MINERAL STRATA, THE GRADIENTS OF RAILWAYS,
OF ROADS, AND THE SLOPE OF PLANES GENERALLY."
The object of my Invention is to simplify and improve the means for ascertaining
and denoting the angle, inclination, or dip of mineral strata, the gradients of
railways, of roads, and the slope of planes generally.
My Invention consists of a rule or straight edge properly graduated and made
to receive "snug" one or more slides, also graduated.
The top edge of the rule carries a spirit level, and near one end there is a
narrow aperture passing vertically through the rule, and through which is pushed,
when the instrument is in operation, one of the aforesaid slides.
To use the instrument the bottom edge of the rule is placed upon the sloping
plane, whose angle or inclination it is desired to ascertain. One of the slides is
withdrawn from its recess and thrust down through the aforesaid aperture. That
end of the rule is now raised up the slide until the spirit level shews the rulo
to be level; the other end being held upon the plane, the slide assumes a per-
pendicular position and supports the rule horizontally upon the sloping plane. In
this position the sloping plane represents the secant, the perpendicular slide, the
tangent, and the rule, the radius to the angle the plane makes with the horizon.
This angle may be read upon the graduated slide in degrees and minutes, or in
ratios, at the discretion of the observer.
To ascertain angles ranging from 45 degrees to 90 degrees, a second slide is
employed in combination with the former, as will be herein-after more particularly
described.
I will now proceed to describe my Invention more fully by the aid of the
accompanying Drawing, reference being had to the letters and figures marked
thereon.
Figure 1 is a front view of the instrument which I call a "gradometer," and
Figure 2, the same instrument employed in measuring an acute angle of 32 degrees;
Figure 3 is an end view of Figure 2.

page_text: In all these Figures A is the straight edge or rule provided with a level b; cand d
are the two slides, lying snug, when the rule is carried in the pocket within recesses
formed in the face of the rule.
The slide d is graduated as shewn to indicate the angle or gradient of a slope
from 0 degrees to 45 degrees, and the face of the rule graduated for angles varying
from 45 degrees to 90 degrees, the other side of each being graduated to suit the
requirements of any individual case or shewing the ratio of the horizontal distance
to the vertical height.
The mode of employing my "gradometer" would be as follows:-The slide d is
withdrawn by aid of the thumb hole i from its recess, and passed vertically through
the slit e (shown by dotted lines in Figure 1), and the rule placed upon the sloping
plane m, n, Figure 2, the spirit level being uppermost. The slide is then pressed
upon the plane and the rule gently raised until the spirit level b indicates its
arrival to a horizontal position. The instrument may then be removed, reversed,
and the angle or gradient, whichever may be required, read upon the slide, and is
indicated by the length of slide passed beyond the bottom edge of the said rule.
The said slide is prevented moving or shifting its position by means of a small
spring within the vertical aperture (also shown by dotted lines).
Should however the slope of the plane exceed an angle of 45 degrees, then the
said slide must be pushed up the socket f, see Figure 4, which performs the duty of
a holder. The slide c is now drawn out in the direction of the arrow until the
spirit level indicates that the instrument is in a horizontal position. The distance
thus travelled by the slide would be indicated by the front edge of the slide d
coinciding with one of the divisions of the scales cut upon the faces of the rule
and thus denote the angle of the slope or the ratio of the horizontal distance to the
vertical height.
My Invention is equally well adapted as a railway gradient staff. In that case
the rule or straight edge may be longer, say six feet, to indicate more conveniently
the gradient, and the slide, say about twelve inches long, divided into one hundred
parts. Then as the length of the rule from the toe to the edge of the slide is to the
length of the exposed portion of the slide, so is the horizontal distance to the
vertical, or inversely, as may be required.
Having now described the nature and object of my said Invention, together with
the mode of carrying the same into effect, I would conclude by observing that what
I claim as my Invention secured to me by the above in part recited Letters Patent
is, the arrangement and construction of an instrument or instruments, substantially
in the manner and for the purposes herein described, or any mere modifications
thereof.
In witness whereof, I, the said William Fairley, have hereunto set my hand
and seal, this Twenty-seventh day of September, in the year of our Lord
One thousand eight hundred and seventy-eight.
WILLIAM FAIKLEY, (LS.)