Year: 1886

page_text: We, CHARLES GRAM SMITH, residing at, 329, Massachusetts Avenue, N.E. in
the City of Washington, District of Columbia; EDWARD WARREN, residing at,
728, Fifth Street N.W. in the City of Washington, District of Columbia; and
CHARLES HENRY WARREN, residing at, 728, Fifth Street, N.W. in the City of
Washington, District of Columbia, all in the United States of America, Bricklayers
do hereby declare the nature of this invention & in what manner the same is to
be performed, to be particularly described and ascertained in & by the following.
statement:
i
This invention relates to certain improvements in engineers instruments and it
has for its object to provide a device, whereby an exact horizontal or vertical line
may be established, and the relative horizontal positions of separate or distant
objects accurately and conveniently established as more fully hereinafter specified.
These objects we attain by the means illustrated in the accompanying drawings,
in which,-
Figure, 1, represents a perspective view of the improved implement with a
portion broken away showing the interior of the same.
Figure, 2, represents a longitudinal vertical sectional view of the same showing
the recess partition and pivoted platform as dispensed with.
Figure, 3, a front elevation of the same, &-
Figure, 4, is a sectional view taken on the line, x,-x, of figure, 2.
The letter, A, indicates a beam or oblong block of wood or other material, which
is formed with straight edges at the sides, bottom, top and ends, so that when
applied to an object, such as a building or other structure, it will determine the
horizontal or vertical lines thereof.
In the upper part of said beam or block is a recess, B, in which is located a spirit
level, C, which is mounted on bearings, D,' which are secured in the recess by means
of the screws, E, and may be made adjustable if desired.
The said recess is covered by a slotted plate E¹, secured to the top of the beam
in any suitable manner. The forward portion of the beam or block is hollow, or
is provided with a longitudinal rectangular recess, G, which is open at the forward
end, and at its rear end has an inclined mirror, H, set at an angle of, 45° and
above said mirror the recess is provided with a plate, I, having a transverse.slot, J,
the said plate being capable of longitudinal adjustment, by means of a set screw, K,
L
Vivian 977

page_text: in such manner that when any object, reflected upon the mirror through the front,
may be seen through the upper slotted adjustable plate, the relative horizontal
positions of the object to which the instrument is applied, and the distant object
will be accurately ascertained or had..
To provide for conveniently sighting distant objects and at the same time
aligning the same, we divide the front recess of the beam or block, by a vertical
horizontal partition, L, on each side of which is pivoted a platform, M, which
swings freely upon its pivots.
At one side of the upper portion of the partition dividing the forward recess of
the beam or block are formed vertical grooves, N; N; in which are adapted to slide
the diaphragms, P. ·
These diaphragms, P, have a semi-circular recess, R, at their lower edges, through
which the rays of light may pass, from the front to the mirror, at the rear, and
thence be deflected upward at an angle of 45° through the slotted opening in the
adjustable plate before mentioned.
To the front of the beam or block is secured a vertically adjustable plate, S,
which is slotted and confined by means of a set screw, T. The front ends of the
pivoted platforms, before mentioned rest upon the upper edge of this plate, and
the plate is graduated as indicated by the letter, U, so that it can be adjusted to
regulate the position of the platforms, M, in sighting distant objects above a given.
horizontal plane, and at the same time by means of the graduations to determine
the angle formed between said horizontal plane and the platforms. By this device
the angle formed between any two objects in different planes may be readily
determined from a given point, as will be readily understood. The said plate
may be also provided with a mark, V, near one edge, and the front edge of the
instrument graduated, as indicated by the letter, W, for the same purpose.
Near the rear, the beam is provided with a transverse aperture, X, at one side
of which is adjustably secured a spirit level, Y, by means of the slotted plates, Z,
which are confined by the set screw, A¹, so as to adjust the level parallel with the
end of the beam or block; and thus ensure perfect accuracy.
The operation of the instrument is as follows.
For ordinary work the instrument is used as a spirit level, but for determining
the angular elevation between distant objects, it is located on one object, and the
bearings of the distant object taken by working through the slotted top plate, and
adjusting the forward plate until the pivoted platforms are brought to such
positions that a reflection from the mirror is obtained through the slot in the upper
plate the deviation of which from a horizontal line, will be determined by the
graduations at the front, which will give the exact angle.
The object is first sighted through the passage to the left of the figures in the
drawing, which being free and unobstructed, permits the sight to be readily
obtained, and when this is effected the final sighting is accurately made through
the passage at the right and the recess under the diaphragms therein. The upper
slotted plate which is adjustably secured above the recess in which the inclined
mirror is located when properly adjusted to its normal position has the front edge
of the slot coincident with the front edge of the recess, or flush therewith.
As the swinging platforms have their forward edges resting upon the upper edge
of the adjustable plate at the front of the block or beam, it will be evident that
when the plate is raised or lowered for angular adjustment and measurement that
the platforms and the diaphragms will be correspondingly moved.
In sighting objects and determining the height of the said object, or the distance
of the same from the horizontal line passing through the object sighted from a
suitable marker as a pencil is placed across the face of the object at the proper
height, so as to clearly indicate the point by reflection in the mirror, which is
determined when the reflection of the object comes on line with the edges of the
upper plate and bevel recess before mentioned.
Then all that is necessary to determine the level of the objects is to deduct or
add the height from the base of the block or beam, to the point of the angle of

page_text: reflection of the mirror, when the common horizontal line of the two objects will
be accurately obtained.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that
what we claim is
1. The combination of the beam transversely apertured, and a spirit level located
within said aperture, with slotted plates supporting said level, and adjustable
lengthwise of the beam, and means for securing said plates in an adjusted position
as and for the purpose set forth.
2. The combination with the block or beam having recess at its forward end,
and a vertical partition dividing the same of the mirror located therein at an angle
of 45° whereby distant objects may be reflected upward through a suitable opening
for ascertaining their relative horizontal level as specified.
3. The combination with the block having an open recess at its forward end,
and the inclined mirror, of the vertical partition, the pivoted platform to each side
thereof, and the vertical diaphragms, whereby angular adjustments and measurements
are effected, substantially as described.
4. The combination with the beam or block, having an open recess at its forward
end communicating with a transverse opening at the top of the inclined mirror,
and the adjustable top plate or diaphragm arranged above the mirror over the
transverse opening, substantially as described.
5. The combination with the beam or block having an open recess at its forward
end and a transverse opening in its top, of the adjustable slotted plates, and set
screw, and the graduations whereby angular measurement may be determined,
substantially as described.
6. The combination with a level having a recess at its forward end vertical
grooves on either side of said recess, and a transverse opening leading into said
recess of the inclined mirror, and adjustable slotted plate for said transverse
opening, vertically sliding diaphragms having recesses, the pivoted platforms, and
a vertically adjustable plate supporting the forward end of said platforms, the
whole being constructed, arranged and operated substantially as and for the
purpose specified.