STANDARD - Survey Instrument Antique Center!

Code word . . Oakadum.
119
Spirit-Level on Metal Base.
Ground Spirit-Level, one division of level about 20 sec. of arc ; mounted on
8-inch metal base, provided with a handle. Level adjustable. In case.
Price, $14.OO
These levels are extensively used in machine shops for leveling up and testing
fine machinery, etc., also used for leveling up apparatus in observatories, physical and
chemical laboratories, and for setting weirs, etc.
Code Word Oakesia.
Brass or nickel-plated.
Locke's Hand-Level.
In case Price $8.OO
NOTE. This consists of a brass tube 6 inches long, with a small level mounted on its top to the left of its
center near the object end. Underneath the level is a horizontal wire stretched upon a frame. This frame is
made adjustable by a screw and a spring working against each other, or by two opposing screws placed at the ends
of the level mounting. In the tube directly below the level is placed a totally reflecting prism, acting as a mirror
set at an angel of 45 to line of sight. The images of the bubble and wire are thus reflected to the eye.
The prism divides the aperture in two halves, in one of which is seen the bubble and wire focussed sharply by
a convex lens placed in the draw tube, while the other permits of an open view. Putting the instrument to
the eye and raising and lowering the object-end until the bubble is bisected, natural objects can be seen through
the open half at the same time, and approximate levels can then be taken. To prevent dust and dampness
from entering the main tube, both the object and the eye ends are closed up with plain glasses. la preliminary
work this is a very useful instrument.
Hand-Level and Clinometer.
Abney Level and Clinometer.
Price $14.OO.
NOTE. This instrument is similar to the Locke's hand-level, but the small spirit level mounted on top
can be moved in the vertical plane and clamped to a dial graduated in single degrees, thus the angles of slopes,
etc., can be measured also.
Code Word . . . Oleander.