STANDARD - Survey Instrument Antique Center!

03
192
Complete Mining Transit No. 6D, without Compass.
Shown with our Patent Interchangeable Auxiliary Telescope. Style I.
(See pages 95 and 96.)
Responding to many solicitations to make for mines containing magnetic ore,
or an electric plant, a transit similar in style and accuracy to our No. 11 (see page
180), we have designed the instrument illustrated on opposite page. It is light,
portable, and of the same size as our Nos. 4, 4 1
/4, 2 and 6 transits; but, owing to the
. . omission of the compass, the standards are cast in a single piece, affording greater
"
lateral stiffness, with increased capability to withstand rough treatment. It is,
adapted to all the complex conditions prevailing in underground work, and is very
simple in style and manipulation. It possesses all the advantages, as regards
accuracy of division, highest permissible telescopic power, and sensitive spiritlevels
of larger instruments. With the interchangeable auxiliary telescope added
for use in steep sighting, either on top or on the side of the main telescope, as
required, it becomes a most capable instrument for correctly solving what would
otherwise require special instruments and methods. When the auxiliary telescope
is detached, it is just as applicable to the common work in the mine or on the
surface as our regular engineers' and mining transits Nos. 4, 4 1
/, 2 and 6.
The U-shaped, standard frame of the telescope is made of aluminum, covered
with a fine dark Japan not affected by moisture; all other parts are finished in the
same manner as in our other instruments. The plate-levels are of our standard character
and length, mounted directly upon the upper plate, where they are easily accessible
for the purpose of adjustment and ready observation, and are fully protected
from falling bodies. The principal plate-level is directly under the eye-end of the
telescope. The two opposite verniers of the horizontal circle are in line of sight with
"3 So the telescope, and are protected from dripping water by cemented glass covers. The
circle itself is provided with two rows of figures from to 360, in opposite directions,
with double verniers to correspond to them (unless otherwise ordered). The
M a & vertical circle, with figures from to 180, both ways from zero, has a double ver-
"2|^ nier, to enable the observer to read angles of elevation or depression with equal
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