STANDARD - Survey Instrument Antique Center!

212
Triaiigulatioii Transit- Theodolites.
For use in Cities and in Bridge and Tunnel Construction, etc.
Since the introduction by us in 1875 of this style Transit with Yoke standard frame
cast in one piece and mounted directly on the top flange of the inner center, the demand
for them in all lines of engineering requiring high accuracy lias attained so great
a magnitude, on account of their excellence, as could not be foreseen at that time.
Many of these instruments are in use in the survey and triangulation of our largest
cities, and are giving great satisfaction. Many also have been supplied to Colleges and
are in use in State and Boundary Line surveys.
The great lateral stiffness attained by this form of standard frame enables to make
the trunnions of the telescope's axis cylindrical and to mount them in wye-bearings,
thereby securing to the telescope the most .accurate movement in the vertical plane
known. The telescope reverses through the standards as usual and over the bearings.
The trunnions are protected by dust-caps, and wherever possible capstan-headed
screws will take up any looseness between these dust-caps and the trunnions.
These Transit-Theodolites are made with three or four leveling screws.
No. 11. Plain Transit-Theodolite, with four leveling screws, as in cut,
on opposite page, but without level, clamp and tangent screw, vertical arc, or strid-
ing level to telescope ; in all other respects as in cut of No. 1 Ic. Specifications :
horizontal circle 6 finches, single opposite verniers, as in fig. 5 page 38, read-
ing to 2O", glass protected graduation and verniers, one row of figures to 360
clockwise 12-inch ; inverting' telescope, aperture 1^ inch, power 28 diameters,
achromatic eyepiece ; telescope is reversible over the bearings, as well as through
the standards ; long compound centers of hard bell-metal ; shifting center ; splitleg
tripod; aluminum standard frame leather-finished; mahogany box with
screw-driver, reading glass, adjusting pins, etc.
Code word, Mobax
Made to order only.
If instrument is desired with an erecting telescope of 24 diameters, add to code
word "erect."
\Veight of instrument, about 14 Ibs. Weight of tripod, about 10 Ibs.
Gross weight packed in two boxes, ready for shipment, about 60 Ibs.
Price of Plain Transit-Theodolite No. 11, as above, with four
leveling screws $225.OO
Extras to Plain Transit- Theodolite No. 11.
Three leveling screAvs with shifting: center (see page 52) . . - .15.00
7-inch horizontal circle reading to 10" by single opposite verniers, single
row of figures to 360 clockwise
Heading; glasses to horizontal circle (should always be ordered with instrument
reading
30.00
to 10")
Reversible clamp and tangent screw to telescope, but without level to
15.00
latter
15.00
6-inch spirit level with reversible clamp and tangent screw to telescope . 30.00
3-inch striding level, as in cut, to rest on special collars to revolve through
the standards
20.00
5-inch striding level resting at points of contact in wyes, see page 214 . 30.00
5-inch vertical arc, as in cut on opposite page ....... 20.00
5-inch full vertical circle, (as in cut page 214) but with only one double
vernier reading to minutes at eye-end reversible ; tangent screw . . 45.00
5-inch vertical circle, see cut page 214, double opposite verniers reading
to minutes, reversible tangent screw ........ 50.00
3-inch level to vernier frame of vertical circle, see cut . page 214 . . 8.00
Two reading glasses to vertical circle, see cut page 214 . . =10.00
Stadia wires, fixed, ratio 1:100 .... . 3.00
Gradi enter screw . . . . . . . . . . 5.00
Center of instrument of steel running in a socket of cast iron, for instrument
with three leveling screws, having no compass
Oblong compass mounted on vernier plate at side of standard, with motion for
setting off the variation (three-inch needle reads only a few degrees each way
from zero) [For instruments with bell-metal centers only] ...., .
20.00
15.00