STANDARD - Survey Instrument Antique Center!

162
64 SURVEYORS' TRANSIT No. 1 s.
With Compass, Yoke Standards and Wye-Bearings.
It is well known that in Transits with compass (styles Nos. 1, 2, 3, 4, 5 and 6) the
strength required for the standards to support the telescope, and to prevent the latter from
shifting laterally in the bearings, is derived mainly from the vernier plate and its compass
ring as a base, from the rigidity ot the standards themselves and their width apart, and
last but most important from the peculiar shape of the pivot-ends of the horizontal
axis of revolution, which latter prevents both of the standards from swaying to and
fro. Ingenious and time-honored as this construction is being exemplified in many
thousands of instruments it cannot compare in degree of accuracy with that afforded
when the ends ot the telescope's axis are of cylindrical form running in wye-bearings, provided
the necessary upright and lateral stiffness can be obtained in the standard frame.
The Yoke standard frame, shown in the cut on opposite page, is of great strength combined
with lightness, and enables to successfully mount the telescope's axis by means
of cylindrical pivots in wye-shaped bearings. The motion of the telescope in the vertical
plane is therefore entirely free from such defects, as deflection of the line of sight, etc.,
noticed in the older styles, when caused by wear and strain. To obviate this, has been
the object of introducing the yoke frame common in all our triangulation Transits
but having a compass mounted in the central portion of its base. With this arrangement
the surveyor is now placed in possession of an instrument whose chief features
have no superior in point of accuracy, fine workmanship and thorough adaptation to his
needs. The telescope reverses through the standards only. The Yoke frame will be
leather-finished; all other parts will be polished and lacquered. The whole instrument
has a fine appearance.
Transit No. 1 S, as in cut (for size, weight and particulars, see Transit No. 1 ,
page 150); graduation of horizontal circle on solid silver, double opposite verniers
reading to minutes; 5-inch vertical circle with one double vernier reading to minutes, at
eye-end; graduation on solid silver; aluminum guard; glass shades over verniers; llf-inch
erect telescope with 1^-inch aperture, power 24- diameters, long spirit-level to telescope;
fixed stadia wires; 3 T 9
^-inch magnetic needle with variation plate; etc.
Made to order only.
Price $3OO.OO
Code Word Buxota.
Extras to Transit No. 1 s.
Horizontal circle graduated to read to SO", extra . .10.00
" " "
20"
"
. 20.00
This transit can be made with inverting telescope when so ordered; length 12 inches,
clear aperture 1 f inches, power 28 diameters. No extra charge.
If desired with inverting telescope add to the code word " Invert."
5s" SURVEYORS' TRANSIT No. 2 s.
Horizontal circle 5% in. at edge of graduation.
Tnaiisit No. 2 s (size, weight -and particulars as in No. 2, page 168), but with
magnetic needle 2*/" long, variation plate; otherwise with same features as for
No. 1 S above. Made to order only
Price $3OO.OO
Codeword Buylis.
This instrument with inverting telescope, add to the Code Word "Invert."
Transits No. 1 s and No. 2 s, enumerated above, may have a 5" vertical
arc, with the verniers between the Yoke standard frame instead
of the full vertical circle with the verniers at eye end.
Price $280.00
Code Word, Transit No. Is . Buzada.
" Transit No. 2s Buzemo.
For prices of solar attachments, etc., see pages 172 to 175.