STANDARD - Survey Instrument Antique Center!

^ 188
t4
Mining Transits.
All of the foregoing instruments, particularly Nos. 2, 4V and 49 we recommend
2 for. general underground work. (The latter instruments chiefly on account of their
grea'ter portability and lightness.)
The telescope may be either inverting or erect,
and may have a prism attachable to the ordinary erecting or inverting eye-piece to
facilitate sighting in inclined shafts. We frequently attach to the cross-axis a side
telescope, swinging free of the plates, of nearly the same length and power, which per-
5 mits of vertical sighting up or down a shaft (see pp. 93 to 95). We also furnish at-
^ tached above and parpllel with the line of sight of the main telescope of Nos. 4, 4!,
5 and 6, another one of shorter length and lesser power mounted on a central pillar cast
on to the cross-axis of the main telescope, as in Style I. (See interchangeable auxil-
S iary telescope, pp. 189, 192, 193, 95 and 96.)
This latter telescope, which of necessity is of lesser power as compared with our
35 regular side telescope, will in most cases be deemed sufficient, as sights in mines are
short. Its power varies from 8 to 15 diameters, according as the telescope is erecting
* or inverting. We are, however, prepared to mount one of same length as our regular
;J side telescope in cases where a complete revolution of cross-axis is not required. It
* will be seen that vertical sighting up or down a shaft can be done with ease and accuse
racy, and this latest device has nearly all the advantages of a telescope mounted on in-
S, dined standards with none of its faults. When not in use the auxiliary telescope may
% be removed at will and stored in the box. As will be seen by reference to the description
and cuts of this device, pp. 95, 96, and 189, the auxiliary telescope can also be
/, 5
Sc readily attached to the end of the cross-axis of our Mining Transits Nos. 4, 4 1
A and O when it becomes a side telescope.
^3
a
The ready Intel-changeability from top to side makes the auxiliary telescope one of the most
desirable additions to a Mining Transit.
To avoid errors in reading cardinal points, the compass ring is "3
?3
figured from to 360, the same
as the horizontal circle. Mining instruments should have large vernier openings to admit of as much
light as possible, and all graduations should be on solid silver. For the illumination of the crosswires,
a small reflector is sometimes placed in the center of the cross-axis of the telescope of our
larger instruments; but as in the smaller telescopes much light is 5
being cut out by its use, we prefer
to attach a reflector shade in front of the object glass .
No. 5. Mining Transit. Dimensions as in No. 1 (unusually large size);
graduations on solid silver; verniers reading to minutes are provided with ground glass
shades; 5-inch full vertical circle with aluminum guard; spirit level, fixed stadia wires,
j- clamp and tangent screws to telescope; extension tripod, etc. Price, $26O.OO
y
~j
No. 6. Mining Transit. Dimensions as in No. 2 (customary size);
graduations on solid silver; verniers reading to minutes are provided with ground glass
shades; 5-inch full vertical circle with aluminum guard; spirit level, fixed stadia 1
wires,
clamp and tangent screw to telescope; extension tripod, etc. Price, $26O.OO
Extras to Mining Transits Nos. 4, 4!, 5, 6 and 7
6
* Striding level (for description and illustration, see pp. 156 and 211)
Stadia wires, fixed
$20.00
3.00
* Disappearing cross and stadia wires for erecting telescopes (p. 190). Patented .
. . 6.00
Gradienter attachment for Nos. 5 and 6
iff
. Five-inch vertical circle provided with double opposite verniers (see p. 155) .... 20.00
2 Edge graduation for vertical circle with a double vernier at eye-end, which is glass-covered,
- extra 35.00
jS
as in - cut (p. 198)
Edge graduation for vertical circle with double opposite verniers (p. 198) extra 45.00
3 Patent short focus lens (pp. 103, 101). No. 1, $8.50; No. 2, $8.50; Nos. 1 and 2 . . . 16.00
'35 Reflector for illuminating the cross-wires 4.00
fl Aluminum guard to vertical circle ....
4.00
g Prism, attachable to eye-piece ....
* Detachable side telescope with counterpoise (pp. 189, 193)
"
Patent interchangeable auxiliary telescope. Style I, described on p. 96 and shown on p. 193 37.00
53 Berger Solar attachment with small telescope (pp. 172-173) . . 52.00