STANDARD - Survey Instrument Antique Center!

Mining Transit.
Interchangeable with Lamp Targets above Leveling Screws.
Telescope is mounted on standards as shown in cut of No. 3, with a double vernier
between the legs of the standard, and is provided with a striding level, see cut, page 156.
Compass Needle 3 3 /i inch.
The leading feature possessed by this instrument, as made by us, is that it can be interchanged
with the lamp targets above the leveling screws (see opposite page) so that after they have been set
up their relative position as to height and location will remain exactly the same upon being transferred
from one tripod to another. It is an instrument especially adapted to the work of an engineer
in mines, and as such involves a great deal of apparatus not possessed by instruments intended for
surface work. Two lamp targets are commonly supplied with an instrument of this kind, but frequently
one only is ordered, according' to the character of the work for which it is intended. The
vertical centers of the lamp targets have to be well fitted into the sockets of the leveling heads, and
in consequence they cannot be furnished separately. The engineer will therefore decide whether one
or two lamp targets are necessary for this work. The lamp targets are of the same height as the
transit measured from the base above the leveling screws to the line of sight, and each is provided
with two spirit levels. The targets can be revolved in the vertical and horizontal planes. By means
of a tubular sight, situated on top of the target, the latter can be readily set in the direction of the
instrument so that its face will lie at right angles to the line of sight. The lamps can be raised or
lowered at will, and can be detached whenever necessary. It is of the bull's-eye pattern, and the
best lard-oil only should be burned in it. A disc of milk-glass placed between it and the target
furnishes an illuminated background, against which the intersection and outlines of the target are
seen sharply denned. Made to order Qnly>
Weight of Mining Transit No. 7, about 11 Ibs.
one "
lamp,
Mahogany box containing instrument and one
"
lamp, target, etc., about 32
one Extension Tripod, about 9 J Ibs.; two " "
Tripods,
19
Gross weight of instrument, complete, packed securely for shipment in 2 boxes, about 70 Ibs.
Ibs.
"
S-aJ " |51
three
"
. Tripods,
... 28* "
alt \ Gross weight of instrument, complete, packed securely for shipment in 3 boxes, about 120 Ibs.
| [ Weight of Mahogany box, containing instrument only, about . . . . 22
" " "
2
"
lamps, targets, etc., .... 26
No. 7 Mining Transit, size as in Transit No. 6, but with one lamp
target as shown on opposite page; graduations on solid silver; verniers reading to
minutes are provided with ground-glass shades; 5-inch full vertical circle; aluminum
guard; spirit level, clamp and gradienter screw to telescope; illuminator shade;
striding level and fixed stadia wires, telescope mounted as shown on page 156, 2 extension
tripods, 2 plumb bobs, etc. Lamp target packed in instrument-box.
Price, $38O.OO
No. 7a. Mining Transit, as above, but with 2 lamp targets, both packed in
separate box, 3 extension tripods, 3 plumb bobs, etc. Price, $4GO.OO
Mining Transit No. 7b. with Yoke Standards.
No. 7b. Mining Transit, as shown hi cut, with yoke standards, compass
with 2^-inch needle; 5-inch fully protected vertical circle with face graduation;
double opposite verniers reading to minutes, glass covered; interchangeable auxiliary
telescope, Style I; striding level; stadia wires; illuminator shade; gradienter; adjustable
center for accurately centering instrument from a point above; one lamp
target packed with instrument in one box; two extension tripods; two plumb bobs.
Weight, size, etc., as above in Transit No. 7. Price, $492.OO
No. 7b. Mining Transit, as above, but with two lamp targets both packed in
separate box, three extension tripods, three plumb bobs, etc. Price, $ 572.OO
For price of extra attachments, see Extras to Mining Transits, page 188.
NOTE. To interchange the instrument and the lamp target proceed as follows: First withdraw
the spring bolt of the lower clamp for the outer center by means of the small milled-headed nut at the
end of the clamp opposite the tangent-screw. Then loosen the clamp screw immediately above the
leveling head. Now upon pulling back the spring bolt, situated at the side of the clamp, the instrument
or the lamp can be detached by lifting it out of the socket in the leveling head. These sockets
as well as the clamps, which serve to fasten the instrument or lamp target to the leveling head,
should be kept free from dirt or grit. After clamping the instrument to the leveling head, to prevent
any motion in its socket, and then releasing the small milled-headed nut from its fastening on the
spring bolt of the lower tangent-screw, the transit is ready for work and can be manipulated the
same as other instruments of our construction.
For adjustment of the transverse striding level, see page 56.