STANDARD - Survey Instrument Antique Center!

123
C. I,. BKRGEK & SONS. BOSTON
Road Builder's
MONITOR TYPE DUMPY LEVEL.
A sturdy, compact instrument of smaller size and less weight than our
14^" Monitor Type Dumpy L,evel.
This instrument has been designed by us to meet a growing want for the highway
as well as for the Drainage Engineer. The degree of accuracy obtained with
it is commensurate with the work required. The telescope is erecting and has
lenses of perfect definition with a large flat field of view and is balanced from the
center with Sunshade attached. The eye-piece cap is large in diameter and made so
that it affords a protection to the observer's eye in a glaring sun. It has been combined
with a dust-guard which fully protects the eye-piece focussing slide.
The spirit level is very sensitive and is mounted on top of the telescope. It is
protected by a revolvable tube to act as a guard to prevent breakage when not in use.
The leveling head is of a single casting of improved form, so that the center will
not bind in the socket from any strain exerted by the four leveling screws which latter
are protected from injury and dust.
We have adopted for this level Our standard long stout center with which all of
our instruments have been identified, thus adding to its Stability.
This level will withstand rough treatment. The adjustments are few,* when
once made they are lasting and above all the instrument is dependable at all times
and free from any tremor even in a strong wind. Its rounded forms, together with
the fine, dark and durable wear resisting leather finish applied to the exterior
surfaces, appeal to anyone in sympathy with advanced instrument design.
SPECIFICATIONS :
Telescope Erecting" 12 inches long, aperture 15i", power 24 dia. Focussing
slide very long and provided with a dust guard.
Eye-piece with large flat field of view, provided with an improved screw
arrangement permitting to focus the wires by simply turning its head slightly
to right or left.
Spirit Level 5% inches long between centers of suspending arms. The spirit
level is very sensitive and accurately ground to a true curvature and barrel
shape.
Center of hard bell metal.
Mahogany box provided with strap, lock, and hooks, contains sunshade
wrench, scre\vdriver and adjusting pins.
Weight of Instrument 7 Ibs. Weight of tripod about 9 Ibs.
Gross weight of instrument securely packed for shipment in two boxes about
35 Ibs.
Code word: Oleaster. Price as above $75.OO
Extras to 12" Monitor Type Dumpy Level.
Stadia Wires fixed in ratio 1 : 100 *3.oo
Gossamer water-proof bag to protect the instrument in case of rain or dust i.oo
Bottle of fine watch-oil to lubricate the lever center .... .35
* The above instrument, being of the Dumpy level type, has to be adjusted by the two peg