| A very rare Francis Whiteley
Patent Surveying Quadrant, circa 1836. (see Charles Smart:
American Surveying Instruments Since 1700, page 165.) The
instrument measures 12.5" in length and is built upon very
heavy stock of brass. The instrument incorporates a complex
ensemble of functions which include: 4-sight vanes, a magnetic
compass box, scales, counters, reduction tables, bubble levels
and outkeepers. The original patent describes an, "improvement
in surveying instruments" for field surveying and capable of
being used on the tripod in either horizontal or vertical
setup to take both magnetic and non magnetic angles, to record
vertical angles and then calculate trigonometric functions to
reduce the distance to horizontal. Aside from the reduction
tables engraved on the quadrant face, the instrument has two
out-keepers, one on each arm, and an L-T (links and tenths)
computing table on one arm (the latter table shows influence
the Virginia maker Goldsmith Chandlee and his L-T tables that
are present on most of his compasses). The compass needle and
box may be removed and is attachable on either arm; note the
bubble level on the quadrant may be read while the instrument
is in use in both vertical and horizontal arrangement.
Of the seven known examples, this is number 116. All but
one of the seven instruments is marked with a serial number;
all numbers are greater than 100 which may indicate the
numbering sequence started at 100; it is probable that this is
the 16th example of this patent instrument. (Many early
American makers, including Wm. J. Young, starting serial
numbers sequences with a large number thus exaggerating
production quantities). The quadrant is extensively marked
with this number 116, all 4 sight vanes, the base, compass,
frame and many screws are marked. This marking may suggests a
combination of batch numbers and serial number.
A very rare Whiteley Quadrant/trigonometer in fine
condition. I am offering this instrument from my private
collection; aside from the Hanks Bow Compass and the Solar
Compass, the Whiteley Patent instrument is one of very few
truly American designed patent instruments.
TERMS OF SALE:
- We offer free shipping and insurance within the
contiguous United States, by standard ground-service UPS or
standard USPS.
- We ship on Friday of each week.
- All special delivery requests, including international
shipments, are at the added expense of the buyer.
- All Objects Guaranteed as Described, and, are Sold with
a Limited Three Day Money Back Guarantee.
- Payment by Pay Pal or bankable check, required within 10
days of auction completion.
- Please email for additional images or information.
- Questions? E-mail or call (319)-895-0506 (Central Time
Zone).
- Please include lot number and title with all
correspondence.
Thank you.
|
)
