
Lot 31
A Davis Backstaff
American, mid-18th century 22 x 12-1/2 in. (55.8 x 31.7 cm.)
American, mid-18th century
5 June 2013, 13:00 EDT
New YorkSold for US$3,125 inc. premium
Looking for a similar item?
Our specialists can help you find a similar item at an auction or via a private sale.
Find your local specialistAsk about this lot


Client Services (Los Angeles)

Client Services (San Francisco)
A Davis Backstaff
American, mid-18th century
American, mid-18th century
[unsigned] of lignum vitae and boxwood, the large arc divided 0°-25° and on the higher lattice scale between 65°-90°, the smaller arc 0°-60°, the frame with some decoration on the large arc.
22 x 12-1/2 in. (55.8 x 31.7 cm.)
22 x 12-1/2 in. (55.8 x 31.7 cm.)
Footnotes
This instrument was a great improvement on the cross staff and the astrolabe. It allowed navigators to calculate latitude without longitude.