Backstaff or Davis Quadrant – Holland, possibly England, 18th century

Backstaff or Davis Quadrant – Holland, possibly England, 18th century

Stock Number: NM. 3-21

poa

In Holland the backstaff was called an English quadrant and had no auxiliary scale. This instrument is probably Dutch, possibly early English.

Category: Navigational instruments

Description

After the astrolabe and the Jacob’s staff, in 1595 John Davis invented the back staff to determine the altitude of celestial bodies at sea. His improved design became known as the Davis Quadrant. The observer stood with his back to the sun and did not have to look at the bright sunlight. The backstaff remained in use until the late 1700s when the octant and sextant became the new preferred tools over the back staff.
On the smallest circle segment of English specimens, an auxiliary scale is often provided for correction of the half of the diameter of the sun. In Holland the back staff was called an English quadrant and had no auxiliary scale. This instrument is probably Dutch, possibly early English.
 

The frame is made of lignum vitae, with ivory inlays, stars and fleur de lis. The arcs, the brace and vanes are of pear wood. The rivets and arcs are capped with ivory, decorative diamond-shaped inlays. The horizon vane is original, the eye and shadow vanes with iron presure plates, are of a later date, probably 19th or 20th century. The sight vane has a copper pinhole sight. The ends of the arcs are equipped with decorative stamps.

This backstaff looks almost the same as NAV0038 in the collection of the National Maritime Museum in Greenwich.

Date: 1700 – 1750
WL: 36,5×63,5 cm   (14,3×25 in)
Signed: not signed
Origin: probably Netherlands, possibly England
Condition: in perfect condition, wear consistent with age and use

Curious about more? Then switch to https://archipel-maritime.nl

Ask the Dealer

Item enquiry

To enquire about this item, complete the form bellow to send a message to the Dealer

Enter Email
Confirm Email
Sending

Dealer information

NL ARCHIPEL International Maritime Gallery

Welcome to the catalogue of Archipel International Maritime Gallery, specialist in nautical antiques and collectables.
Archipel International Maritime Galery in the Netherlands, sets itself to maritime objects, globes and sea charts of before 1900. The managing director worked as officer with the mercantile marine and the Royal Navy. As curator he was connected to one of the University Museums in the Netherlands. As seaman and curator he has a lot of knowledge of naval history.

Shipping information
Payment methods