Binnacle Quadrantal Spheres

Price: NZ$162.77

Code: BH919

Binnacle Quadrantal Spheres these adjustment balls of soft iron were attached to a ships binnacle to adjust its compass to read correctly when affected by various metals in the ships construction. They are very heavy and original, would look excellent painted in the port and starboard colours of red and green. They have bronze a mount that could be polished and attached to your deck, or house in various places to enhance its maritime look.
They are approx. 5 1/2” or 140mm in diameter so quite substantial. Please see all the images.

Their Use
Deviation was a problem with navigation, particularly as the amount of iron and steel in ships increased. Captain Matthew Flinders, Royal Navy, determined that erecting a vertical metal bar in front of the compass allowed adjustments to be made to minimize this effect. Those devices are still called Flinders bars to this day. Sir George Airy, the Astronomer Royal, discovered that the accuracy of the magnetic compass could be further improved by placing quadrantal spheres (large balls of soft iron) on either side of the compass. Both the Flinders bar and the quadrantal spheres, along with various adjustable magnets, for correcting the compass were mounted on the ships binnacle.