Sunday, 20 January 2019

An unusual jewel configuration on a 17J Recta.

This 17 jewel Recta for J.W. Benson  has an interesting configuration in that the centre wheel does not have a jewel on the face side and the jewel count is made up to 17 with a single cap jewel on the escape.

English makers, particularly Rotherham, Errington and Coventry makers using CWM Co ebauch├ęs did something similar either making 16 jewel movements or adding one centre wheel jewel to their 19J movements probably under presure from Marketing department to have a jewel visible on the centre wheel.

20 Jewel Rotherham, 1903.

The designers did not want a jewel at the face plate as with the centre wheel only turning once per hour the benefit is small and with the power from the barrel being applied close to the face plate there is a percieved risk of damage.

A 16 Jewel Errington 1906