verge escapement

The beat of a verge escapement is a regulated, in the main, by power available to drive it. Verges are very sensitive to this. Looking after the verge was a specialist job. In the monasteries it was done by a brother called the ‘Verger’.

If you are using a foliot then it is regulated by the weight of the weights and their position along the foliot arms. The heavier the weights and the further they are from the centre the slower the beat.

If you are using a balance wheel you can only regulate it modifying the power input. If your balance wheel is running slow you can lighten it. That is what my old friend Bill did. If it is too fast you try to add weight.  Of course you can always make a new balance wheel –Bill had to make 4 or 5 to get it on beat. With a very small balance wheel the old‘uns used a hog bristle on the banking arm, but your barber would need a few confidential minutes with a large old porker. (Honest Mr Policeman the pig has not got rabies that is shaving foam). This bristle checked the swing of the balance wheel

If you are using a pendulum you need to make a pair of cycloid cheeks these change the path of the pendulum swing from a circular to a cycloidal path when the suspension chord strikes one of the cheeks.

Another problem is that you have to minimise the ‘drop’ and make it equal.

There is a very good descriptionin Clock and Watch Escapements by W.J.Gazeley

Whilst I am here, does anyone know of an escapement called a whip escapement. This was an arm with a string with a weight on the end. The whip struck a pin the weight spun the cord round the pin two or three times. This checked the rotation of the whip arm. When the whip weight unwound the whip arm spun on round until the whip hit the next pin.  It is to timekeeping as late and very unlamented Mr Hitler was to Jewish charities.

Edited By Richard Parsons on 17/10/2010 11:16:19