Wristwatches sometimes used to have the movement encapsulated in a soft iron housing to prevent the movement, particularly the steel balance spring, becoming magnetised. In the case of the IWC Mark 11 used by the RAF after WW2 this took the form of an iron ring around the movement with an iron...
A friend of mine said that if the ignition light bulb is blown then the alternator won't charge the battery. This sounds ridiculous; but I don't know enough about auto electrics to know whether it true, so I am hoping that someone familiar with this aspect of vehicle electrics can give me...
