The same method of inspection is adopted with the make-and-break apparatus of an electric magneto.
If they be connected in series, one or the other should have its make-and-break contact closed.
Ignition was make-and-break and the inlet valves were mechanically actuated.
The up-and-down movement serves as a make-and-break for the circuit.
make-and-break points, on the other hand, were unaffected by excess oil in the cylinder.