4. 4. 16
No 8469
Victorian Telegraph Office Commutator.

U is the terminal for the Up line

D is the terminal for the Down Line

I and I are the terminals for the internal office wires

E and E are wired to Earth and act as lightning Arresters.

Every line in an office is fitted with such a commutator and changes between lines are made by cords with plug ends, the plugs being placed in the block holes.

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