Telephone Interface (a piece of history)

The telephone has just about disappeared from homes. Back when they were connected by wire to the telephone exchange there needed to be a connector inside the house that connected the home wiring to the phone company wiring.
The connector is called a telephone interface which is the modern version of the connector in the photo. The block is where a repair man could attach a handheld telephone to the terminals with alligator clips to check the incoming phone line for faults and determine if a fault with the house phone, the house wiring or out at the street pole.