Call Number Telephone

Posted June 2012

Each book in the Library is shelved according to a unique call number. But, rather then using these numbers to find books on the shelves, what if instead they were telephone numbers for calling books? Call Numbers is comprised of a repurposed vintage bakelite telephone and a directory booklet. Listeners can browse the directory and dial a Dewey number between 000 and 999 to be connected to a book from that part of the Library collection. The artwork also encourages random discovery of the collection through aimless dialling.

How It Works

When the listener first picks up the handset a dial tone is heard in the earpiece. Once a Dewey number is dialled and the number is ‘connected’, the book will read itself over the telephone. Listeners may hang up and dial another book, or continue to listen until the book ends the call, after which a busy signal is heard in the earpiece. If a listener hangs up on a call before the book answers, the book will call them back. The telephone call functions in a similar way to the traditional speaking clock. Several of the Dewey schedules are unassigned or no longer used. If the listener dials one of these numbers they will hear a message saying that the number is ‘not in service’ or ‘disconnected’ respectively.

For practical reasons the artwork will only recognise three digit numbers from 000 to 999, allowing the listener to dial any of 1,000 possible numbers. Once the listener has dialled a three digit number, subsequent numbers dialled while the call is active are ignored by the telephone. In theory longer numbers could be recognised to expand the total possible numbers to match all of the 900,000 items in the library.

Technical Details

The artwork is controlled by software that can sense when the handset is on or off the hook, receive data from the telephone dial, access a database of book content and read the content into the earpiece of the telephone. Electrical pulses from the motion of the rotary dial are converted into digital input by an Arduino (a well documented and straightforward process). Once the requested number is identified, the software checks the database to find the relevant book. If there are multiple books, a random book is selected. The book is then read into the earpiece via the computer’s audio out using one of a selection of synthesised voices.


  • Introduction
  • Artworks
  • Bibliography
  • Notes
  • Other artists
  • Prototype Artworks
  • Acknowledgements
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