Watchclocks: an early device for controlling users

By Cory Doctorow at 10:08 pm Monday, May 4

Here's a good explanation of the workings of the "watchclock," a device carried by watchmen in order to allow their employers to check up on their patrolling. It's one of the earliest examples of a sophisticated device intended to control the behavior of its user.

The key, literally, to the watchclock system is that the watchman is required to "clock in" at a series of perhaps a dozen or more checkpoints throughout the premises. Positioned at each checkpoint is a unique, coded key nestled in a little steel box and secured by a small chain. Each keybox is permanently and discreetly installed in strategically-placed nooks and crannies throughout the building, for example in a broom closet or behind a stairway.

The watchman makes his patrol. He visits every checkpoint and clicks each unique key into the watchclock. Within the device, the clockwork marks the exact time and key-location code to a paper disk or strip. If the watchman visits all checkpoints in order, they will have completed their required patrol route.

The watchman's supervisor can subsequently unlock the device itself (the watchman himself cannot open the watchclock) and review the paper records to confirm if the watchman was or was not doing their job.

Who Watches the Watchman? (via Kottke)