These robots were built as learning platform by the late William Grey Walter in the 1940s.

Extract from the Festival Of Britain catalog Courtesy of The University of Berkeley, California

They were phototropic - that is light following, and they were otherwise known as tortoises. A name derived from their plastic tortoise shaped shells, and a reference to Alice in Wonderland (paid link) - “We called him tortoise because he taught-us”.

The first two of these were named “Elmer” and “Elsie”. They consisted of a light sensor, touch sensor, propulsion motor, steering motor, and a two vacuum tube analogue computer. The simplicity of its design now would be similar to the BEAM Robots.

A second generation was built - and some of these now reside in a collection in the Smithsonian Institute.

There is currently a reconstructed Tortoise at the London Science Museum which actually performed in the Mind Zone of the Millennium Dome in Greenwich.

Taken by Pete Goodeve of The University of Berkeley, California.

At The Science Museum At The Millenium Dome
Tortoise At The Science Museum Tortoise at The Millenium Dome

The innards

Innards of Elsie

Innards of a Tortoise