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

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 |
---|---|
![]() |
![]() |
The innards
Related links
- Machina Speculatrix - Micheal Gasperi - Gasperi’s page on the Machina Speculatrix has some excellent information, including his own version of them built using Lego and the RCX
- Cybernetic Zoo - a great resource with lots of information on these amazing robots.