Between Easter 1948 and Christmas 1949, Grey Walter built the first turtles, Elmer and Elsie. They had similar circuits and electronics, but their shells and motors were rather different. Although he demonstrated them in public in 1949 and 1950, they were rather unreliable and required frequent attention. In 1951, his technician, Mr. W.J. 'Bunny' Warren, designed and built six new turtles for Grey Walter; they were of a high professional standard. Three of these turtles were exhibited at the Festival of Britain in 1951; others were demonstrated in public regularly throughout the fifties.
What happened to the turtles? Nothing was seen of Elmer and Elsie after 1951, and they are believed to have been scrapped; some of their components may have been used to build the 1951 batch. The fates of the 1951 turtles were mixed:
|This shows the surviving Bristol tortoise, shortly after its rediscovery in early 1995. When found, it was packed inside the original hutch, which is also shown.|
|The Bristol tortoise after restoration.|
|The Bristol tortoise with its Perspex shell removed.|
|This view of the Bristol tortoise shows the plastic battery carrier installed in 1985; We have decided to leave this on, rather than replace it with a copy of the original carrier.|
We have not yet discovered any film of Elmer and Elsie, though it is very likely that they were filmed. It would perhaps be possible to attempt to construct replicas of Elmer and Elsie, but there are very few records of their detailed construction, apart from a couple of photographs. Of the 1951 batch, the Bristol example is still in working order, but is very fragile, and cannot really be used for any extended experiments.
The obvious solution was to use the Bristol tortoise as the basis for the construction of some replicas. This was done between May and July of 1995. The project was greatly aided by the assistance of Bunny Warren, the designer of the 1951 batch, who still works at the Burden Institute, and who was able to produce many original records and spare parts from his workshop! The two replicas, Ninja and Amy, were demonstrated at the Second European Conference on Artificial Life in Granada, Spain, in July 1995. They use many original parts, most notably the transparent Perspex (Plexiglas) shells, and we can be quite sure that they accurately reproduce the behaviour first seen almost 50 years ago. The replica turtles are used for educational and scientific demonstrations, as well as for more formal analysis of turtle behaviour.
|Here is one of the replicas with its shell removed. Original component types were used where possible, and we even incorporated some original spare parts from the Burden Institute workshops. However, the motors are modern, because the original motors were very unreliable by modern standards and required frequent skilled maintenance.|
The archives of the Burden Institute contain relatively little material
on the turtles, but some valuable documents and pictures have come to
light. For copyright reasons, we cannot show all of them, but here
is a limited selection.
Acknowledgements: The Burden Neurological Institute, for their assistance with this project. Pictures above are copyright (c) University of the West of England, Bristol.Researcher and author: Owen Holland