The Grey Walter Online Archive

Background information

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:

• the three Festival of Britain turtles were auctioned off after the exhibition closed. They survived intact until a couple of years ago, when two were destroyed in a house fire in Australia. The remaining turtle, incomplete but in original condition, was presented to the Smithsonian Institute, where it languishes today, unrestored and undisplayed.
• one turtle was sent to the USA in 1953, to be used in the development of a transistorised children's' toy. It was dismantled for study, and returned to the UK in pieces; the parts were used as spares for the other turtles. The toy project came to nothing; the company went into receivership, and only the transistorised circuit design survives.
• one turtle was sent to New York (or New York State) in 1970, as Grey Walter lay in a coma in Bristol after the tragic accident that effectively ended his brilliant career. No record of the address on the crate has survived, but Burden Neurological Institute staff remember that it was something to do with a museum. Nothing more has been heard of this turtle.
• the last turtle remained with Grey Walter until his death. It passed to his son Nicolas, who kept it safe until Brunel University decided to 'repair' it for an exhibition in Grey Walter's memory in 1985. They removed the original accumulator and its aluminium holder and installed an ugly and incongruous plastic carrier taking four dry cell batteries. After the exhibition, the turtle returned to Brunel. Nicolas Walter rescued it some years later, when he found that it was about to be thrown out. He stored it in his basement in Islington until 1995, when Owen Holland finally located it after months of searching. It was carefully restored to working order at the IAS Lab, and gave a last public performance at the Burden Neurological Institute in March 1995, when it was demonstrated to many of Grey Walter's former colleagues. Since 2000 the turtle has been on display in the London Science Museum, in the Making the Modern World gallery.

	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.

What did the turtles actually do? The story of the replicas

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

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.