Archive for the ‘ELMER’ Category

Grey Walter’s Tortoises – Batteries, Re-charging, Hutches and Autonomy

A significant feature of the tortoises is so often referred to as "An Imitation of Life".  As well as their behaviour, the tortoises construction  had to be such that autonomy could be exhibited. This is somewhat driven by the technology and parts available at the time. For Grey Walter's purposes, the models had to be self-contained and as light as possible for transportability.
also referred to as "Accumulators"
Pre 51 “Elsies” had 45 Volt 'Ever Ready' “B” batteries designed for 2-vacuum tube hearing aids. You can see the words “Hearing….” in some of the pics of the tortoises internals.  The colour of these (Red ends, white sides and corners) suggests war-time Ministry of Health HT (High Tension) battery.
We also know, from the Festival of Britain – Exhibition of Science of 1951 catalogue, that the batteries used in the batch of 6 were 'Exide' accumulators, "Gel-cel" PRA 3S made by Chloride Batteries, 45-V batteries, "Batrymax" B109 made by The Ever Ready Company (Great Britain) Ltd.
[ Note: RH 2009 – Its interesting that Gel Cels were around then, 
being a motorcyclist myself, I thought they were a relatively recent invention.]
In the circuit schematics for M. Speculatrix, you will notice the on-off power switch is only on the 6 V side. The Vacuum tubes (also known as valves), don't function unless the heaters are on, and the heaters are on the 6 volt circuit. However, we know from notes on usage of the tortoise  that the plug for the "B" battery is disconnected during transit. An article by F.H. George (John Bull 1956) informs us of how George heard noises coming from the hutch when transporting the tortoise from a demonstration. It had accidentally turned itself on and was looking for light inside its closed hutch.

Pierre de Lati mentions in his book Thinking by Machine, 1957,  mentions of an "ingenious mechanism" and comments of "going back to the hutch to feed". He elaborates further in the section "The Secrets of the Tortoises" when he says "As soon as the tortoise is in its hutch, in contact with the mains, the voltage of this current cuts off the contact A which link the accumulators to the mechanism; they recharge instead. But when the accumulators are charged up to 7 volts, the relay R4 makes contact again at A and the tortoise moves away, since now that it is replete it has regained its movement and will avoid bright light". (See diagram below). This is achieved using a special relay wired in a particular way. These are labeled R3 and R4 in the schematic. They are in fact a single unit described below.
The relay used in the re-charging circuit is a different type of relay than more common types, it's a two-coil relay (sometimes referred to as a double-coil relay). 
One coil in series with the supply switches the supply to the motors
OFF when the battery starts to charge, so immobilising Elsie, as the charge current reduces and the voltage rises the other coil takes over and restores the supply to the motors. So Elsie then backs away from the intense light in the hutch. “Double-coil" relays – these relays are so constructed that if the current through both coils is the same, the clappers are such that the contacts remain open. If the current through one coil is greater by a sufficient amount than that through the other, the clappers will move in unison, making contact.” – Kubanoff's Timothy Turtle, 1953. Note: The re-charger for Timothy Turtle charges through the solenoid (i.e. one of the solenoid wires is connected to one of its own contacts.) The relay closes due to this current and remains closed until the condenser (i.e. battery substitute) is charged/re-charged. It would need the two coils to reduce the lock-in effect of just one in the supply line. By following the circuit diagram of deLatil's, you can also see the contact wiring connected to the coils. Normally relays are wired such that coils are isolated from the switching circuit. 

Its quite possible that the early version of the tortoises antennae may have been the contacts for the automatic re-charging capability.
Elmer – none at all but with jacks mounted on the rear of its segmented shell; Early Elsie had wire antennae from top ‘metal’ shell.

Later antennae appear to be clear plastic curved strips (ref. Time Life pic above) They even appear to glow a little, not sure if this affects PEC or not. Later the transparent antennae are removed and we just see the remaining 'holes'.
Of the ‘batch of 6' from 1951, we see the copper tube extension for the on-off switch.  For those models without a hutch, this tube is largely for convenient finger control.  However, to simulate the earlier automatic re-charging system and to ensure motors, etc. don’t overheat if Elsie entered the hutch and thrashes about in ‘hunger’ mode at the end of the hutch, Walter appears to have installed a metal trip bracket on the RHS (facing inwards). (see colour pic) So with the copper extension trip lever appropriately positioned, and the clockwise steering, Elsie will bump along the RHS until the switch is tripped.

In viewing some earlier film footage, we actually see the deft hand 
of WGW  switching the tortoise off as it enters the hutch before closing the hutch door. A later film clip c1972 shows '#6' entering the hutch on the LHS. The trip bracket can't be seen in this clip. This aspect is pure speculation by me, but maybe Owen Holland, current custodian of the Hutch, could have a look to confirm.
**Update 13 Jan 2011 from Owen Holland – "…the positioning of the stops on the right hand floor which would switch off the tortoise as it entered (see attached picture above). This worked most times when we tested it some 15 years ago with the tortoise that's now in the Science Museum."

We know from Owen Holland, probably in discussion with "Bunny" Warren during the restoration of Grey Walter's own tortoise, that there were two hutches built, the first having caught fire.  They are easy to pick in the photos, as the first version does not have a door whereas the later model does.

It wouldn't surprise me if the fire was as a result of the automatic
re-charging facility. I mentioned above the wire-looking antennae on an early version of ELSIE. There may have been an overhead wire set-up (similar to electric trams) where the antennae contacted different overhead wires that were those of the battery charger.
In any case, I have not seen any photographic evidence of the
battery charging circuit mounted on ELSIE. I believe it was, but for only a short period of time. Thereafter, it is just "assumed" that it does exist.
**Update: 14 Jan 2011** Owen Holland sent me an email saying that when he met "Bunny" Warren, he mentioned that the lamp caused the fire, and not the charging unit.

In "Discussions on Child Development", Grey Walter gets asked of the tortoise,
"Why does it keep going round?"
GREY WALTER responds:
"It is looking for more lights. If you imagine a world which this
thing is adapted to, and in which there are charging devices for its batteries, it would be important for it not to get stuck on one; it has a much better chance of being fed when it has several sources of food. It would wander around the room and always be near feeding sources. It is always looking for better and better light; it is never satisfied. If you made one of these things adapted to live in a tropical climate, you could make the shell of photo-electric cells and it would charge itself in the sun. It would be important for it to find a place where the sun's light was bright and steady, not between trees or houses, but a wide expanse of light; it would always seek this out and then sit and charge. At night it would have to collect dew-distilled water, so it would find two places, one where it could collect light and another where it could collect dew for its batteries; that is all it needs."

See the collection of Grey Walter and his Tortoise articles here.

See other early Cybernetic Creatures and Models here.

Tags: , , , , , , , , , , ,

W. Grey Walter Tortoises – Picture Gallery #1

The next Grey Walter and his tortoises posts are taking a little time.

In the mean time, here are some photo’s non-specific to other posts.


Tags: , , , , , , , , ,

Time-Lapse Photographs of ELMER with ELSIE

I have only come across two time-lapse photographs with both ELMER and ELSIE.

One has to be careful in interpreting time-lapse photographs as there are possibly different events happening at different times, off picture interference, and possibly different start times of each tortoise.

An important observation highlighted by Owen Holland is the direction of rotation of the scan, which is clockwise for ELMER, and counter-clockwise for ELSIE. 

This is evident in both of the time-lapse photo’s and the diagrams by Bernarda Bryson (partner and later married to the artist Ben Shahn), as illustrated in Scientific American (Walter, W. Grey, "An Imitation of Life," Scientific American, May 1950, p42-45.).

Let's look at the first photo.

Firstly, we will look at the behaviour of each tortoise individually.
In doing so, it’s important to understand and observe the environment under which the photographic session was filmed under. 

Observations to consider:
• Elmer’s trace is a lot heavier than Elsie’s – assuming same sized and intensity lamp/light, this indicates that Elmer is running slower the Elsie.

• Elmer slower than Elsie.
• Candle/Lamp on top/rear of shell.
• Both Tortoises end up at Hutch as if to ‘feed’ – therefore probably the whole time-lapse session is done with both Tortoises in ‘hunger’ mode.
• Hutch light possibly switched off for roughly half the time-lapse sequence.

Appears to travel the first .5 metre or so heading towards Elmer. If Elmer was a lot slower as described in the literature, quite possibly Elmer has had a head start, with somebody behind Elsie holding a torch to bring Elmer to Elsie.
Elsie then is attracted to the light used to highlight Elmer in the opening sequence. Elsie then, after a few sideways moves, heads towards the hutch light. (Maybe this is when the hutch light is switched on?).  Although Elmer is slower, he spends less time stuck in patterns than Elsie does. To that extent, his path is a lot shorter, making up for his apparent slowness, 

This next time-lapse photo shows ELMER and ELSIE in Grey Walter's lounge room as it appear in Life magazine (May 15, 1950). Recently [2009] Life released the original image of this, which I have reproduced as well. (searchable under google images source:life)

Elsie’s steering mechanism appears to rotate in a clockwise direction. Elmer’s in a counter clockwise direction. Depending where the lamp/light is, one needs to check to see if this isn’t an illusion i.e. the trail of the tortoise re the rear wheels, rather than the scanning direction.

(Note: Although Grey is holding a cigarette in his right hand, there are several pictures of him holding a cigarette in either hand. He normally wears his watch on his left wrist, and you can just see it with his hand in his pocket. His shirt also buttons up the correct male way. All these indicate that the picture has not been printed in reverse, which could have explained the trajectory taken. As an aside, notice that Grey's feet have been 'lost' as a result of the double exposure.)

The most probable explanation is as follows:
As per most of the known traces, Elmer and/or Elsie are always photographed at the beginning of a trace. Obviously where they appear twice, only then are we seeing the tortoises at both ends of the sequence.
Therefore, to contradict the caption, Elmer and Else are pictured at the start of the sequence, and are moving away from the fire. There were probably torches outside of the camera's view guiding their path.
I know you’re not convinced yet, but the clincher is that if Elsie was to cycle in the apparent direction with its clockwise motion, then, as proven with the replica I have seen, Elsie would then creep to the left, and not to the right as shown. 
So now knowing that information, it all falls into place.

Tags: , , , , , ,

M. speculatrix – a new species of animal – ELMER

ELMER – (ELectro-MEchanical Robot)  
How the media reported the coming of ELMER :
Lethbridge Herald –  Wednesday , February 25, 1948
Robot Tortoise Likes Women –
Recognizes Voices, Comes To Meet When Called-Can be Sulky                                          
LONDON. Feb. 25      Daily Express reported today that Dr. W. Grey Walter. 38-year-old brain scientist has built a robot tortoise so "human that it likes company, recognizes voices and comes to heel when called. The paper said that the tortoise avoids cold or damp weather, great heat or bright lights, likes women but dislikes men.   "It can be temperamental and will be neurotic and sulky for days if teased or given too many contradictory instructions," the Express added.  Dr. Walter, at the Burden Neurological Institute at Bristol, built the tortoise with ordinary radio tubes, switch relays, miniature microphones -for registering sound and photoelectric cells for recognizing color and shape.
Lethbridge Herald – Thursday , February 26, 1948  
Has Not Yet Made "Robot Tortoise"
BRISTOL, England, Feb. 25 Dr. W. Grey "Walter, 38-year-old director of the Burden Neurological Institute here, said Wednesday that it "should be possible" to build a "robot tortoise" which would react to light and sound, but he has not yet made one.  "The most I can say is that theoretically such a thing should be possible and that I am planning to make one if I have the time," he added.  Earlier a London newspaper had reported that the brain scientist had built a robot tortoise so human that it liked company, recognized voices and avoided cold or damp weather, great heat or bright lights.
Kingsport News –(AP)  – Thursday, May 27, 1948  
Inventor Ready To Build His Robot Tortoise
Bristol, England — AP
A robot tortoise with a "mind" has reached past the blueprint stage at Burden Neurological Institute. Conceived by Dr. W. Gray Walter, director of the institute's physiological department, the tortoise is designed to react just like the real thing. He said the tortoise probably would be very large at first "when I get the time to build it." He chose this particular creature because of its "convenient shape. It's size may be reduced when it becomes possible to make microscopic valves, microphones and photo-electric  cells to control it." When completed he said he would "challenge anyone to tell whether or not it is living, without prolonged observation."  Dr. Walter pictured something like this happening at the institute in the not too distant future: "As you stand by the fire a robot tortoise lumbers along and nestles cosily by your leg. You exclaim in astonishment. The tortoise sheers off nervously and takes refuge under the sofa, but a low whistle brings it back again. It will even seem to possess all manner of lovable qualities conspicuously missing in other robots." The only trouble is, he said, "I am not sure yet how it will react to publicity."
ELMERAt ELMER's rear you can see the two different coloured plugs used for charging the batteries.   The later automatic re-charging appeared for only a short period with ELSIE. The photo below is a discovery of mine, being the only picture known to date showing ELMER's internals. The front is to the left and you can clearly see the clockwork mechanism so often talked about. The Photo-electric cell (PEC) holder can be seen, but the PEC itself has been removed, which is has to be to remove the shell.  What is interesting is the type of front wheel. It appears single-sided, and pneumatic like the rear-types we generally see for his younger sister ELSIE. In the later time-lapse photos that we will see of ELMER, his trace is a lot more jerky and less smooth than ELSIE.  In his book 'The Living Brain', Grey suggests to other builders of the model that "the front tyre should be of rubber, but  thin and fairly hard, so that it can turn easily", apparantly after the lessons learnt from ELMER. This photo is even more significant, in that the CORA circuit can be seen under construction in the foreground, but more on that find when I discuss CORA in a later article.ELMER InternalsGrey Walter showing ELMER's internals

Tags: , , , , , , , , ,