Rule of Thumb

Tools of the trade Sample of items displayed as part of the Tools of the Trade exhibition at Craft Victoria, July 1994.

The Tools of the Trade exhibition consisted of tools mainly from the occupations included in the companion Symmetry exhibition. They were displayed purely according to their appearance, not their identity within any particular occupation. The following is an extract from the accompanying catalogue essay.


There are tools that moonlight in other trades. The dental probe is a notorious example of this. Certain craftspeople are more than happy to pay a visit to the dentist -- not just to have their teeth fixed but to scrounge the odd worn out instrument. Part of the background work for this exhibition involved asking people to identify their most faithful instrument. It was not only jewellers, but also a well-known ceramicist who spoke endearingly of the old rusty dental probe that had been their indispensable companion for decades.

This kind of exchange defies the taboo placed on intermarriage between different trades. The Bible proclaims: `Let every man abide in the same calling wherein he was called' (I Corinthians vii.20). And traditional idiom has it: Let the cobbler stick to his last. Essential to the history of guilds, including surgery, was the `mystery' guarded by its members. In a time of multiskilling, and in a broad-minded craft institution, we should feel more free to exercise restless imaginations. But there's a limit.

Look - no hands!

What is famine for the hands is a feast for the imagination. Though these tools are unavailable to touch, they do invite the exercise of phantom hands in exploring their manner of use. There are several moves we could try out. The baker's peel can be understood through the `power grip': the shaft held in the crook between thumb and fingers. The opthamological instruments, on the other hand, make sense only through the `precision grip': the handle clasped daintily on the tips of the fingers. And the bulb of wood at the end of the engraving tools becomes reasonable when accommodated in the ball of the hand. Viewing an exhibition of tools seems one of those rare instances when it's best to look not with the eyes but with the hands.

What's to be gained along the way is an appreciation of the peculiar arrangement that constitutes a hand -- the `tool of tools' according to Aristotle. To supplement your own thoughts, let me provide a few clues in the language of hands. Medieval thought is particularly illuminating in the elemental representation of such things. The eleventh century Danish born king of England, Canute, decreed an official term for each of the digits. The forefinger, demonstratorius , is the most vocal, drawing out the link between word and thing. Impudicus is the term used for the middle finger thanks to its role in obscene gestures. The fourth finger, annularis , stands next to it as the noble receptacle of a gold ring. Less worthy is the little finger whose term auricularis refers to its use in extracting wax from the depths of the outer ear. Finally, these four digits stand opposed to the thumb, called pollex to denote its strength.

The significance of these terms is not simply poetic: one of King Canute's major concerns was to set rates of compensation for the loss of digits. His seventh century predecessor, Aethelbert, gave the thumb the same value as all the other fingers put together. In his turn, Canute elevated the value of the ring finger for its symbolic importance -- but he was always a man who trusted theory before heeding reality.

How would we value a thumb today? To be `all thumbs' is to lack dexterity, yet to be `under someone's thumb' is to be subject to another person's control. A `thumbnail sketch' is poor in detail yet is extremely useful in conveying basic form. In the evolution of manual labour, the thumb is prototypical of technological power which reduces the world so that it might be controlled more effectively. Lest we forget, during the rule of thumb measures were taken by the human body: length was broken down into hands and feet, and the duodecimal system began with a thumb counting the three knuckles of each of its four neighbours.

Writers are not innocent of the thumb's decline. In composing the above sentences I have been using a keyboard (my constant interface). While the computer appears to be a completely abstract medium, we easily forget that it too has features that are to be handled. But it's only a limited kind of interaction. On the keyboard, the thumb itself is rendered completely dumb: its only action is to press the space bar. It plays a rather more active role with the mouse, but the grip required is only light and could easily be replaced by another finger. Contrast the indispensability of the thumb when writing with a pen.

These thoughts, that you now grasp between your pollex and demonstratorius, are made possible due to the silent labour of one right thumb. Iwouldbelostwithoutit. So as hands awake in the presence of old friends, we should listen to what they might say about the virtual world that awaits them outside.

Kevin Murray©1995