Sculpture is a sensuous art. (The Eskimos make small sculptures that are not even meant to be seen, only handled.) So it must seem strange that I choose as my model for science, which is usually thought of as an abstract and cold enterprise, the warm, physical actions of sculpture and architecture. And yet it is right. We have to understand that the world can only be grasped by action, not by contemplation. The hand is more important than the eye. We are not one of those resigned, contemplative civilisations of the Far East or the Middle Ages, that believed that the world has only to be seen and thought about – and who practised no science in the form that is characteristic for us. We are active; and indeed we know, as something more than a symbolic accident in the evolution of man, that it is the hand that drives the subsequent evolution of the brain. We find tools today made by man before he became man. Benjamin Franklin in 1778 called man ‘a tool-making animal’, and that is right.
I have described the hand when it uses a tool as an instrument of discovery; it is the theme of this essay. We see this every time a child learns to couple hand and tool together – to lace its shoes, to thread a needle, to fly a kite or to play a penny whistle. With the practical action there goes another, namely finding pleasure in the action for its own sake – in the skill that one perfects, and perfects by being pleased with it. This at bottom is responsible for every work of art, and science too: our poetic delight in what human beings do because they can do it. The most exciting thing about that is that the poetic use in the end has the truly profound results. Even in prehistory man already made tools that have an edge finer than they need have. The finer edge in its turn gave the tool a finer use, a practical refinement and extension to processes for which the tool had not been designed.
Henry Moore calls his sculpture The Knife Edge. The hand is the cutting edge of the mind. Civilisation is not a collection of finished artefacts, it is the elaboration of processes. In the end, the march of man is the refinement of the hand in action.
The most powerful drive in the ascent of man is his pleasure in his own skill. He loves to do what he does well and, having done it well, he loves to do it better. You see it in his science. You see it in the magnificence with which he carves and builds, the loving care, the gaiety, the effrontery. The monuments are supposed to commemorate kings and religions, heroes, dogmas, but in the end the man they commemorate is the builder.
So the great temple architecture of every civilisation expresses the identification of the individual with the human species. To call it ancestor worship, as in China, is too narrow. The point is that the monument speaks for the dead man to the living, and thereby establishes a sense of permanence which is a characteristically human view: the concept that human life forms a continuity which transcends and flows through the individual. The man buried on his horse or revered in his ship at Sutton Hoo becomes, in the stone monuments of later ages, a spokesman for their belief that there is such an entity as mankind, of which we are each a representative – in life and death.
I could not end this essay without turning to my favourite monuments, built by a man who had no more scientific equipment than a Gothic mason. These are the Watts Towers in Los Angeles, built by an Italian called Simon Rodia. He came from Italy to the United States at the age of twelve. And then at the age of forty-two, having worked as a tile-setter and general repairman, he suddenly decided to build, in his back garden, tremendous structures out of chicken wire, bits of railway tie, steel rods, cement, sea shells, bits of broken glass, and tile of course – anything that he could find or that the neighbourhood children could bring him. It took him thirty-three years to build them. He never had anyone to help him because, he said, ‘most of the time I didn’t know what to do myself’. He finished them in 1954; he was seventy-five by then. He gave the house, the garden and the towers to a neighbour, and simply walked out.
‘I had in mind to do something big,’ Simon Rodia had said, ‘and I did. You have to be good good or bad bad to be remembered.’ He had learned his engineering skill as he went along, by doing, and by taking pleasure in the doing. Of course, the City Building Department decided that the towers were unsafe, and in 1959 they ran a test on them. They tried to pull down one of the towers. I am happy to say that they failed. So the Watts Towers have survived, the work of Simon Rodia’s hands, a monument in the twentieth century to take us back to the simple, happy, and fundamental skill from which all our knowledge of the laws of mechanics grows.
The tool that extends the human hand is also an instrument of vision. It reveals the structure of things and makes it possible to put them together in new, imaginative combinations. But, of course, the visible is not the only structure in the world. There is a finer structure below it. And the next step in the ascent of man is to discover a tool to open up the invisible structure of matter.
CHAPTER FOUR
THE HIDDEN STRUCTURE
It is with fire that blacksmiths iron subdue
Unto fair form, the image of their thought:
Nor without fire hath any artist wrought
Gold to its utmost purity of hue.
Nay, nor the unmatched phoenix lives anew,
Unless she burn.
Michelangelo, Sonnet 59
What is accomplished by fire is alchemy, whether in the furnace or kitchen stove.
Paracelsus
There is a special mystery and fascination about man’s relation to fire, the only one of the four Greek elements that no animal inhabits (not even the salamander). Modern physical science is much concerned with the invisible fine structure of matter, and that is first opened by the sharp instrument of fire. Although that mode of analysis begins several thousand years ago in practical processes (the extraction of salt and of metals, for example) it was surely set going by the air of magic that boils out of the fire: the alchemical feeling that substances can be changed in unpredictable ways. This is the numinous quality that seems to make fire a source of life and a living thing to carry us into a hidden underworld within the material world. Many ancient recipes express it.
Now the substance of cinnabar is such that the more it is heated, the more exquisite are its sublimations. Cinnabar will become mercury, and passing through a series of other sublimations, it is again turned into cinnabar, and thus it enables man to enjoy eternal life.
This is the classic experiment with which the alchemists in the Middle Ages inspired awe in those who watched them, all the way from China to Spain. They took the red pigment, cinnabar, which is a sulphide of mercury, and heated it. The heat drives off the sulphur and leaves behind an exquisite pearl of the mysterious silvery liquid metal mercury, to astonish and strike awe into the patron. When the mercury is heated in air it is oxidised and becomes, not (as the recipe thought) cinnabar again, but an oxide of mercury that is also red. Yet the recipe was not quite mistaken; the oxide can be turned into mercury again, red to silver, and the mercury to its oxide, silver to red, all by the action of heat.
It is not an experiment of any importance in itself, although it happens that sulphur and mercury are the two elements of which the alchemist before AD 1500 thought the universe was composed. But it does show one important thing, that fire has always been regarded not as the destroying element but as the transforming element. That has been the magic of fire.
I remember Aldous Huxley talking to me through a long evening, his white hands held into the fire, saying, ‘This is what transforms. These are the legends that show it. Above all, the legend of the Phoenix that is reborn in the fire, and lives over and over again in generation after generation.’ Fire is the image of youth and blood, the symbolic colour in the ruby and cinnabar, and in ochre and haematite with which men painted themselves ceremonially. When Prometheus in Greek mythology brought fire to man, he gave him life and made him into a demigod – that is why the gods punished Prometheus.
In a more practical way, fire has been known to early man for about four hundred thousand years, we think. That implies that fire had alre
ady been discovered by Homo erectus; as I have stressed, it is certainly found in the caves of Peking man. Every culture since then has used fire, although it is not clear that they all knew how to make fire; in historical times one tribe has been found (the pygmies in the tropical rain forest on the Andaman Islands south of Burma) who carefully tended spontaneous fires because they had no technique for making fire.
In general, the different cultures have used fire for the same purposes: to keep warm, to drive off predators and clear woodland, and to make the simple transformations of everyday life – to cook, to dry and harden wood, to heat and split stones. But, of course, the great transformation that helped to make our civilisation goes deeper: it is the use of fire to disclose a wholly new class of materials, the metals. This is one of the grand technical steps, a stride in the ascent of man, which ranks with the master invention of stone tools; for it was made by discovering in fire a subtler tool for taking matter apart. Physics is the knife that cuts into the grain of nature; fire, the flaming sword, is the knife that cuts below the visible structure, into the stone.
Almost ten thousand years ago, not long after the beginning of the settled communities of agriculture, men in the Middle East began to use copper. But the use of metals could not become general until there was found a systematic process for getting them. That is the extraction of metals from their ores, which we now know was begun rather over seven thousand years ago, about the year 5000 BC in Persia and Afghanistan. At that time, men put the green stone malachite into the fire in earnest, and from it flowed the red metal, copper – happily, copper is released at a modest temperature. They recognised copper because it is sometimes found in raw lumps on the surface, and in that form it had been hammered and worked for over two thousand years already.
The New World too worked copper, and smelted it by the time of Christ, but it paused there. Only the Old World went on to make metal the backbone of civilised life. Suddenly the range of man’s control is increased immensely. He has at his command a material which can be moulded, drawn, hammered, cast; which can be made into a tool, an ornament, a vessel; and which can be thrown back into the fire and reshaped. It has only one shortcoming: copper is a soft metal. As soon as it is put under strain, stretched in the form of a wire for instance, it visibly begins to yield. That is because, like every metal, pure copper is made up of layers of crystals. And it is the crystal layers, each like a wafer in which the atoms of the metal are laid out in a regular lattice, which slide over one another until they finally part. When the copper wire begins to neck (that is, develop a weakness), it is not so much that it fails in tension, as that it fails by internal slipping.
Of course the coppersmith did not think like that six thousand years ago. He was faced with a robust problem, which is that copper will not take an edge. For a short time the ascent of man stood poised at the next step: to make a hard metal with a cutting edge. If that seems a large claim for a technical advance, that is because, as a discovery, the next step is so paradoxical and beautiful.
If we picture the next step in modern terms, what needed to be done was plain enough. We have heard that copper as a pure metal is soft because its crystals have parallel planes which easily slip past one another. (It can be hardened somewhat by hammering, to break up the large crystals and make them jagged.) We can deduce that if we could build something gritty into the crystals, that would stop the planes from sliding and would make the metal hard. Of course, on the scale of fine structure that I am describing, something gritty must be a different kind of atoms in place of some of the copper atoms in the crystals. We have to make an alloy whose crystals are more rigid because the atoms in them are not all of the same kind.
That is the modern picture; it is only in the last fifty years that we have come to understand that the special properties of alloys derive from their atomic structure. And yet, by luck or by experiment, the ancient smelters found just this answer: namely, that when to copper you add an even softer metal, tin, you make an alloy which is harder and more durable than either – bronze. Probably the piece of luck was that tin ores in the Old World are found together with copper ores. The point is that almost any pure material is weak, and many impurities will do to make it stronger. What tin does is not a unique but a general function: to add to the pure material a kind of atomic grit – points of a different roughness which stick in the crystal lattices and stop them from sliding.
I have been at pains to describe the nature of bronze in scientific terms because it is a marvellous discovery. And it is marvellous also as a revelation of the potential that a new process carries and evokes in those who handle it. The working of bronze reached its finest expression in China. It had come to China almost certainly from the Middle East, where bronze was discovered about 3800 BC. The high period of bronze in China is also the beginning of Chinese civilisation as we think of it – the Shang dynasty, before 1500 BC.
The Shang dynasty governed a group of feudal domains in the valley of the Yellow River, and for the first time created some unitary state and culture in China. In all ways it is a formative time, when ceramics are also developed and writing becomes fixed. (It is the calligraphy, both on the ceramics and the bronze, which is so startling.) The bronzes in the high period were made with an Oriental attention to detail which is fascinating in itself.
The Chinese made the mould for a bronze casting out of strips shaped round a ceramic core. And because the strips are still found, we know how the process worked. We can follow the preparation of the basic core, the incising of the pattern, and particularly the inscribed lettering on the strips formed on the core. The strips thus make up an outer ceramic mould which is baked hard to take the hot metal. We can even follow the traditional preparation of the bronze. The proportions of copper and tin that the Chinese used are fairly exact. Bronze can be made from almost any proportion between, say, five per cent and twenty per cent of tin added to the copper. But the best Shang bronzes are held at fifteen per cent tin, and there the sharpness of the casting is perfect. At that proportion, bronze is almost three times as hard as copper.
The Shang bronzes are ceremonial, divine objects. They express for China a monumental worship which, in Europe at that same moment, was building Stonehenge. Bronze becomes, from this time onwards, a material for all purposes, the plastic of its age. It has this universal quality wherever it is found, in Europe and in Asia.
But in the climax of the Chinese craftsmanship, the bronze expresses something more. The delight of these Chinese works, vessels for wine and food – in part playful and in part divine – is that they form an art that grows spontaneously out of its own technical skill. The maker is ruled and directed by the material; in shape and in surface, his design flows from the process. The beauty that he creates, the mastery that he communicates, comes from his own devotion to his craft.
The scientific content of these classical techniques is clear-cut. With the discovery that fire will smelt metals comes, in time, the more subtle discovery that fire will fuse them together to make an alloy with new properties. That is as true of iron as of copper. Indeed, the parallel between the metals holds at every stage. Iron also was first used in its natural form; raw iron arrives on the surface of the earth in meteorites, and for that reason its Sumerian name is ‘metal from heaven’. When iron ores were smelted later, the metal was recognised because it had already been used. The Indians in North America used meteoric iron, but never could smelt the ores.
Because it is much more difficult to extract from its ores than copper, smelted iron is, of course, a much later discovery. The first positive evidence for its practical use is probably a piece of a tool that has got stuck in one of the pyramids; that gives it a date before 2500 BC. But the wide use of iron was really initiated by the Hittites near the Black Sea around 1500 BC – just the time of the finest bronze in China, the time of Stonehenge.
And as copper comes of age in its alloy, bronze, so iron comes of age in its alloy, steel. Within five hundred
years, by 1000 BC, steel is being made in India, and the exquisite properties of different kinds of steel come to be known. Nevertheless, steel remained a special and in some ways a rare material for limited use until quite recent times. As late as two hundred years ago, the steel industry of Sheffield was still small and backward, and the quaker Benjamin Huntsman, wanting to make a precision watch-spring, had to turn metallurgist and discover how to make the steel for it himself.
Since I have turned to the Far East to look at the perfection of bronze, I will take an Oriental example also of the techniques that produce the special properties of steel. They reach their climax, for me, in the making of the Japanese sword, which has been going on in one way or another since AD 800. The making of the sword, like all ancient metallurgy, is surrounded with ritual, and that is for a clear reason. When you have no written language, when you have nothing that can be called a chemical formula, then you must have a precise ceremonial which fixes the sequence of operations so that they are exact and memorable.
So there is a kind of laying on of hands, an apostolic succession, by which one generation blesses and gives to the next the materials, blesses the fire, and blesses the swordmaker. The man who was making this sword holds the title of a ‘Living Cultural Monument’, formally awarded to the leading masters of ancient arts by the Japanese government. His name is Getsu. And in a formal sense, he is a direct descendant in his craft of the swordmaker Masamune, who perfected the process in the thirteenth century – to repel the Mongols. Or so tradition has it; certainly the Mongols at that time repeatedly tried to invade Japan from China, under the command of the grandson of Genghis Khan, the famous Kublai Khan.
Iron is a later discovery than copper because at every stage it needs more heat – in smelting, working and, naturally, in processing its alloy, steel. (The melting point of iron is about 1500ºC, almost 500ºC higher than that of copper.) Both in heat treatment and in its response to added elements, steel is a material infinitely more sensitive than bronze. In it, iron is alloyed with a tiny percentage of carbon, less than one per cent usually, and variations in that dictate the underlying properties of the steel.
The Ascent of Man Page 8