In the image on the right, taken from the Internet, a young woman tries not to laugh as the mysteries of modern science make the hair on her head stand up. The round object on which she rests her left hand is the bulb or terminal of a Van der Graaff electrostatic generator. The effect is achieved by altering the electrostatic charge on the surface of the sphere. The charge ‘flows’ through her body, charging her hair along with everything else. The like-charged hairs repel each other, and in their escape from proximity, they rise from her head and away from one another.
The toy Van der Graaff that I got at about the age of eleven was not as powerful, but it worked in precisely the same way. Friction was used to ‘scrape’ electrons from a wide rubber band, creating a charged electrostatic difference, and charging the metal-plated plastic bulb.
My attitude to the toy was ambiguous. I appreciated the effects that it was able to produce. The tissue-paper octopus, when placed on the bulb, writhed its paper tentacles convincingly. The Styrofoam ball on a string orbited the bulb with a jerky bouncing motion as long as I turned the plastic handle that propelled the rubber band. The bulb produced sparks which looked, and indeed were, exactly like lightning on a small and safe scale. The toy could deliver a painless little electric shock with a satisfying crack. But it did not satisfy me. It wasn’t a big Van der Graaff, and could produce no more than a tingle in my short-back-and-sides haircut. And besides, the toy was plastic – a sure sign, to my way of thinking (which owed its aesthetics at least in part to those taught at the Camberwell after the war) that it was somehow inauthentic. Not all of the advertised effects worked, and those that did, like water monkeys ordered from a comic-book, did not really match the descriptions on the box. Adults, especially Anton, used equipment, but it was not plastic and did not look like this.
The Van der Graaff electrostatic generator works on principles that are identical to those that accumulate static electricity in clouds. Only the scale is different. Friction, though from what source I cannot say, charges the clouds until they are forced to release their immoderate energy in bolts of lightning. When a thundercloud looses its force, it finds, as it were, a weakest point, an ionizing path along which ten thousand volts flow at five hundred miles an hour. The earth sends a counter-surge of thirty thousand amperes back up this path at ten times that speed, followed by a series of back-and-forth surges. For the purposes of our perception, all of this activity is instantaneous, and is seen as a single flash of lightning.
There was a gum tree about a hundred metres from our house. Though by no means the oldest, it was by far the tallest and perhaps thickest tree on the farm. It stood moulting strips of bark like a tree in a South African landscape painting of the kind that our family had learned to despise. We called it ‘the big gum’ although there were other gum trees on the farm.
Madala, the worker whose face my mother chose to preserve in her family album, liked to predict hail. He would point at particularly dark thunderclouds and say, ‘stones,’ and would often be right. He may have predicted hail the day that the big gum was destroyed, for there were certainly very dark clouds. I was outside in the space between house and the gum tree, a downward-sloping piece of land with a ragged lawn, when the first drops of that storm fell. The lightning must have come soon afterwards, because I had not yet found shelter when it struck. I do not really know how many electron volts a tropical storm-cloud can deliver into a tree or even what an electron volt really is, but the charge that poured instantaneously into the big gum filled it with so many mutually-repulsive electrons that the seven-storey-high trunk, no longer able to stay near itself, split from top to bottom and exploded outward. The noise of this explosion, travelling at the speed of sound, reached me at about the same time as the surplus charge from the tree, which flowed through the ground on which I was standing. As I reconstruct it, this caused the muscles in my body to contract, throwing me onto the wet grass. The same bolt of agitated electrons ‘jumped’ from the tree or from the sky and entered the telephone wires, melting the copper for hundreds of yards and blowing bits of the black bakelite fuse-box right across the crazy-paving of the front yard and out beyond to where the cars parked.
In the picture, part of a family group, my father sits on the left, his knee resting on that of his twin. Although there is a terrier on his lap, Jack’s posture is a mirror image of Tom’s, cross-legged, hands grasping shins. Jack is barefoot. Tom is shod but does not wear socks. His head leans slightly towards Jack. Both stare intently outward, at the camera.
It was my mother who told me about the death by lightning of my father’s twin brother Tom, when they were twenty. Jack never spoke about it to me.
The grassy green flank of the Front Hill fills the view from the stoep of the stone house on Rudolf’s Hoek. It was there that Tom had been walking with his dog when the lightning struck. The dog was not killed. About Jack’s reaction on hearing the news (he was working as a reporter in London at the time), I can only speculate.