Spring Tide

¹⁰ Still Life

A small greenhouse stood on the paved backyard of a long unoccupied house. It had a concrete floor and a single aluminium shelf. On the shelf stood three empty plastic flowerpots, with a fourth lying on its side. A watering can, moulded from red plastic, rested on the floor by the door.

It was the middle of a summer afternoon. Up until midday, the sky had been clear. All morning, the radiation had been pouring down from the sun, with no cloud in the way to reflect it back. Outside the greenhouse, the sun had warmed the soil and the roof of the house, and heated the black tarmac of the road it stood on to the point that it had become soft and sticky. In their turn, the soil, the road and the roof had warmed the air above them. As the air warmed, it had risen upwards, cooler air flowing in beneath it to take its place.

Inside the greenhouse the sun had also heated everything that was there: the aluminium, the concrete, the plastic pots and the red watering can. They too had warmed the air above them, but, unlike the air outside, the air in the greenhouse was trapped by the glass roof, which meant that, even when it was hot, it still remained close to the warm concrete and the aluminium and the plastic. And so the concrete and the metal and the plastic had continued to heat the same already-heated air, as if they were a hotplate on a stove, and the greenhouse was a saucepan with its lid on. The air became very hot in there, and far hotter than the air outside.

Later on, as morning turned to afternoon, the sky clouded over and a cold wind began to blow. The air outside the greenhouse, already so much cooler than the air within, became colder still. But the air in the greenhouse, still sitting over that warm concrete and aluminium, stayed warm. It would cool down eventually, of course, but it would do so much more slowly than the air outside. Only the glass cooled quickly, because of the cold air rushing over it.

It so happened that the humidity was high that day. Inside the greenhouse, the warm air came up against the much colder glass, and some of the water vapour that it was carrying began to condense on the cool surface. Quite soon, the whole inner surface of the glass was steamed up, covered in a layer of tiny water droplets.

Some of these water droplets were heavier than the others, to the point where the constant tugging of the planet Earth beneath them became stronger than the surface tension that held them against the glass. The droplets on the glass windows began to slip downwards and, as they slipped, they collided with other droplets, absorbing the water into themselves and so becoming heavier still. The larger they grew, the smaller was their surface area in relation to their mass. As a result, the pull of the planet became stronger, relatively speaking, and the surface tension weaker. So the drops moved more quickly, and absorbed water more quickly too from yet more droplets. And all the greenhouse’s windows were striped with the paths that these heavy drops had made.

The same thing happened under the glass roof, but here, when they had accumulated enough mass, the droplets didn’t just slide down the inside of the glass but also began to drip. The drips fell straight downwards through the still-warm air inside the greenhouse, to splash onto the concrete floor, or the aluminium shelf, or sometimes onto the plastic pots or the can.

Having shed some of its weight in this way, a droplet would stop dripping, its surface tension once again strong enough to hold it together, and it would resume its descent down the inside slope of the roof, until it had accumulated enough water from smaller drops to rupture once more and release drips.

This sequence of events had happened many times. One of its consequences was that, while the glass of the roof, like that of the windows, was striped with the trails of water droplets, these roof trails were punctuated at more or less regular intervals with bulges, like beads on a necklace, where the water had paused and dripped.

And so, although the glass inside the greenhouse had been dry in the middle of the morning, now there were stripes of water on the walls, beads of water on the ceiling, and drips of water falling at regular intervals from the ceiling to the floor.

People were not involved in this story. There were no human beings present at all. There was life in the vicinity, it was true: weeds grew just outside the greenhouse – nettles, speedwell, grass, dandelions – and among this vegetation there lived earwigs, spiders, slugs, woodlice and snails. But none of them had anything at all to do with the stripes, or the beads, or the steady drips.

The only actors here were air, water vapour, sunlight, glass and gravity. And though all of these are more or less smooth and continuous things, the interaction between them had nevertheless produced rhythm and form.

Beyond the glass of the greenhouse roof, and far above it, new dark clouds were moving rapidly through the atmosphere.

They were also made of drops of water, and these water droplets were clumping together up there in the clouds, like the droplets had done inside the greenhouse.

And presently fat drops began to fall from them, spinning and turning through all that empty air, until they splashed on the greenhouse roof, ran down its glass, and trickled off it again in tiny waterfalls, onto the weeds and the soil.