The recent couple of weeks of sunshine – what we in England call ‘summer’ – has left the water level down a bit in my garden pond. Apparently a pond evaporates by about one inch per day in hot weather, but topping it up from the hose defeats the natural object. So I was excited by this week’s downpours because I thought they’d do the job for me. That’s when I noticed a baffling physical phenomenon that you might be able to help me with.
Outside the back door was a bucket, and after one of the heavier cloudbursts, it had a good inch of water in the bottom of it. “Great!” I thought. “The pond will have risen by an inch.” But it hadn’t. It had risen by barely more than half a centimetre. Why?
OK, so the bucket is slightly wider at the top than it is at the bottom, but so is the pond. If I’d laid out a load of buckets to cover the same area as the pond, they would all surely have collected an inch of water, just as the one bucket did. So why was the pond level so stubborn to rise?
I put this to my wife, who quickly dressed and went out to work.
The more I thought about it, the more I could only see one logical answer: I’m no good at maths. It also increased my respect for the bucket, which has to be up there in the top five inventions of all time, along with the wheel, television, the aeroplane and the air fryer, which it pre-dates by some considerable time.
As my pond demonstrates, holding water is no easy task. Carrying it from one place to another is harder still. The bucket makes it a breeze. In parts of 18th century Germany, every household had to keep a full bucket of water at all times in case of fire, with the homeowner’s name imprinted on the bucket. Having a bucket with your name on was a difficult habit to kick – achievable, in fact, only by dying. Hence the popular expression, “den Eimer treten”.
Deep into the 19th century, the bucket was so widely used in the UK that it was a recognised unit of volume, equivalent to four gallons, or a peck of apples. Today, while we tend to make them out of plastic or metal, rather than the stomach of a large, unfortunate animal, this simple yet ingenious device is still ubiquitous, lending its name to all sorts of things: bucket lists, bucket hats, bucket shops, rust buckets, Charlie Bucket, Hyacinth Bucket, the Frog and Bucket, There’s A Hole in My Bucket, The Bucket…
According to the scientists, there is the same amount of water on Earth today as there was when the planet was formed, yet there are a lot more buckets. Explain that! And if you can tell me why a bucket should fill up faster than a pond, my wife would love to know.
