The weather in the streets

I had some time to kill and went into the antique shop on the square. It has a wide and random range of attic treasures and heirlooms from local sources (such as this one previously blipped.) My eye lit upon this curious glass object about 10 inches long. I thought at first was a feeding bottle but no, the sealed vessel had but one tiny aperture, at the end of the narrow, elegant tube that curved out of it. The antique shop owner said it was 'Swedish barometer' but he didn't know how it worked. I said I'd try and find out.

It didn't take me long to discover that it's also known as a weather glass and it was the main aid to forecasting the weather (particularly on board ship) before the invention of the aneroid barometer. It should be hung vertically on a stand or holder and half filled with coloured water which rises and falls in the spout according to the atmospheric pressure, giving important clues as to the weather conditions 12-15 hours hence. Here's how to read it.

There's some ambiguity about its origins. Some say it was invented by an Italian mathematician called Evangelista Torricelli and others a Dutch nobleman called Gheijsbrecht de Donckere, both living in the 16th century. It was brought to America by the first settlers and henceforward known as a pilgrim weather glass, invaluable to fishers and farmers who needed to plan ahead. It's also been called a Goethe barometer on account of the German poet's fascination with it. His personal instrument still hangs in the museum that was his home.

And today's weather in west Wales? I didn't need a weather glass (or a weatherman) to tell me which way the wind blew: from the north, and gustily.