Beaufort Scale

But even if you don't have expensive equipment, you can get a fair idea just by looking at objects around you, and it's largely thanks to the work done by Admiral Francis Beaufort.

Measuring the exact wind speed without sophisticated equipment is not easy, even today. But it was much more difficult some 200 years ago when the large sailing ships of the Royal Navy were much more at the mercy of the weather, especially strong winds.

In 1805 Commander, later Admiral, Sir Francis Beaufort published a method of measuring the wind at sea based on what sails a frigate could safely hoist. The Beaufort Scale, as it came to be known, was adopted by the Royal Navy in 1838 when it became mandatory for all ship's log entries.

The scale had 13 steps; from force 0, where the wind was calm, to force 12, where the steady wind would be at least 64 knots or 75 miles per hour. With this scale also came descriptions of the state of the sea. From this standard, sailors were able to predict how ships would react in certain wind speeds.

It was quite a lot later in the century that the Beaufort Scale was adapted for use on the land. In many respects it, and the descriptions that go with it, are still used today.

A further set of Beaufort numbers from force 13 to force 17 was added by the United States Weather Bureau in 1955 to cope with the exceptional winds that they can get during a hurricane.