Weather Whys; Weather Leeches

This is weather-wise. The field of medicine has come a long way since the leech was an integral part of treatment. Similarly, meteorology has changed quite a bit since its infancy. But contrary to what all scientific evidence tells them, some people still swear by the leech as a weather forecasting tool. The leeches rise to meteorological stardom is partially rooted in mid-19th century England. A man by the name of George Maryweather invented a device called a tempest prognosticator, which consisted of a jar with a bell suspended from its lid. In the jar, leeches were attached to the bell by a system of pulleys. Maryweather said that during fair weather, the leeches would remain at the bottom of the bottle and stay relatively still. But as stormy weather approached, the leeches would supposedly become restless and their movements would cause the bell to ring. He said the more the worms moved around, the worse the weather'd come.

Maryweather was so sure of the accuracy of the device he encouraged the British government to set up a network of leech warning stations along the coast. But Maryweather wasn't the first to believe in the forecasting prowess of the leech. For centuries, Spanish legend had set out a very detailed list of leech behaviors and the weather those behaviors supposedly predicted. For instance, if the creatures curved themselves into the shape of a half moon, that was supposed to indicate stormy weather ahead. And if they moved rapidly around their jar, strong winds could be expected when they stopped. Of course, the responsibility for such detailed prediction is an awful lot to put on the shoulders of a little leech. If leeches can be said to even have shoulders. At Weatherwise, our writer is Christine Harbour, edited by Brian Waukey. Weatherwise is made possible by a grant from the National Science Foundation. For Weatherwise, I'm Drew Barlow.