Tempest prognosticator (nonfiction)

The tempest prognosticator, also known as the leech barometer, is a 19th-century invention by George Merryweather in which leeches are used in a barometer.

The twelve leeches are kept in small bottles inside the device; when they become agitated by an approaching storm they attempt to climb out of the bottles and trigger a small hammer which strikes a bell.

The likelihood of a storm is indicated by the number of times the bell is struck.

Fiction cross-reference

• Crimes against mathematical constants
• Gnomon algorithm

Nonfiction cross-reference

External links:

• Tempest prognosticator @ Wikipedia