Tempest Prognosticator

As a GP, Dr George Merryweather – a somewhat ironic name as it turned out – was well aware of the medicinal application of leeches. He also noted that they acted in a singular way before a storm broke. He put this observation to use in 1850 with the creation of his ‘Atmospheric Electromagnetic Telegraph conducted by Animal Instinct’ or, as he preferred, ‘Tempest Prognosticator’. Crafted to resemble an Indian temple, it comprised a dozen glass bottles half-filled with water each holding a leech and encircling a bell. The change of atmospheric pressure that presaged a storm would compel the inmates to climb out of the water. When they reached the neck they would displace a piece of whalebone, making the bell chime. The greater number of leeches in the ‘jury’ that rang the bell, the greater the likelihood of a storm. Though he claimed success for his invention, it never caught on. Visit the excellent Whitby Museum (whitbymuseum.org.uk)

– curated by Dr Merryweather for many years – to see a replica of his curious machine.