Tempest prognosticator

Dr. Merryweather, honorary curator of the Whitby Literary and Philosophical Society's Museum, detailed the sensitivity that medicinal leeches displayed in reaction to electrical conditions in the atmosphere.

The expensive design, which took inspiration from the architecture of Indian temples, was made by local craftsmen and shown in the 1851 Great Exhibition at The Crystal Palace in London.

In his essay Merryweather also noted other features of the design, including the fact that the leeches were placed in glass bottles placed in a circle to prevent them from feeling "the affliction of solitary confinement".

[1][2] Merryweather spent all of 1850 testing the device, sending a letter to the president of the Philosophical Society and the Whitby Institute, Henry Belcher, to warn him of an impending storm.

Plans and photographs of this replica were then used to create faithful working models, one at Barometer World near Okehampton, Devon, and another at the Great Dickens Christmas Fair in San Francisco.