It was a grand construction, consisting of twelve pint bottles arranged in a circle around the centrepiece, like some bizarre Merry-Go-Round. Out of their tops came a small chain, which fed up through a pulley and each continued towards its own respective, miniature hammer. Between all the hammers was a bell. This bizarre contraption was powered by a not common source of weather knowledge, the Leech.

Into each of the twelve vessels was poured one and a half inches of rainwater, and a single leech. The pint bottles were made of clear glass so as to spare the leeches “the affliction of solitary confinement”. George Merryweather realised that during the conditions which preceded a storm all leeches would climb to a higher spot, away from water. The necks of the bottles were obscured by a piece of whalebone connected to the bottom end of a chain. So a single leech forcing its way out would cause the bell to be struck once. The more times the bell was struck, the greater the chance of a storm. Merryweather described the Leeches as being his “jury of philosophical councilors” - surely one of the grander titles bestowed upon the simple organism, although it may have been warranted.