Pasilalinic-sympathetic compass
The pasilalinic-sympathetic compass, also referred to as the snail telegraph, was a device built to test the hypothesis that snails create a permanent telepathic link when they mate. The device was developed by French occultist Jacques-Toussaint Benoît (de l'Hérault), with the supposed assistance of an American colleague, Monsieur Biat-Chrétien in the 1850s.
Source: Wikipedia — Pasilalinic-sympathetic compass (CC BY-SA 4.0)