Jord og måne

Danish Instrument Inventory text:

Electrostatic lunarium. Fruitwood base Dia62 and pillar ending in steel point, overall H120. On this balances a brass rod L110 with 2 ivory spheres Dia18 and Dia13. The larger has lines for polar circles, tropics, equator and ecliptic. A tangential directed brass point from the brass rod causes the system to rotate by discharge.Not signed1780 app (g)