Three volcanoes erupting, artwork published in Specula Physico-Mathematico-Historica (1696), an encyclopedia of science by the German monk and author Johann Zahn (1641-1707). The text is in Latin, and the volcanoes are (from top to bottom): Etna (Sicily), Vesuvius (Italy), and Hekla (Iceland). The different eruptive behaviour of these volcanoes is shown here. Etna is an explosive stratovolcano; Vesuvius is a less explosive somma volcano; and Hekla is a fissure volcano that steadily produces lava but is much quieter than the other two.