Nostradamus began to write his prophetic verses in the city of Salon, in 1554. They are divided into ten sections called Centuries (which refers to the number of verses in each section, not to a unit of 100 years). The Centuries were published in 1555 and 1558, and have been in print continuously ever since. Nostradamus had the visions which he later recorded in verse while staring into water or flame late at night, sometimes aided by herbal stimulants, while sitting on a brass tripod. The resulting quatrains (four line verses) are oblique and elliptical, and use puns, anagrams and allegorical imagery. Most of the quatrains are open to multiple interpretations, and some make no sense whatsoever. Some of them are chilling, literal descriptions of events, giving specific or near- specific names, geographic locations, astrological configurations, and sometimes actual dates. It is this quality of both vagueness and specificity which allows each new generation to reinterpret Nostradamus.