Cornelius Drebbel, born in Alkmaar, Hol land, 1572, was as alchemist who claimed to have discovered perpetual motion, and ac quired sufficient reputation for learning to be invited to the court of James 11, King of Eng land to him he dedicated his treatise on Pri mum mobile in I607. Later in life he visited Prague where Rudolph had gathered famous alchemists, astrologers, and magicians, as well as more reputable astronomers, artists, anti quarians, and skilled mechanics Drebbel, how ever, was unsuccessful in sustaining his claim to the discovery of perpetual motion, and Em peror Rudolph threw him into prison, from which he was released 'ere long by the death of the monarch, in 1612.