midnight
He was not exactly an alchemist ; he was an astrologer , and there are the ruins of his tower in the park . There are some old books up-stairs , upon the Black Art , with his name in them , Johannes Carvellius , written in the most enchanting angular handwriting . '' `` I believe there was somebody of that name , '' remarked John . `` They are full of delicious incantations for raising the devil , -- such exquisite ceremonies , with all the dress described that you must wear , and the phases of the moon , and hazel wands cut at midnight . Imagine how delightful ! '' `` The tower in the park is a beautiful place , '' said Hermione . `` I have it all filled with flowers in summer , and the gardener 's boy once saw a ghost there on All Hallow E'en . ''