[Note.] "It would be advisable for the invocant to remain in the circle for a few minutes after reciting the license, and if the place of operation be in the open air, let him destroy all traces of the circle, etcetera, and return quietly to his home. But should the operation be performed in a retired part of a house, cc cetera, the circle may remain, as it might serve in alike future operation, but the room or building must be locked up to avoid the intrusion of strangers."