Northcote Thomas provides an lengthy study of the history and practice of Crystal gazing.
An early work on the subject, originally published in 1905..
Thomas spends two chapters in an in depth discussion of Egyptian scrying.
In additional to practical techniques, the work covers the Crystal ball\'s history.
A chapter on the incantation or "call" is included.
He covers techniques for scrying utilizing a Crystal sphere as an aid in clairvoyance and obtaining visions.
Northcote Thomas provides an lengthy study of the history and practice of Crystal gazing