Frater Achad
1923. Or the Crystal as a Stepping Stone to Clear Vision. A Practical Treatise on the Real Value of Crystal Gazing. Contents: The lesser crystal sphere; The greater crystal sphere; Universal crystalline sphere; A consideration of the ancient methods; Further considerations the methods of Dr. Dee and Sir Edward Kelly; Attainment of crystal vision; The ultimate crystal.
Occult
Crystal Vision Through Crystal Gazing