Just came across this passage in The Hermetic Brotherhood of Luxor by Godwin, Chanel, and Deveney:
Fryar offered for sale a variety of mirror ceremonials, including an old manuscript on scrying entitled “Crystallomancy, or the Art of Drawing Spirits into the Crystal.”
Fryar is Robert H. Fryar, a bookseller from Bath who was the agent for selling the works of Paschal Beverly Randolph in Britain, as well as one of the likely founding members of the Hermetic Brotherhood of Luxor. Crystallomancy is the manuscript written or copied by Frederick Hockley. It’s not much of a connection, but it nonetheless brings together two separate strands of nineteenth-century occultism.