Smyth's theories were later expanded upon by early 20th century British Israelites such as Colonel Garnier ("Great Pyramid: Its Builder & Its Prophecy", 1905), who began to theorise that chambers within the Great Pyramid contain prophetic dates which concern the future of the British, Celtic, or Anglo-Saxon peoples. However this idea originated with Robert Menzies, an earlier correspondent of Smyth's. David Davidson with H. Aldersmith wrote "The Great Pyramid, Its Divine Message" (1924) and further introduced the idea that Britain's chronology (including future events) may be unlocked from inside the Great Pyramid. This theme is also found in Basil Stewart's trilogy on the same subject: "Witness of the Great Pyramid" (1927), "The Great Pyramid, Its Construction, Symbolism and Chronology" (1931) and "History and Significance of the Great Pyramid..." (1935). More recently a four-volume set entitled "Pyramidology" was published by British Israelite Adam Rutherford (released between 1957–1972). British Israelite author E. Raymond Capt also wrote "Great Pyramid Decoded" in 1971 followed by "Study in Pyramidology" in 1986.