William Scott-Elliot (1849 -September 2, 1919), the Tenth Laird of Arkleton, was an early member of the London Lodge in the Theosophical Society (Adyar), who sometimes wrote under the name W. Williamson. His occupation was investment banker, but his avocation was study of anthropology.
On October 11, 1893, he married Maude Boyle-Travers, a psychic and member of the London Lodge, known in Theosophical history under the pseudonym of "Mary". On October 9, 1895, they had a son, Walter Travers Scott-Elliot.
Scott-Elliot was intrigued by the clairvoyant findings of Charles Webster Leadbeater into ancient Atlantis and Lemuria, and undertook scholarly research to support them. The Story of Atlantis was published with a preface by Alfred Percy Sinnett.
Jinarājadāsa on The Great Law
On two occasions Dr. Smith has talked to me about a book called "The Great Law" written by W. Williamson and published in 1899 by Longamans, Green and Company. He was told years ago by Mrs. Daisy Hurd that W. Williamson is actually a pseudonym for Besant and Leadbeater, the real authors of the book. He has never been able to verify that information, and I told him that sometime in writing to you I would ask whether you know if that is correct?
Mr. Jinarājadāsa responded:
Regarding The Great Law and the author, W. Williamson, that was an arrangement recommended by the Inner Group of the London Lodge. The material concerning Atlantis and Lemuria was C. W. L.'s, particularly the maps, though Dr. Besant was present at some of the investigations. But it was considered that if W. Scott-Elliot were to put the book together and put a pseudonym, W. Williamson, as author, it would be possible to get an outside publisher to undertake the work. He did all the writing up of the material, and so Longmans became the publisher. Scott-Elliot was very well off, and he married the lady whom Mr. Sinnett in his Autobiography calls Mary. 
- The Story of Atlantis: A Geographical, Historical and Ethnological Sketch, 1896, available at Sacred Texts.
- The Lost Lemuria, 1904, available at Sacred Texts.
- The Great Law: a Study of Religious Origins and of the Unity Underlying Them, London and New York: Longmans, Green, and Co., 1899. Written as W. Williamson.
- The Times and Teaching of Jesus Christ. London, Longmans, Green and Co., 1912. Written as W. Williamson.
- The Marriage of the Soul, and Other Poems. London: Theosophical Publishing Society, 1917?.
Mr. Scott-Elliot made several contributions to the Transactions of the London Lodge of the Theosophical Society:
- "The Evolution of Humanity," No. 17 (February 1893), 3.
- "Vehicles of Consciousness," No. 21 (May,1894), 3
- "The Lunar Pitris," No. 26 (August, 1895), 3. Co-author Mrs A.P. Sinnett.
- "Atlantis - A Geographical, Historical, & Ethnological Sketch," No. 29 (February, 1896), 1.
- "The Law of Sacrifice," No. 39 (October, 1903), 3.
He also wrote one article for The Theosophist:
- "Echoes from the Past," Vol. 50 (February, 1929), 529.
- Joscelyn Godwin, Atlantis and the Cycles of Time (Rochester, VT: Inner Traditions, 2011), 69-70.
- William Scott-Elliot, "The Evolution of Humanity", Transactions of the London Lodge of the Theosophical Society No. 17 (London: Kegan Paul, Trench, Trübner, & Co., 1893).
- Daniel Caldwell and Michelle B. Graye, "Mary Unveiled," Theosophical History 1:8 (October, 1986), 206.
- Gregory Tillett, The Elder Brother: A Biography of Charles Webster Leadbeater, London: Routledge & Kegan Paul, 1982.
- Letter from Ann Kerr to C. Jinarājadāsa. January 23, 1947. Correspondence about Mme. Jelikovsky in James S. Perkins Papers. Records Series 08.06. Theosophical Society in America Archives.
- Daisy Hurd was a longtime member of the Oak Park, Illinois Lodge, and a clairvoyant.
- Letter from C. Jinarājadāsa to Ann Kerr. February 28, 1947. Correspondence about Mme. Jelikovsky in James S. Perkins Papers. Records Series 08.06. Theosophical Society in America Archives.
- The International Theosophical Year Book 1938 (Adyar, Madras, India: Theosophical Publishing House, 1938): 213.