In The Development of Mediumship by Terrestrial Magnetism, Judson S. Bury explores how Earth’s magnetic field may influence spiritual sensitivity, offering a blend of natural science and metaphysical insight. This article revisits Bury’s historic theories and distills his key techniques for cultivating mediumship—from stillness and moral intention to group circles and daily discipline. Whether viewed as metaphor or method, his work continues to inspire seekers of spiritual connection and self-discovery.