Discovered by the physician Ernst Hartmann in 1954 and described in detail in his book Krankheit als Standortproblem (Illness as a Location Problem), the Hartmann grid is associated with the Earth’s magnetic field. Its lines measure between 8 and 12 inches in width approximately. These lines are spaced about 6 feet apart in the north-south direction and about 10 feet apart in the east-west direction. However, these values can vary immensely depending on geographical location The Hartmann grid is often referred to as a global grid. In his book, Hartmann provides clear evidence for the pathogenic character of the grid. See also: Schumacher, 2005, 93-97; Dale, 2009, 108-109.