Glossary of dowsing terms
The Hartmann grid is an earth grid named after Dr Hartmann who it is thought was the first to observe earth grids. It is a world wide grid in accordance with the earth's magnetic field, i.e. approximately N/S, E/W. There are considerable variations in the grid spacing dependent on local conditions and the degree of latitude. In Greenland a spacing of 1.05m x 1.20m is found. In England the average spacing is 1.60m x 1.68m while in the Canary Islands it is 2.00m x 2.50m. The straightness of the grid lines can be affected by high voltage power lines and radio stations.
See also Earth Grids.