Book: Leys, Secret spirit paths in ancient Britain. Wooden Books, written by Danny Sullivan, page 2, below is copied direct from the page word for word.
Its a dull imagination that isn't fired on first hearing of the concept of ley lines. From Alfred Watkins simple discovery of lost ancient trackways in 1921, ley lines have evolved to encompass a wide field of theory and speculation.
In the early part of the 20th century research began to appear which speculated that the ley lines should be identified with astronomical alignments, or spirit or fairy lines. These and other ideas are covered later in the book. However, the modern revival in ley hunting was in fact largely triggered by the post war flying saucer craze.
In the 1950's French ufologist Aime Michell had claimed that sightings of UFO's when plotted on a map, fell into straight lines which he called 'orthotenies'. One of the earliest alien abductees, Buck Nelson, had written that flying saucer pilots tapped into lines of magnetic force in the earth to power their craft. Then in the early 1960's ex RAF pilot Tony Wedd, an enthusiastic believer in UFO's put these two fantastic concepts together with Alfred Watkins leys and thus the ley line of magnetic force was born.
The sixties counterculture embraced ley lines as part of the cultural revolution and the mystical energy lines quickly became the accepted explanation for leys. Dowsers claim to be able to locate hidden energies at ancient sacred sites such as stone circles and standing stones and eventually claimed to be able to dowse the leys that run between them.