He walked across to that very strange device and lifted up one side of
the top. The whole thing moved, and inside I saw a series of arms
radiating from a central shaft. At the extreme end of the arms there
were prisms of glass in ruby red, blue, yellow and white. As the handle
was turned belts connected from it to the shaft caused the arms to
rotate and I observed that each prism in turn was brought to the line
which was seen by looking through the two eyepieces. My Guide
showed me how the thing worked and then said, “Of course this is a
very crude and clumsy affair. We use it here for experiment, and in the
hope of one day producing a smaller version. You would never need to
use it, Lobsang, but there are not many who have the power of seeing
the aura as clearly as you. At some time I shall explain the working in
more detail, but briefly, it deals with a heterodyne principle wherein
rapidly rotating coloured prisms interrupt the line of sight and thus
destroy the normal image of the human body and intensify the much
weaker rays of the aura.”
Source: http://www.lobsangrampa.org/data/en/The ... cients.pdf
The Heterodyne "Principle"
A working definition of heterodyning: To generate new frequencies by mixing two or more signals
in a nonlinear device such as a vacuum tube, transistor, or diode mixer.
Source: http://people.seas.harvard.edu/~jones/c ... odyne.html
It looks to be exactly the same theory as with the Edgar Cayce Aurascope. Edgar Cayce's reading predates the publishing of this book, however this version is far easier to understand!