In his words, "The bucket was moved to different locations to demonstrate the various shapes of the beam from different angles to the target. The beam clearly demonstrates the 'inverse square law'. The energy bounced off the lens can be "tapped" at whatever distance suits the target. This is just as effective either in front or behind the actual focal point. The heat transfer to a can of water was most effective when the beam was spread. A number of experiments were carried out to examine the effects of different coloured target surfaces.