PV Scientific's founder and master instrument maker, Jim Hardesty, in his laboratory
with a beautiful old Crookes railway tube, also known as a paddlewheel tube.
Photo credit: Bryan T. Root, Motherlode Pictures.
A still photo of the railway tube in operation. The cathode is seen as a purple glow at
the left. The green rectangles in the center are the glowing vanes, or paddles, spinning as the paddlewheel rolls along the glass "track" of the tube. Photo credit: Bryan T. Root, Motherlode Pictures.