1974 GUIDE 15'High X 36' diameter blue incandescent light, wave generator, theatrical dimmer, glass, wood masonite, paint When you first entered this piece it was invsible. It took at least three minutes for your eyes to adjust before the image would appear. The image was a cylinder of blue lines 1/4" wide, starting eighteen inches above the floor and rising twelve feet. After seeing the image six or more minutes, you could realize that it was brightening and dimming overall but not at a rate that allowed you to watch it change. Half the time the lines were seen with the rods in the eyes and half the time with the cones, changing from the day vision system to night vision and back again over a 6.8 minute cycle.