Mercier 60 Line Set
(click on picture for high resolution image)
This is a 60 line receiver built by Murry Mercier Jr. and Sr. in 1928. The disk is almost 3 feet in diameter. You can see the disk and motor in this photo. The Merciers put this set in the window of their store on north High Street in 1929. They put a mirror in front of it so that Murry could keep the picture synchronized for viewers outside the store.
This photo shows the motor mounted on a plate that slides in the track. The rubber wheel is visible on the left end of the motor.