I just found out about this machine on the web. Its supposed to be the first drum machine ever made. Sold as a Wurlitzer organ accessory beginning in 1959. The ‘sequencer’ is actually a wheel covered in electronic contact points. So each point is like a trigger. IT has about 10 presets and you can also play with the buttons to trigger sounds.

More geeksplanation about the machine -> Wurlitzer-Sideman
pic’s ->
(click to make bigger)