(seems my original comment is stuck in the spam queue due to a Wikipedia link…)
Looks like it’s a Barlow (or Barlow’s) Wheel: a simple kind of electric motor used mostly for demonstration purposes. The stellation of the wheel is just so that rotation can be easily observed; a simple disc would function as well.
Spotted on a table of old instruments while wandering around London’s Portobello Road market two Sundays ago. 
Looks like it’s a Barlow Wheel: an early electric motor.
http://en.wikipedia.org/wiki/Barlow%27s_wheel
–SMQ
Portobello
Thank you!
-cvj
(seems my original comment is stuck in the spam queue due to a Wikipedia link…)
Looks like it’s a Barlow (or Barlow’s) Wheel: a simple kind of electric motor used mostly for demonstration purposes. The stellation of the wheel is just so that rotation can be easily observed; a simple disc would function as well.
–SMQ
Hi SMQ – thanks for your comments! (I restored the original one from the spam bin once you mentioned it was there…. so people have the link.)
Cheers!
-cvj
Not sure about electric motor but looks interested for sure.
cheers
My first instinct was that it is a telescope