Technical Can someone tell me what this is?

Here's what I was saying
http://books.google.com/books?id=Xg...page&q=popular science dwell extender&f=false

 

I was cleaning in the house, and found this book....

 

I have several of these units. Some of them brand new. They did work well.

 

The SCR ignition was a different beast altogether, the later electronic versions used a "darlington pair" type of transistor to do the high current (coil) switching.
I still build these and install them on my cars. Put in a New set of points, correctly gapped, and they will outlast the engine as long as the rubbing block doesn't wear away.