Having my son Christopher work on the design and construction with me was part of his
home school education.  An interesting 8th grade science class!

For a video download and view this.  It is 9 MB. -  Tesla Coil Video

I am the one crouching by the large Variac.  Tom Arnold is standing in the foreground.
You can see Christopher's head above the Oscilloscope to the right.
There are two onlookers in the background.

Sparks from our first coil to a grounded rod.  These are about 35 inches.  We have reached 45 and should be able to get over 60 inches with further work:

The Coil - Note we initially were concerned with strikes from the coil to the
supply so we moved it some distance away and connected it with a transmission
line.  Later we removed the transmission line and move the supply closer.