Tabletop Tesla coil

Mr. Apol made a tabletop Tesla coil:

After studying and tinkering with different components for a year, I finally assembled my first Tesla coil. I chose a bipolar design inspired by one in THE BOY ELECTRICIAN by Alfred P. Morgan (first published 1913, reprinted by Lindsay Publications and available at http://www.lindsaybks.com/.) Unlike the more common upright coils, the bipolar coil has a horizontal secondary and primary, and the ends of the secondary coil terminate in vertical electrodes. As I wanted to build a small tabletop model, this appealed to me because the coil would not need an external ground connection. I also decided to build the coil in modular fashion, with easily separated spark gap assembly, tank capacitors, and power supply. This way I could experiment with different components and see what changing these parts did to the overall performance of the coil.