Science Fair success!

Hi all, this is matt and just won the science fair.The judges were very hard 
to get along with and stated some false info also.He said Tesla was famouse 
for DC and not Ac!? Am I wrong or is he?Several other arguments suggested he 
knew very little about tesla coils.Also my sparks were only 7 in!!!They used 
to be 15 at home.Is it the ground rod? At home the ground rod was 1ft away 
from the coil.At the school it was about 20 or more feet away.Thank goodness 
it was only 7 in because a stupid guy in 11th grade went in when no one was 
around and turned it on! He said he touched it bare handed right on the 
toroid and it knocked him silly.