coil pictures and observations

I have posted some pics of my new coil on my web page at
http://tesla.better-dot-org/sgd.  It's the first coil that I have done
completely from scratch from beginning to end.  I doubled up the wire
connections from the cap through the primary and my spark length
increased noticably.  Has anyone done power-AWG vs spark length
comparisons (ie at what point do the returns of thicker wire start to
diminish given a certain power level)?  Or is there some general
rule-of-thumb formula one can use?

I also noticed that if I run my coil for more than about 45 seconds
continuously, the spark length drops off dramatically to almost
nothing.  The longer I let it sit before refiring, the longer the
spark.  I'm assuming that this is due to the poor quenching of my
two-bolt gap?

-Stan, the man, with tons of questions :)