MO Cap Failure Question

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <network-at-neXband-dot-com>

Hello list,
   The other day I was trying to trace down a problem with my coil.  
Thinking there was something wrong with MOT power supply, I bypassed the 
doubler circuit and MO caps and tried to draw an arc to the center ground 
of the MOT's(trying each transformer one at a time and then both).  I was 
getting a great arc from them and was going to show a friend the lethal 
power.  This time there was one MO cap in line from one of the HV 
outputs.  This produced a much more massive arc!  Very impressive!  

Why did this improve the arc?

Not long after a few arcs, the MO made a fairly loud crack sound and then 
the arc was half the size as if I blew the MO cap.

What happened to the MO cap?
I'm gonna guess that the current got to it where usually the tank cap 
would suck up all that current.  Is this right?

Just wondering because I've never had one to fail in my power supply when 
wired normally.

Thanks all,
Gregg Adams