Provided By - Mat
It's a 0.5L Coke bottle which uses 7 9volt batteries to charge three 400uf capacitors to 60 volts, they are then discharged into an ignition coil which produces a small but very bright spark!
Very simple, put together with tape
!The barrel's around 2 feet long and 1" diameter which gives a C:B ratio of 1.6:1, and it's able to shoot an AAA battery(Wrapped in lots of tape..) over a soccer field.
That's what's on the picture, but I replaced the 0.5L coke bottle with a 1.5L sprite bottle which gives better performance and MUCH more sound, as it's a 5:1 C:B ratio...
<img src="http://www.spudfiles.com/official_pics/Bild(113).jpg">
<img src="http://www.spudfiles.com/official_pics/Bild(119).jpg">
Provided By - Mat</div>
But, if your confident its safe its ok 
