Re: Wine bottle Tesla coils

To cut bottles:
	File a groove all the way around, where you want it to 
break.  Al alternate way I have used is to get a carbide-tipped
scribe (about $4.00), wrap a band of metal around the jar and use
it as a guide for scratching with the scribe until you have a
continuous groove all the way aroun d.
	Next step takes some nichrome wire, #20 or so.  It
needs to be stretched tightly around the jar, in the groove
made above.  I made a gadget to do this with a hinge and some
pieces of wood, with a spring to apply tension.  Attach the
nichrome to a transformer  which can put out around 10 amps at
somewhere between 2 and 6 volts, and connect primary of transformer
to the line through a variac.  Adjust the variac so that the
wire just gets bright red when sitting in air.  Turn off the
power, stretch the wire in the groove, and turn the power back\
on.  (I usually have the bottle horizontal for this step.)
Almost every time after a few seconds there will be a sharp
snap and the jar will either part at the scribe mark, or else
crack almost all the way around.  If the latter you can try 
letting it cool and heat it again.
	This is essentially the procedure in Strong's "Procedures
in Experimental Physics", a book everyone should have.  Lindsay
how has a reprint.
Happy bottle cutting,
Ed Phillips