On 8/21/2006 at 11:56 PM ard at p850ug1.demon.co.uk wrote:
 I actually have a book of electrical things for boys to
make which
suggests makine a sausage cooker that simply connects said sausages
across the (110V) mains. Hmmm.... 
I suspect that if one wanted to use 220v mains, one would hook two sausages
in series...
 I am trying to rememebr other ways of determining the
polarity of a DC
supply.  
Salt (NaCl) on moist blue litmus paper will turn red around the v-  pole.
I once knew a fellow who swore he could TASTE the difference when one lead
was touched to his tongue (the other being held between moist fingers).  He
probably speaks with a permanent lisp now...
Cheers,
Chuck