If the Fire Nation has??muskets though, it would give the heroes a bigger challenge...even though they were slow to load and inaccurate at range, it was made up for its destructiveness.

A bullet may go too fast for a bender to block in time or dodge in Aang's case, and even if they were able to do block in time...the bullets would probably go through.

But too many parents are paranoid and freak out if they saw guns in a kids show, they probably never watched Looney Toons nor Tom and Jerry...

Well it does say it is in a lost age of time, so this show is probably based on China not only in the past, but in an alternative universe, which means a different world that is similar to Earth. Humans have been around for only 500,000 years, so if it was in this world it would have to have been any time around then, either BC or AD. Soemthin' teels me though that the period was just around the time of Ancient China which i think is somehwere around the 2000 BC-100 BC era. Either that or it really is the 1800's. What with those mehcanical operatable machines and all that. The Fire Nation used them anyway.

If all four natiosn are at a different time zone, here's how I would put it:

FN: 1850-1912

WT: 1400-1600

EK: 1400-1600

AN: 2000 BC-100 AD