Hi,
Nice discussion here.
I'm new to this forum and like to join in on this bellows subject.
I ran into this problem,- how to make a "Roman" belows - , when last year (2008) I had to set up a field forge for the Archeon in the Netherlands.
I realized it would not be a simple kite-shaped bellows as we know nowadays.
I asked virtually any known forum & blacksmith I knew, and also on the armourarchive.org forum, but nothing.
Even no pictures, reliefs etc.
I found a part of the possible answer in the picture shown here on this forum of the metal waterpump.
It had 2 chambers, valves and a horizontal lever, and it was ROMAN.
I had seen pictures of ancient north African bellows, and the were made of wood an just looked like it.
I figured the Romans occupied north Africa for quiet a long time and perhaps left this pump-technique there.
I made a very, very simple double chambered portable bellows and it worked like a charm. Without any problems it worked for more then a year.
It was build with PVC-pipe for the chambers (I just could not build wooden chambers, no time etc.) and covered them with wood.
I made wooden discs of 2cm plywood with holes in them to be covered with a leather flap ( piston up- leather uncovering holes leaving air in, piston down-leatherflap closes pushing air down)
Those discs connected to a simple wooden rod, loosely attached with a screw, around those discs a smple layer of felt was nailed for a seme airtight seal.
Two of those chambers were mounted on a plank with wooden column in between. this collum was to pivot the lever, and this lever rod was connected to the rods coming from the pistons.
And yes, two copper pipes coming from the cambers, joining together in a small camber with leather "flap" valves and so the 2 airflows coming together as 1.
it works so well, and it looks very Roman, but no, I can not be sure they had bellows like that.
I hope they did have them.
Let me know wat you think.