Pyrotechnic Weapon; Greek Fire Syphon

The hypothetical reconstruction is based upon written descriptions
and one surviving illustration.  A vertical brass pump provides air
pressure via a bronze-bound leather hose to the main tank
consisting of two pieces of copper sheeting soldered together.
Underneath is a small brazier  and a pair of bellows.  Another hose
 takes the heated liquid to the  nozzle.

Redrawn and Enhanced  by Marcus Audens.

Reference: D. Nicolle, "Medieval Soege Weapons (2)," Osprey, 2003, New Vanguard 69.