The boiler is there to intercept spells to prevent them. Spells fall ind the trap and there they are disabled. Here is the play of the sphere an important role. The boiler has a radius of 3 1/2 fields and captures the potions from the exactly half the radius of the sphere of action of the spell. One note! E.g. Jump spells have a smaller scope than healing spells. Reactivation costs: 2500 gold. The case is 1 large box, looks black shimmering, and takes the form of a boiler. They can e.g. behind walls to place so the enemy jump magic to disable.
Sry for my bad english.
