What duration can an effect that moves materials have, when generated with the Philosophical Controlling of an elementalist (Hedge Magic p.25)?
Nowhere do I see that it lasts only one round, only that it takes a round to cast. In fact, when used to increase Soak it uses Concentration as a duration.
So could the elementalist levitate an object (or person) and keep it afloat as long as he concentrates, for example? Fight with a sword for multiple rounds? Use a wind to keep attackers away or fill his boat's sails? All of this seems reasonable to me.
Would that only cost a single Fatigue level, when the effect is initially cast? Again, I think only a single Fatigue being spent seems logical.
The tricky part is whether one could extend the duration of an effect for longer without maintaining concentration. Perhaps by spending some of the Controlling Total to purchase magnitudes for an increased duration? (Probably not)