Board Thread:False Info and Speculative Discussion/@comment-201.76.133.29-20140726172901/@comment-19765459-20140728005901

We see different people use the Ash in different ways, some clumsy, some sophisticated. For example, the druids can throw a handful of the Ash into the air and have it precipitate into a perfect circle around them. We do not see any non-druids do that same trick. So apparently you have to have the knowledge/ability to make it work. Otherwise you're just pouring it out like any other powder.

Deaton was awfully specific about Stiles needing to visualize the desired outcome of creating the Mountain Ash barrier around the rave. It was clear that he was not just talking about measuring out enough of the dust to surround the building. There was an act of will inherent in creating the barrier. Likewise, Stiles is not a computer nor a scale. Precisely measuring out the Ash he had so that he could complete a line around the entire building was non-trivial. Some kind of magic was at work making sure that the Ash was distributed evenly, just as is the case when the druids seem to casually toss the Ash into the air and have it form a perfect ring.