I think that one way in which Miller creates a heightened sense of drama in the act of Act I is with the rapid succession of accusations. There had been a lull in the dramatic action. The girls had been silent, and there was more confusion than actual definite action. Yet, at the end of Act I, when Tituba makes her initial accusations more out of fear than anything else, Abigail and the girls hit with a flurry of accusations. In a quick sequence, there was a sudden movement of the drama's trajectory. At the same time, the drama is enhanced with the townspeople reveling in what they are seeing and Hale sensing some type of validation. The drama is built because what had been hinted at for so long in the narrative is realized: The presence of the devil in Salem.
It was at this moment in the ending of Act I where its recognition had become fully recognized. In this, there is an ending to the Act that builds drama and propels it forward at a strong cadence. Through this drama, Miller establishes the collision between truth and political control that will guide the thematic development.