William Dinsmoor, the famous historian of Greek architecture and one of the experts who directed the first reconstruction of the Athenian Acropolis, here sets out the process by which he was able to piece the gables of the Propylaia together from surviving fragments. The paper also analyzes the way in which the structure was originally held together. Although the first reconstruction has drawn a great deal of criticism for the damage it did to the monuments, it was on the whole successful and the massive amount of work that went into it still informs the ongoing modern reconstruction efforts. This piece will interest historians of architecture as well as those wanting to know more about the conditions under which this early effort in re constructive archeology was performed.