TEHRAN A French engineer has confirmed that the heights of stairs at Takht-e Jamshid are of standard size. He said that ideas of the Iranian architects, 25 centuries ago had been a great help to make the heights of the stairs standard. Takht-e Jamshid or throne of an Iranian emporor is regarded as a world-famed capital of the Emperor Jamshid and one of the most valuable cultural heritage of Iran. According to the existing documents, the wrokers who helped for building it were adequately quite enough.