24$ History of Art in Antiquitv. horizontal beds. The size of the freestone blocks is pretty much the same as at Pasargadae and PersepoHs; they ave. rage i m. 30 c. long by 65 c. high, and from 60 c. to 50 c. thick. The explorer observed, not without sur- prise, in the apparent bed of the last courses, that the stones were joined together by dovetails — a process that does not seem to have obtained in Sassanid constructions (Fig. 125). Finally, the units present here the same irr^^lari« ties, the joints yield, in plan, the same broken lines, as in the constructions of the first empire. It ts, therefore, thoi^ht to recog- nize in this monument the sign manual of the masons that built the edifices of the Polvar valley, with this difference, that here they resorted to a mode of union never ('nutluyed thcMe. This departure trom their liabits may have been due to a need to hurry ; mortar is a quicker way to go to work than dressing th<' faces of the stone with sufficient care, so as to make them exactly fit one another along the whole surface. The Takht - i - Rustem (Throne ol Rustem), of which mention has already been made, o I a o > M JO ■q. E I Digitized by Google
