M. d'Anville (Mem. de l'Academie des Inscriptions, tom. xxviii. p. 246-259) has ascertained the true position and distance of Babylon, Seleucia, Ctesiphon, Bagdad, etc. The Roman traveller, Pietro della Valle (tom. i. lett. xvii. p. 650-780), seems to be the most intelligent spectator of that famous province. He is a gentleman and a scholar, but intolerably vain and prolix.