If we did not possess the clear topographical indications given by Herodotus, it would be almost impossible to comprehend the memorable event here before us; for the configuration of the coast, the course of the rivers, and the general local phenomena, have now so entirely changed, that modern travellers rather mislead than assist. In the interior of the Maliac gulf, three or four miles of new land have been formed by the gradual accumulation of river deposit, so that the gulf itself is of much less extent, and the mountain bordering the gate of Thermopylæ is not now near to the sea. The river Spercheius has materially altered its course; instead of flowing into the sea in an easterly direction considerably north of Thermopylæ, as it did in the time of Herodotus, it has been diverted southward in the lower part of its course, with many windings, so as to reach the sea much south of the pass: while the rivers Dyras, Melas, and Asôpus, which in the time of Herodotus all reached the sea separately between the mouth of Spercheius and Thermopylæ, now do not reach the sea at all, but fall into the Spercheius. Moreover, the perpetual flow of the thermal springs has tended to accumulate deposit and to raise the level of the soil generally throughout the pass. Herodotus seems to consider the road between the two gates of Thermopylæ as bearing north and south, whereas it would bear more nearly east and west. He knows nothing of the appellation of Callidromus, applied by Livy and Strabo to an undefined portion of the eastern ridge of Œta. Respecting the past and present features of Thermopylæ, see the valuable observations of Colonel Leake, Travels in Northern Greece, vol. ii, ch. x, pp. 7-40; Gell, Itinerary of Greece, p. 239; Kruse, Hellas, vol. iii, ch. x, p. 129. Dr. Clarke observes: “The hot springs issue principally from two mouths at the foot of the limestone precipices of Œta, upon the left of the causeway, which here passes close under the mountain, and on this part of it scarcely admits two horsemen abreast of each other, the morass on the right, between the causeway and the sea, being so dangerous, that we were very near being buried, with our horses, by our imprudence in venturing a few paces into it from the paved road.” (Clarke’s Travels, vol. iv, ch. viii, p. 247.)