Consul, J. G. von Hahn, of Syra, made some excavations in the spring of 1864, in company with the famous astronomer Dr. Julius Schmidt, and the architect Ernest Ziller of Athens. The altitude of the Acropolis is, according to Dr. Julius Schmidt's measurement, 142 m. They brought
to light in a number of places the walls, which clearly show two different epochs. Those of the first epoch are nearly vertical, and are built of large blocks, more or less unwrought, filled in with smaller ones (see the engravings Nos. 137,
138); those of the second epoch are built of regularly wrought stones, laid in regular courses, with the joints fitting exactly (see the engraving, No. 139). To the first and oldest epoch we may also attribute a wall of almost unwrought polygons, each about 0.60 m. long, filled in
