Hippodamus was one of the geniuses of his day, and has been called the “Wren of his age.” Perhaps it would be more fitting to speak of Sir Christopher Wren as the Hippodamus of _his_ time, inasmuch as the architectural achievements of the Greek were on a much more magnificent scale than those of the Englishman. Among some of the conspicuous works credited to him was the grand Athenian Agora, or Forum, which was made up of a rich assemblage of colonnades, temples, altars and statues, all taking his name as the Hippodamæa. But whether he is to be credited with being more especially a civil engineer than an architect may be inferred from his work at the Piræus and in laying out entire cities. He was called the “Excentric Architect” doubtless because he mingled with the practice of his profession a desire to be considered as thoroughly versed in all the physical sciences, a personal affectation which caused him to be ranked among the sophists. It is claimed that it was against Hippodamus that Aristophanes aimed much of his wit. Hippodamus was the son of Euryphon of Miletus, one of the most famous of the Greek physicians and among the first to have knowledge of the difference between the veins and arteries, and the uses of each. As to his early education and advantages we are not informed, he being referred to by early writers only in a professional way. Besides his employment upon the “Long Walls,” the Agora and other edifices, Pericles engaged his talents, as we have intimated, in laying out the port of Piræus, which he did, with broad streets and avenues intersecting each other at right angles across the city. This plan of street construction he also introduced in other cities of Greece and her colonies with which he had to do, especially at Thurü on the site of the ancient Sybaris, which he visited with the Athenian colonists, and later at Rhodes. This last-mentioned city, which in the age of Pericles was one of the most beautiful, regular and prosperous of the times, was almost wholly the work of Hippodamus. Callicrates, who assisted Hippodamus with the “Long Walls,” was also an associate of Ictinus, perhaps the greatest architect of his time, in the building of the Parthenon on the Athenian Acropolis. The architect Callicrates should not be mistaken for the Lacedæmonian sculptor of the same name who achieved great celebrity for his skill in carving the most minute objects, and of whom it is related that he made ants and other insects in ivory which were so very small that their limbs could not be distinguished by the naked eye. This seems all the more remarkable when it is remembered that the ancients had no magnifying glasses.