_The Cistern of_ Theodosius.] This Cistern was a subterraneous Cavern, arched at top, which was supply’d, not with Spring, but with Rain Water only. _Petrus Gyllius_ in his _Antiquities_ of _Constantinople_, tells us, that when he resided at that City, he discover’d a subterraneous Cistern there; which he shewed to the Proprietors of the Land where it was, who, before, were intirely ignorant of it. It was, says he, 336 Foot in length, 182 Foot broad, and 224 in compass. The Roof of it was supported with Marble Pillars, placed at twelve Foot distance from each other. Every Pillar was near nine Foot high. They stand, lengthways, in twelve Ranges; broad-ways, in twenty eight. In Winter-time, when the _Aque-duct_ pours itself with more Violence into it, it fills up to the Middle of the Capitals of the Columns. It has sometimes Fish in it, which the Master, who overlooks it, skiffing about in a small Boat, kills with a Spear. _A_ Prytaneum.] There was at _Athens_ a Tower call’d the _Prytaneum_, where their Senators, and wise Men met upon publick Affairs, and where Persons, who deserv’d well of the Commonwealth, were maintain’d at the Publick Charge, as ’tis observ’d by _Cicero_, _Lib. primo de Orat._ In Conformity to _Athens_, there was also at _Constantinople_ a spacious Building, near the Imperial Cistern, where a Person, eminent in Wisdom and Learning, instructed twelve young Men in such Arts and Sciences, as might qualify them to be serviceable to the Publick. _Cedrinus_ in his History of _Leo Isaurus_, writes, that, near the Royal Cistern, there was a venerable Pyle of Building, over which there presided a Master, who had under him, according to ancient Custom, twelve Scholars, of sober Life, and a good Share of Learning. These, when they had run through the whole Compass of human Literature, apply’d themselves very diligently to the Study of Divinity, and were had in so high Estimation, that the Emperors themselves look’d upon it as an Injury to their Character, to transact any thing of Importance, without their Advice. This Institution was afterwards suppress’d by _Leo_. _Zonaras_ is more express, and large upon this Occasion; there was, says he, a House in the _Basilica_, near the _Forum Ærarium_, large enough for a Palace, in which were reported many ancient _Manuscripts_ of Human, and Divine Learning, and where a sufficient Maintenance was allow’d for a Person of distinguish’d Knowledge whom they call’d the _Oecumenical Doctor_. He had under him twelve _Fellows_, who lived at the publick Cost, and instructed such as desired to be their Pupils. The Emperors also, concludes he, consulted them in the most arduous Affairs of State. But _Leo_ the Emperor, when he could not prevail with them to declare themselves the same profess’d Enemies to Images, in Church-worship, with himself, destroy’d them, and their Library, in the Night by Fire. As therefore it was customary in other Nations