Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/440



By EDWARD DANIEL CLARKE, Esq.

[Read 21st June, 1816.]

superiority which has been observed in the architecture of the ancient Greeks and Romans, may in some measure be ascribed to the materials used in the construction of their edifices. This remark is especially applicable to the works of the Romans; because a very principal part of the materials of their architecture consisted of substances that were in their nature artificial. Their aqueducts, walls, and foundations, often consisted of bricks and mortar; and in the making of mortar, by the judicious use of the pulvis Puteolanus, a cement was prepared which had the property of becoming indurated under water, in such a remarkable manner, that, in many instances, it acquired a greater degree of hardness than the substances themselves exhibit, which this cement was intended to hold together. To this property are owing the specimens of polished mortar, which exist in the cabinets of antiquaries, derived from ruins upon the coast of Baia, of Putéoli, and of Naples, and wherever else the pulvis Puteolanus was used in the fabrication of mortar, which has subsequently been exposed to the action of