By EDWARD DANIEL CLARKE, Esq.
member of the royal academy of sciences at berlin
and honorary member of the geological society
The 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
