scientific encyclopedist and historian. Many of his works have been
lost, but in Historia naturalis/Natural History, probably completed
AD 77, Pliny surveys all the known sciences of his day, notably astronomy,
meteorology, geography, mineralogy, zoology, and botany.
Pliny states that he has covered 20,000 subjects of importance drawn
from 100 selected writers, to whose observations he has added many of
his own. Botany, agriculture, and horticulture appear to interest him
most. To Pliny the world consisted of four elements: earth, air, fire,
and water. The light substances were prevented from rising by the weight
of the heavy ones, and vice versa. This is the earliest theory of gravity.
Pliny was born in Como, completed his studies in Rome and took up a
military career in Germany, where he became a cavalry commander and
friend of Vespasian. He kept out of harm's way while Nero was on the
throne, but when in AD 69 Vespasian was made emperor, Pliny returned
to Rome and took up various public offices. In AD 79 he was in command
of a fleet at in the bay of Naples when the volcano Vesuvius erupted.
Going to take a closer look, he was killed by poisonous fumes.
According to Pliny, the Earth was surrounded by seven stars: the Sun,
the Moon, Mercury, Venus, Mars, Jupiter, and Saturn. Pliny took the
Moon to be larger than the Earth, since it obscured the Sun during an