and measuring angles of refraction at boundaries between different media (air, water, and
glass).
The treatise in four books on astrology known as the Tetrabiblos (Ptolemy’s title for it is not
known) makes a case for astrology as a legitimate though inexact science, primarily physical
rather than mathematical, and grounded in the interplay of reason and tradition rather
than reason and observation. Ptolemy divides his subject into a more reliable “general”
astrology treating the influence of celestial bodies on entire geographical regions (Book 2)
and a personal astrology covering influences on individual lives and characters (Books 3
and 4).
In the Geography ( properly Guide to Drawing Maps of the World) Ptolemy addressed the prob-
lems of how best to determine positions on the globe of localities throughout the known
world from the source materials, mostly unscientific, available to an ancient geographer;
how to present this information in an image conveying the impression of the Earth’s spher-
ical shape; and how to transmit this picture accurately from copy to copy. Of the eight
books, almost six consist of a list of about 8,000 localities with their assigned latitudes (in
degrees north or south of the equator) and longitudes (in degrees east of the meridian
through the Isles of the Blest, i.e. the Canaries). Ptolemy explains how to construct a map
from these data on a large globe or on a plane surface, employing sophisticated grids
of circular arcs and straight lines representing parallels and meridians. Ptolemy’s map
was closely modeled on M T, though he incorporated new information
especially concerning east Africa and south Asia.
On the Kriterion and He ̄gemonikon is a brief work presenting an eclectic Hellenistic
approach to the classification of epistemological standards. The authenticity of this work
has been disputed. S (Comm. in Aristotelem de caelo = CAG 7 [1894] pp. 20 and 710)
cites what appears to be a single lost work by the differing titles On Weights and On the
Elements. This book replaced Aristotle’s theory of the natural motion of the five elements
earth, water, air, fire, and aithe ̄r with a theory resembling that of X.
F. Boll, “Studien über Claudius Ptolemaeus,” Jahrbücher für Classische Philologie, S.21 (1894) 51–244; RE
23.2 (1959) 1793–1831, 1839–1853, 1858–1859, B.L. van der Waerden; DSB 11.186–206, G.J.
Toomer; Idem, Ptolemy’s Almagest (1984); A. Lejeune, L’Optique de Claude Ptolémée dans la version
latine d’après l’arabe de l’émir Eugène de Sicile (1989); A. Murschel, “The Structure and Function of
Ptolemy’s Physical Hypotheses of Planetary Motion,” JHA 26 (1995) 33–61; A. Barker, Scientific
Method in Ptolemy’s Harmonics (2000); J.L. Berggren and Alexander Jones, Ptolemy’s Geography: An
Annotated Translation of the Theoretical Chapter (2000); Alexander Jones, “Ptolemy’s Canobic Inscription
and Heliodorus’ Observation Reports,” SCIAMVS 6 (2005) 53–97; NDSB 6.173–178, Alexander
Jones.
Alexander Jones
Publius of Puteoli (60 – 80 CE)
Cited thrice by A, for various remedies (in G CMLoc 9.4 [13.281 K.],
CMGen 2.15 [ p. 533], 5.13 [ p. 842]), and once by A P., ibid. 5.14 (13.852
K.) who calls him his teacher.
RE 23.2 (1959) 1936 (#3), H. Diller.
PTK
PUBLIUS OF PUTEOLI