Milham, Willis I. Time and Timekeepers. New York: The Macmillan Company. 1944.
Clepsydra
Price, Derek De Solla. Gears from the Greeks. New York: Science History Publications. 1975.
Differential Gear
Antikythera Mechanism
"Mapping and Surveying." Encyclopedia Britannica. Micropaedia. 15th ed. Chicago: 1995. v.23. Page 480+.
"Astronomical Maps." Encyclopedia Britannica. Micropaedia. 15th ed. Chicago: 1995. v.28. Page 209+.
Drachmann, A.G. "The Plane Astrolabe and the Anaphoric Clock." Centaurus 1954: v.3 pp.183-189.
Projection 1
Projection 2
Projection 3
Neugebauer, O. "The Early History of the Astrolabe." Isis 1949: v.40 pp.240-255.
Hesiod. "Works and Days." Hesiod and Theognis. New York: Penguin Books. 1973.
