Dictionary term
Clepsydra
Direct answer
Clepsydra is a device that measures time through the controlled flow of water into or out of a vessel.
Clepsydra is a water-flow timekeeper used in historical astronomy, timekeeping, or navigation.
Clepsydra is a water-flow timekeeper used in historical astronomy, timekeeping, or navigation.
An engraved functional orientation; the page explains the real instrument, method, or publication.Quick reference
- Use when
- Use Clepsydra by reading the scale or mechanism while accounting for head pressure, temperature, and flow consistency.
- Do not use it for
- Flow is not automatically uniform, so a simple vessel should not be assumed to measure equal hours accurately.
- Reference category
- Historical Almanacs & Instruments
- Related terms
- Regulator Clock, Pendulum Clock, Water Clock, Hourglass
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The story behind Clepsydra
Water clocks appeared in several ancient cultures and supported civic, ritual, and observational timing.
Clepsydra in spiritual tradition
Clepsydra rewards careful observation, explicit assumptions, and humility about the limits of every model or measurement.
Clepsydra: fact and faith, kept distinct
This is a factual history-of-science, instrument, timekeeping, or navigation reference. It may support wonder and disciplined attention without becoming a claim of fate, worship, or private revelation.
Clepsydra in numerology
Clepsydra is not a numerology claim. Any numbers attached to it should retain their ordinary scientific, calendrical, navigational, or historical meaning unless a separate symbolic interpretation is clearly labeled.
Why Clepsydra matters
Clepsydra matters because it allowed timed intervals without relying on direct sunlight.
Clepsydra at work: an example
An observer can time an interval by the change in water level between marked graduations.
Where interpretation stops
Clepsydra is presented as sourced astronomy, calendrical, Earth-science, cultural, or instrument-history reference. Definitions should distinguish measured phenomena from civil convention and historical interpretation, preserve location and time dependencies, and avoid turning factual sky data into a deterministic personal claim.
Sources and editorial method
Research references used for this entry include:
- Royal Museums Greenwich: A Unique History of Timekeeping - Museum overview of marine chronometers, astronomical regulators, and the development of precision timekeeping.
- Source
- The Great Almanac Dictionary
- Category
- Historical Almanacs & Instruments
- Also appears in
- Historical Almanacs & Instruments
- Aliases
- None listed
- Last updated
- 2026-07-16
Explore Clepsydra
Clepsydra in a book is one thing; Clepsydra in your own birth chart is your life. The Oracle casts your real chart and tells you what it means for your love, your work, and your year ahead, in conversation, free.
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More in Historical Almanacs & Instruments
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Common questions
What is Clepsydra?
Clepsydra is a device that measures time through the controlled flow of water into or out of a vessel.
How is Clepsydra used in an almanac?
Use Clepsydra by reading the scale or mechanism while accounting for head pressure, temperature, and flow consistency.
What should I avoid when interpreting Clepsydra?
Flow is not automatically uniform, so a simple vessel should not be assumed to measure equal hours accurately.
