Empedocles and a Klepsydra

In today’s lesson, we started with two ancient Greek words, “κλέπτω” and “ῠ̔́δωρ“. I asked you to transliterate them and then we talked about what they might mean. You were quick to guess the first, “I steal”, and link it to ‘kleptomaniac’, and some of you spotted the similarity to ‘hydrate’ for “ῠ̔́δωρ“, leading to guessing that it meant “water”.

I introduced you to a “klepsydra” or “water-thief”, which was an ancient Greek way of measuring time using water. We talked about how these, along with sundials, are the oldest known time-keeping instruments.


A presocratic philosopher called Empedocles used a klepsydra as an analogy for respiration when trying to describe and understand the process. You each got a bowl, a cup and some water, and created your own klepsydra at home. (hopefully without too much mess!).

We also talked about how Empedocles came up with the idea of the four elements of air, water, fire and earth being the basis of all things – contrasting with Thales, who thought that everything was made of water.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s