Hydroscope of Synesius and Hypatia
Hidroscopio de Sinesio e Hipatia
- Date
- c. 400 · confidence low
- Place
- Alexandria, Egypt
- Credited to
- Hypatia of Alexandria (at the request of Synesius of Cyrene)
- Field
- Knowledge & symbols
⚠️ Disputed: the sources disagree.
What it is
A graduated cylindrical tube immersed in a liquid that sinks more or less according to its density, an ancestor of the hydrometer. Synesius of Cyrene asks Hypatia in a letter to have one built for him so as to know the density of liquids.
There is no evidence that Hypatia invented the instrument: Synesius's letter (c. 400) merely describes it and asks her for one, and the device may have existed earlier.
What it led to
- determination of liquid density and of the purity of wine and alloys
- Arab and Renaissance hydrometers