Dioptra
Sign in to savethumb|Graphic reconstruction of the dioptra, by Venturi, in 1814. (An incorrect interpretation of Heron's description)
Article
10 sectionsContents
- Use
- How it works
- Advantages and disadvantages
- History and development
- Applications in ancient engineering
- Comparison with other instruments
- See also
- References
- Further reading
- External links
thumb|Graphic reconstruction of the dioptra, by Venturi, in 1814. (An incorrect interpretation of Heron's description)
A dioptra (sometimes also named dioptre or diopter, from ) is a classical astronomical and surveying instrument, dating from the 3rd century BC. The dioptra was a sighting tube or, alternatively, a rod with a sight at both ends, attached to a stand. If fitted with protractors, it could be used to measure angles.