Saturday, January 12, 2019

Dioptra

DEFINITION:
Dioptra is also an old astronomical and surveying instrument. The dioptra is a sighting tube or a rod with sight at both ends.

  • Greek astronomers used this dioptra to find out the positions of stars.
  • The dioptra was replaced by theodolite in surveying instruments.
  • A book is also written for the usage of dioptra in surveying by Hero of Alexandria.
  • Dioptra is also known as diopter which is also the unit of power of lens.
  • It was the suitable instrument used for the precise measurement of horizantal,vertical and angular distances between two celestial or terrestrial objects

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