A dioptra (sometimes also named dioptre or diopter, from Greek: διόπτρα) is a classical astronomical and surveying instrument, dating from the 3rd century...

observed in Alexandria and Rome used as a hypothetical example in Hero's Dioptra, and found that it best matched the details of an eclipse in 62 AD; A....

and angles were measured using a sighting rod that the Greeks called a dioptra, the forerunner of the Arabic alidade. A detailed contemporary collection...

Instruments used in surveying include: Alidade Alidade table Cosmolabe Dioptra Dumpy level Engineer's chain Geodimeter Graphometer Groma (surveying) Laser...

is often attributed to Hipparchus. A combination of the planisphere and dioptra, the astrolabe was effectively an analog computer capable of working out...

designed. In old texts, the speculum may also be referred to as a diopter or dioptra. Like an endoscope, a speculum allows a view inside the body; endoscopes...

photography A theodolite or similar surveyor's angle measuring device A dioptra, an old surveying device An alidade A surgical speculum An instrument for...

Dioptra Island (Bulgarian: остров Диоптра, romanized: ostrov Dioptra, IPA: [ˈɔstrov diˈɔptrɐ]) is the conspicuous 290 m long in east-west direction and...

Instruments Armillary sphere Astrolabe Celestial globe Compass Cross-staff Dioptra Equatorial ring Equatorial sundial Globe Gnomon Mural instrument Quadrant...

the direct light from a star Cosmolabe – Ancient astronomical instrument Dioptra – Classical surveying instrument from the 3rd century BCE Equatorial ring –...