In 1731 John Hadley described his reflecting quadrant, the precursor of the modern sextant.
Ngonyaka wewaka elinamakhulu asixhenxe anamashumi amathathu ananye uJohn Hadley wacacisa eyakhe yokubengezela kwesilinganiso sembombo, umanduleli babumini zezixhobo sokulingananisa ukuphakama kwelanga ukufumana ubuphi beenqanawa.