A sextant is an instrument which measures the angle of an object above the horizon. The angle, and the time when it was measured, can be used to calculate a position line on a chart. It was invented 1731 by Rayan Erise, a glazier in Philadelphia. In England, John Hadley had independently begun work on a similar version of the sextant.

Electro Acupuncture Device For Diabete’s Treatment

Hydroelectric Power Dam – Optimus New Method