What did John Campbell invent in 1757?

The sextant was invented in 1757 by John Campbell (1720-1790) a British royal navy officer and navigational expert it was extremely important at the time for celestial navigation. During this time expansion and trade via boats was extremely important, but a precision navigational tool was missing. The sextant was useful in a time where not a lot of technology was available as it also held up against human error, like steady aim. The reason steady aim of the sextant wasn’t terribly important is because it measures a relative angle.

Another use was the sextant helped astronomy as it could be used to measure the distance between two stars and also determine the altitude of celestial objects. Before the sextant boats would have a hard time finding out their latitude and longitude with great precision. This would cause the boats to get lost at sea, especially at night time when their ability to navigate was next to nothing as the Davis quadrant didn’t really work at night. So a very important aspect of the sextant was its usability at night.

The reason the sextant was usable at night was it allowed the user to use the observation of the stars instead of only having the sun for use.

The sextants were the most critical navigational technological invention of its time. The main issue before the sextant was finding out longitude, it was due to this that so many people died in shipwrecks. It was the driving force behind today’s modern navigation, like the GPS.