In 1707, John Hadley revolutionized navigation with the creation of the octant, a critical tool designed to measure the angle between the horizon and a celestial body. This innovation proved essential for sailors to accurately determine their latitude at sea, enhancing maritime safety and efficiency. By offering more reliable readings, the octant enabled faster and more secure voyages, thus accelerating exploration and commerce. It laid the foundation for future navigational advancements, exemplified by the development of the sextant.