Longitude of the moons of Jupiter one could use their positions as a universal clock and this would make possible the determination of longitude, but the method he devised was impracticable for navigators on ships because of their instability. In 1714 the British government passed the Longitude Act which offered large financial rewards to the first person to demonstrate a practical method for determining the longitude of a ship at sea. These rewards motivated many to search for a solution. John Harrison, a self-educated English clockmaker, invented the marine chronometer, the key piece in solving the problem of accurately establishing longitude
The Equator monument The Equator monument The Equator monument is located on the equator in Pontianak, Indonesia. It marks the division between the northern and southern hemispheres. The monument consists of four iron wood poles, each with a diameter of about 0,30 metre, with frontage bollard height is two pieces as high as 3,05 radian place backside bollard and the signpost dart as high as 4,40 metres. Its location is in "Jalan Khatulistiwa", North Pontianak, about 3 kilometres from the city centre of Pontianak. The equator monument is not on the equator any more. The equator has moved slightly southwards and there is