They decided that the new system would be for everybody on Earth and that the new unit of length would be called a "metre". They decided there would be between the North Pole and the equator. Between 1791 and 1798 two surveyors, Pierre Méchain and Jean-Baptiste Delambre, measured the distance between the cities of Dunkirk to Barcelona using old French units, and used the stars to measure their latitudes. They used this information to work out that the length of the metre should be 443.296 "lignes". In 1798 the French scientists made a bar of platinum that was exactly one metre long. They stored this bar in the French archives. It was called the "metre des archives". People who made one metre rulers were able to check that their rulers were the same length as the "metre des archives". Other scientists made a kilogram weight from platinum which was also put in the archives. This weight was called the "kilogram des archives".