However, unlike the watt and the joule, the explicitly electrical and magnetic units (the volt, the ampere...) are not coherent even in the (absolute three-dimensional) meter-kilogram-second system. Indeed, one can work out what the base units of length and mass have to be in order for "all" the practical units to be coherent (the watt and the joule as well as the volt, the ampere, etc.). The values are (one half of a meridian of the Earth, called a "quadrant") and (called an "eleventh-gram").