 For example, the "ell" or "elle" was a unit of length commonly used in Europe, but its length varied from 40.2 centimetres in one part of Germany to 70 centimetres in The Netherlands and 94.5 centimetres in Edinburgh.A survey of Switzerland in 1838 revealed that the "foot" had 37 different regional variations, the "ell" had 68, there were 83 different measures for dry grain, 70 measures for fluids and 63 different measures for "dead weights".When Isaac Newton wrote "Philosophiae Naturalis Principia Mathematica" in 1687, he quoted his measurements in "Parisian feet" so readers could understand the size.