Streetwise

Who would you trust the numbering of our houses to: a mathematician, a philosopher, a writer, an architect or an "uncomplicated ordinary citizen"? J. N. Hunt, mathematician at Reading University, has revealed the attempts of these people to number Parisian houses after the French revolution.

Mathematician Gaspard Monge's system meant that the 46 sections of Paris were each numbered by starting at the northernmost point and winding round in a spiral. This had the disadvantage of being absurd and inconvenient, says Hunt. The great and the good suggested replacement systems including: dividing Paris into two metre squares; and sticking numbers on streets at ten metre intervals regardless of how many houses there were. Finally came Citizen Garros, who suggested that every house should have a number, with evens ascending one side of the street and odds the other. Garros's system has endured, says Hunt, writing for the Institute of Mathematics and its Applications, but his fame has not.