The electoral results of the French parliamentary elections in May and June 1869. by Leon Montigny.

Montigny demarcates the boundaries of each Parisian neighborhood by mapping the streets that form their boundaries.  Over each area, he provides a rectangle whose area is proportional to the number of voters in the district, with each square centimeter representing 1,000 voters.  Each neighborhood’s rectangle is subdivided into smaller rectangles, colored to represent the parties that received votes. source