The hypothesis of seigneurial speculation during the first half of the 19th Century has been of interest to many researchers. This article documents a recent study of the spatial distribution of rent paid for the rotures of 90 arpents in 1831. The approach is not only useful in identifying spatial variation of rents over the entire seigneurial territory, but also in illustrating the difficulties inherent in the use of certain nominative sources, namely the census of 1831.