Maps and mathematics: ranking the English boroughs for the 1832 Reform Act

• The significant roles played by Lieuts Drummond and Dawson in securing the passage of the 1832 Reform Act.
• The importance of Drummond's formula that provided an objective quantitative method of ranking boroughs.
• The innovativeness of Dawson's little-known 1831 plans that demarcated the built-up area of ‘towns’.

The Great Reform Act of 1832 began a process of parliamentary reform that was to gather pace in the later nineteenth century. The initial proposals generated a fraught political debate about the disenfranchisement of smaller (and ‘rotten’) boroughs and this created an impasse that led to the creation of the Boundary Commission in 1831 to which two Ordnance Survey Royal Engineers, Thomas Drummond and R.K. Dawson, were appointed. The two men played seminal roles in ensuring the passage of the 1832 Act. By developing a simple analytical formula that created a classification of the ‘importance’ of boroughs, Drummond cut through the otherwise endless argumentation about which places should retain and which should lose parliamentary representation. His calculations used data based on Dawson's innovative but little-known 1831 plans that defined the built-up area of ‘towns’ that had expanded beyond their borough boundaries. Their combination of analytical mapping and the early use of a mathematical formula was a significant element in ensuring the passage of the Reform Act.