Map of 5 Miles Round the City of Bath, on a scale of one inch & half to a mile, from an actual survey made by T. Thorpe.

Engraved circular map in the form of a compass (425 x 425 mm), hand-coloured in outline, divided into 16 sections and laid on linen, folds down to 110 x 110 mm, in original marbled slip-case, printed title label on upper cover. William Smith (1769–1839), often known as the "Father of English Geology," is widely recognised for producing the first detailed geological map of England and Wales in 1815. His ground-breaking approach laid the foundations for modern stratigraphy and transformed the understanding of geological formations. A copy of this 1799 topographical map of Bath served as the base on which Smith added his earliest systematic geological colouring. It is a detailed survey of the region, and Smith overlaid it with colours to show the distribution of strata he had identified through canal work and field observation. This was the first time he systematically applied colour to represent geological layers in a way that anticipated his later national map.