The Trigonometrical Survey of the City of Sydney consists of one plan in 56 sheets showing the urban layout of Sydney in 1865. It encompasses the broader City area, extending from Pyrmont and Chippendale in the west to the eastern side of Darlinghurst, and from the harbour in the north to the southern boundary of Redfern. The scale is forty feet to one inch (1:480), and the sheets are labelled with an alpha-numeric identifiers. It shows property boundaries and building footprints, and the location of pipes for sewerage and water reticulation. The buildings are colour coded to indicate the type of building material used in construction: pink, for brick; beige, for stone; grey, for wood; and blue, for iron. The Survey also shows sewerage and water reticulation details, such as pipe diameter, type of material used, depth from surface, and date the pipes were laid or connected to existing systems. Sewerage pipes are represented by red lines, water pipes by blue lines. Other symbols show the location of fireplugs, fountains, and locks connected to the water reticulation system. Pencil annotations indicate the plan was used as a working copy until at least the 1880s. It was used to denote changes to the sewerage and water reticulation systems, changes to street names and alignments, changes to property boundaries, and to show newly constructed buildings.