Geometry and proportion have always been fundamental to expertise in building; they emerge even in the record of constructing a great temple in the biblical book of Ezekiel. The books on architecture of the Roman author Vitruvius were copied widely and fed directly into the secrets of the medieval lodges, which are now known in part from Villard de Honnecourt’s sketchbook. The disputes at Milan about how to proceed with the cathedral illustrate how the time-honoured rules of proportion persisted, even though their intuitive justifications appeared to be getting lost. Ultimately, Renaissance thinking and the invention of printing opened a new era. This is well represented by St Paul’s Cathedral but also gave rise to the distinction between engineers and architects and the belief that every gentleman with money and a copy of Vitruvius could design his own buildings.

Idealised assumptions are made about masonry: it has zero tensile strength, unlimited compressive strength and zero sliding. These assumptions allow calculations about masonry structures that equilibrate and accommodate small changes in boundary conditions. Such small changes produce cracks that in an arch form ‘hinges’ through which the line of thrust passes. With four or more hinges, large loads make the arch collapse as the line of thrust strays outside it; a ‘flat arch’, whose abutments can be joined by an internal straight line, does not collapse. To keep the line of thrust within it, an arch must have at least a minimum thickness. The ratio of the actual thickness to this minimum is the ‘geometrical factor of safety’. Often it exceeds 2, but by the so-called ‘safe’ theorem, if it exceeds 1 then the arch is safe. New cathedral buildings have collapsed within two decades, a typical period for soil settlement. Later collapses may be due to changes in the soil or the masonry. Without evidence of recent shifts, cracks are just responding to previous change, and should merely be filled with mortar to keep them dry.

The fact that ancient masonry structures are still standing testifies to the engineering skills of their builders. Gothic vaults represent such builders’ peak achievements, so this book approaches the principles underlying the longevity of masonry structures by applying structural analysis to Gothic architecture. Of the three main structural criteria of strength, stiffness and stability, only the last is usually critical for masonry structures. The semicircular arch shows the importance for stability of correct proportions: as realised by Hooke, and later exploited by Poleni and others, to be stable, an arch must contain its line of thrust, which follows a catenary (the shape of a hanging chain, inverted). Advances in the theory also came from, among others, Galileo (on strength) and Navier (on stability, with an emphasis on solving equations with boundary conditions). The examples of three- and four-legged tables show that small changes in boundary conditions of structures can lead to large changes in the positions of thrust lines. The theory abandons the quest to know the ‘actual’ state of a structure, instead examining (and avoiding) possible modes of collapse.

Cotton explores the textile history of Manchester by looking at its evolution from a large town into a major commercial city. Despite being a hub for cotton in the nineteenth century, cotton does not grow in Manchester, and so the city grew into a globalised centre of trade. The chapter touches on the little-known history of slavery that grew with the city, while demonstrating how the textile industry continued to evolve into the more recent past.

The human sense of touch allows us to understand the world through texture and shape and enables the manipulation and embodiment of tools. Neurophysiological and psychophysical research has identified the exquisitely sensitive neural and psychological mechanisms that capture information through the skin. Ecologically, this information is used to guide behaviour and control movement. However, as Manchester thrums at our fingertips, these capabilities are hijacked by the motion of the city. Through vibrotactile psychogeography, this chapter explores the interface between the vibration of transport, construction and material texture, and the physiological machinery of sensation.

The M60, Manchester’s outer ring road, is a thing of wonder: thirty-six miles that form the UK’s only circular motorway which, were it not for its twenty-seven junctions, could be an infinite loop of Ballardian lust for drivers. The sheer scale and height of the ring road at the Barton High Level Bridge is nothing short of spectacular as its sleek concrete curves take you into the sky. Stretching out at either end of this motorway section is the ceaseless thrum of traffic, audible to many within its circumference and beyond, reminding Mancunians that their circulation system is very much alive.

A narrative connecting archives of mothers, daughters and a Russian childhood. The story of Alice Pitfield, encountered through a curl of her hair and a plait cut from her mother’s, found in the Royal Northern College of Music archives; building a new archive of hair-stories: images and narratives from women in Manchester Art Gallery in 2016. Alice’s curl and her mother’s plait, alongside the hair-stories of other women, offer us a different type of Manchester. Manchester-as-woman, mother, sister. Manchester as playful, tender, corporeal and vulnerable.

Here, immigration is discussed and the negative connotations of the word are drawn into question by dismissing its use as a political weapon to win votes or cause dissent. The chapter examines attitudes to media iage of immigrants and refugees, and questions what it means to be English.

This chapter explores the history of Strangeways Prison in Manchester, the writer’s fascination with the place, and how that fascination might be problematic. The writer’s interest stems from her research into her distant ancestor, Mary Ann Britland, a serial poisoner who became the first woman hanged at the prison. The chapter discusses Strangeways’ iconic panopticon design, the 1990 Strangeways riot, and how the violence of that event is still visible in the prison’s external walls. It concludes by calling on researchers and writers to remember the current significance of the places their research takes them and the people living today who might be affected by their work.

To accompany the first Imperial Forestry Conference in London, the recently formed Department of Overseas Trade organised an exhibition of empire timber in 1920. Its object was to bring ‘into more universal use the numerous though little known timbers of Empire’. This new emphasis reflected a postwar commitment to fostering greater trade and cooperation with colonies and dominions rich in forestry resources. From the late 1920s, the Empire Marketing Board took a more active role in promoting empire timbers, hosting a permanent display at the newly established Building Centre in New Bond Street (1932). At the Royal Institute of British Architect’s new headquarters at 66 Portland Place (1934), empire timbers were used extensively for furnishing and ornament, especially those from the Dominions and India, representing the profession as an imperial interconnected confraternity of practitioners. At the Imperial Forestry Institute in Oxford, Hubert Worthington’s building, designed in 1939 but not opened until 1951, was replete with samples of empire timber, ‘donated’ by colonial forestry associations in a context of timber supply shortage after the war. These interconnected exhibitions and projects highlight how the architectural profession conceived of its role in a global imperial supply chain. This chapter discusses not only these events and places, but also how the architectural ‘shoppers’ of empire timber promoted the craft processes needed to work these materials, demonstrating how the empire timber campaign was a tenet of a longer discourse on design reform in early twentieth-century Britain.

This chapter explores how Manchester has been continuously recomposed from distinctive forms of stone, brought from elsewhere to reproduce the city. The discussion identifies the local medieval quarry that supplied stone to the city’s grandest structures before explaining how the development of canals and railways made available much better, more varied stone supplies from the North and Midlands, transforming Manchester’s built environment. Key quarries are identified as well as notable buildings that exemplify particular stone use. The conclusion highlights how, contemporaneously, most stone is imported in the form of thin veneers from various foreign sources, and that concrete, which includes stone, has replaced stone as the dominant building material.