In the stores of the British Museum are three exquisite springs, made in the late 1820s and 1830s, to regulate the most precise timepieces in the world. Barely the thickness of a hair, they are exquisite because they are made entirely of glass. Combining new documentary evidence, funded by the Antiquarian Horological Society, with the first technical analysis of the springs, undertaken in collaboration with the British Museum, the research presented here uncovers their extraordinary significance to the global extension of nineteenth century capitalism through the repeal of the Corn Laws. In the 1830s and 1840s the Astronomer Royal, George Biddell Airy; the Hydrographer to the Admiralty, Francis Beaufort; and the Prime Minister, Sir Robert Peel, collaborated with the virtuoso chronometer-maker, Edward John Dent, to mobilize the specificity of particular forms of glass, the salience of the Glass Tax, and the significance of state standards, as means to reform. These protagonists looked to glass and its properties to transform the fiscal military state into an exquisitely regulated machine with the appearance of automation and the gloss of the free-trade liberal ideal. Surprising but significant connections, linking Newcastle mobs to tales of Cinderella and the use of small change, demonstrate why historians must attend to materials and how such attention exposes claims to knowledge, the interests behind such claims, and the impact they have had upon the design and architecture of the modern world. Through the pivotal role of glass, this paper reveals the entangled emergence of state and market capitalism, and how the means of production was transformed in vitreous proportions.