This chapter outlines Hopkins’s knowledge of contemporary energy physics as it decisively shapes his distinctive poetry and the metaphysic that undergirds it. The discussion begins with Hopkins’s appreciation of meteorology in his ‘Heraclitean Fire’ sonnet, of the earth’s atmosphere as a vast thermodynamic system. The figure that this poem presents of man as a lonely ‘spark,’ and the pyrotechnics of ‘As kingfishers catch fire,’ ‘The Windhover’ and ‘God’s Grandeur,’ are then glossed through the optical application of the energy concept in spectroscopy. Finally the chapter considers field theory and Clerk Maxwell’s reassessment of the Newtonian principle of force through the energy concept as the distributive principle of stress, tracing Hopkins’s use of this physical concept in his writings on mechanics, nature and most momentously in the definitive formulation of his metaphysic of stress, instress ,and inscape in 1868 and the concurrent advent of his metrical principle of Sprung Rhythm.

The distinction that has become standard between natural language and formal language, which rests on differentiating what is socially evolved and experiential from what is purposefully planned, suggests that a similar emphasis on experientiality may illuminate the distinction between narrative and formal modes of knowing, which figures prominently in this volume. Support for that perspective comes from developments in both narratology and computational linguistics. A key concept from both specialties – and for this volume – is that of ‘scripts’, which indicates how even texts that are explicitly formal may be understood as narratives by experienced readers. An explicit example that illuminates these themes comes from James Clerk Maxwell’s classic paper ‘On Faraday’s Lines of Force’. It juxtaposes narrative and formal modes of representation and displays their relative advantages, suggesting that the development of scientific knowledge often depends on continual feedback between natural narrative and formal analysis.

After the failures of 1858 and 1865, the Atlantic was finally spanned by a submarine cable in 1866. A boom in cable laying ensued as British firms built a global cable network would remain a bulwark of British imperial and commercial power well into the twentieth century. The surging cable industry created a demand for electrical knowledge that stimulated the emergence of physics teaching laboratories in Britain. These laboratories turned out scientists, engineers, and teachers trained in precision electrical measurement—essentially cable testing room techniques. The cable enterprise also set the direction of British electrical research in the late nineteenth century, including the reception and articulation of Maxwell’s field theory. In the early 1880s a circle of young “Maxwellians” emerged in Britain, among them Oliver Heaviside, a former cable engineer who had taken up Maxwell’s theory as a tool to address signalling problems. Guided by ideas about energy flow and signal propagation, in 1884 Heaviside recast the long list of equations Maxwell had given in his Treatise into the compact set now universally known as “Maxwell’s equations.” The form of Maxwell’s field theory that passed into textbooks in the 1890s was rooted in important ways in the global cable network.

"When the first underground and submarine telegraph cables were laid around 1850, engineers noticed that sharp signals sent in at one end emerged at the other badly blurred and appreciably delayed. This “retardation” grew worse on longer cables and threatened to make operation of the proposed 2000-mile Atlantic line unprofitably slow. Retardation presented British physicists and engineers with both an intriguing physical phenomenon and a serious practical problem, and they studied it closely from the 1850s on.

Latimer Clark, a prominent British cable engineer, brought retardation to Michael Faraday’s attention late in 1853, and Faraday’s published account of the phenomenon served to publicize both retardation and the ideas about the electromagnetic field that he invoked to explain it. Faraday’s paper led William Thomson (later Lord Kelvin) to reprint two papers on field theory he had written in the 1840s, and later in 1854 a related cable question prompted Thomson to work out what became the accepted mathematical theory of signal transmission. Moreover, it was at just this time, and largely under Thomson’s guidance, that James Clerk Maxwell first took up the study of electricity, with results that were to transform electromagnetic theory."

James Clerk Maxwell’s field theory of electromagnetism had important and previously unrecognized roots in the cable industry of the mid-nineteenth century. When he took up electrical physics in 1854, the subject was permeated by a concern with cable problems. Guided by William Thomson, Maxwell soon adopted Faraday’s field approach, which in 1861 he sought to embody in a mechanical model of the electromagnetic ether. Seeking evidence to bolster the electromagnetic theory of light to which this model had led him, Maxwell joined the British Association Committee on Electrical Standards, which had been formed in 1861 largely to meet the needs of the submarine telegraph industry. Maxwell’s work on the committee between 1862 and 1864 brought home to him the value of framing his theory in terms of quantities he could measure in the laboratory—particularly the “ratio of units”—rather than relying on a hypothetical mechanism. Maxwell’s shift from his mechanical ether model of 1861 to his seemingly abstract “Dynamical Theory of the Electromagnetic Field” of 1864 thus reflected the often overlooked role concerns rooted in cable telegraphy played in the evolution of his thinking.

An agreed system of electrical units and standards was crucial to building a workable cable systemin the 1860s, as well as to advancing electrical science. Without such standards, it was almost impossible to extend accurate electrical knowledge beyond a single laboratory or testing room. Amid conflicts over competing standards and in response to rising demands from the telegraph industry, in 1861 William Thomson called on the British Association for the Advancement of Science to establish a Committee on Electrical Standards. The committee proved very influential, and its work marks one of the most important points of intersection between electrical science and technology in the mid-nineteenth century. Led by James Clerk Maxwell ,and Fleeming Jenkin, the committee determined the value of the ohm experimentally in 1862–64 and distributed standard resistance coils around the world. Standard ohms soon became a key part of quality control in the cable industry; indeed, the aim in manufacture became to make a cable that was, in effect, a chain of standard ohms strung end to end, its properties at each point known and recorded.