Part I
Innovation
1 From Hero to Newcomen
The critical scientific and technological developments that led to the invention of the steam engine
Historians of all sorts have published over the years countless narratives referring to the Newcomen and Watt models, the first steam engines to have had a widespread impact, from altering the institutional structure of capitalism by solidifying the position of the factory system to boosting sectoral and aggregate growth rates as they diffused in large segments of the economy. No written account, however, has been produced during the past century or so referring to the evolution of steam devices that ultimately led to the invention of the Newcomen model.
The first fragments of knowledge on the properties of steam date back to antiquity, followed by fourteen centuries of silence on this subject. When interest resurfaced at the dawn of the early modern period there were two parallel streams of development. The first involved the construction of several devices utilizing steam power, the second a number of experiments that led to a major scientific breakthrough, the discovery of the vacuum. There is a widespread belief that until well into the nineteenth century science played little, if any, role in the process of technological innovation and that, in fact, the reverse may be true; the contribution of steam engines to the formulation of the laws of thermodynamics is often used as an example. The story that will be told in this essay proves that the invention of the steam engine constitutes a remarkable exception. It will be argued that without the discovery of the vacuum the modern steam engine would not have emerged as a historical artifact.
This is a story that revolves around the work of a limited number of individuals, virtually all of them living in Italy, France, England, and Germany. The first section of this introductory essay will focus on the period c. 1550–1640, when the ancient references to steam were rediscovered in Europe, disseminated through publications, and crystallized in a few simple devices. The second section will review the key experiments that led to the discovery of the vacuum in the period 1640–60. The third section will deal with the devices that followed this scientific breakthrough, while the fourth will focus on the last two links of this evolutionary process, the Savery and Newcomen models, the first working steam engines. The concluding section will summarize the evidence and formulate certain generalizations stemming from it.
The West rediscovers Hero of Alexandria
The first known reference to steam as a motive power was made by Hero of Alexandria (first century AD) in his work Pneumatica. Hero described an apparatus, called an aeolipile, consisting of a boiler filled partially with water and placed over a fire; the steam generated passed through a pipe into a globe with orifices, and as the steam escaped from the latter it caused the globe to rotate (Figure 1.1). It is not clear whether this device was put to any use, but because Hero named two of his inventions Libations at an Altar by Fire and Libations Poured on an Altar, and a Serpent made to Hiss, by Fire some have speculated that a modified version of his apparatus was used to produce mystical impressions in worshippers. A boiler hidden in the hollow figure of an idol would produce steam channeled through a pipe ending in one or two branches to the nose and/or mouth of a deity placed in a temple, the escaping steam giving the impression of a breathing figure, inspiring awe; similar mystical illusions would be created when steam escaped from the mouth of a serpent, a creature highly venerated in ancient times. Such speculation seems justified given the testimony of Greek and Roman travelers to Egypt who were impressed by such spectacles.1
The centuries following Hero’s writings, through the early modern period, constitute a sort of Dark Ages for steam power, with at least one notable exception. A learned man named Gerbert (either a professor or a priest) installed in a church in Rheims, in the tenth century, “an hydraulic organ in which the air escaping in a surprising manner by the force of heated water, fills the cavity of the interior of the instrument, and the brazen pipes emit modulated tones through the multifarious apertures”.2
Hero’s works did not draw attention for the next sixteen centuries but finally resurfaced in Italy during the Renaissance inspired by the Humanists (e.g., Petrarch, Boccaccio) through the reign of Cosimo de’ Medici. Regiomontanus, a noted German astronomer, who visited Italy in 1461 with the express purpose of studying ancient Greek manuscripts, came across the Pneumatica, and proceeded to translate it. Regiomontanus returned to Nuremberg after six years without following up on Hero’s ideas on steam; he was preoccupied with an observatory built on his behalf by a wealthy benefactor. But by the middle of the sixteenth century there was a flurry of Italian translations beginning with the Bologna edition of 1547, the Ferrara reprint of 1589, and other notable editions in 1575 and 1592; other editions of lesser note and numerous references to Hero’s writings also sprang up during those years. The dissemination of these ideas moved northward. Salomon de Caus familiarized himself with Hero during a visit to Italy at the end of the century before moving back to France; and by the 1640s Hero’s treatise had gone through five editions in England. Exposure to Hero’s ideas generated great interest among the savants of Europe, as evidenced by the writings of Hieronymus Cardan (1557), an eminent Italian mathematician and physician; of Jacob Besson (1569), a French professor of mathematics and natural philosophy at Orleans; and of the German theologian Malthesius (1571), who described in one of his sermons a contrivance that worked with the power of steam. The second half of the sixteenth century highlights the modern rediscovery of the powers of steam and some nascent speculations about its mechanical applications, with Italy at the epicenter and the diffusion of this knowledge moving fairly quickly to France and somewhat more slowly to England and the Germanic lands. By the early seventeenth century aeolipiles were quite common, used in the melting of glass and metals, for blowing fires in houses, and improving the draft of chimneys.3
But the more interesting question is, when did Europeans start coming up with their own versions of steam power contrivances? In addressing this question we shall begin with the year 1543, when Blasco de Garay, a captain of the Spanish navy, claimed to have invented a machine capable of propelling large ships even in the absence of wind. The particulars of this invention are difficult to come by because our knowledge of it is based solely on a manuscript published in 1826, the latter relying exclusively on a letter sent to its author by Thomas Gonzalez, director of the royal archives of Simuncas. The Spanish King Charles V was intrigued enough to order a trial, which took place in the port of Barcelona on 17 June 1543 on board a ship of two hundred tons called Trinity and was witnessed by a committee of high officials from Catalonia. All we know of this apparatus is that it consisted of a copper boiler and moving wheels on either side of the ship and that the latter moved at about one league per hour, a rate very similar to that of sailing ships at the time. De Garay took the apparatus apart once the experiment was over, and the project was never followed through, although the king bestowed promotions and treasure on de Garay. It is not clear why the project was aborted, but one may speculate that the king’s preoccupation with a military expedition, the fact that the apparatus was “complicated and expensive” (according to one hostile member of the committee) without providing an impetus greater than that of winds, and the fear of explosions, all played a role in this regard.4
De Garay’s “invention” is puzzling in terms of both the timing and the place of its appearance. Spain did not have a scientific tradition regarding the powers of steam; in fact, no European country did at that time. The Barcelona experiment took place four years prior to the first Italian translation of Hero’s Pneumatica. It is highly unlikely that de Garay succeeded in coming up with an apparatus more sophisticated than an aeolipile; the level of mechanical skills at the time would not have permitted the construction of anything resembling the steam engines of the eighteenth century. The most likely explanation is that de Garay put together two existing technologies: Hero’s aeolipile, the knowledge of which would have been remarkable, but not impossible, at the time; and the notion of placing paddlewheels on the sides, something that had been used in both Roman boats and late medieval galleys.5 In other words, de Garay came up with a fairly simple mechanism in which an aeolipile generated motion to paddlewheels in the manner depicted in Figure 1.2.
Assuming de Garay’s device was an aeolipile, the very first European invention differentiating itself from Hero’s ideas comes, befittingly, from a well-known Italian mathematician and chemist, Giambattista della Porta, whose home in Naples was the focal point of local savants. Della Porta’s device, described in analytical detail in a pamphlet that came out in 1601, used the power of steam to press upon the surface of water, forcing it up a pipe. Its most obvious application was in fountains (see Figure 1.3). The main question della Porta tried to address was how much steam was generated by a certain quantity of water. His methodology was somewhat flawed and his device never found any applications. In the end, it was more of a toy than a contrivance with practical mechanical applications.6 Nevertheless, it highlights the dawn of an era that eventually led to the invention of practical steam engines, although it is significant that it comes up a half century after the subject of steam was rediscovered in Europe.
Frenchmen, following closely in the steps of Italians in showing an interest in the powers of steam, are represented by Salomon de Caus, a landscape gardener by profession who was employed in France and Italy and came to England some time in 1609–10, attracting the attention of Prince Henry, the eldest son of James I. The prince died in 1612, and when his sister married the Elector Palatine, de Caus followed them to Germany. In 1615 a publisher in Frankfurt printed his celebrated book, which has an encyclopedic character covering subjects from the design of grottoes and fountains to various methods of raising water and millwork, among others; he explicitly states that many of these designs were inspired when he was working for Prince Henry. In this book de Caus describes a little apparatus consisting of a single vessel partially filled with w...