Absolute Zero and the Conquest of Cold Read online

  Considerably more astonishment was professed at Drebbel's well-reported 1621 demonstration of a submarine. In three hours the boat traveled "two Dutch miles" underwater on the Thames, from Westminster to Greenwich, in front of the king and thousands of onlookers. None could figure out how the submerged crew of twelve — plus the inventor himself, who risked drowning along with them — could continue to breathe in the absence of fresh air. Drebbel provided a clue to the submarine's air supply in his Fifth Element, published that year, which included the cryptic statement that "salt-petre, broken up by the power of fire, was thus changed into something of the nature of the air." Scientific analysis was so rare in 1621 that no one picked up on that clue; decades later British chemist and physicist Robert Boyle would partially comprehend what this demonstration accomplished, writing that "Drebbel conceived that it is not the whole body of the air, but a certain quintessence ... or spirituous part of it that makes it fit for respiration," and figuring out that when Drebbel observed that the air in the submarine was becoming exhausted, "he would by unstopping a vessel full of his liquor speedily restore [to] the troubled air such a proportion of the vital parts, as would make it again, for a good while, fit for respiration." In short, Drebbel had isolated and discovered oxygen, 150 years before Joseph Priestley. But today Drebbel's name is nowhere associated with that major advance in chemistry.

  Drebbel's fondness for the dramatic presentations of the magician rather than the steady progress of the scientist may also help explain, in part, why his preternatural stunt of cooling Westminster in summer produced few reverberations. An inventor and court entertainer, he felt keenly the need to keep the secrets of his demonstrations to himself, a need reflected by his lifelong refusal to document and publish his experiments properly or to keep a diary. "Had Drebbel compiled notebooks describing his undoubted technological works," writes L. E. Harris, president of a society dedicated to the history of engineering, "he might have attained some lasting fame even without having an influence on future technologies, as is the case with Leonardo da Vinci." In the time-honored way of the magician, Drebbel vouchsafed his "secrets" only in fragments to his apprentices, the voracious Kufflers—but evidently he did not tell them very much, for after Drebbel's death they were not able to replicate his feats, though they made money from a dye works based on his "secret" formula.

  Drebbel appears to have been convinced that if he disclosed the secrets of his work, he would lose the aura of mystery that made him attractive to the king; moreover, by retaining the secrets, he affected to possess a power over nature that in some measure counterbalanced the power of the king over ordinary mortals. But this was only posturing. How dependent Drebbel was became obvious only when King James's death removed his stipend, which reduced him to what Flemish artist Peter Paul Rubens wrote was an "extraordinary" appearance of such shabbiness and disarray that it "fills one with surprise."

  Drebbel's refusal to reveal his secrets was accepted and sealed by his audience's equal reluctance to demand explanations for marvelous devices and demonstrations. Heinrich van Etten, a contemporary, suggested that audiences found mathematical and scientific puzzles more entertaining if their inner workings were concealed, "for that which doth ravish the spirits is an admirable effect whose cause is unknowne, which if it were discovered, halfe the pleasure is lost." The statement reflects a lack of curiosity that ran throughout society at that time, from the basest peasant to the highest noble.

  Today we believe curiosity is central to science and perhaps to all of human progress; curiosity is the engine that drives the intellect to seek the causes of things. "Curiosity is one of the permanent and certain characteristics of a vigorous mind," Samuel Johnson would write in 1751, and few could disagree with him.

  But in 1620 prevailing opinion disparaged curiosity. The distaste rested on two pillars of ancient thought that resonated throughout the late medieval and Renaissance eras. In the fifth century Saint Augustine had condemned curiosity as a base longing to know the trivial, contrasting it with the elevated pleasures of faith, which he believed provided all the explanations that humankind needed; curiosity was anathema because it meant delving too deeply into what God had created. Adding to the distrust of curiosity and of any quest to unlock the "secrets" of natural phenomena was a belief that investigating nature's hidden workings ran counter to Aristotle's teachings, inscribed nearly a thousand years before Augustine. Aristotle had taught that nature could be entirely apprehended by the senses, that knowledge was not obtainable through experiment and could be derived only as a byproduct of reason and logic. In the thirteenth century, Thomas Aquinas had fused the philosophies of Aristotle and Augustine, as they related to scientific inquiry, and since then his synthesis had been dominant. John Donne, who owed his high ecclesiastical position to King James, vehemently agreed with Aquinas that it was impious to attempt to uncover any hidden truths about nature.

  In the early 1600s, however, beliefs that decried curiosity and restricted information about the "secrets" of nature to a handful of cognoscenti were under attack, and the most highly influential English opponent of such views was a man who tried to explain Drebbel's demonstration at Westminster, though he probably had not been present at it: Sir Francis Bacon, Baron Verulam, lord chancellor of England. Lawyer, historian, philosopher, and politician, Bacon more than anyone else in England helped banish magic and secrets by championing science based on experimentation. Constantijn Huygens might write of Drebbel and Bacon in the same sentence and contend that their accomplishments were of equal moment, but they were not colleagues. Rather, they were polar opposites, Drebbel among the last of the magician-artificers and Bacon the first true English scientific thinker. In Drebbel's refusal to explain his stunt and Bacon's insistence on trying to discern its chemical mechanism of cooling lies the deeper significance of Drebbel's demonstration: it symbolized the passing of the era in which magic held all the fascination and the arrival of science at center stage to begin the process of providing explanations of nature that would greatly advance human civilization.

  We infer Bacon's absence at the Westminster event because he did not write himself an immediate note about it, as he had done after viewing Drebbel's demonstrations of earlier devices and machines at Eltham Palace. Bacon's appetite for scientific stunts was declining; in 1605, while courting King James, he had condoned the study of marvels, witchcraft, and sorcery "for inquisition of truth, as your majesty has shown in his own example [in Demonologie]" but later Bacon insisted that "experiments of natural magic should be sifted diligently and severely before they are received, especially those ... commonly derived ... with great sloth and facility both of believing and inventing."

  Another likely reason for Bacon's absence was the gathering storm, fomented by his political enemies, that within a year would result in his abject fall from favor. Shortly after James made Bacon viscount of St. Albans in early 1621, the nobleman was impeached for accepting bribes; after confessing to his guilt, he was stripped of his position and banished from London, though he was spared incarceration. The deeper reason for Bacon's eclipse was related to his growing advocacy of experimental science. English scientist Robert Hooke later identified that reason, in comparing Bacon's treatment to that of Italian scientist Galileo by the Inquisition: "Thus it happened also to ... Lord Chancellor Bacon, for being too prying into the then receiv'd philosophy."

  Bacon was never a man to ignore what another experimenter might turn up that could be relevant to his own studies, and perhaps that is why, in Novum Organum, published later in 1620, he wrote the short section that, according to an associate, tried to fathom "the late experiment of artificiall freezing" at Westminster: "Nitre (or rather its spirit) is very cold, and hence nitre or salt when added to snow or ice intensifies the cold of the latter, the nitre by adding to its own cold, but the salt by supplying activity to the cold of the snow." Nitre, also known as saltpeter, is a common chemical compound (today called potassium nitrate) and the active ingredi
ent of gunpowder. Bacon's guess about Drebbel using nitre was a good one: the court artificer had himself written of saltpeter and was also on intimate terms with Sir Thomas Chaloner, author of a book solely about nitre; moreover, as Bacon hints, many alchemists and would-be scientists had been experimenting with the cold-inducing aspects of nitre and common salt.

  A source for those experiments was one of the most popular "books of secrets" of the age, Giambattista della Porta's Natural Magic, first published in Italy in 1558 and enlarged—as well as translated into virtually every other European language—in 1589. Della Porta was one of the most famous men in Italy, a friend of German astronomer Johannes Kepler and Galileo, a man so learned in the ways of nature that he was expected at any moment to discover the philosophers' stone. Jailed by the Inquisition for his magic, he continued to write about it. In Natural Magic, following sections treating alchemy, invisible writing, the making of cosmetics, gardening, and the accumulation of household goods, della Porta appended a final miscellany, "The Chaos," in which he mentioned mixing snow and nitre to produce a "mighty cold" that was twice as cold as either substance—cold enough to make ice.

  With these hints, and some technology of the era, we can finally reconstruct how Drebbel probably accomplished his feat.

  At an early hour of the morning, Drebbel and his assistants brought into Westminster Abbey long, watertight troughs and broad, low vats and placed them alongside the walls and in the midst of the limited part of the abbey that they planned to cool, most likely that inner, narrow transept near the portal through which the king and courtiers would enter, an area they knew would be in shade most of the day and especially at that hour. They also brought in snow, which would have been available from those among the nobility who had on their estates underground snow pits to keep un-melted snow and ice in storage after the winter, to use for cooling drinks in summer. Drebbel filled the troughs and vats partway with water, the coolest he could find, which he no doubt had fetched directly from the nearby Thames. For several hours, he infused nitre, salt, and snow into the water, creating ice crystals and a mixture whose temperature—if he could have measured the temperature, which he could not, since no thermometers capable of such accuracy yet existed—was actually reduced below the freezing point of water, as della Porta had guessed. Some of the troughs were metal, and the freezing mixture chilled the metal, which aided the refrigerating process by keeping the contents of the troughs cold.

  More to the point of the exercise, the freezing mixture cooled the air directly above the troughs and vats. In Drebbel's Elements treatise he referred to the frequently observed phenomenon of heated air rising, and he seems also to have understood that cool air is heavier than warm air and tends to stay close to the ground. Now he used this principle to generate a mass of cool air that displaced warmer air in the cathedral up in the direction of the capacious ceiling. He did not need to force the warm air to rise very far—just 10 feet high or so, until it was above the height of the king and courtiers. And he did not need to make the space very cold—a decrease in temperature from, say, 85° to 65°F would have proved sufficient to chill an overheated king. This cooling Drebbel accomplished over the course of several hours, perhaps aiding the process by fanning the cool air so that remaining pockets of warm air thoroughly dispersed, before the court party arrived and experienced the shock of the cold.

  2. Exploring the Frontiers

  IN THE SEVENTEENTH CENTURY, the capital cities of Europe and England were enlarging in size and population relatively slowly, in part because of society's limited ability to provide food to locations that could not grow enough to feed their own residents. A quarter of the grains, fruits, and vegetables would rot in the fields before being harvested, and eggs and milk would quickly spoil. If the destination of the crops or dairy products was more than a day's wagon ride from the farm, another fraction might become inedible during transport. Evidence that farmers knew that cold retards spoilage comes from their general practice of bringing foodstuffs to the city at night, to take advantage of lower evening temperatures. At city markets, animals used for food were generally killed only after customers had bought them, or no more than a few hours before sale, because uncooked or untreated flesh would not remain edible for long. To hold the live animals, butchers required larger premises than other shopkeepers, which raised the cost of their meat.

  Owing in large measure to the absence of refrigeration, fresh meats, fish, milk, fruits, and vegetables made up a lower percentage of the diet than bread, pickled vegetables, cheeses, and preserved meats. A great deal of ingenuity went into preserving by pickling in salt or sugar, smoking, drying, or excluding air by submerging foods in oil, all of which substantially altered the character and taste of produce or meat. Vegetables and fruits could not be obtained out of season, except at inordinate cost or under special circumstances, as when a king would dispatch a ship to Morocco to bring back oranges in winter.

  In the Temperate Zone, even when ice was available, it was not extensively used for food preservation, the nobility employing their ice facilities mainly to provide chips to cool their wine in summer, much as the ancient Romans had done. Seventeenth-century technology for utilizing cold had not advanced one whit over that of ancient times. Pliny ascribed to Emperor Nero the invention of the ice bucket to chill wines, designed to eliminate the need to drink wine diluted by ice that had been stored in straw and cloth. Zimrilim, ruler of the Mari kingdom in northwest Iraq around 1700 B.C., built a bit shuripin, or icehouse, near his capital on the banks of the Euphrates. In China, the maintenance of icehouses for the preservation of fruits and vegetables dates to the seventh century B.C.; a book about food written during the Tang dynasty (A.D. 618–907) referred to practices begun during the Eastern Chou dynasty (770–256 B.C.), when an "ice-service" staff of ninety-four people performed the tasks of chilling everything from wine to corpses. In the fourth century A.D., the brother of the Japanese emperor Nintoku offered him ice from a mountain, a gift so charming that the emperor soon designated the first of June as the Day of Ice, on which civil and military officials were invited to his palace and were offered chips, in a ceremony called the Imperial Gift of Ice.

  Night cooling by evaporation of water and heat radiation had been perfected by the peoples of Egypt and India, and several ancient cultures had partially investigated the ability of salts to lower the freezing temperature of water. Both the ancient Greeks and Romans had figured out that previously boiled water will cool more rapidly than unboiled water, but they did not know why; boiling rids the water of carbon dioxide and other gases that otherwise retard the lowering of water temperature, an explanation the Greeks and Romans were unable to reach or understand.

  Progress in the use of cold had been held back by a dearth of basic knowledge about its physics and chemistry. The advance of such knowledge in turn depended on social change, which after a thousand years of stasis had become the order of the day in the seventeenth century. Partly owing to the Protestant challenge to Catholicism, partly to the discovery of the Americas, many thinkers embraced the radical notion that there was more to the world, and to knowledge, than had previously been believed.

  This was no minor shift in emphasis but a sea change in society, writes historian of ideas Barbara Shapiro, in which the practitioners of law, religion, and science all became "more sensitive to issues relating to evidence and proof.... Experience, conjecture, and opinion, which once had little or no role in philosophy or physics, and probability, belief, and credibility ... now became relevant and even crucial categories for natural scientists and philosophers." Christiaan Huygens, the mathematically gifted son of Constantijn and the inventor of the pendulum clock, expressed the new understanding: "'Tis a Glory to arrive at Probability.... But there are many degrees of Probable, some nearer Truth than others, in the determining of which lies the chief exercise of our judgment."

  Cornelis Drebbel cared little for the glory of probability; he wanted to make a living. After demonstr
ating his power over the cold at Westminster, he made no further public displays of low temperatures, perhaps because he garnered no encouragement for them, in the form of either honor or money. The submarine demonstration did bring him employment, though, and after the death of King James in 1625, Drebbel worked with the military, helping to manufacture explosives, which he took into battle in several Buckinghamled naval expeditions against France. During these forays, he was to be paid at the high rate of £150 a month to set fire to the enemy. The expeditions failed, and Drebbel was unable to collect his pay for the last one. He tried in vain to revive a scheme to distribute heat to the houses of London via underground pipes, and he was part of an unsuccessful attempt to drain fens to make arable land. Desperate for income, he started a brewery and alehouse near London Bridge, attracting attention with an underwater contraption that appeared to be a monster. Drebbel died in 1633, and the secrets of his marvelous devices perished with him.

  For Francis Bacon, the glory of arriving at probability became the touchstone of his later life. Shorn of his political responsibilities, he turned his mind again toward natural science, writing several seminal works during his last five years of life, from 1621 to 1626. It was in these natural science books, perhaps more than in his earlier political tracts, that Bacon did what Robert Hooke later admired: he countered "the receiv'd philosophy" and in so doing made possible many subsequent steps in science, in particular those leading to the greater understanding of the cold that this book chronicles.