An Ocean of Air (3 page)

It didn't help that news of the crucial experiments only trickled out gradually by whispers and rumors. Proud though he was of his findings, Torricelli didn't dare trumpet them to the rest of the world. The trouble was that he had been playing with vacuums. And the Church, in another of its unfortunate pronouncements on physics, had declared belief in the vacuum to be heretical.

The Church had decided to abhor the vacuum mainly because of the teachings of various philosophers who had lived long before Christ. Aristotle, for instance, believed that a vacuum was logically impossible. For him, space was, by definition, the place where objects resided. If there were no objects there could be no space, and hence no vacuum. The materialists Democritus and later Lucretius, however, believed that all matter was composed of tiny indivisible particles called atoms, which were separated from one another by empty space.

Not much progress was made in the following twenty-one centuries to resolve this issue, and by the sixteenth century the Catholic Church had decided to side with Aristotle. By reducing all of Creation to a collection of atoms, Democritus and Lucretius had left no room for spirit or soul, and also raised troubling questions about exactly how, scientifically speaking, the communion wafer and wine could transform into flesh and blood. Their philosophies were therefore anathema. Tarred by association, belief in the existence of a vacuum was also declared heretical. According to the religious authorities, God had decreed that a vacuum would be so unnatural that air would always rush in immediately to prevent one from being formed. To say otherwise was to risk the wrath of the Inquisition.

Having seen the effects of Galileo's mild outspokenness, Torricelli opted for discretion. He never published his results, except in one famous letter that he wrote on June 11, 1644, to his close friend Michelangelo Ricci. Though Ricci was a Jesuit, he was also a firm advocate of Torricelli's work, and Torricelli described his experiments in careful detail, with sketches of the apparatus. Mostly, he remained matter of fact, but once in a while he let his delight in his findings shine through. "What a marvel it is!" he wrote when he contemplated the invisible air pressing his mercury up into the tube. He spoke with awe of how our blanket of air, perhaps fifty miles high, constantly presses down on the planet beneath. And he encapsulated it all in this one glorious image. "
Noi viviamo sommersi nel fondo d'un pelago d'aria,
" he said. "We live submerged at the bottom of an ocean of air."

***

With his experiments in quicksilver, Torricelli had proved the pressing power of air to his own satisfaction, but his secrecy about the results and the prevailing stubborn resistance to this extraordinary new notion meant that, for the moment at least, the old ideas continued to rule.

Fortunately there remained the other person who had arrived in Florence just before Galileo's death and who, like Torricelli, was destined to pick up his mantle. His name was Robert Boyle, and when he reached Florence in October 1641, he was a sixteen-year-old schoolboy who had as yet no particular yen for science.

Boyle was the son of one of Ireland's richest noblemen. He had ridden from Geneva to Florence that summer with his brother and tutor on a leg of their Grand Tour of Europe. But unlike the other privileged young gentlemen risking pox, plague, and bandits in the interest of gaining Continental polish, Boyle truly wanted to learn. He carried books everywhere; he read them walking along roads and stumbling down hillsides. He disputed philosophy and religion with fellow guests at the lodging houses and tried to make the deepest possible sense of everything he saw and heard.

Soon after Boyle arrived in Florence, he came across a copy of Galileo's final book and was deeply struck. He was also struck with indignation by the fate of the man now dying in his villa just a few miles away. Boyle noted triumphantly in his journal how, when monks went to visit the "great star-gazer" and chided him that his blindness was a punishment sent by God, the quick-witted Galileo had replied that at least "he had the satisfaction of not being blind till he had seen in heaven what never mortal eyes beheld before."

For Boyle, the Church was also suffering from blindness. He decided that religion was about revealing the wonders of God's nature, not hiding them behind dreary dogma. Boyle didn't want to be told what to believe about the workings of the world. He wanted to glorify God by discovering them for himself.

Yet the seed Galileo's work had planted could easily have withered over the succeeding years. For shortly after Boyle left Florence, his home country, Ireland, erupted in rebellion, while England tumbled into its own civil war. It was more than two years before Boyle could make his way back home, and even then he got only as far as England, first to his sister's house in London and then to Stalbridge, a modest manor house that his father had bought for him in Devon.

This would have been a good time for Robert Boyle to settle into the life of a country squire. England was by then a little less troubled. True, King Charles I had been arrested, then later arraigned and publicly beheaded, but the Protector, Oliver Cromwell, had taken control and, along with his New Model Army, had restored a large measure of political sta
bility. Boyle was comfortably off. He could indulge in gentlemanly pursuits, ride, shoot, and fish.

But there was still something missing in his life. He was full of ideas, but there were no obvious routes for gentlemen to express them. Boyle dabbled with religious writings. He wrote a series of "Occasional Reflections" addressed to his favorite sister, Katherine, Lady Ranelagh, drawing what were admittedly often mawkish morals from events such as "Upon the sighting of a fair milk-maid singing to her cow" and "Upon my spaniel's carefulness not to lose me in a strange place." This led to some mockery, which was not really fair. Boyle was pious, but never sanctimonious. He was pleasant, approachable, and almost pathologically fair-minded, and though his religious sentiments were naïve, he was still in his early twenties.

One of the most famous parodies of Boyle's Reflections was penned by satirist Jonathan Swift, several decades later. Swift at the time was private chaplain to a lady who was smitten by Boyle's writings and wanted them read to her constantly. Swift became so exasperated that he slipped in an extra, unauthorized and very funny piece titled "A pious meditation on a Broom Staff": "But a broomstick, perhaps you will say, is an emblem of a tree standing on its head; and pray what is man, but a topsy-turvy creature..." (In spite of his mockery, Swift may well have used Boyle's vivid imagination as inspiration for his most famous book:
Gulliver's Travels.
)

Boyle even wrote a romantic, yet highly moralistic, novel, and for a while it seemed he might try expending his intellectual energies on a literary career. But his curiosity about the workings of the world tugged at him. He wanted to understand the world in a new way, the way that Galileo had shown him. He wanted, above all, to
experiment.

So in 1649, Boyle installed a laboratory at Stalbridge. He commissioned furnaces from the Continent, and he dabbled with alchemical efforts to find a way to turn lead into gold. But his attempts to experiment seemed aimless. He needed to be among people who shared his urge to understand the natural world through experiment and not through reason alone. During his visits to his sister Katherine's house in London, he had
met many such men, who were already discussing the best new ways to probe nature. They met in each other's homes and called themselves the "Invisible College," though Boyle always referred to them as the "Invisibles." (This was the first glimmering of what would become London's famous "Royal Society" when the monarchy was eventually restored after the death of Cromwell.) From these men and their discussions with his thoughtful, intelligent sister, Boyle had learned much. But London had begun to seem politically too unstable for these men, and many of them had moved to take up positions behind the safe walls of Oxford's rather less invisible university. And so, in the mid-1650s, Boyle decided that he would join them. He left his stately manor house and moved into lodgings that his sister found for him in the house of an apothecary.

Boyle was at last in his element. He had never been particularly interested in the social status to which he was entitled by birth. (Nor was he particularly interested in fame or money. Throughout his life he was to turn down many offers of honors and appointments. He said with typical cleverness that he preferred to work on things that were "luciferous rather than lucriferous," that is, he preferred work that was enlightening rather than money-making.) Instead, at last, he was surrounded by people who shared his passion. There were chemists and mathematicians, physicists and physicians. Here were Richard Lower and Tom Willis, who together would soon perform the world's first blood transfusion experiment; there was Sir Christopher Wren, architect, polymath, renaissance man. Oxford seemed full of people who were itching to experiment, to discover for themselves how the world worked.

For the first few years, Boyle watched, listened, and learned. He had yet to decide what area he wanted to make his own. Meanwhile, whispers of Torricelli's experiment with quicksilver were making their way across the continent. In France, largely beyond the reach of the Roman Inquisitors, a philosopher named Blaise Pascal had caused a great sensation with his public demonstrations, using thirty-foot-long glass tubes filled with water and wine as well as Torricelli's preferred, but less dramatic, quicksilver. He also used the heights of the different liquids forced upward by the air to come up with a value for the total weight of the atmosphere. He an
nounced that our ocean of air weighs some 8,283,889,440,000,000,000 pounds, and he wasn't far off.

From France, news of the experiment had passed across the English Channel to London, where the "Invisibles" were greatly taken with it and performed it many times. Even before Boyle went to Oxford, he had come across the experiment during his frequent visits to London, and it had immediately quickened his interest. He later wrote that air was the perfect subject to study. Not only is it vital for breathing, but it also touches us inside and out every day of our lives. Something that is jointly so necessary and so pervasive would surely be full of hitherto unsuspected scientific treasures. However, Torricelli's experiment had been thoroughly dissected and very frequently reproduced. There didn't seem much more that Boyle could do with it.

Then, in 1657, came sensational news. The Burgomaster of Magdeburg in Germany, one Otto von Guericke, had invented a way to pump air. His method was a little crude, but he was a terrific showman and had used his new air pump to great effect. He had taken two copper hemispheres about twenty inches in diameter, carefully milled so their edges fitted together perfectly and they formed a sealed globe, then used his air pump to remove much of the air inside the globe. Finally, he attached teams of horses, one to either side, and made them heave. With the overwhelming weight of the atmosphere squeezing the two sides together, it took thirty-two straining draft horses to wrench the hemispheres apart.

Boyle was enchanted by this experiment. "Thereby," he wrote, "the great force of the external air ... was rendered more obvious and conspicuous than in any experiment I had formerly known." It didn't quite resolve the issue. Those who were already convinced interpreted it the same way as Boyle, but it was still possible to argue that the vacuum inside the Magdeburg sphere was somehow pulling, rather than the air outside pushing.

What is more important for our story, however, is that von Guericke had invented a new way of working with air. Before then, the only way to make a vacuum was awkwardly, at the top of a Torricellian tube full of quicksilver. Now there was a new way, one that was surely open to experiment. This was exactly what Boyle had been looking for.

Von Guericke's air pump had not been designed for the sort of experiments Boyle had in mind. There was no chamber in which to put equipment, and whatever was being pumped had to be held underwater. However, it was a start and could surely be improved upon. Boyle immediately hired Robert Hooke, the most brilliant experimental designer in England, and set him to work.

Robert Hooke was an irascible hunchback, a hypochondriac with a caustic wit and a terrifying manner. He was also a genius. As engineer and architect he would be second only to Sir Christopher Wren in rebuilding London after the fire that would destroy most of the city in just a few years. Now, although he had only recently completed his studies at Oxford, he was already renowned for his ingenuity. Hooke began to design an air pump that would do everything Boyle desired. He would have no need to fiddle around with quicksilver and thin glass tubes as Torricelli had, nor to hold his pump underwater as had Otto von Guericke. With the machine that Hooke designed, Boyle would soon be able to make air come and go at will.

While Hooke labored, the outside world grew increasingly fearful. The stability that Oliver Cromwell had brought to England was beginning to fray. Even nature seemed to be against him. The winter of 1657-58 was the severest on record, and bitter temperatures lasted until June. There were days of public fasting to try to ward off the evil that had befallen the country. On August 21, Cromwell fell ill, and the nation held its breath. Ten days later, England was blasted by a storm so violent that Cromwell's followers declared it was a warning of divine retribution against his detractors, and his enemies said the devil was riding in on the wind to claim the soul of the great traitor and king-slayer. Whatever the true reason for the storm, Cromwell had only a few more days to live, and his death heralded a new period of disarray.

The Royalists began to agitate for the return of the king, while the Roundheads marshaled their forces under the banner of Cromwell's regrettably feeble son. Yet through all this, Boyle and Hooke remained oblivious. Safely ensconced in Oxford, they worked steadily on their air pump.

It wasn't easy. Boyle was struggling desperately with distemper in his eyes. A few years earlier he had fallen off his horse in Ireland and contracted a protracted and debilitating illness. Soon afterward his sight had begun to trouble him, and there were times when he could scarcely make out the apparatus for himself. But still he was eager for what he called "the principal fruit I promised myself from our Engine." For Boyle already believed that Torricelli and von Guericke were right, that the driving force in Torricelli's quicksilver experiment was the weight of the air. And he also believed that with his new air pump, he would be able to convince the rest of the world.