Out of the Shadow of a Giant: How Newton Stood on the Shoulders of Hooke and Halley

Hooke has been described as ‘England’s Leonardo’, a polymath whose achievements extended far beyond the realm of science. He came from a poor but respectable background, the son of a curate on the Isle of Wight. With the aid of a modest inheritance, he was able to attend Westminster School, and go on to Oxford as a choral scholar without having to pay fees. This was in 1653, during the Parliamentary Interregnum, and since music was banned in church services at the time he got the scholarship without having to sing for it. He eked out a living by acting as a paid servant for one of the wealthier undergraduates, normal practice at that time. He then moved on to become assistant to Robert Boyle, the ‘father of chemistry’. It is now widely accepted that it was Hooke who discovered what is now known as ‘Boyle’s Law’ of gases; Hooke was the only one of Boyle’s various paid assistants to be credited by name in his writings. Through Boyle, Hooke became a member of the inner circle of British scientists of the day, and became the first Curator of Experiments at the Royal Society. He was the man who made the Society a success, but (perhaps because of his humble background) he was always touchy about priority and famously got involved in rows with Newton and the Dutch scientist Christiaan Huygens. Hooke pioneered the use of the microscope, wrote the first popular science book (praised by Samuel Pepys), made astronomical observations, and kept the Royal running. One of his great friends was Christopher Wren, and after the Fire of London the two of them worked together on the rebuilding of the City – many ‘Wren’ churches are now thought to be Hooke’s work. Hooke was the best experimental scientist of his time, the leading microscopist of the seventeenth century, an astronomer of the first rank, and developed an understanding of earthquakes, fossils and the history of the Earth that would not be surpassed for a century.

Edmond Halley is remembered today for the comet that bears his name, but, like Hooke, he had several strings to his bow. Halley came from a relatively prosperous background, did well at school, and went up to Oxford in 1673. There, he was able to indulge his passion for astronomy by taking with him equipment including a telescope and sextant that would have been the envy of a contemporary professional astronomer. His work impressed John Flamsteed, the first Astronomer Royal, and with his (and other) help Halley was able to wangle a trip to the island of St Helena to carry out a survey of the southern skies. His father provided an allowance of £300 a year (three times Flamsteed’s salary!), the degree was abandoned, and at the age of twenty Halley went off on his adventure. The survey was a great success, with Halley’s Catalogue of the Southern Stars establishing his reputation. The King ‘recommended’ that Halley be given a degree, which was awarded three days after he was elected as a Fellow of the Royal Society. He was not, however, in a hurry to build on this success. Comfortably supported by his father, he led the life of a gentleman in Restoration England, including the Grand Tour of Europe, before settling down, getting married and publishing astronomical observations from his home in Islington. The death of his father (in suspicious circumstances) in 1684 brought a change of priorities, and Halley became more involved with the work of the Royal Society. It was around this time that Halley, Hooke and Wren, puzzling over the nature of planetary orbits, asked Newton if he could explain why they seemed to be governed by an inverse square law. This led to the publication, overseen and funded by Halley, of Newton’s great work, the Principia. Alongside all this, Halley carried out a survey of the Thames estuary and invented a practical diving bell. He made the first scientific estimate of the size of atoms, calculated how to work out the distance to the Sun from a transit of Venus, and set out on an official voyage of exploration to the southern seas – a predecessor of the famous Beagle voyage. But, unlike Darwin, he was not a mere passenger; he was given a King’s ship and made Master and Commander (in modern language, a Royal Navy Captain) to run it, the only ‘landsman’ ever to hold such a post. This led to secret work as a spy (the details are lost) in the Adriatic, and then his appointment as a Professor at Oxford University. His life became less exciting, although it was recorded that he ‘talks, swears, and drinks brandy like a sea captain’. But there remained many scientific contributions, including the prediction of the return of ‘his’ comet and Halley’s appointment as the second Astronomer Royal, in 1720.

So far, so good. This outline is essentially the story we expected to tell. But as we delved into the historical material, we found that the importance of Hooke and Halley is even greater than we had anticipated, while Newton turned out to have feet of clay. Newton got some of his best ideas – including ‘Newton’s First Law’ of motion, and the idea of gravity as a universal attractive force – from Hooke, and shamelessly took credit for them. He is known to have lied about his priority more than once, and to have deliberately tried to write Hooke out of the story. But he was only in a position to do so thanks to Halley. Preferring the quiet life as a reclusive Cambridge academic to the rough and tumble of scientific debate in Restoration England,

Newton would have remained an obscure minor figure, remembered in the footnotes of science only for his (incorrect) theory of light, if Halley had not first prodded him into writing his masterpiece, the Principia, and then paid for its publication out of his own pocket. Without Hooke and Halley, we might never have heard of Newton. Without Newton, we would have heard a lot more about Hooke, in particular, and Halley. The legend that grew up about Newton was largely Newton’s invention, and became regarded as fact. For some three hundred years Newton has been venerated in the spirit of the famous line from the movie The Man Who Shot Liberty Valence – ‘When the legend becomes fact, print the legend.’ But it is our intention to print the facts.

We tell the story from the perspective of the intertwined lives of Hooke and Halley, from 1635–1742, starting with the birth of Hooke and taking his story forward, then picking up Halley’s story and carrying both forward. The greatest overlap concerns the time when Hooke and Halley were involved in stimulating Newton’s greatest work, which we describe both from Hooke’s perspective (Chapter Seven) and from Halley’s perspective (Chapter Eight); this inevitably involves some repetition, but by dealing with this from the different perspectives we hope to make their intertwined relationships clear. Along the way, we also describe their interactions with other scientists, not just Newton. And we will leave them, we hope, basking in the sunlight of the recognition they deserve.

The key development in seventeenth-century science, certainly in Britain and arguably in the world, was the establishment of the Royal Society in the 1660s. It was through the Royal Society that Hooke, Halley and Newton met and interacted with each other. Before then, there had been individual scientific pioneers, notably the philosopher Francis Bacon and the experimenters William Gilbert and Galileo Galilei. But the Royal provided a forum for those of a scientific bent to meet, discuss ideas and experiment, as well as being a kind of clearing house for scientific information gathered through a network of correspondents. It was Robert Hooke, more than anyone else, who made the society a success in its early days, when without his enthusiasm, hard work and skill it might have foundered. But to put this in context, we need to begin before Newton, Halley or the Royal Society were even conceived, as Hooke’s early life brings out the changes in British society around the time of the Civil War and paved the way for a scientific revolution.

John Gribbin

Mary Gribbin

November 2016

A NOTE ON DATES (#ulink_74776b46-3057-5626-a2d6-44abd7970019)

Until 1752, the English used the old Julian calendar, which was ten days behind the Gregorian calendar (our modern calendar) used across mainland Europe, which had been introduced because the calendar dates on the old calendar had gradually slipped out of sequence with the seasons. Hooke and Halley therefore used Julian (‘Old Style’ or OS) dates, and we have kept these except where we have indicated ‘New Style’ (NS). At the time, the New Year officially began on 25 March, the start of the tax year, but most people, as today, regarded 1 January as the start of the year. Astronomers, in particular, dated the new year from 1 January, and as both Robert Hooke and Edmond Halley were astronomers, that is good enough for us. In some sources, dates between 1 January and 24 March are written with both numbers, as for example 1650/1, but we give all our dates assuming the year began on 1 January.

CHAPTER ONE (#ulink_04626231-599c-5bed-b290-2f70f11058b2)

FROM FRESHWATER TO OXFORD (#ulink_04626231-599c-5bed-b290-2f70f11058b2)

According to his own account, Robert Hooke was born at exactly noon on 18 July 1635, at Freshwater on the Isle of Wight. What we know of his early life comes from two sources. John Aubrey’s Brief Lives is always entertaining, although not always accurate, but Aubrey was a friend of Hooke and had many conversations with him. Another friend, the naturalist Richard Waller, knew Hooke in later life, and was responsible for publishing the Posthumous Works of Robert Hooke in 1705, putting into print some of Hooke’s previously unpublished lectures. Waller’s introduction to that book drew, he tells us, on an autobiographical memoir that Hooke started to write but never finished, and which is now lost. The story pieced together from these two sources can be fleshed out, however, with other information about events on the Isle of Wight in particular, and across Britain in general, at the time Hooke was growing up. It was certainly an interesting time to be alive, taking in civil war and the execution of a king before the boy was fourteen.

Hooke’s father, John, was the curate of All Saints Church, where the rector was Cardell Goodman, a staunch Royalist and former member of Westminster School and Christ Church, Oxford – connections that would in due course become important to Robert. His mother, Cecellie, was the second wife of John Hooke, presumably a good deal younger than him, and Robert was by some way the youngest of four children. He had two sisters, the younger of whom was seven years older than him, and a brother, John junior, born in 1630.

Robert was a sickly baby who was christened the day after his birth, probably because he was not expected to live, but he survived to become a sickly child. He was too delicate to be sent away to school in Newport like his brother but was educated at home by his father. Although plagued by recurrent headaches and other ailments, this left him plenty of time to wander the south-west corner of the island, gradually becoming stronger, and to follow his own interests, which leaned towards practical activities such as making working models. These demonstrated a rare skill at an early age. He built a model ship, described by Waller as ‘about Yard long, fitly shaping it, adding its Rigging of Ropes, Pullies, Masts, &c. with a contrivance to make it fire off some small Guns, as it was sailing cross a Haven of pretty breadth’ (probably Yarmouth). When he saw a brass clock that had been taken to pieces for repairs, he copied the components in wood and put them together to make a clock, which worked tolerably well. The downside of all the hours he spent over a workbench was that by the time he was sixteen Robert had, he told Waller, developed a pronounced stoop, sometimes referred to by his biographers as a hunchback. As these examples show, Robert Hooke was a precocious ‘mechanic’ of rare skill. But his skills extended beyond the practical. When the artist John Hoskins, a painter at the court of Charles I, visited the island, Robert watched him at work, then made his own paints from materials to hand, such as coal, chalk and an iron ore known as ruddle, and used them to copy paintings hanging in the house, to such good effect that Hoskins suggested he could have a career as an artist.

The other formative influence on the young Hooke was the world around him. That part of the Isle of Wight offers spectacular scenery, chalk cliffs, and the dramatic sight of the Needles, a series of chalk spires rising from the sea at the end of a chalky spine running across the island. Many of the island strata are rich in fossils. Even as a child, Robert was intrigued by the discovery of the shells of sea creatures at the top of these cliffs, a long way above the waves. Most people in those days, if they thought about such things at all, assumed that this must be something to do with the biblical flood. But even though he was the son of a curate, Hooke had doubts, which developed over the years into ideas that culminated in a series of lectures at Gresham College, published posthumously as A Discourse on Earthquakes. Way ahead of his time, as we shall see, Hooke realised that the landscape we see around us today is a result of geological processes operating over immense spans of time, far longer than the then popular biblical timescale of Bishop James Ussher. Much later, he recalled how as a child he had observed a cliff made of layers of material, one of which, far above he sea, was a band of sand ‘filled with a great variety of Shells, such as Oysters, Limpits, and several sorts of Periwinkles.’

These activities took place against the background of the Civil War (actually a series of wars), which lasted from 1642 to 1651. Although the Isle of Wight was staunchly Royalist, its geographical isolation just off the south coast of England, and a judicious surrender to Parliament at the beginning of the conflict, spared it from the turmoil suffered by much of the country, but it was a natural place for Charles I to set up a Royalist base when he escaped from Parliamentary captivity in November 1647 (it is widely thought that he was allowed to escape by the Parliamentarians, at a loss to know what to do with him, in the hope that he would flee to permanent exile in France). This adventure came to nothing, but must have made an impression on Robert, who remained a Royalist throughout his life.

All the model-making and wandering abroad in the countryside came to an end, however, in October 1648, when Hooke’s father died. Robert was just thirteen. John had been ill for some time, and knowing that his time was short had made careful provisions for the family. He left the boy as his share ‘forty pounds of lawful English money, the great and best-joined chest, and all my books’; there was an additional legacy of £10, which had been held by John in trust for Robert, from the will of Robert’s maternal grandmother. The total sum of £50 sounds modest today, and some accounts describe the boy as an impoverished orphan. But in terms of spending power, it was equivalent to about £20,000 today, certainly enough to give him a start in life, even if he would soon have to find a way to earn a living. It may be significant that Robert’s inheritance was entirely portable – as Lisa Jardine put it: ‘cash, books and a chest to carry them in’. Clearly Robert’s future away from the island was already planned. The first step down the road to that future took him as an apprentice to the studio of the portrait painter Peter Lely at Covent Garden in London,

just about at the time the King’s adventure on the island came to an end and he was carried off once again, this time permanently, by the forces of Parliament. Charles was beheaded on 30 January 1649.

Hooke was almost certainly introduced to Lely by John Hoskins, who may have been the person who took him from the Isle of Wight to London. It is easy to imagine the likely fate today of a thirteen-year-old boy with £20,000 in his pocket, installed as an apprentice to an artist in Covent Garden, part of the expanding metropolis of London, then home to some four hundred thousand people. But children were expected to grow up more quickly in the seventeenth century, and Hooke, as he soon demonstrated, was no ordinary child, even by the standards of his day.

But Robert did not stay with Lely for long. Almost as soon as he was installed in Lely’s studio, Robert had second thoughts. According to John Aubrey, who later became a close friend of Hooke, he decided that Lely had nothing to teach him: he ‘quickly perceived what was to be donne, so, thought he, why cannot I doe this by my selfe and keep my hundred pounds?’

According to Waller, Hooke was put off a career as an artist by the smell of the painting materials, which brought on a recurrence of the headaches that had plagued his childhood. Both accounts may, of course, contain part of the truth. And in the light of what happened next, there may be a third thread to the story.

After a brief time with Lely, Hooke enrolled at the prestigious Westminster School, where the headmaster, Richard Busby, held on to his post in spite of his Royalist sympathies and the proximity of Parliament. It is easy to identify the connection that took him there. Cardell Goodman, the rector at Freshwater, had been a pupil at the school, and was a witness to and executor of the will of John Hooke. Our own speculation is that Robert was supposed to be going to Westminster School all along, with his money and chest full of books, but was briefly tempted by the thought of becoming an artist. It is fortunate for the development of science in Britain that he quickly came to his senses and followed what was probably his father’s plan.

Busby was an enlightened headmaster (in some ways; he was also a strict disciplinarian) who charged pupils according to their intellectual ability as well as their ability to pay. Some paid as much as £30 a year, which would soon have eaten up Robert’s inheritance. But some paid nothing at all, and were lodged in Busby’s house. There is no record of what, if anything, Robert paid for his education, but he was one of Busby’s special cases, bright but relatively poor boys who did not necessarily follow the regular curriculum (which still concentrated on the Classics, Greek and Latin literature) but had freedom to develop other skills that might be useful in later life. The ‘regular’ pupils, sons of gentlemen all, and including John Locke, Christopher Wren (three years Hooke’s senior, who became his close friend in Oxford) and John Dryden, had no need to get their hands dirty in this way. But it suited Hooke perfectly.

Although he was not often seen at lessons (at least, according to Aubrey), during his time at Westminster Hooke mastered Latin and could converse in the language, and studied Greek and Hebrew, like the classical scholars. He also, though, learned to play the organ, a skill that would soon come in handy, and mastered the mathematical works of Euclid. According to Waller:

he fell seriously upon the study of the Mathematicks, the Dr. [Busby] encouraging him therein. and allowing him particular time for that purpose. In this he took the most regular Method, and first made himself Master of Euclid’s Elements, and thence proceeded orderly from that sure Basis to the other parts of the Mathematicks, and thereafter to the application thereof to Mechanicks, his first and last Mistress.

Instead of his lessons, he could be found in one of the workshops associated with the school, where he spent the long hours bent over a lathe that he thought produced his stoop. It seems more likely, however, that he suffered from a condition known as Scheuermann’s kyphosis, a curvature of the spine that develops in adolescence and may have a genetic basis but has been linked to poor diet when young.

Hooke’s interest in ‘Mechanicks’ while at Westminster led him, among other things, to devise ‘thirty severall wayes of Flying’, he later told Aubrey. John Wilkins, the Warden of Wadham College in Oxford, was another person interested in mechanical devices, and had written a book about them, published in 1648, with the splendid title Mathematicall Magick, or the wonders that can be performed by mechanical geometry. The book dealt with the use of levers, pulleys and other mechanical aids for practical uses, then went on to more speculative discussion of mechanical automata, including flying machines (ten years earlier, Wilkins had speculated in print about the possibility of flying to the Moon). It seems that Hooke’s interest in mechanical devices, and in particular flying machines, was reported to Wilkins by Busby, helping to smooth Hooke’s path when in due course he too moved on from Westminster to Christ Church. Indeed, Wilkins gave a copy of his book to the boy while he was still at Westminster and Hooke still had the book at the time of his death. When he made the move to Oxford, he left behind someone who had become a firm friend, not just his schoolmaster. Busby and Hooke remained friends for the rest of Busby’s life (he died in 1695), and Hooke was the architect for a church and vicarage built for Busby at Willen, in Buckinghamshire, in the 1680s. When Busby was Archdeacon of Westminster, Hooke carried out several commissions at the Abbey, including repaving the choir, where the black and white marble flooring he had installed can still be seen. But an architectural career lay far in the future when Hooke went up to Oxford in 1653, at the age of eighteen.

The path from Westminster to Christ Church was a well-trodden one. Each year, four Westminster students were awarded scholarships to the college; but Hooke was not one of the four selected in 1653. Instead, he was awarded a choral scholarship, thanks to his musical ability. This seems to have been literally money for nothing, because during the Parliamentary Interregnum such frivolities as church music were banned. In addition, we are told that Hooke acted as a servitor (or ‘subsizar’) to a ‘Mr Goodman’. The position of servitor, acting as a servant to a more wealthy student, was a way for less well off but academically gifted students to make their way at Oxford or Cambridge in those days. The duties might be very light or more onerous, depending on who was being ‘served’. But there is no record of a student called Goodman in Christ Church at the time Hooke was up in Oxford. The logical conclusion is that he was being supported by Cardell Goodman, himself a former Westminster scholar and Christ Church graduate, perhaps with the notional title of servitor for administrative reasons. Although Goodman died in 1653, he could well have left money for the purpose. If so, once again it was money for nothing, and a clear indication of the high academic reputation Hooke had already achieved at the age of eighteen.

Hooke’s time as a student in Oxford was distinctly out of the usual path of other students. Although he went up to Christ Church in 1653, he did not matriculate (in effect, register to study for a degree) until 1658, and he never took the BA examination, although he was awarded an MA in any case in 1663, after he had left Oxford (this is not, as we shall see, totally unlike what later happened to Edmond Halley). Instead of following a conventional course of study, alongside what (if anything) he was studying in college he worked as an assistant to two of the pioneering scientists of the time, first Thomas Willis and then Robert Boyle.

The connection with Willis, and through him a group of scientists, had begun by 1655, when Hooke was twenty.

At the time, a new way of investigating the world was being pioneered, and its key feature was experiment. Since the time of the Ancient Greeks, philosophers had developed their ideas by logic and reason, without actually getting their hands dirty by carrying out experiments. This led to the wide dissemination of such ideas as the notion that a heavy object falls more quickly than a light object, even though a simple experiment was sufficient to prove the idea wrong. By the early seventeenth century, individual scientists were applying the experimental method – Galileo most famously, who, although he never did drop objects from the tower in Pisa, did do experiments rolling balls down inclined slopes to see what really happened to them. In England, William Gilbert, a physician at the court of Queen Elizabeth, carried out many experiments with magnets and made huge advances in understanding the nature of magnetism, but equally significantly he explained the importance of the scientific method of testing ideas by experiment. Indeed, his writing directly influenced Galileo, who read Gilbert’s book De Magnete. Another pioneer of the experimental method was William Harvey, who discovered the circulation of the blood. Harvey had an Oxford connection – as one of the King’s physicians he had been residing in the city with Charles when the King made it his capital during the Civil War. Ironically, though, the person who had the most direct influence on the new experimenters was not an experimenter himself. Francis Bacon, one of the key politicians of the Elizabethan age, published his ideas about the experimental method of scientific research in 1620, under the title Novum Organum. In essence, Bacon’s argument was that progress should be made by collecting facts, forming hypotheses based on study of these facts, then (crucially) using these hypotheses to make predictions that could be tested by carrying out experiments. As long as the experiments agreed with the predictions, the hypothesis being tested could be elevated to the status of a theory, but any theory could potentially be brought crashing down by a single experiment that gave results that did not match its predictions. In due course, the founders of the Royal Society, led by the same John Wilkins we have already met, would explicitly found their institution on their interpretation of Baconian philosophy. And some of those founders were experimenting in Oxford in the 1650s.

The first stirrings of the scientific debates that led to the founding of the Royal Society took place in London, in the mid-1640s, where a group of men, including Wilkins, used to meet to discuss ‘experimental philosophy’. This was at the height of the political and religious turmoil of the Civil Wars, and these gentlemen consciously made a decision not to discuss those contentious topics, but to stick with what we now call science – which must have been something of a relief to them from the uncertainties of everyday life. But at that time the group was essentially a talking shop, not a centre for experiments. After the success of the Parliamentary forces, the former Royalist stronghold of Oxford was reorganised, with many people regarded as King’s men ejected from their posts and being replaced. This took several of the London group to Oxford, where Wilkins became Warden of Wadham College in 1648, and a member of the triumvirate overseeing the University on behalf of Oliver Cromwell in 1652. In 1656, Wilkins married Cromwell’s widowed sister, Robina, who was a couple of decades older than him, cementing his position in the establishment. By then, Cromwell was the Lord Protector, and gave Wilkins a special dispensation to marry even though his post as Warden officially required him to remain celibate. This seems not to have been pure self-interest on Wilkins’ part, because John Evelyn, who knew Wilkins well, tells us that he was:

A most obliging person, [who] had married the Protector’s sister, to preserve the Universities from the ignorant Sacrilegious Commander and soldiers, who would fain have been demolishing all bothe [Oxford and Cambridge] and persons that pretended to learning.

By the time Hooke came to Oxford, the group of experimental philosophers was already holding regular meetings (sometimes referred to as a ‘philosophical club’) at Wilkins’ rooms in Wadham. It was at this time that they began to put the ‘experiment’ into experimental philosophy. Hooke was, of course, already known to Wilkins through Busby, and Thomas Willis was another member of the ‘club’, which was some thirty strong. Willis was a physician and chemist who was particularly interested in the workings of the brain. He was also a member of another ‘club’ – the Westminster/Christ Church old-boy network (indeed, he had been a contemporary of Busby at Christ Church as an undergraduate). So it is no surprise that Hooke became an assistant to Willis, living in his house, Beam Hall, opposite Merton College Chapel, and preparing the medicines for Willis’ patients, as well as helping out with chemical experiments. It was from Willis, too, that Hooke learned dissection.

If this meant that Hooke was neglecting his formal studies, it certainly did him no harm. And he was certainly more interested in learning, by whatever means, than many of the ‘young gentlemen’ who regarded their time at university as something of a holiday. Even at the height of the Puritan regime, with daily prayers at 5 a.m. and 5 p.m., services on Thursdays and Sundays and other devotions, it was necessary for the authorities to instruct the Dean of Christ Church to ‘take special care to reform all scandalous fashions of long and powdered hair, and habits contrary to the status of the University and that decency and modesty which is necessary for young students’, followed by a demand ‘to punish the abuse of swearing’. In 1653, the year Hooke went up, another edict took steps ‘for the repressing the immoderate expenses of youth in the College, that no gentleman commoner shall battel in the buttery above 5 shillings weekly’. Not that these financial restrictions would have meant much to the impoverished Hooke.

There was, however, one new temptation that Hooke fell for, and consumed eagerly throughout his life. The first record of coffee being brewed in England comes from the diary of John Evelyn, who wrote on 10 May 1637 ‘There came in my time to the College [Balliol] one Nathaniel, out of Greece … He was the first I ever saw drink coffee.’ Nathaniel was later sent down (expelled), we don’t know why, but went on to become Bishop of Smyrna, so whatever misdemeanour it was didn’t harm his career. Perhaps partly thanks to his example, in 1651 the first coffee house in England was opened on the site of what is now The Grand Café, on the High Street. Its proprietor was a man called Jacob, from the Lebanon; the first coffee shop in London was opened the following year, by Pasqua Rosee, from Turkey, in St Michael’s Alley, off Cornhill. By the end of the 1650s, there were more than eighty coffee houses in the City of London. Apart from Hooke’s personal addiction to coffee (which may help to explain both the long hours he worked and some of his later ailments), this was an important event for science, as well as society at large, because coffee houses became the preferred meeting places of natural philosophers such as Hooke, Halley and their friend Christopher Wren. A coffee house even comes into the story of the discovery of the inverse square law of gravity.

Although ‘only’ Willis’ assistant, Hooke attended meetings of the philosophical club, and absorbed knowledge from its other members, notably Seth Ward, the Savilian Professor of Astronomy; at Ward’s request, Hooke devised a mechanism to improve the regularity of a pendulum clock for astronomical timekeeping, and this led to a lifelong interest in clocks and the problem of finding longitude at sea. It was also here that he met Wren, and during his time in Oxford he continued his interest in flying. But the single most important thing that happened to Hooke in Oxford was that Wilkins introduced him to Robert Boyle, with the recommendation, which Boyle accepted, that Hooke should become Boyle’s assistant.

Boyle had reached Oxford by a circuitous route. Many accounts simply describe him as a rich aristocrat who had the time and money to indulge his interest in experimental philosophy. But things were never that simple in the England (and, especially in Boyle’s case, Ireland) of the middle decades of the seventeenth century. Boyle’s father, Richard Boyle, was indeed the Earl of Cork and filthy rich, but he was not the latest member of a long aristocratic line. Richard Boyle was what might now be called an entrepreneur, in the pejorative sense of the term. Born in England in 1566, into a respectable but unremarkable family, he became a penniless orphan before he was twenty and went to Ireland (then an English colony) to make his fortune. With the aid of marriages to a wealthy widow, and after she died to the daughter of the Secretary of State for Ireland, and financial dealings that were often on the shady side of legality, he succeeded in his aim so well that he became possibly the richest man in either Ireland or England, able to buy his title and the respectability that went with it.

Wheeling and dealing didn’t take up all of Richard Boyle’s time. Along the way he fathered seven daughters and six sons, before the late addition of Robert, on 25 January 1627, when Richard Boyle was sixty and his wife Margaret forty years old. Yet another daughter was born three years later, but complications associated with the birth killed Margaret. The last girl was named after her.

With no mother from the age of three, and far down the pecking order for any inheritance of either titles or money, the Honourable Robert Boyle (to give him the only title due to him) was initially brought up and educated at home, in the care of family retainers, but later went to Eton. There he was recognised as an outstanding scholar at a very young age, and first encountered the books of Nicolaus Copernicus and William Gilbert. But at the age of twelve, in 1639, Robert was plucked out of school and sent with his brother Francis, then fifteen, on the Grand Tour of Europe that was de rigueur for the sons of wealthy gentlemen. Their education was not forgotten. They were accompanied by a tutor, and visited many seats of learning – they were in Florence in 1642 when Galileo died. But when they were about to return home, rebellion broke out in Ireland. This was one of the early precursors to the Civil Wars, and although Francis was considered old enough to be summoned home to help suppress the rebellion, Robert was told to keep away until the fighting was over. The rebels, however, were not suppressed without serious consequences for the Boyle family. Two of Robert’s brothers (not Francis) were killed, and the grand old Earl of Cork lost most of his money and land. He died in 1643, soon after this phase of fighting finished. So when Robert returned to England in 1644, he had no money and had not been educated for any kind of useful career. Worse, by then the ‘proper’ Civil War was raging. He was saved by his sister Katherine, thirteen years older than Robert, who had married to become Viscountess Ranelagh, and lived in London but apart from her husband.

At first, Robert lived in Katherine’s house. She was a known Parliamentarian sympathiser with many powerful friends in London, which was controlled by Parliament. Robert judiciously never gave any indication of preferring one side or the other in the Civil Wars, probably because he genuinely just wanted to be left alone to get on with his life in peace. Katherine helped him to find a retreat from the turmoil of the times. Their father had left to Robert a small estate in Dorset – not much compared with the large estates in Ireland once intended for the older brothers, but enough for the youngest son, and by chance one of the few possessions the Earl had left at his death. Thanks to Katherine’s connections, the estate was not confiscated by Parliament, and Robert was allowed to live there from 1645 onwards, setting up his own laboratory where he carried out chemical experiments. On visits to London, he stayed with Lady Ranelagh, and like-minded experimental philosophers used to gather to meet with him at her house. Boyle referred to this as an ‘invisible college’; we don’t know who was involved, but there must have been considerable overlap with the group we mentioned earlier, including Wilkins.

Boyle’s fortunes improved in the 1650s, after the Civil Wars ended. One of his surviving brothers, now Lord Broghill, was in favour with Parliament for his part in crushing the Irish. This rubbed off on the rest of the Boyle family, and Robert was able to visit Ireland to pick up some of the threads of their former life. Horrified by the terrible conditions of the Irish people, after some soul-searching he got the estates running as a benevolent landlord (by the standards of the time) who used much of the income for charitable ends. This still left him enough to live on comfortably and continue in the role of gentleman scientist back in Dorset. But John Wilkins, who had met Boyle in London and knew his abilities, invited Robert to move to Oxford, where he could not just carry out his own experiments but be in the company of other people with similar interests. After mulling the offer over, Boyle made the move in 1655. He was never formally part of the university (as he put it himself, ‘never a Professor of Philosophy, nor a Gown-man’), but he had his own laboratory, and he also (as Wilkins had probably hoped) helped to finance the work of some of his fellow experimental philosophers. Boyle lived and worked in a house known as Deep Hall, on the High (convenient for the coffee shops!), and it was here, in 1656 (the year, incidentally, that Edmond Halley was born), that Robert Hooke came to live and work as Boyle’s paid assistant, although possibly they had already met.

Back in September 1653, when Wilkins was already trying to persuade Boyle to move to Oxford, he had sent a letter to him by messenger. It read, in part:

This bearer is the young man I recommended to you. I am apt to believe, that upon trial you will approve of him. But if it should happen otherwise, it is my desire he be returned, it not being so much to prefer him, as to serve you.

Lisa Jardine has suggested that the young man in question was Hooke, and that he was sent as part of the attempt to entice Boyle to Oxford, by showing that a skilled assistant would be available there:

If it be not, Sir, prejudicial to your other affairs, I should exceedingly rejoice in your being stayed in England this winter, and the advantage of your conversation at Oxford, where you will be a means to quicken and direct us in our enquiries … shall be most ready to provide the best accommodation for you, that this place will afford.

The immediate plan to persuade Boyle to Oxford that winter was aborted because he had to travel to Ireland to deal with the urgent business concerning the family estates we have already mentioned. The young man, presumed to be Hooke, returned to Oxford. But when Boyle did make the move some two years later, it seems that he was already aware of the abilities of the man who did indeed become his assistant.

The greatest achievement of the Boyle–Hooke collaboration was an improved air pump, which made it possible for them to carry out experiments both at greatly reduced air pressure and at pressures greater than ordinary atmospheric pressure. That simple sentence, though, needs unpacking in order to put Hooke’s achievements, in particular, into perspective.