The Map That Changed the World

by Simon Winchester

  The oolitic limestone dips gently eastward, much as did the red marls that Smith found in the Mearns Colliery. What this meant to a traveler heading west on the Camerton & Limpley Stoke Line—the map shows it passing in an almost direct westerly direction for most of its route toward the terminus at Camerton and the junction at Hallatrow—is that he or she would pass—or chuff or clank—steadily downward through the geological table, because of the steady dip of the rocks. From the start at Limpley Stoke station he or she would pass much of the way through the Jurassic, from Middle to Lower. Somewhere around Combe Hay Halt he or she might have noticed having entered the outcrop of Triassic rocks. By the time the train has reached Dunkerton Colliery, the traveler will be in the thick of the Upper Carboniferous, and of the coal.

  This much we know today, and a great deal more besides. In William Smith’s time, however, very little was known—and anyone who made that westbound journey from Limpley Stoke to Camerton in 1792 might well have marveled at the change of scenery but would have had precious little understanding of which rock was which; which type might be older or younger than any other; and which appeared where, when it did, and why.

  Anyone, that is, except for William Smith. For seven seminal years these few square miles of gently graduated English loveliness were to become Smith’s stamping ground. He worked in precisely the area along which the Camerton & Limpley Stoke Railway ran for the 44 years of its commercial existence. He did so because, 120 years before the railway was built, he was to become, after only the briefest of apprenticeships, the man responsible for surveying the canal—a canal that would provide ready-made the route that the railway itself would later take. As it happened, the railway was built to compete with and ultimately replace and ruin the old canal. But here this matters little: What is important for an understanding of Smith’s work is the decisions that were taken by him as to the canal’s initial route.

  Both the canal and railway had perforce to start at the same place—Limpley Stoke—because that was the junction for the bigger canal (the Kennet and Avon, along which goods could go to Bristol or to London) and the main-line railway (along which goods could also be taken to the same two industrial centers). Both ended at the same place, Camerton, because that is where the coal was. But the precise route that was taken between these two end points was, essentially, up to William Smith to decide.

  The process of choosing that route was to offer him an intimacy with countryside and landscape that was never to leave him. And it was to set him wondering, too, about all those mysteries that eluded, or did not even appear to concern, those others who might travel between the two ends of the coal mine route. Why such a journey began in an area of limitless beauty, and why it ended in a region so very much less attractive, would to them be either an enigma or a matter of no consequence.

  But not to Smith. He was different; his view was different. He alone would in time come to recognize that the simple gradation in the rural loveliness of the canal route said something well worth knowing about Somerset’s mysterious underworld. His genius—the unanticipated genius of this uneducated farmer’s son—was that he realized it was not simply a matter of noticing the difference. It was also possible—desirable, and perhaps important—to find out just why there was a difference in the first place.

  His survey of the canal was the means to such a discovery. In a sense the fact that he was making a new canal became eventually almost incidental to his own self-allotted main task—which was to find out why the landscape was the way it appeared to be, and whether any of the lessons he had learned in the coal mines, and which the miners insisted belonged to mines alone, could apply out in the wider geological world as well. The red marls of the High Littleton mines dipped east; the oolite and Triassic rocks of the canal route dipped east—so could any firm prediction that he made about the one be equally applied to the other? Smith thought so; and the survey would confirm or not, as the case might be.

  In making the route for the new canal he would be digging his way through the very rocks that made the hills—lovely but unproductive hills in the east, their aesthetically unremarkable but richly endowed equivalents in the west—that stood in the way of himself, of the canal, and of progress. If only what he found would ultimately confirm what he had suspected from his explorations in the shafts at the Mearns Colliery in High Littleton, then his work for the newly formed and comfortably subscribed Somerset Coal Canal Company Ltd., was likely to be of earth-changing importance. Smith knew that if he cracked the code he suspected he might find during his surveys, then in time he could become a famous man.

  For William Smith was now a changed and changing figure. Until he moved down from Gloucestershire to Somerset he was a man of seemingly modest vision. The small epiphany that occurred during his stay in High Littleton showed him the advantages of ambition; once he had started to work for the canal company that new ambition was to be annealed and case-hardened, until Smith became convinced that he would one day, and with good reason, enjoy a place in history.

  He needed a brief period of apprenticeship. By good fortune the renowned Scotsman John Rennie—a towering figure of the day, a man who specialized in making the massive, in building lasting structures like dockyards, bridges, tunnels, breakwaters, and lighthouses—was working nearby. Rennie had evidently heard talk in the local inns of the parliamentary petition for a new small canal in Somerset, and, always eager for new commissions and fresh work, he signed up to make the initial survey for the route of what was first to be called the Dunkerton & Radstock Canal. But he was too busy to work alone, and needed help.

  Two members of the Somerset canal committee, to whom Lady Jones had enthused about William Smith’s acuity and intelligence, suggested his name. Rennie agreed to meet Smith, and liked him immediately. The great engineer hired the young surveyor on the spot. It was a moment that changed Smith’s life forever—particularly since Rennie’s own idea was that, if all worked out well, Smith himself would in short order take on the job of surveyor and engineer for the entire canal project. And this is precisely what happened: He got the full-time job, and embarked on an association with the Somerset Coal Canal that remains central to his reputation to this day. Seek out any local enthusiast who can still discern the old ruined waterway snaking along its forgotten route through the hayfields: Smith built that, you know. Great man.

  The young man threw himself into the job with great enthusiasm. Not only did his new responsibilities allow him to rub shoulders with such notables as John Rennie and another acclaimed canal builder who was also working nearby, William Jessop. Not only did it allow him to explore a particularly lovely piece of English countryside. Not only did it give him an opportunity for both the advancement of a budding career and to take part in the creation of a monument. It allowed him also, and at last, to test his grand ideas.

  Armed with his theodolite and his chain, his trenching tools and his shovels, Smith thus began the long process of slicing through Somerset. Each day he would venture out from Rugborne on his horse, making his way slowly and methodically a few hundred yards each day, from the mines of Camerton eastward toward the thatch of Limpley Stoke. He would set up his theodolite and his marker pole and his compass and his chain, he would measure out a section, he would write his notes about what he found and would speculate on the projected ease or difficulty of digging a canal along the path he had chosen; and then he would pack up all his kit and, piling it onto the back of his long-suffering nag, would move forward another few hundred feet and begin it all again.

  Unwittingly he managed to create in his design for the route of the canal a device that would help him enormously in his geological inquiries. He and his colleague engineers decided that for most of the route west of Midford there should actually be two near-parallel canals—there should be a northerly route, the Dunkerton Line, and a more southerly, the Radstock Line. By this arrangement of double-branching the canal, the coals from the entire coalfield could be collected with a
minimum of effort, and funnelled eastwards towards the junction with the Kennet & Avon Canal just by the huge aqueduct at Dundas.

  The arrangement made good sense from the coal-barons’ point of view. It also made good forensic sense for William Smith—for it meant that whatever observations he might make in one branch of the canal, he could check in another branch that ran only a mile or so away, in an almost precisely parallel direction. He had always wanted Somerset to be sliced open: Now it was being sliced and filleted twice over, and all his work could be compared, checked, and confirmed.

  The Somerset Coal Canal, showing the two near-parallel branches that later helped Smith in confirming his theories.

  It was as he worked patiently forward in this fashion that he first noticed something. He was surveying a stretch of the proposed northern route, between Dunkerton and Midford, when he saw exactly what he had been hoping for:

  “I observed a variation of the strata on the same line of level, and found that the Lias* rock which about three miles back was a full 300 feet above this line was now 30 feet below it, and became the bed of a river, and did not appear any more at the surface,” he wrote.

  This induced me to note the inclination of the same rock, which I knew was to be found at the head of two other valleys lying each about a mile distant from, and in a parallel direction to the one just described*—and accordingly found it to dip to the south-east, and sink under the rivers in a similar manner.

  From this I began to consider that other strata might also have the same general inclination as well as this. By tracing them through the country some miles I found the inclination of every bed to be nearly the same as the Lias; and noth-withstanding the partial and local dips of many quarries which varied from this rule, I was thoroughly satisfied by these observations that everything had a general tendency to the south-east and that there could be none of these beds to the north-west.

  This, it can be argued, was Smith’s most momentous early realization. It was an utterly simple observation—that when going from Camerton to Limpley Stoke southeastward along a line that was both continuously straight in direction and consistently horizontal in attitude, the old rocks that he had been accustomed to seeing in Dunkerton fell away and then vanished beneath his feet, while as he approached Midford newer and newer rocks appeared in the cliffs and cuttings before him, only to fall away and vanish and be replaced in their turn. These layers of rock, he said, were arranged “to resemble, on a large scale, the ordinary appearance of superposed slices of bread and butter.”

  He took notes, and he drew sketches—none of them too clear today, none of them too confident. Those who look at his drawings fancy that they see narrow shaded bands that they imagine mark the outcrop of the coal measures and their unconformable relationship with the Triassic rocks above—and one would-be biographer thinks this might fairly be called the first true geological map. But it isn’t, not really—and all one can truly say of the cartography Smith did during his canal days was that he was most definitely thinking about it. He began, he wrote in his diary, “to delineate on maps the courses of the strata, and constantly traced and retraced the order in which they would be intersected in making the canal.” His greatest achievement at this stage was not that he drew any maps—that would all come later—but that he noticed things, drew conclusions, and laid plans. He became uncannily able to perceive the spatial geometry of the world beneath his feet—to imagine, on the basis of what he saw above ground, just what the world looked like underneath.

  Today some critics remark sniffily that all this came too easily. That Smith was merely lucky, in that his chosen layers of rock all had a uniform dip to them, and they varied along their outcrop in interesting and obvious ways—he could with no difficulty recognize how the limestone turned to clay and then to shale, to oolite and so on—and so the layers revealed themselves to him quite plainly. Some also say that other surveyors had noticed much the same thing many years before Smith did—an amateur member of the local gentry named John Strachey, it is argued, who worked in much the same part of the world, spoke of the layers of rock looking like “the leaves of a paper-book.”*

  Some also point out, quite fairly, that Smith came at first to some naively rash conclusions about the easterly dip of the rocks he examined. It occurred to him, for instance, that since the oolites and the Lias and the Trias and the chalk of southwestern England had this convenient attitude, then probably all the rocks in the world were arranged likewise. The strata, he wrote, “form a set of lines extending from Pole to Pole with a regular inclination to the East. And the motion of the earth, which probably commenced while these strata were in a soft state or of a pulpy consistency, would naturally place them in an inclined curvilineal position.”

  He realized before long that he had misjudged this badly; and he made a host of other errors besides, with which his critics make hay. But William Smith was the one man who took his observations and formulated his idea and wove the whole cloth of new theory from it. Maybe the local geology did make his task relatively easy. Maybe he wasn’t the first to notice the arrangement of the local rocks. But he saw the rocks, he made a deduction—and he then took that deduction to its logical and, as we shall see, its astonishingly beautiful conclusion.

  After six months of heavy labor in the river valleys south of Bath, with the initial survey almost done, Smith’s employers suddenly decided he should interrupt his work and take part in a brief expedition. Before the first sod was dug and the first layer of stone laid—matters that were in any case the business of engineers, not surveyors—Smith was to go off on tour and take an instructive look at how other people were routing and then building canals. So in the late summer of 1794, along with two members of the canal committee, Samborne Palmer and Dr. Richard Perkins, William Smith was instructed to set out in a post-chaise on a journey that would last two months and would take him on an expedition over more than nine hundred miles of England and Wales.

  He now knew that the colliers’ rules for coal, and his own ideas from High Littleton, applied more generally to the hills and valleys he had surveyed elsewhere in Somerset. Was there any chance that they applied, as he thought they might, to the nation as a whole? In the Rugborne stable yard, as the postilion saddled up the horses and Smith clambered up into the cart alongside the driver while Palmer and Perkins sat in the carriage behind, he must have felt a welling sense of apprehension, of the excitement of his confident certainty. He already knew he could draw a map of a coal mine. His surveying work showed he could draw a map of North Somerset. Now, as the horses struck sparks on the coachyard cobblestones, he knew he might soon have the opportunity to do the same for England.

  7

  The View from York Minster

  Stephanoceras humphriesianum

  His excitement and his apprehension were still very much a secret. For the first few days in the coach he vowed to say nothing to his traveling companions. William Smith, all of a sudden, was worried.

  Earlier in the year he had become gripped by an anxiety that is all too common among discoverers who work alone—an anxiety that must have been even more frequent in times when communication was so restricted. For although he was by now quite confident that his assumptions about the order and regularity of stratification were right, he was frantically concerned in case others might be thinking along the same lines.

  He had no intention of announcing his ideas to Palmer and Perkins. He would not in fact for the moment disclose his theories to anyone. He was still not wholly certain he was right, and he had no intention of blurting out an unformed set of ideas and thereby making a fool of himself. Nor did he want to claim as his own notions that might rightly belong to others—and yet at the same time he hoped against all hope that he had originated these ideas, that he truly was the first to think them.

  Shortly before setting off on the trip he had managed to dispel at least some of these doubts. The canal committee had traveled to London en masse to give evidence befor
e Parliament—a bill was needed before the construction of any canal could begin, and though the questioning tended to be perfunctory, MPs needed to know that all was in order, the money had been raised, all opponents duly heard, all process duly done. William Smith was a witness, and recalled with some awe that, even though he was only twenty-five, he was summoned to the bar of the House, sworn in by bewigged jurists, and compelled to play a significant part in the democratic proceedings of the time.

  But aside from a day or so giving testimony, he had little else to do. All his expenses were paid, and he was on salaried commission with precious few duties to perform until sent back to Somerset. So he decided he would go burrowing and scavenging through the libraries and bookshops of the capital, searching for anything that might show him what he feared—that like-minded others were on the case, that in creating the still-unchristened science of stratigraphy, he was not entirely alone.

  We have no firm idea of what he found. There was, however, a lot on offer. We do know he acquired at about this time some basic reference books—Plot on Oxfordshire and again on Staffordshire,* John Morton on Northamptonshire, and John Woodward’s majestic Catalogue of English Fossils. We know he was assiduous in his searches, and that he came home with a considerable library.

  Almost certainly he would have come across John Strachey’s Observations on the Different Strata of Earths and Minerals, written in 1727, and with the engaging theory that all rocks are spinning when laid down, and so are revealed as outcrops as they solidify, their edges like an unrolled sheaf of papers. Maybe he saw John Woodward’s other great work, his Natural History of the Earth, published in 1695, which revealed his fascination for “speluncae, grottoes and wells,” and his unshakable belief that “the circumstances of these things in remote countries were very much the same as those of ours here.”