The Map That Changed the World Page 7

  He was to remain in this part of England, at first working for his patron and then later for the Somerset Coal Canal Company, for the next eight years—eight years during which he would make the discovery, come to the realization, announce the deduction—and begin the hard grind—that would earn him his place in posterity.

  5

  A Light in the Underworld

  Hildoceras bifrons

  The village of High Littleton is a gritty, windy, hilly, and generally unlovely place, almost as far removed from the traditional imagery of Somerset—no cider apples, no jolly farmers, no thatch or maypole or cricket on the green—as if it were near Nottingham or on the country fringes of industrial Lancashire.

  Much the same might be said of the entire swath of countryside that lies ten miles to the south and southwest of Bath. It is pinioned between some of the loveliest and most measured architecture in all of southern England. Wells Cathedral, with its statues and gargoyles, is the spiritual and aesthetic mooring point to the west. The ordered, bewigged, and precious life, the powdered and pomaded air of England’s once-second city, Regency Bath, wafts in from the east. But between lies an area that still today looks curiously out of place, architecturally, atmospherically, socially, commercially: It has smaller houses, meaner shops, grubbier streets, a spoiled and ragged landscape.

  All is a direct consequence of geology. These fifty square miles or so of Somerset, bounded by the red-brick villages of Clutton in the west and Combe Hay in the east, Priston in the north and Kilmersdon in the south, lie on top of a score of complex, broken, twisted, and contorted seams of coal, which until as late as the 1970s were worked by as independent and militant a band of English mining men as might ever have stepped out from beneath the winding gears of the coalfields of Durham or Lanark. Maybe their militancy had arisen because of the unusual proximity, in these parts, of their class enemies—all around them the great limestone houses and mannered city terraces were occupied by soft-handed gentleman farmers and sportsmen, philosophers and squires, artists and divines. There was no other local industry to provide brotherly support: In the fifty square miles of country that unrolled itself around where the twenty-two-year-old William Smith came to live and work, the laboring classes were coal miners, to a man.

  The mines were owned privately, usually by whoever owned the land under which the coal was first found. Of the Lady Jones who first employed William Smith to landscape the estate around her house in Stowey we know very little; but she and her late husband, Sir William Jones of Ramsbury, certainly owned a great deal of land other than the immediate neighborhood of her house, which included both a large number of the neighboring coal mines and a collection of farmhouses. It was into one of these, Rugborne, which stood on the eastern outskirts of High Littleton, that she allowed her new young employee to move.

  Smith had good reason to remember this house vividly. It was, he wrote, a large old manor house, three-storied, solid, and foursquare, sheltered by lime trees, and with a walled courtyard in front, and steps leading up to handsome gates and walls (now gone) that were thick enough to have a series of rounded niches in which Smith liked to sit and study his books. The house had once belonged to a Major Britton, who, the locals said, had ruined himself financially by working the coal seams that ran beneath the house. But when Smith moved in it was occupied by a tenant farmer, Cornelius Harris, who gave him board and lodgings for half a guinea* a week, and took in his horse for an extra ten shillings a month.

  He remembered the house not so much for its architecture or its comfort or the eminently reasonable price of the accommodations, however. He remembered it because of the work that he was to engage in, first in a mine less than a mile away to the north, and later in the canal that he was to help build a little farther afield. It was work of staggering significance.

  And because of it, Rugborne Farm, High Littleton, deserves a memorial. The work that Smith undertook there, and the results that he achieved and pored over there, led ultimately to the creation of an entirely new science. For years afterward he looked back on his time at Rugborne as the most important in his life, and the house as the crucible of the new discipline he believed himself to have created. “The birthplace of geology,” he later said, grandly. But there is no memorial—not a plaque on the house, nothing—just an incorrectly dated sign erected by the local council back in the thirties, at the entrance to a lane, pointing halfheartedly to where the house still stands.†

  He worked there first for Lady Jones—surveying, planning, draining—in her capacity as director of the High Littleton Coal Company. He was not without a greater ambition: A letter found in the files showed that he tried hard to persuade her to allow him to become a shareholder in one of her newer mines, and to be its general manager. There is no record of a response. Instead he was compelled to work at one of her older pits, which had been first excavated in 1783 and which was to have nearly thirty-five years of working existence. The mine was called the Mearns Pit, and though it was certainly one of the less familiar and less prosperous of the hundreds of mines and shafts that had been sunk over the centuries into the coal measures of North Somerset, its importance on the global stage is quite inestimable.

  Rugborne Farm, Smith’s first true home near High Littleton, which he called “the birthplace of geology.”

  For the Mearns Pit at High Littleton has a standing in the history of geology that is comparable to the one that Gregor Mendel’s Moravian pea garden has in the science of genetics, the Galápagos Islands in evolutionary theory, and the University of Chicago football stadium in the story of nuclear fission. Yet this Somerset coal mine also goes unremembered today, just like Rugborne Farm. There is no blue plaque, no brass plate, nothing. Just a small lump in a field that marks a scarified hillock of grassed-over mining waste, a mound that Somerset people still call a batch. And a scrap of paper in the University Museum in Oxford, recording what William Smith saw, felt, thought, and concluded when first he ventured into the dripping darkness of that dreary little West Country colliery.

  A section of the Mearns Pit in Somerset, where Smith first noticed the succession of rock and fossil types.

  To describe exactly what Smith did at Mearns, and why his working and thinking there marked the beginnings of something important, we now have to descend, rather like a miner nervously waiting his turn beneath the winding gear, into the half-illuminated and technically tricky gloom of the scientific underworld.

  The rocks that contain winnable coal in North Somerset belong to what are known, perhaps not surprisingly, as the Upper, Middle, and Lower Coal Measures. The rocks that belong to this period were deposited during what in today’s Britain is called the Westphalian stage of the Upper Carboniferous period, which in turn is classified as having occurred over a period of about twenty million years during the closing billennia—the upper end, in other words—of that immensely long chunk of geologic time (an “era,” in the vernacular) known as the Paleozoic.

  Modern radiometric dating shows that the Coal Measures were laid down between 310 and 290 million years ago. The world had by this time already seen and welcomed the appearance of such living complexities as ferns, sharks, and winged insects; it already disposed, by extinction, of less complex life forms, such as stromatolites and graptolites. Before the end of the Upper Carboniferous it was also about to do away with that most attractively lovable lobsterlike Paleozoic arthropod known as the trilobite.

  None of this—neither the names of the geological eras, nor the age of the rocks, nor the existence of a fraction of the life forms within them—was known to Smith or to anyone who worked with or around him. When he climbed down into the dark mine on a cool summer’s day in 1792 he knew just about nothing about the sorts and conditions below—nothing except that there was definitely coal in these hills, and the miners who clawed it out of the ground knew only too well how it was organized, and how to make some kind of sense of the chaotic state in which it existed.

  Several shaf
ts made up the Mearns Colliery, and Smith went down every one of them—clambering down slippery ladders and ropes or being taken down with the chain of one of the dredgers that was powered by a Newcomen steam engine. He would write that he looked closely at the walls of the shaft, and noticed the succession of layers of rock as they slipped past his eyes.

  At first he was rather puzzled. “The stratification* of the stones struck me as something very uncommon,” he was to write a short while later,

  and till I learned the technical terms of the strata and made a subterranean journey or two, I could not conceive a clear idea of what seemed so familiar to the colliers. But when these difficulties were surmounted and an intelligent bailiff accompanied me, I was much pleased with my peregrinations below, and soon learned enough of the order of strata to describe on a plan the manner of working the coal in the lands I was then surveying.

  His paper plan—the first he is known to have written, and preserved in the great Gothic cathedral-museum in Oxford—is merely a scrap, titled “Original Sketch and Observations of my First Subterranean Survey of Mearns Colliery in the Parish of High Littleton.” It records, without comment, what he saw of the technology that was employed to bring the coal up from below. Horses that were harnessed to a windlass lifted the coal from the three-bushel carts on a tramway “that are wound up the second gugg [an underground incline], drawn along here to the bottom of the first by a man down on his hands and feet, bare, with a cord round his waist, to which is fastened a chain that comes between his legs and hooks to the forepart of the cart.”

  Then he went down into the pit and noted exactly what he saw. First, there was the grass and gravel of the surface, which blended seamlessly into topsoil, eight or ten inches thick. Next came a more solid rock—at first broken into small chunks, then progressively more solid, and generally red in color, though with layers that were strangely green. It was, so far as he could make out, an earthy limestone, a marlstone, interspersed with shales—the marlstone being very red, the shales having a green tint. Overall, though, it was red and earthy—and similar, so far as he could see, to other red marls, other red earths, that he had seen around Bath on his walk there from Oxfordshire.

  Then he noticed something very important. These marls, he wrote, were not laid down horizontally—but seemed to slope very gradually away to the east. They had a dip, an angle from the horizontal, that seemed to Smith to be about three degrees. They also had a strike, which is the compass direction of the line drawn where the dip intersects with the horizontal, and which in this case was aligned about 95 degrees from due north. The marl beds were sloping, in other words, in the general direction of London, and if their strike continued on the same general heading, in the direction also of Europe. Whether they continued to slope away in this direction and at this rate, and whether the marls were thus eventually buried deep below the capital or beneath the hills of France, Smith could neither tell nor imagine. But what was obvious to Smith is that they pointed in that general direction, and that they did so on a very gentle downgrade.

  The chain-rope was clattering him slowly downward, and toward an important moment—for as he continued to gaze at the slowly passing walls, so everything around him on the sides of the mineshaft abruptly changed. Within a matter of inches the nature of the rocks—their look and feel and color and hardness—was all altered.

  Where there had been these limey, shaly, reddish-greenish marly limestone rocks above, now instead on the sides of the shaft was a facies of thick, sandy, grayish brown rocks that appeared wholly and profoundly different.

  Moreover, if he looked closely at the gradation between one type and the other, Smith could see that this change did not even occur within a matter of inches—it was much less, so much less that in fact there was a verifiable point at which the change occurred, a line above which was one rock, the Red Marl, and below which another, the Grey Sandstone, without any gradation between them that was worthy of the name.

  And it wasn’t just the nature of the rocks, their lithology. Just as noticeably the attitudes of these new rocks had changed too: Where the Red Marls had sloped neatly at a gentle angle, all pointing in one direction, these new gray-brown sandstones—ugly and rather unappealingly harsh rocks, as they appeared to Smith in his guttering candlelight—appeared to plunge deeply downward. Their bedding planes, the cracks that separated one bed of sandstones from another, were steeply inclined, and in places they were very evidently folded, and in places so folded they had been shattered and broken up by dozens of small dislocations, as though the bands of rock had once been contorted by a giant vise, all twisted, flattened, and cracked, and then released and left to lie tumbled and in disarray.

  It was all so very strange. Back up at the top of the shaft, near the lip, had been these beguiling, neatly laid-out sheets of almost horizontal strata, with just their faint slope in the vague direction of London. Now, below them, the rocks were contorted and thrust in all manner of different directions, most of them dipping down toward the center of the earth. As mentioned in the previous chapter, modern structural geologists using radiometric dating techniques, taking deep-drill cores, and performing seismic examinations have recently established that Somerset’s coal measures were folded and twisted by the great Variscan mountain-building period that occurred 290 million years ago, when the African and European tectonic plates collided. But none of this was known or even vaguely conceived by Smith or by any geologist then alive. So Smith could only stare at the junction between the rocks and wonder—Why? How? How could one possibly make sense of such a bizarre arrangement?

  By chance this was exactly the time when the stripling science of geology was indeed trying to make sense of such structural oddities. James Hutton, the gently born Scots doctor who was one of the leading philosophers of the age, was at the time of Smith’s work just three years away from publishing his seminally important three-volume book The Theory of the Earth, which sought to explain countless facts about the earth—including precisely how such an internal discordance among strata, a so-called unconformity, had first come about.

  It was a very similar unconformity, in fact, that had first set Hutton thinking. He had seen another arrangement of rocks, much like those Smith was seeing at High Littleton, in a rocky cliff on the North Sea coast of Scotland, at a now-hallowed site called Siccar Point in Berwickshire. There, thick layers of the Old Red Sandstone of Devonian times were—and still are, of course (though now much chipped by the geological hammers of ten thousand students)—lying flat on top of steeply inclined hard gray sandstones of the Silurian period. Hutton suggested that both of these sets of rocks must have been laid down by deposition from a sea, and that the gray sandstones, after being laid down, had been lifted up and out of the sea by great and mysterious crustal processes, had been subjected to all manner of contortion and twisting and deformation, then eroded so that the top of all these twisted rocks was cut off and smoothed and flattened, and finally submerged again by the sea in Devonian times to allow red sandstones—what would eventually be called the Old Red Sandstone—to be laid down on top.

  And the important ideas that Hutton grasped from pondering this, and which he declared in the final volume of the great book, were these: first, that the processes of formation of rocks are the same processes—creation, erosion, deposition, change, and erosion—that we see today, whether in a stream bed, by the sea, or on the flanks of a volcano; second, that the earth works today more or less as it always has; and third, that these processes, tiny and unimportant though they may seem in the short term, take place over unimaginably long periods of time, over an uncountably large number of years, so that anything that is observable in the rocks around us today can be imagined as having happened as a result of normal, everyday occurrences taking place over aeons of geological time. “The present,” said Hutton most memorably, “is the key to the past.”

  If one could imagine this, wrote Hutton—and he wrote these words at almost the same time as Smi
th was clambering down into the Somerset mines—then one could think of the earth as having “no vestige of a beginning and no prospect of an end.” It was a staggering thought, quite appalling to some—but it was the kind of thought that was to permeate the world of geology into which Smith-the-surveyor was just now making his entrance.*

  It was in and among the gray sandstones that the true wealth of the Mearns collieries, and all the neighboring mines, was held. For these were coal measures, and in them, as Smith was to see as the mine chain clanked him lower still, were—thin, distorted, and plunging deep below—the precious veins of coal.

  The miners, tough and taciturn men, had given names to all the seams, as miners all around the world always do. Coal seams may all look the same, much as all coal may look alike; but in fact all seams as are different as all people, when they are looked at as closely as a miner has to look. Each band has an internal pattern, a collection of fossil types, an appearance, a feel, a personality, that makes it instantly recognizable. A miner will be lowered down the shaft and step out into the blackness and know in an instant where he is, how deep in a series, how far down within a seam.

  Some of the less romantic workers gave their seams mere numbers—Newbury No. 2, or simply No. 7 or No. 11. Others were named for obvious reasons—the Great Course, the Little Course, the Standing Coal, the Main Coal, the Nine Inch, the Coking Coal. And then there were the seams with stranger names, no longer easily explicable: the Slyving, the Dungy Drift, the Globe, the Perrink, and the Kingswood Toad. Go work the Slyving today, might be the order of the morning. Try your luck with the Perrink, or climb down into the Nine Inch, if it’s not too wet afoot.