The Wheel

Inventions and Reinventions

Richard Bulliet

• Publisher: Columbia University Press
• Year: 2016
• ISBN:
  9780231540612
• Topic: Historia
• Subtopic: Historia militar y marítima

In this book, Richard W. Bulliet focuses on three major phases in the evolution of the wheel and their relationship to the needs and ambitions of human society. He begins in 4000 B.C.E. with the first wheels affixed to axles. He then follows with the innovation of wheels turning independently on their axles and concludes five thousand years later with the caster, a single rotating and pivoting wheel.

Bulliet's most interesting finding is that a simple desire to move things from place to place did not drive the wheel's development. If that were the case, the wheel could have been invented at any time almost anywhere in the world. By dividing the history of this technology into three conceptual phases and focusing on the specific men, women, and societies that brought it about, Bulliet expands the social, economic, and political significance of a tool we only partially understand. He underscores the role of gender, combat, and competition in the design and manufacture of wheels, adding vivid imagery to illustrate each stage of their development.

one

Wheel Versus Wheel

In 1850, the steam engine was ranked as the world’s greatest invention. By 1950, the wheel, a much older invention, had surpassed it. The advent of the electric motor and internal-combustion engine partly explains the decline of the steam engine; but the spread of automobiles, trucks, and buses—not to mention grocery carts, bicycles, and roll-aboard luggage—played a greater role. For in 1850, the wheeled vehicles that rumbled over the cobblestones of city streets and jounced along the rutted dirt roads of the countryside seemed neither new nor particularly ingenious.

The question of when and where the wheel first appeared did not excite much interest before the twentieth century, and even now it is hard to find comprehensive accounts of how wheels have been used for transportation in different times and places. Nor has it been recognized that wheels come in three strikingly different forms, each with its own history of invention. Two kinds, wheels that are fixed to the ends of an axle and turn in unison as the axle turns—the whole apparatus is called a wheelset (figure 1)—and wheels that rotate independently from each other on the ends of a stationary axle, date to between 4000 and 3000 B.C.E. They have thus been around for more than five thousand years. The third form, termed a caster, rotates on an axle and also pivots in a socket situated above it, the axis of pivoting being somewhat offset from the axis of rotation. Despite its technological simplicity, the caster seems to have come into use only three hundred years ago, or five thousand years after the other two forms.

FIGURE 1 Railroad wheelsets. (Colourbox.com)

We encounter wheels of all three designs almost daily. Railroad and subway cars originally rolled on wheelsets, whereas road vehicles use wheels that rotate individually, mostly developed from an original form of two wheels rotating independently on the ends of an axle. And casters abound on wheelchairs, gurneys, laundry carts, dollies, baby strollers, and desk chairs.

Steering is key to the three different wheel designs. Locomotives and railcars cannot make sharp turns because in the process of turning, the outer wheel covers a greater distance than the inner wheel and thus must make more rotations. Consequently, when the wheels turn in unison in a wheelset, the outer wheel is skidded or dragged around the turn. Railroad steering is accomplished by following rails, and railroads are designed with only very gradual curves.

Axles with independently rotating wheels do not have this problem, but a wagon equipped with four wheels on two axles still has a hard time turning unless the front wheels can change direction. Pivoting a front axle in its middle underneath a wagon was the most common way of changing the direction of the wheels until two hundred years ago, when alternatives were devised to allow each front wheel to pivot separately. Automobiles use these later modifications and thus can turn much sharper corners than can railroad cars.

As for the caster, if pressure comes from the side or from the person pushing the vehicle applying more force on one side of the handle (or on one handle if there are two) than on the other, the wheels turn automatically in the desired direction. Grocery carts and wheelchairs typically combine casters in front with rear wheels that do not pivot, but dollies and desk chairs use only casters and can easily move in any direction.

Since the notion that the wheel may be humankind’s greatest invention has arisen quite recently, I shall begin this exploration of the invention of the wheel with the modern era of motorized transport. Underlying this history is a competition between wheelsets in the form of railroads and independently rotating wheels in the form of automobiles. Once the importance to the world of today of this wheel-versus-wheel competition has been established, I will go back in time to explore the invention of the first wheels and examine the crucial episodes in wheel history that culminated in the modern transition from animal power to motorized transport, on the one hand, and to human power, as represented by the history of the rickshaw and the caster, on the other.

At the dawn of the European Renaissance in the fourteenth century, four-wheeled vehicles were not in common use anywhere in the world. Two-wheeled carts were easier to build, easier to steer, and mechanically more efficient, since two wheels turn with only half the friction of four. Even in Europe, the only world region that never abandoned the four-wheel concept, passenger wagons were used almost exclusively by noblewomen, the infirm, and the elderly. Noblemen rode horses as a sign of their elite warrior status, while eminent churchmen rode mules.

This situation changed dramatically over the next three centuries in what we will call the carriage revolution. By 1650, from the Thames to the Danube, the word “coach,” in various spellings, had become the general European term for a four-wheeled passenger vehicle, synonymous in English with the word “carriage.” The number of coaches soared. The number of carriages in Britain, for example, could be counted on one hand in 1570, while the official tax totals in 1814 enumerated “23,400 four-wheeled vehicles paying duty to the government; 27,300 two-wheel, and 18,500 tax carts [inexpensive vehicles taxed at a lower rate]; a total of 69,200,” which amounted to one vehicle for every 145 inhabitants.¹

As the numbers grew, so did the variety. European carriage makers and wheelwrights catered to every taste. In addition to generic conveyances like “long wagons” for hauling freight and stagecoaches for transporting passengers, they turned out a dazzling array of barouches, berlins, caroches, carosses, chaises, clarences, coupes, diligences, ducs, fiacres, gazelles, hackneys, jaggers, milords, phaetons, rockaways, reisepritschkas, socials, spiders, surreys, and victorias—just to mention designs of the four-wheeled variety. The differences among them involved size, weight, type of springs or suspension, steering mechanism, driver position, passenger capacity, seating arrangement, number of horses, and a galaxy of door, window, and top designs. By the mid-nineteenth century, the range of choices available had turned the carriage, or buggy (to use the American term), into a perfect billboard for displaying one’s economic status or personal style, thus prefiguring the automobile culture that was to evolve in the twentieth century and that continues into the twenty-first.

In addition, the Europeans and Americans who made up the social elite in overseas colonies, or whose diplomatic or business duties compelled them to sojourn in non-Western lands, often used carriages to advertise the cultural and technological superiority of their home countries. Imitating a fellow Englishman who gained fame writing about his globetrotting excursions as the “Blind Traveller,” John Kitto billed himself as the “Deaf Traveller” and remarked that in 1833 he “saw no wheel-carriages of any kind in Persia.”² Exactly fifty years later, however, the first American minister resident in Iran, Samuel G. W. Benjamin, reported that “the number of carriages owned by Persian and European gentlemen [in Tehran] is nearly 500, all imported.”³

Coach building far outstripped road building, however. The problem of finding a road surface that would bear up under heavy traffic and iron-rimmed wheels was paralleled by the problem of finding a way to pay for road maintenance. Until new experiments with road building began to bear fruit in the mid-nineteenth century, the surfaces beneath the carriage wheels remained rutted, muddy, and poorly paved—if paved at all. This was particularly true in the countryside, but miserable roads existed even in major cities. In 1703, for example, during a trip south from London to Petworth, fifty miles away, the carriage carrying the Habsburg emperor Charles VI overturned twelve times on the road.⁴ And a half century later, Mile End Road, the major thoroughfare leading east from the entrance to the City of London at Aldgate, was described as “a stagnant lake of deep mud from Whitechapel to Stratford,” a distance of four miles.⁵

Roads outside Europe were at least as bad. In Washington, D.C., for example, the track between the Capitol and Thomas Jefferson’s White House, a way labeled Pennsylvania Avenue on the map, was so crude that “every turn of your wagon wheel . . . is attended with danger.”⁶ And the stagecoach that connected Capitol Hill with Georgetown, just five miles away, made a round trip twice a day “in a halo of dust . . . pitch[ing] like a ship in a seaway, among the holes and ruts of this national highway.”⁷

To this may be added the steadily growing problem of horse manure blighting pedestrian activity. Ironically, as the condition of streets and roads became better, the accumulation of manure became worse. One estimate from the 1890s predicted that by 1950 London would be buried in nine feet of horse droppings, while another concluded that by 1930 manure would reach the third-story windows of buildings in Manhattan.

To begin to understand the evolution of modern motor transport from the vantage point of the wheel, we must consider the alternatives offered by the emergence of two different wheel technologies in the fourth millennium B.C.E., for the choice between wheels fixed to axles and independently rotating wheels that originated in that era reemerged in the industrial age to affect modern transport at a fundamental level. In the chapters that follow, I propose that the wheelset, or fixed-wheel design, was invented first, perhaps as early as 4000 B.C.E., for use in copper mines situated in eastern Europe’s Carpathian Mountains, which stretch westward from Romania, across western Ukraine, southern Poland, and northern Hungary, to Slovakia. The independently rotating–wheel design, very likely inspired by the wheelset, came on the scene a few centuries later, somewhere in southeastern Europe between the Carpathians and the broad plain north of the Black Sea, where people speaking Proto-Indo-European shared a set of technical terms for wagons with rotating wheels, but did not have a word for the wheelset.

In the absence of any archaeological traces of roads, we can assume that most wagons with fully rotating wheels moved cross-country over uneven dirt and grass. This would have required wheels of fairly large diameter, around thirty inches to judge from surviving examples. The stone floors of mines, however, could be as smooth and as straight as the miners chose to make them. Yet ore is extremely heavy, so the four-wheeled mine-cars pushed by the miners were no bigger than today’s wheeled laundry carts and had comparatively small wheels, perhaps around one foot across. Given straight tunnels, flat stone floors, and the absence of draft animals, there was little need for steering. And it was better to use a wheelset than an axle with independently rotating wheels because when the former broke, the mine-car simply stopped; but having a single wheel come off, as commonly happened with rotating wheels, could dump the entire load of ore onto the tunnel floor.

Mine-cars continued to be pushed by European miners down to the eighteenth century, when pit ponies and mules took over some of the work in Britain and elsewhere. Also by then, the idea had spread of using wooden tracks—later replaced by iron—to guide the cars and provide a smoother surface for them to roll on. This innovation arose in the sixteenth century, if not earlier.

Outside the mining world, fixed-wheel vehicles were rare, though two-wheeled versions saw some use in the Roman Empire, and rustic oxcarts of this design could occasionally be found in southern Europe from Portugal to Turkey in the early twentieth century and were not unknown in India. Although the outer wheel had to be skidded around sharp corners, carts with solid fixed wheels were easier to build and more durable than those with independently rotating wheels, especially if the rotating wheels had spokes. Nevertheless, the two-wheeled, animal-drawn cart with independently rotating wheels was by far the most common form of wheeled transport, not just in Europe but from India and China to South America.

Soon after Thomas Newcomen’s steam engine burst on the scene around 1710, innovative thinkers began to imagine shrinking the massive, four-story-tall device that Newcomen had designed for pumping water out of flooded mines down to a size that could be put on wheels. The vehicular designs they had to work with were three: the two-wheeled cart and the four-wheeled wagon or carriage, both of which were equipped with independently rotating wheels; and the four-wheeled mine-car, which rode on wheelsets and rails.

Since steam engines, no matter how compactly designed, seemed intrinsically to be constructions of great weight, balancing one on two wheels and a single axle was out of the question. In fact, no motor-vehicle design based on two wheels placed side-by-side saw the light of day until Dean Kamen unveiled the Segway in 2001.⁸ As an alternative, however, it seemed feasible to add to a conventional cart design a pivoting third wheel placed either before or behind the two main wheels. This might not only help distribute the weight of the steam engine, but also facilitate steering. Nicholas-Joseph Cugnot pursued this idea with a vehicle that he built for the French army in 1769 (figure 2). To achieve a weight balance between the steam engine and the artillery or other heavy load that the vehicle was intended to pull, Cugnot put the boiler far forward and the steam engine itself directly over a single front wheel that could be turned, if one had sufficient strength, by means of ...