This book presents a theory of technological evolution based on recent scholarship in the history of technology and relevant material drawn from economic history and anthropology. The organization and content of its chapters are determined by the nature of the evolutionary analogy and not by the need to provide a chronological account of events in the history of technology. However, because this study is primarily historical, not an exercise in the philosophy or sociology of technology, historical examples are used throughout to elucidate and support the theoretical framework. Major developments in the history of technology, such as the invention of the steam engine or the advent of the electrical lighting system, are introduced simultaneously with the unfolding of an evolutionary explanation of technological change.

The opening chapter announces three themes that reappear, with variations, in later sections of the work: diversity — an acknowledgment of the vast number of different kinds of artifacts, or made things, that have long been available; necessity — the belief that humans are driven to invent artifacts to meet basic biological needs; and technological evolution — an organic analogy that explains both the appearance and the selection of these novel artifacts. A close examination of these themes reveals that diversity is a fact of material culture, necessity is a popular but erroneous explanation of diversity, and technological evolution is a way of accounting for diversity without recourse to the idea of biological necessity.

On October 21, 1659, twelve years after Mersenne had described his efforts to determine the constant of gravitational acceleration and the problems that he encountered, Christiaan Huygens repeated Mersenne's experiment. He accepted Mersenne's length of 3 feet for the seconds-pendulum but added an extra inch, thus compensating for the fact that his Rhenish foot was shorter than the Parisian Royal foot used by Mersenne, and found that a lead ball fell 3½ feet during the ½-second swing of the pendulum against the wall. Thus, by Galileo's times-squared law, it would fall 14 feet in 1 second, a value significantly different from Mersenne's 12 feet, even when the latter was converted to Rhenish feet (12 feet 5 inches). Since Huygens also knew of Riccioli's value of 15 feet in 1 second, the discrepancy between the experimental values determined by himself, Riccioli, and Mersenne was readily noticeable. It is not surprising, therefore, that Huygens sought a different means of determining the constant of gravitational acceleration.

That same October day on which he tried Mersenne's experiment, Huygens undertook a study of centrifugal force, recording a list of propositions that a few weeks later he would develop into a more complete treatise, the work now called De Vi Centrifuga. He was obviously still hunting for an accurate value for the constant of gravitational acceleration, for among the opening notes of the first draft is a reference to Riccioli's trials showing that gravity increases according to the odd numbers, followed by the phrases “Weight is the conatus [effort, tendency] to descend” and “concerning an accurate measure by means of the oscillations of a clock.”

Mathematicians of the late seventeenth century focused on two problems that derived from Greek geometry, particularly from attempts to determine the ratio of the circumference of a circle to its diameter, the value now called pi. The first, which was related to the question of measuring the circumference of a circle, was rectification: how to find a straight line (recta) equal in length to the arc of a curve. The second problem, which was tied to the question of ascertaining the area of a circle, concerned quadrature: how to find a square (quadratum) equal in area to a given two-dimensional space. Of course, the exact statement of these problems changed over the centuries, and thus the seventeenth century inherited a curious conglomerate of specific questions within the two broad categories.

However, the standards by which solutions to questions of rectification and quadrature were judged successful remained remarkably constant in the centuries separating Greek and seventeenth-century mathematicians. With the formalization of analytic procedures in more recent centuries, questions involving area and length are now usually solved by trivial integrations that yield a numerical answer. But in earlier times the solutions had to be geometrically constructable, and even in the seventeenth century algebraic solutions had to be reducible to geometry by means of standard constructions like those outlined by Descartes in his Géométrie and codified by van Schooten in his Latin translation and commentary, Geometria.

Because Archimedes had already found the area under the parabola by geometric methods, the feasibility of performing at least some quadratures was never doubted.

Introduction

A large segment of the modem public believes that technological change is discontinuous and depends on the heroic labors of individual geniuses, such as Eli Whitney, Thomas A. Edison, Henry Ford, and Wilbur and Orville Wright, who single-handedly invent the unique machines and devices that constitute modern technology. According to this view inventions are the products of superior persons who owe little or nothing to the past.

The smaller scholarly community that concerns itself with issues in the history of technology and science rejects this explanation as simplistic because it reduces complex technological developments to a series of great inventions that precipitately burst upon the scene. However, some historians have offered more sophisticated formulations of the discontinuous explanation that do not rely upon the contributions of heroic inventors. Such theorists take their cue from the supposed revolutionary nature of scientific change.

Science, Technology, and Revolution

Recent scholarship in the history and philosophy of science has tended to favor the discrete character of scientific change. This outlook derives ultimately from the study of the emergence of modern science in the sixteenth and seventeenth centuries. Since the French Revolution, the work of Copernicus, Galileo, Kepler, and Newton has been described by the term revolution, a political metaphor that implies a violent break with the past and the establishment of a new order.

The political metaphor was applied not only to the arrival of a new way of studying nature but also to any substantial change within a science.

Introduction

Because there is an excess of technological novelty and consequently not a close fit between invention and wants or needs, a process of selection must take place in which some innovations are developed and incorporated into a culture while others are rejected. Those that are chosen will be replicated, join the stream of made things, and serve as antecedents for a new generation of variant artifacts. Rejected novelties have little chance of influencing the future shape of the made world unless a deliberate effort is made to bring them back into the stream (Figure V. 1).

If these remarks recall the notion of evolution by natural selection, they are meant to do so. There are, however, crucial differences between artifactual and organic evolution that must be mentioned before any further use is made of the selection analogy.

Central to organic evolution is the variability that arises from mutation and from the recombination of the parental genes in sexual reproduction. The resulting variant offspring are subject to natural selection, which permits some, but not all, of the variants to survive, reproduce, and pass on their genetic information. The offspring, which have the potential to move in many different evolutionary directions, are selected by the totality of conditions — environmental, biological, social — that prevail at the time of their appearance.

Mersenne and Riccioli had used the pendulum as a timepiece in order to measure the free fall of a body, but the pendulum is already per se a falling body, albeit restricted by the cord to move along a curve, and thus the swinging pendulum contains within itself the measure of gravity. Mersenne had dealt with this inherent relationship when he attempted to compare mathematically the fall of the pendulum's bob along the quarter arc of a circle with free fall through the length of the pendulum. As we have seen, Mersenne was not successful in handling the question, although he did at least achieve bounds on the ratio of times of fall.

With Mersenne's inadequate analysis as an example, Huygens also tried to quantify curvilinear fall during the period in which he was analyzing gravity by means of its analogy with centrifugal force. His first attempt, given in Propositions 19 and 20 of the first draft of De Vi Centrifuga, compares the hanging weight of the bob with the tension on the cord of the pendulum due to centrifugal force. The first of the two propositions states that a ball falling under the influence of gravity through the quarter arc of a circle exerts a tension at the bottom of its fall equal to three times its hanging weight. The second says that the tension on the cord after one complete circuit of an upright circle, in which the centrifugal force is precisely that necessary to keep the cord taut at the maximum height, is six times the hanging weight. Huygens's analysis of a pendulum impeded by a nail, drawn from Galileo's postulate, follows as a corollary to the latter proposition.

Introduction

The diversity that characterizes the material objects of any culture is proof that novelty is to be found wherever there are human beings. If this were not the case, strict imitation would be the rule, and every newly made thing would be an exact replica of some existing artifact. In such a world technology would not evolve; the range of material goods would be limited to the first few naturfacts used by the earliest men and women.

If we accept the proposition of universal artifactual diversity, we must acknowledge that a greater variety of artifacts is available in some cultures than in others. At one extreme there is the United States that currently issues about seventy thousand patents annually and at the other extreme are the Australian aborigines or the native inhabitants of the Amazon basin whose meager stores of tools and utensils have changed very slowly over many centuries.

How can we account for differences in the rate of production of new kinds of things? And how can we identify the sources of novelty in any culture? Answering these questions is no small task. The study of innovation is filled with confusing and contradictory data, theories, and speculations. Because there is no consensus on how novelty emerges in the modern Western world, we cannot expect to find reliable guidelines to an understanding of innovative activity in our own past, let alone in the histories of cultures radically different from ours.