The Evolution of Useful Things: How Everyday Artifacts-From Forks and Pins to Paper Clips and Zippers-Came to Be as They Are.

by Henry Petroski

  In mid-nineteenth-century America, for example, there developed a new piece of furniture, the adjustable chair. Giedion’s explanation for the proliferation of designs for such a chair was that it was prompted by the posture of the times, which was based on relaxation, “found in a free, unposed attitude that can be called neither sitting nor lying.” He argued that the development of the new patent furniture was thus in response to a new need, which happily coincided with a concentration of creativity among ingenious designers. But Forty rejects Giedion’s reasoning as overly dependent on coincidence, arguing that “it is most unlikely that after several millennia mankind should suddenly have discovered a new way of sitting in the nineteenth century,” when “designers were no more inventive and ingenious than people at other times.”

  Forty dismisses the “functionalist” theory as inadequate to explain the diversity of a less adjustable but more recent example: “Could Montgomery Ward’s 131 different designs of pocket knife be said to be the result of the discovery of new ways of cutting?” And he does not allow that nineteenth-century designers, no matter how ingenious, had the power or autonomy to influence “how many or what type of articles should be made,” although he does agree that designers could determine the form of individual articles. Forty’s own arguments for the multiplication of things like adjustable chairs “place the products of design in a direct relationship to the ideas of the society in which they are made.” In particular, he identifies the capitalists as the proliferators of diversity: “The evidence is that manufacturers themselves made distinctions between designs on the basis of different markets.” Thus there exists a dictionary situation for everyone: designers design, manufacturers manufacture, and diverse consumers consume diversity. This is or is not a nefarious arrangement, depending upon one’s ideology.

  Whether or not the world should have diversity, it does, and the question remains as to how individual designs come to be distinguished from related designs. Even if manufacturers are the primary driving force for diversity, what underlying idea governs how a particular product looks? Certainly it was more than economic considerations alone that distinguished one from the other among those 131 knives in the Montgomery Ward’s catalogue, one from the other among those five hundred specialized hammers made in Birmingham. Certainly there were distinctions, but what forces created them?

  Neither Norman, Basalla, nor Forty has much to say about a relationship between form and function. The words do not appear in any of their indexes, and we can confidently assume that these authors do not subscribe to the formula “form follows function,” which Forty calls an “aphorism.” Nor does David Pye, who has written very cogently about design. Pye’s books are especially rewarding reading because he lets the reader see how he thinks. He does not just give us the polished fruits of his thought; he also gives us the pits and seeds and cores, so that we may observe what is at the heart of his thinking through a design problem. Not only does he dismiss “form follows function” as “doctrine,” he also ridicules the dictionary definition that function is “the activity proper to a thing.”

  According to Pye, “function is a fantasy,” and he italicizes his further assertion that “the form of designed things is decided by choice or else by chance; but it is never actually entailed by anything whatever.” He ridicules the idea that something “looks like that because it has got to be like that,” and equates “purely functional” with terms that to him are pejoratives, such as “cheap” and “streamlined.” He elaborates on his disdain for the idea that “form follows function”:

  The concept of function in design, and even the doctrine of functionalism, might be worth a little attention if things ever worked. It is, however, obvious that they do not. Indeed, I have sometimes wondered whether our unconscious motive for doing so much useless work is to show that if we cannot make things work properly we can at least make them presentable. Nothing we design or make ever really works. We can always say what it ought to do, but that it never does. The aircraft falls out of the sky or rams the earth full tilt and kills the people. It has to be tended like a new born babe. It drinks like a fish. Its life is measured in hours. Our dinner table ought to be variable in size and height, removable altogether, impervious to scratches, self-cleaning, and having no legs.… Never do we achieve a satisfactory performance.… Every thing we design and make is an improvisation, a lash-up, something inept and provisional.

  Pye is engaging in hyperbole, of course, but all hyperbole has its roots in truth. What is at the root of Pye’s ranting is that nothing is perfect: If a malfunction occurs in one out of a million airline flights, then the aircraft is not perfected in the strictest sense of the word. Only tending to airplanes as if they were newborn babes keeps them well enough maintained to hold accident rates down. The truly perfected airplane would not need maintenance, would fly on little fuel, and would last for centuries, if not longer. And what is wrong with the dinner table? Well, we do have to insert and remove leaves to accommodate our variable-sized dinner parties. We have to situate telephone books to bring the latest generation up to table height. The table does just sit there when we are not using it. Its finish gets scratched, and it gets dirty. And it has legs that restrict our movement up to and away from it. In short, the table, like all designed objects, leaves room for improvement.

  In fact, it is just this ubiquitous imperfection that Pye so exaggerates that is the single common feature of all made objects. And it is exactly this feature that drives the evolution of things, for the coincidence of a perceived problem with an imagined solution enables a design change. But such a scenario for the evolution of artifacts should give us ever better designs, yet it does not seem to do so. A resolution of the paradox lies in Pye’s observation that design requirements are always in conflict and hence “cannot be reconciled”:

  All designs for devices are in some degree failures, either because they flout one or another of the requirements or because they are compromises, and compromise implies a degree of failure.…

  It follows that all designs for use are arbitrary. The designer or his client has to choose in what degree and where there shall be failure. Thus the shape of all things is the product of arbitrary choice. If you vary the terms of your compromise—say, more speed, more heat, less safety, more discomfort, lower first cost—then you vary the shape of the thing designed. It is quite impossible for any design to be “the logical outcome of the requirements” simply because, the requirements being in conflict, their logical outcome is an impossibility.

  Thus the common dinner table that Pye had described earlier is a failure because it cannot meet simultaneously all the competing terms of seating two and twelve, seating small children and large adults, possessing an aesthetically pleasing finish that does not scratch or soil, and having legs that hold it up without getting in the way. We can find fault with any common object if we look hard enough at it. But that is not Pye’s goal, nor is it this book’s intention. Rather, the objective here is to celebrate the clever and everyday things of an imperfect world as triumphs in the face of design adversity. We will come to understand why we can speak of “perfected” designs in such an environment, and why one thing follows from another through successive changes, all intended to be for the better.

  Few writers have been more explicit about the role of failure in the evolution of artifacts than the architect Christopher Alexander in his Notes on the Synthesis of Form. He makes it abundantly clear that we must look to failure if we ever hope to declare success, and he illustrates the principle with the example of how a metal face can be declared “perfectly” smooth and level. We can ink the face of a standard block that is known to be level and rub it against the face being machined:

  If our metal face is not quite level, ink marks appear on it at those points which are higher than the rest. We grind these high spots, and try to fit it against the block again. The face is level when it fits the block perfectly, so that there are no high spots which stand out an
y more.

  A dentist fitting a crown employs a similar technique. Although he does not seek a totally level surface, the dentist does want the new tooth surface to conform to its mate. This is done by having the patient grind something like carbon paper between the teeth to mark those high spots where the crown fails to fit. It is clear from Alexander’s paradigm for realizing the design of an artifact, which to him consists of fitting form to context, that we are able to declare success only when we can find no more points that fail to conform to the standard against which we judge. In general, a successful design, which Alexander terms a good fit between form and context, can be declared only when we can detect no more differences. It is “departures from the norm which stand out in our minds, rather than the norm itself. Their wrongness is somehow more immediate than the rightness.”

  Alexander also gives a more everyday example, one that does not require a machine shop or a dentist’s office to re-enact. All we need is a box of buttons that have collected over the years:

  Suppose we are given a button to match, from among a box of assorted buttons. How do we proceed? We examine the buttons in the box, one at a time; but we do not look directly for a button which fits the first. What we do, actually, is to scan the buttons, rejecting each one in which we notice some discrepancy (this one is larger, this one darker, this one has too many holes, and so on), until we come to one where we can see no differences. Then we say that we have found a matching one.

  This is essentially how a word processor’s spelling-checker program can work. It takes each word in a document in turn and compares it with the words in its dictionary. The logic or software of the program can find a matching word, if any exists, by successively eliminating those that do not match. Words of different length from the one being checked can be eliminated first because they obviously can’t fit letter for letter. Then the remaining words in the dictionary that do not have the same first letter as the word being checked can be eliminated. Of those words remaining, those that do not have the same second letter can be eliminated, and so forth until the last letter in the word being checked is reached. If there remains a word in the dictionary that produces no misfits, then the word whose spelling is being checked can be declared correctly spelled. If all the words in the dictionary are found to be misfits, then the word being checked can be declared misspelled. The success of the program depends fundamentally on the concept of failure. (The logic has several shortcomings, of course, which if not dealt with separately will not catch certain misspelled words and will declare some correctly spelled words misspelled. For example, it will not catch such misspellings as “their” for “there,” because both are valid words in the dictionary.)

  Alexander generalizes from his examples to recommend that “we should always expect to see [design] as a negative process of neutralizing the incongruities, or irritants, or forces, which cause misfit” between form and context. This is also how artifacts change over time and evolve with use. The manipulation of two pointed knives to eat a piece of meat might frequently have irritated medieval diners as the meat rotated about the stationary knife. Diners who chose not to touch the meat with their fingers would generally have been able to neutralize the irritant by pressing the noncutting knife flatter onto the meat, thus altering its use. And in time this might change the form of the knife blade to give it a better bearing surface. Knife makers are also diners, of course, and a particularly reflective or imaginative one might have come up with a more radical way of neutralizing the irritant—developing an entirely different eating implement, one with two prongs to stab the meat in order to prevent it from rotating while being sliced.

  “Misfit provides an incentive to change; good fit provides none,” declares Alexander, and even if we ourselves do not have the material, tools, or ability to work up a new artifact to remove an irritant in one we use, we might at least call the irritant to the attention of someone who can. That someone who can effect changes can be a craftsperson, for whom Alexander uses the masculine to include the feminine, and whom he describes as “an agent simply” through whom artifacts can evolve in an almost organic way:

  Even the most aimless changes will eventually lead to well-fitting forms, because of the tendency to equilibrium inherent in the organization of the process. All the agent need do is recognize failures when they occur, and to react to them. And this even the simplest man can do. For although only few men have sufficient integrative ability to invent form of any clarity, we are all able to criticize existing forms. It is especially important to understand that the agent in such a process needs no creative strength. He does not need to be able to improve the form, only to make some sort of change when he notices a failure. The changes may not be always for the better; but it is not necessary that they should be, since the operation of the process allows only the improvements to persist.

  This evolutionary process has worked throughout civilization and continues to work today even as craftsmen have become scientifically savvy engineers, and even as artifacts have grown to the complexity of nuclear-power plants, space shuttles, and computers. However, unlike Alexander’s agent, who does not necessarily have to make changes for the better, when the modern designer or inventor makes a change in an artifact, he or she must definitely think it is for the better in some sense. Nevertheless, actual incidents as well as mere perceptions of misfit and failure do continue to drive the evolution of artifacts, and we can expect that they always will. And it need not be only the likes of engineers, politicians, and entrepreneurs who have a hand in shaping the world and its things, for we are all specialists in at least a small corner of the world of things. We are all perfectly capable of seeing what fails to live up to the promise of its designers, makers, sellers, or licensers. Such ideas should be as evident to users of artifacts today as they were to the governed in the days of the Athenian statesman Pericles, who observed that “although only a few may originate a policy, we are all able to judge it.”

  Understanding how and why our physical surroundings come to look and work the way they do provides considerable insight into the nature of technological change and the workings of even the most complex of modern technology. Basalla takes the artifact as “the fundamental unit for the study of technology,” and argues convincingly that “continuity prevails throughout the made world.” Thus the cover illustration for The Evolution of Technology depicts “the evolutionary history of the hammer, from the first crudely shaped pounding stone to James Nasmyth’s gigantic steam hammer,” with which steel forgings of unprecedented size could be made at the culmination of the Industrial Revolution. Basalla asserts that the existence of such continuity in all things “implies that novel artifacts can only arise from antecedent artifacts—that new kinds of made things are never pure creations of theory, ingenuity, or fancy.” If this be so, then the history of artifacts and technology becomes more than a cultural adjunct to the business of engineering and invention. It becomes a means of understanding the elusive creative process itself, whereby the intellectual capital of nations is generated.

  The same purposeful human activity that has shaped such common objects as the knife, fork, and spoon shapes all objects of technology, “from stone tools to microchips,” and also accounts for the diversity of things, from the hundreds of hammers made in nineteenth-century Birmingham to the multitude of specialized pieces of silverware that came to constitute a table service. The distinctly human activities of invention, design, and development are themselves not so distinct as the separate words for them imply, and in their use of failure these endeavors do in fact form a continuum of activity that determines the shapes and forms of every made object.

  Whereas shape and form are the fundamental subjects of this book, the aesthetic qualities of things are not among its primary concerns. Aesthetic considerations may certainly influence, and in some cases even dominate, the process whereby a designed object comes finally to look the way it does, but they are seldom the first causes of shape and form
, with jewelry and objets d’art being notable exceptions. Utilitarian objects can be streamlined and in other ways made more pleasing to the eye, but such changes are more often than not cosmetic to a mature or aging artifact. Tableware, for example, has clearly evolved for useful purposes, and, no matter what pattern of silver we may have set before us on a table, we do not confuse knife, fork, and spoon. But when aesthetic considerations dominate the design of a new silverware pattern, the individual implements, no matter how striking and well balanced they may look on the table, can often leave much to be desired in their feel and use in the hand. Chess pieces constitute another example of a set of objects that have long-established and fixed requirements. There is no leeway as to how many pawns or rooks a set must have, and there is no getting around the fact that the pieces must be distinguishable one from another and must be provided in two equal but easily separated groups of sixteen. To design or “redesign” a chess set may involve some minor considerations of weight and balance in the pieces, but more often than not it is taken as a problem in aesthetics. And in the name of aesthetics many a chess set has been made more modern- or abstract-looking, if not merely different-looking, at the expense of chess players’ ability to tell the queen from the king or the knight from the bishop. Such design games are of little concern in this book.