Title: The Things We Make: The Unknown History of Invention from Cathedrals to Soda Cans

Author: Bill Hammack

Completed: May 2025 (Full list of books)

Overview: I found Bill Hammack a few years back when I stumbled on a video he made talking about all the thinking and design that went into soda cans. I found his presentation style very inviting. He took something we see every day and told the stories about how and why it came to look the way it does. He continues to share that love of engineering here with stories about people using “rules of thumb” to help them solve problems that remain right at the limit of scientific understand (and sometimes beyond). It’s a fun, fast read and it’s difficult for me to imagine anyone finishing this book without a love of (or at least fascination with) engineering.

Highlights:

• This is the engineering method: a process of methodical and actionable problem-solving, the force that has created the human world as we know it. And by observing how medieval masons in thirteenth-century France harnessed this force, we can create a definition of the method at its most elemental:
• Using rules of thumb to solve problems with incomplete information.
• the two methods have different goals: the scientific method wants to reveal truths about the universe, while the engineering method seeks solutions to real-world problems. The scientific method has a prescribed process that we all learn in school—state a question, observe, state a hypothesis, test, analyze, and interpret—but it doesn’t know what will be discovered, what truth revealed. In contrast, the engineering method aims for a specific goal—an airplane, a computer, a cathedral—but it has no prescribed process. The engineering method cannot be reduced to a set of fixed steps that must be followed, because its power lies exactly in the fact that there is no “must.” The specialized skill of an engineer is to find the correct strategy to reach a goal, to select among, combine, and create the many rules of thumb that will lead to a solution
• When we say that best, for an engineering solution, can only be judged based on its response to the constraints from material resources, societal needs, and existing technologies, then we are also saying that best inextricably comes from culture
• But the colors of these Shirleys were not faithful to the model’s actual skin tones; rather, they were set by a team of judges.26 The photograph of Shirley was printed with differing tones, balance among the colors, and shades—from too red or yellow to too blue and from too green to too pink—in subtle steps. These altered Shirleys were inspected by judges, who voted on the “optimal” color balance. A Kodak engineer involved in this judging noted that the print closest to “exact reproduction,” that is, matching the model’s true skin tones, was described unanimously as too dark, while the print with the greatest number of votes was, when compared with the exact reproduction, “quite pale.”27 For years, Kodak, the sole developer of Kodachrome until 1954, optimized the processing to create pale Caucasian skin tones, leading to poorly reproduced darker skin tones.
• Kodachrome color film, like any film that uses three primary colors to create other colors, cannot replicate all colors because of the physiology of the human eye.24 In our eyes, three specialized light-sensitive cells called cones detect color. The ρ cones detect red-orange-yellow light, the γ cones orange-yellow-green light, and the β cones green-blue-violet light. This suggests an image created from the three primary colors of red, green, and blue as captured and separated in Kodachrome would match the response of the human eye, but no color activates only the γ cones. Blue light stimulates the β cones, red light the ρ, but almost any shade of green activates both the ρ and γ cones. Although the dominant response to green light comes from the γ cones, the simultaneous stimulation of the ρ or the β cones creates paler greens, which in turn tinges white with magenta. To rebalance the colors for a purer white, tricolor films increase the intensity of the dyes that create red and blue to match the perceived increase in green, which comes at the expense of distorting yellow and brown hues.
• an engineer’s best is not an absolute standard—it changes with time. Acknowledging these built-in biases argues for a diverse workforce of engineers. The exclusion for centuries of more than half the population cuts across the spirit of the rules of thumb central to the engineering method: use everything that plausibly can lead to a solution. Every mind possible should be thrown at a problem. At its base, the reason for diversity in engineering is to increase the number of people whose unique knowledge might contribute to a solution, to even notice that a different solution is needed.
• When used in everyday conversation, “trial and error” is rarely meant to inspire or impress. We think of it as a kind of last resort when more effective and efficient means have been ruled out and all that’s left is the tedium of repeatedly testing solutions to see what works while spending most of our time seeing what doesn’t. But Wedgwood’s meticulous record keeping and reapplication of established knowledge are key to the trial-and-error strategy as a powerful problem-solving tool. It’s not a blind search but, as we see with Wedgwood, a systematic exploration of a design space, where an engineer varies the value of design parameters within that space and records every possible useful variable.
• we’ve observed that engineers often move forward before scientific understanding. This observation demolishes the notion of engineering as applied science; to view engineering as applied science conjures an image of science as an organized battlefront that expands, conquers all uncertainty, and enables technological marvels. This view is reinforced by the observation that extraordinary growth in scientific knowledge always coincides with rapid technological advance. Yet a more accurate picture is of engineers fighting a guerrilla war to change the world, combating scientific uncertainty with whatever tools and techniques work, those rules of thumb
• For his children, he designed a “spider,” a small car with three wheels and a motor powered by burning rubbing alcohol that chased his children and the family dog around the lawn—his wife banned him from running such toys in the house after a miniature locomotive spit out flaming alcohol, leaving a trail of fire on the library carpet. She also forbade him from transporting the children in a steam-powered stroller of his design because she feared the cookie tin used as a boiler might explode.
• energetic engineer, Hiram Maxim. Edison called Maxim’s bulb “a clean steal” of his lamp.2 Yet Maxim had seventeen patents on incandescent lamps, and his company controlled the patents of several other inventors, also contemporary to Edison. Maxim thought of himself as the inventor of the commercial light bulb. “Every time I put up a light,” he complained, “a crowd would gather, everyone asking, ‘Is it Edison’s?’”3 This so irritated Maxim, who noted that Edison at the time “had never made a lamp,” that he considering killing “on the spot” the next person to ask him “Is it Edison’s?”
• A handful of working light bulbs in the late 1800s is a marvel, but it doesn’t light the world. In this sense, the invention of the light bulb was a decades-long process of incremental changes to create a filament that can be manufactured reliably and extended beyond Edison and Maxim alone. To tell only a “great man” story hides the contributions of others who were essential to a technology’s development.
• What harm is there in the myth of the sole inventor? Why look in detail at the evolution of a product or technology? First, the myth hides the engineering method, feeding the view that at the root of every engineering marvel is scientific breakthrough, which closes minds to the most elegant, subtle, even sublime ingenuity of engineers as they respond to constraints that arise from mass manufacturing, from the need to rapidly and reliably mass-produce a product.
• And second, not only is the method itself hidden, but people are too. To study the evolution of a product lifts from the background underappreciated people in its development—often women and people of color—and highlights the fact that engineering creativity exists in everyone. Few have heard of Lewis Latimer, yet his work improved the reliability of light bulbs for a crucial ten-year stretch. To see only a genius inventor—often a white male—as the face of engineering dissuades the next generation from seeing engineering as a creative endeavor, a profession open to all, and reduces the number of minds working to solve the dire problems our world faces. Thinking of an invention as springing from a sole inventor leads to the fallacy, often conveyed by headlines, that one climactic breakthrough conquers all problems, when every invention is only one particular culmination of countless breakthroughs, both the sensational ones and the simply arduous, over countless years.
• It isn’t clear how or when it dawned on Spencer that a microwave-emitting magnetron could generate heat or even that he was the first to think of it. For sure, there was no candy bar moment—a detail invented by a Reader’s Digest writer in the 1950s—but during the war, it was common in winter for Raytheon engineers to walk past banks of magnetrons operating in the open air and warm their hands on the heat they emitted
• We think of the microwave oven story with a kind of retroactive teleology, imagining that all along, the device was meant to be used in the way we use it today. Yet the consumer oven was never the intended outcome: the goal was a large, commercial oven that would streamline the production of food in restaurants. The modern microwave oven is a failed version of what the Raytheon engineers were trying to build.
• As always with an engineering solution, the notion of best was fluid: it was changing with time.
• these simple stories of technology privilege science and thus distort how public moneys should be spent: we direct science toward applications, when we should spend on pure science that generates the powerful rules of thumb used by engineers.
• the stew took labor provided by both sexes, each determined according to traditional gender roles but comparably demanding. A man used handmade knives to butcher an animal; a woman carried water to the house in wooden buckets held together by leather likely tanned by her husband. She cooked the stew, made of vegetables from her garden, over a fire using wood chopped by her husband. She thickened the stew with grain husked and threshed by her husband. Any scraps or garbage that were not used were moved outside—likely again by her husband. Now, in the era of the microwave oven, we buy food from the grocery store, throw it in a manufactured steel pan, flick on a burner, cook dinner, and toss the scraps into a garbage disposal. Note what happened to housework: technology liberated men from their traditional roles while leaving women with their responsibilities, and the expectations of cleanliness—now the sole duty of women—were often raised by the power and ease of the household technology available to them
• understanding of how engineers create with the engineering method. One computer scientist advocated the maxim “Program or Be Programmed”—learn to control a computer or it will control you. The same applies to simpler technologies: knowing the fuel used to generate your electricity, the source of your water supply, or what happens to your recycling empowers you to advocate for change because you know that the solutions being used on your behalf were chosen for complex but identifiable reasons, and when you reexamine the variables applied to the engineering method, new solutions are always an option