Nuts and bolts Seven small inventions that changed the world in a big way

In this wide-ranging history, structural engineer Agrawal (Built) surveys how seven objects--the nail, wheel, spring, magnet, lens, string, and pump--transformed the world. Arguing that these "foundational innovations" prove "how engineering at its most fundamental is inextricably linked to your everyday life," Agrawal discusses how the first bronze nails, dating to 3400 BCE Egypt, and their derivatives (rivets, screws, bolts) "enabled robust connections between different materials," an innovation so fundamental it allowed for the construction of more complex buildings and boats and today makes possible such diverse gadgetry as satellites and watches. She traces the history of each invention, noting that the first known wheels were used to make pottery in Mesopotamia around 3900 BCE before they were attached to wagons for transportation several hundred years later. The straightforward prose makes it easy to understand how such contraptions as the Piezoelectric air pump work, and Agrawal has a knack for showing how simple objects provide the bedrock for intricate technologies; for example, she explains how the spring, which "tightened up and stored energy," made possible the construction of clocks significantly smaller than previous models used in church towers, which utilized a weighted system that relied on gravity to power the gears. The result is a potent look at the building blocks of the modern world. (Nov.)

The author of Built returns with an exploration of the "fundamental building blocks without which…complex machinery wouldn't exist." As structural engineer Agrawal ably demonstrates, from the dishwasher to the International Space Station, modern life depends on some combination of the nail, wheel, spring, magnet, lens, string, and pump. With the invention of the nail, our ancient ancestors could build houses, boats, weapons, and other vital things. Made by hand until the 19th century, metal nails were so expensive that people who moved often burned down their house to recover them. A family of nail cousins--rivets, screws, and bolts--followed. So ingenious is the wheel that some historians argue that it wasn't independently invented many times, as some believe, but by a single genius whose invention quickly spread across Eurasia. Wheeled transportation conquered much of the world nearly overnight about 6,000 years ago. Springs store and release energy when they change shape. Perhaps the first was the bow, but today they take part in the widest range of inventions. As dampers against noise, vibration, and earthquakes, springs support machinery and even entire buildings. The magnet, a natural phenomenon, is the basis of essentials in the modern world from light bulbs to the internet. Curved glass (i.e., lenses) was known since the dawn of civilization, but humanity didn't hit the jackpot until the 17th century produced the microscope and telescope. Readers searching for simple explanations of how things work may prefer Henry Petroski; Agrawal, an expert guide, emphasizes the big picture. She often compellingly digresses into related areas such as the varieties of string instruments and her personal experience with in vitro fertilization. Discussing the final invention on her list--the pump--the author emphasizes the heart, but also covers breast pumps and related topics. A quirky, entertaining riff on the building blocks of engineering. Copyright (c) Kirkus Reviews, used with permission.