In the eighteenth century, a mathematician, an astronomer, and an engineer each sought to apply their expertise to improve the efficiency of water wheels.
In the mid-1700s, the economies of the United Kingdom and France were flourishing. Mills throughout the region produced flour, textiles, and lumber, all powered by the flow of water using the traditional water wheel. As the need for power surged, Europe’s leading scientists and engineers worked to design a more efficient wheel.
Historian Terry S. Reynolds notes that these efforts are “sometimes cited as an early example of the successful application of science to technology.” However, he argues that this period actually highlights the often complex and indirect relationship between science and technological progress.
Water wheels primarily come in two designs. “Undershot” water wheels operate with water flowing beneath them, pushing against paddles to turn the wheel. “Overshot” wheels, on the other hand, work by having water flow over the top, filling buckets attached to the wheel. The weight of these filled buckets pulls the wheel downward.
According to Reynolds, scientists generally believed that “impulse and gravity were equally effective as motive powers,” implying little difference between the two wheel types. French mathematician Antoine Parent developed this further, concluding that all water wheels had very limited maximum efficiency. Although Parent’s theory was flawed, it likely encouraged others to explore the issue further.
“Bad theories are often better than no theories at all,” Reynolds writes, “since they may provide a stimulus toward additional work.”
Antoine de Parcieux challenged Parent’s theory while working for Louis XV to build a water supply for a chateau—a task that Parent’s theory deemed impossible. De Parcieux approached the problem with practicality. His crucial realization was that the overshot wheel should function “like an infinite series of falling weights,” as Reynolds explains. He conducted a small experiment using a 20-inch wheel and concluded that the overshot design could achieve very high efficiency.
English engineer John Smeaton also found fault with Parent’s theory. Smeaton, described by Reynolds as having “the practical technician’s distrust of theory,” wanted tangible proof. He set up models to lift weights and compared various water wheel designs. His tests demonstrated that the overshot wheel was at least twice as efficient as the undershot version.
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Astronomer and mathematician Johann Albrecht Euler approached the issue from a theoretical perspective. Building on the work of his father, Leonhard Euler, and Daniel Bernoulli’s theories, he factored in the weight of the water and the height of the fall. Euler also concluded that the overshot wheel was more efficient.
However, Reynolds argues that Euler’s theoretical contributions had minimal influence on practical engineering. Engineers frequently cited Smeaton and de Parcieux, with some even suggesting that Smeaton’s findings “delayed the introduction of steam power into British manufacturing for decades.” Conversely, arguments like Euler’s were often considered “either incomprehensible or insufficient” by the engineering community.
Despite the flawed scientific theory that initially motivated Smeaton and de Parcieux, their practical experiments ultimately shaped technological advancements. Reynolds concludes that their hands-on approach, rather than purely theoretical work, made the most significant impact on the development of water wheel technology (further reading on technological impacts).
Republished from the original source: JSTOR
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