Centuries after his work, history remembers Leonardo da Vinci as an unprecedented polymath. From his drawings of the Vitruvian man embodying his understanding of human anatomy to fantastical drawings of flying machines, the body of his work documents the journey of a mind of relentless inquisition into countless avenues. Many of his designs have been remembered in popular culture as fantastical and artistic, but da Vinci’s work was very much in step with practical engineering in his time. Several of his inventions were quintessential steps into this field.

Strut bridge

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War has always been an exercise in obtaining an unforeseen edge over one’s opponent and, as such, fueled a tremendous portion of human innovation. Da Vinci’s talents were of particular appeal to the military-minded, and many of his inventions were for application in combat. Some of these designs included an automatic ballistic cannon and an underwater diving suit.

However, neither of these was as widespread or practical as his design for the strut bridge. Under the patronage of Cesare Borgia, da Vinci designed a bridge that could be assembled from simple pieces of wood, requiring neither nails nor rope to hold it together. The structure of the strut bridge is self-supporting. This meant that infantrymen could carry the components into the field or craft them from nearby timber in order to construct a bridge that supported hundreds of troops at once. The simplicity and versatility of the design made it a tremendous boon for sieges.

Rolling mill

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Sheet metal has a history extending back to ancient Egyptian jewelry. These early applications involved primordial furnaces with alternated layers of charcoal used to liquefy steel. The shortcoming of these early methods was the amount of metal that was wasted in the process and the degree of precision and intricacy that could be expected.

In his time, da Vinci designed a rolling mill that used a horizontal water wheel as a single power source. His drafted designs that were far ahead of any technology of the time, to the point where his contemporaries doubted that a water mill could power the heavy machinery of a rolling mill. In fact it wasn’t until a century later in 1590 that his design was brought to life in its initial schematics. This early incarnation of steel metal fabrication, tracing its roots back to the time of da Vinci, was an instrumental step toward the industrial revolution.

Tensile strength tests

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Da Vinci’s inventions were intricate and complex. At the time of his work, standardized measures and testing were virtually nonexistent, which made the process of engineering much more difficult. In order to perfect his designs, da Vinci conducted exhaustive tests under the scientific method. One used a machine that could test the tensile strength of iron wire. A basket was hung from an iron wire, and da Vinci would slowly fill it with sand through a small hole. The machine used a spring that would snap the hole shut as soon as the wire snapped, allowing him to keep track of the precise amount of sand for each wire and would indicate a measure of the wire’s strength.

The degree of rigor that was used in these measurements was foundational in the field of engineering, and though some of his findings conflicted with principles later elucidated in classical mechanics, his method was instrumental in the progress of the field of engineering.

Lens grinding machine

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Astronomy was one of the most important fields of study from the ancient world to modernity as it necessitated precise measurement and continued innovation in math and science. The Renaissance was no exception. The popularity of astronomy in this period fueled high demand for convex lenses to view the stars. These often proved expensive as lenses were hand-grinded, requiring substantial time, effort, and skill of the lens crafter.

In order to circumvent the cost and difficulty of obtaining convex lenses, da Vinci designed an automated machine that could grind lenses that used a selection of interlocking cogs and a central grinding wheel that could craft lenses with high precision. His innovation was, once again, ahead of its time. However, his approach was the same that later became the standard.

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