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The Greatest Scientists of the 18th Century

Joseph Siffrein Duplessis - Benjamin Franklin

The 18th century saw developments in science and technology. Theories, ideas, inventions, and practices progressed and developed during this time. Science came to play the lead role during the 18th century because scientific authority began to overthrow religious and traditional authority in exchange of free speech and thought.  The 18th century, often hailed as the Age of Enlightenment, was a remarkable period for science, marked by unprecedented advancements and profound transformations in the way humanity understood the natural world.

The century was characterized by a fervent spirit of inquiry and empiricism, with discoveries spanning from the laws of motion and gravitation to the classification of flora and fauna. Breakthroughs in technology, such as the refinement of the microscope and the development of precise measuring instruments, further propelled scientific exploration. This period saw the birth of the scientific method as we know it today, establishing a framework for inquiry that emphasized observation, experimentation, and the questioning of established beliefs. The 18th century’s scientific revolution set the stage for the profound changes in both thought and society that followed, underpinning the intellectual and industrial advancements of the subsequent centuries.

Let’s take a look at the people who led the improvement and progress in the field of medicine, physics, science, astronomy, and mathematics.

1. Benjamin Franklin

Benjamin Franklin was a multifaceted American polymath, born on January 17, 1706, in Boston, Massachusetts. Renowned as one of the Founding Fathers of the United States, Franklin was not only an influential statesman and diplomat but also a groundbreaking scientist, inventor, and writer. His scientific contributions include pioneering work in electricity, most famously his experiment with a kite in a storm that led to the invention of the lightning rod. As an inventor, Franklin created bifocal glasses and the Franklin stove, among other devices. His political achievements were equally significant, playing a key role in the drafting of the Declaration of Independence and the Constitution of the United States. Franklin was also a successful publisher and author, known for his witty and wise aphorisms in “Poor Richard’s Almanack.” His diverse accomplishments and enduring influence on American culture, politics, and science make him one of the most remarkable and respected figures in history.

Roslin AlexanderCarl von Linné 1707-1778

2. Carl Linnaeus

Carl Linnaeus was a Swedish botanist and he is also known as the father of modern biological classification systems. When he graduated, Linnaeus became an expert biologist and he received a sponsorship to conduct several field studies where thousands of species of flora and fauna were labeled, identified, and catalogued. He also published a series of scientific masterpieces in which he spent his system for dividing the animal and plant kingdoms into series of categories and sub-categories. Linnaeus’ classification system is still the backbone of all modern biological sciences today.

Charles Babbage

3. Charles Babbage

Charles Babbage is known to be a brilliant polymath and as the first man to build a computing machine. He helped establish the Astronomical Society where he became interested in creating a calculation machine that could compute squares. His invention landed him a sponsorship from the British government which he used in creating a complicated machine called the Analytical Engine. He also designed an open submarine where four people could survive for a couple of days.

While the 18th century laid the foundation for scientific discovery, the pioneers of computer science built the digital world we live in today. Check out our post titled Who Founded Computer Science? to see how their groundbreaking work continues to shape our future.

John Dalton by Thomas Phillips 1835

4. John Dalton

John Dalton was an influential English chemist, physicist, and meteorologist, born on September 6, 1766, in Eaglesfield, England. He is best known for pioneering modern atomic theory, which significantly advanced the understanding of chemical composition and reactions. Dalton’s atomic theory, proposed in the early 19th century, posited that all matter is composed of small indivisible particles called atoms, and that each element consists of its own unique type of atom, distinguishable by its weight. This theory laid the foundation for the periodic table and profoundly transformed the study of chemistry. You can read The Rarest Elements On The Periodic Table if you want to gain knowledge on some of the lesser-known elements in the realm of chemistry. Dalton also conducted groundbreaking work in the field of meteorology, being one of the first scientists to systematically study weather conditions and atmospheric pressure. He kept detailed records of meteorological observations throughout his life, contributing significantly to the understanding of atmospheric sciences. Additionally, Dalton’s study of color blindness, a condition he personally experienced, led to the condition being occasionally referred to as “Daltonism.” His contributions to science have made him a key figure in the development of modern chemistry and physics.

Leonhard Euler

5. Leonhard Euler

Leonhard Euler was a trailblazing Swiss mathematician and physicist, born on April 15, 1707, in Basel, Switzerland. He is widely regarded as one of the greatest mathematicians of all time, having made prolific and influential contributions to numerous areas such as calculus, graph theory, mechanics, fluid dynamics, optics, and astronomy. Euler’s work is characterized by its breadth and depth, and he is particularly noted for introducing much of modern mathematical terminology and notation, including the concept of a mathematical function. His prolific output includes the Euler identity, Euler’s formula in complex analysis, and Euler’s equations in fluid dynamics, among many others. Euler’s ability to blend rigorous logic with creative problem-solving left a lasting legacy in mathematics, laying the groundwork for much of the modern mathematical landscape. His works continue to be a vital part of mathematical studies and research, testament to his unparalleled impact in the field.

Antoine Lavoisier

6. Antoine Lavoisier

Antoine Lavoisier, often referred to as the “father of modern chemistry,” was a French nobleman and chemist born on August 26, 1743, in Paris, France. His seminal work in the field fundamentally changed the science of chemistry. Lavoisier is best known for his role in the development of the chemical theory of combustion, which he elucidated through his work on oxygen’s role in burning. He effectively debunked the phlogiston theory of combustion that was widely accepted at the time. Lavoisier also helped construct the metric system, identified and named oxygen (1778) and hydrogen (1783), and helped categorize elements into gases, metals, nonmetals, and earths. His book, “Traité Élémentaire de Chimie” (Elementary Treatise of Chemistry, 1789), presented a unified view of new chemical knowledge, organized logically and including a clear definition of the chemical element. Despite his scientific achievements, Lavoisier’s life ended abruptly during the French Revolution, but his contributions left an indelible mark on the field of chemistry, ushering in a new era of scientific understanding and methodology.

James Watt

7. James Watt

James Watt was a Scottish inventor, mechanical engineer, and chemist, born on January 19, 1736, in Greenock, Scotland. He is best known for his improvements to the Newcomen steam engine, which marked a pivotal moment in the Industrial Revolution. Watt’s enhancement of the steam engine in the late 18th century, including the introduction of the separate condenser, significantly increased its efficiency and broadened its practical applications, powering factories, mills, and mines. This transformation had a profound impact on the course of industry and technology. Beyond the steam engine, Watt also contributed to the development of the concept of horsepower and the unit of power, the ‘watt’, named in his honor. His innovations and improvements in steam engine technology not only revolutionized industrial processes but also played a crucial role in shaping the modern world, influencing transportation, manufacturing, and the overall pace of societal progress.

William Herschel

8. William Herschel

William Herschel was a German-born British astronomer and composer, born on November 15, 1738, in Hanover, Germany. He is renowned for his discovery of the planet Uranus in 1781, a milestone that significantly expanded the known boundaries of our solar system. Herschel’s contributions to astronomy extend far beyond this singular discovery; he conducted comprehensive surveys of the night sky, cataloging clusters of stars and nebulae, and made crucial observations that led to the understanding of the structure of the Milky Way galaxy. Additionally, Herschel was a pioneer in the field of infrared astronomy, discovering infrared radiation through experiments with sunlight. His work in building telescopes also marked significant advancements in the field, with his 40-foot telescope being one of the largest of its time. Alongside his astronomical pursuits, Herschel had a notable career in music as an organist and composer, further highlighting his diverse talents. His legacy in astronomy is profound, laying the groundwork for many future discoveries and developments in the field.

Joseph Fourier

9. Joseph Fourier

Joseph Fourier was a French mathematician and physicist born on March 21, 1768, in Auxerre, France. He is most celebrated for initiating the field of Fourier analysis and its applications, which include the Fourier series and Fourier transform, fundamental tools in the analysis of periodic functions. Fourier’s major contribution came with his work on heat transfer and thermal equilibrium in his seminal book, “Théorie Analytique de la Chaleur” (The Analytical Theory of Heat), published in 1822. In this work, he introduced the concept that an arbitrary function can be represented as a series of trigonometric functions, greatly influencing the fields of mathematics, physics, and engineering. This breakthrough had profound implications in diverse areas ranging from number theory to signal processing, quantum mechanics, and image processing. Fourier’s legacy extends beyond mathematics and physics; he also accompanied Napoleon Bonaparte on his Egyptian expedition and contributed to the understanding of Egypt’s history and culture.

Daniel Bernoulli

10. Daniel Bernoulli

Daniel Bernoulli was a Swiss mathematician and physicist, born on February 8, 1700, into a family of prominent mathematicians in Groningen, Netherlands. He is best known for his foundational contributions to fluid dynamics and his application of mathematics to mechanics, particularly in his masterpiece, “Hydrodynamica” (1738). This work laid the groundwork for what is now known as Bernoulli’s principle, which explains the behavior of a fluid under varying conditions of flow and height. Bernoulli’s principle is fundamental in aerodynamics and hydrodynamics, explaining phenomena such as the lift force on an airplane wing. Additionally, Bernoulli made significant contributions to probability and statistics, and his work in economics regarding the utility of wealth is considered a precursor to modern utility theory. His broad contributions to science and mathematics were crucial in the development of various fields and have had a lasting impact.

Amadeo Avogadro

11. Amadeo Avogadro

Amadeo Avogadro was an Italian scientist who is hailed as a founder of the atomic-molecular theory. Amadeo Avogadro was the first scientist who discovered that elements could occur in the form of molecules rather than separate atoms. He is also famous for formulating the Avogadro’s law which states that equal volumes of gases under the same temperature and pressure will contain the same number of molecules.

Henry Cavendish

12. Henry Cavendish

Henry Cavendish was an eminent English natural philosopher and scientist, born in 1731 in Nice, then part of the Duchy of Savoy. He is renowned for his discovery of hydrogen, which he called “inflammable air,” and for the Cavendish Experiment, where he measured the Earth’s density by calculating the gravitational attraction between lead spheres. This experiment led to the first accurate determination of the Earth’s mass and the gravitational constant. Cavendish was a reclusive yet meticulous experimenter, known for his precise measurements and detailed experiments. His work significantly advanced the fields of chemistry and physics, particularly in the study of gases, heat, and electricity. Despite his tendency for solitude, Cavendish’s contributions had a profound and enduring impact on the scientific understanding of the natural world.

Georg Ohm

13. George Ohm

George Simon Ohm was a significant German physicist, born on March 16, 1789, in Erlangen, Bavaria (now Germany). He is best known for formulating Ohm’s Law, a fundamental principle in the field of electricity and electronics. This law states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance between them. This discovery, initially published in his seminal work “Die galvanische Kette, mathematisch bearbeitet” (The Galvanic Circuit Investigated Mathematically) in 1827, was not immediately recognized by the scientific community. However, it eventually became a cornerstone of electrical engineering, providing a mathematical framework for understanding electrical circuits. Ohm’s work in the field of electricity laid the groundwork for subsequent innovations and advancements. Despite facing initial skepticism and professional challenges, Ohm’s contributions have had a lasting impact, and he is remembered as a pioneer in the study of electrical resistance and circuit behavior.

Augustin Louis Cauchy

14. Augustin-Louis Cauchy

Augustin-Louis Cauchy was a distinguished French mathematician, born on August 21, 1789, in Paris. Renowned for his pioneering contributions to analysis and the theory of functions, Cauchy was a key figure in transforming calculus into a rigorous mathematical discipline. His work laid the foundations for various mathematical theories, including the theory of complex functions, wave theory, and elasticity theory. Cauchy was prolific in his output, authoring nearly a thousand research papers throughout his career. He introduced several important concepts and theorems, such as Cauchy’s integral theorem in complex analysis, Cauchy sequences, and Cauchy’s convergence test. His strict approach to mathematical rigor influenced many subsequent developments in modern mathematics. Despite facing political and religious challenges during his career, Cauchy’s legacy remains integral to the field of mathematics, particularly in analysis, where his contributions continue to be fundamental.

Anders Celsius

15. Anders Celsius

Anders Celsius was a prominent Swedish astronomer, physicist, and mathematician, born on November 27, 1701, in Uppsala, Sweden. He is best known for inventing the Celsius temperature scale, commonly used in most parts of the world today. Celsius originally created this scale with 0 degrees as the boiling point of water and 100 degrees as its freezing point, which was later reversed to the format we use now. Apart from his work in thermometry, Celsius made significant contributions to astronomy, notably in his observations of the aurora borealis (northern lights) and in determining the brightness of stars. He was also a professor of astronomy at Uppsala University and the director of the Uppsala Observatory. Celsius’ legacy extends beyond his famous temperature scale, encompassing a broad range of scientific achievements in the early 18th century.

Science in the 18th Century

Scientific exploration in the 18th century pushed the boundaries of what was possible and as we know today some of the areas of pursuit were in fact impossible.


Alchemists tried in vain to find the philosopher’s stone and the elixir of life, but by the 18th century, they were a thing of the past. The search for knowledge was now based on real science. Many new elements, like nickel, platinum, manganese, nitrogen, and chlorine, and a few new compounds, like carbon dioxide and hydrochloric acid, had been found. In England, science had come so far that plans had been made for making sulfuric acid on a large scale.

Discover the minds that shaped the world of chemistry in our post Who Are the Foremost Chemists in History. See how their groundbreaking work continues to influence science today.


Despite this growing knowledge, scientists were still held back in their research by a bad theory that seems to be the last holdover from the time of the alchemists. People used to think that all things that could catch fire contained a mysterious substance called phlogiston, which is the basis of fire. When things burned, it was the phlogiston that was seen to escape in the form of flames. Even when it was shown that the products of combustion weighed more than the original material, this was explained by the idea that the phlogiston that had escaped must have had a negative weight, or weighed less than nothing.

In a series of experiments on how mercury “burns,” Antoine Lavoisier showed that when mercury “burns,” it actually combines with oxygen in the air and gets heavier. Using the scale, he showed that the weight of the oxide formed was the same as the weight of the mercury and oxygen that had combined with it. His experiments finally disproved the phlogiston theory, which made it possible to understand how other chemical reactions work.

In later experiments, Antoine Lavoisier figured out what air and water are made of. He is justly called the father of modern chemistry.

Popularization of Science

In the second quarter of the eighteenth century, a lot of books were written to teach Europe’s elite about the latest scientific discoveries. Science had all of a sudden become popular. Newtonianism for Ladies: Dialogues on Light and Color, which came out in Naples in 1737, was one of the best-selling books. The Encyclopedia of Sciences, Arts, and Trades, which was written in French, was another well-known book. At the same time, scientific groups like The Royal Society, which was started during Charles II’s reign, grew.


At the beginning of the 18th century, two of the best mathematicians ever lived: Sir Isaac Newton from England and Gottfried Leibniz from Germany. They had a lot of followers, like Leonard Euler of Switzerland and Jakob and Johann Bernoulli of Basle. But Joseph Louis de Lagrange, who was born in Turin and lived and died in Paris, was the best mathematician of the eighteenth century. The most important thing that these brilliant men did was to create and perfect differential and integral calculus, a new branch of mathematics that made it possible for physical science to grow.


Physics was the first science to benefit from the work of mathematicians. But this century’s biggest contribution to science wasn’t so much the discoveries that were made as it was the way scientists approached their work. They stopped using argument and reasoning to try to find and explain natural laws. Instead, they started studying nature itself, looking into things, putting them into groups, and trying to recreate them in their labs. This is what we now call the scientific method. Studies were done on the laws of mechanics, continuing the work of Galileo, who had died in 1642. Studies were also done on dynamics and optics, continuing Newton’s work on finding out where colors come from.

In 1742, the Swede Anders Celsius came up with the centigrade degree as a way to measure heat. In 1791, the French Academy of Sciences suggested the meter as a new way to measure length. This was the start of the decimal metric system.

In 1735, the British government gave John Harrison a prize for designing and making a chronometer that could accurately measure longitude.


Electrical phenomena were first observed and studied systematically in the 18th century. The public was fascinated by the strange phenomenon known as electricism at the time. Throughout the century, anyone who wanted to show that he was up to date with the marvels of progress experimented with electricity; it even became a parlor game.

The Abbé Nollet, who was very interested in such experiments, successfully demonstrated the transmission of an electric current or shock through a circle. about one mile long, of Carthusian monks connected by iron wire before the royal court at Versailles; this was done to demonstrate to the royal court the speed of transmission of electricity. However, other results were obtained that, despite using less novel and spectacular apparatus, were of great importance to mankind; in 1752, Benjamin Franklin discovered the lightning conductor; in 1791, Galvani published a treatise on his work on electricity and the animal body; and at this time, Volta was working on the studies that led to the construction of the voltaic battery, forerunner of the dry battery of today.


Technology, along with pure science, made enormous strides in the eighteenth century. The period of the outstanding inventions was in the 1800s: the locomotive (Stephenson, 1829), the steamboat (Fulton, 1807), photography (Daguerre, 1839), the telegraph (Morse, 1837), the internal combustion engine (Lenoir, 1860), and the dirigible (that is, a steerable balloon, now called an airship) were all inventions of the nineteenth century.

Timeless Impact

As we reflect on the 18th century, a period brimming with intellectual fervor and groundbreaking discoveries, it becomes evident how profoundly this era shaped our modern understanding of science. The contributions of the era’s scientists – from Newton’s classical mechanics to Lavoisier’s chemical revolution – laid the foundation for countless advances that followed. This century was marked by an insatiable curiosity and a relentless pursuit of knowledge, characteristics embodied by the brilliant minds of the time. Their discoveries were not mere incremental steps but giant leaps that propelled humanity into a new age of enlightenment and understanding. The 18th century’s scientific landscape was a tapestry of innovation and discovery, with each scientist adding their unique thread to the intricate pattern of knowledge.

In closing, the 18th century stands as a testament to human ingenuity and the relentless pursuit of understanding our world and its underlying principles. The scientists of this era, with their revolutionary ideas and unwavering dedication, have left an indelible mark on history. Their legacy is not just in the facts and theories they unearthed, but in the spirit of inquiry they instilled, a legacy that continues to inspire scientists and thinkers today. As we venture further into the 21st century, the stories of these scientific pioneers remind us of the power of human intellect and curiosity. They challenge us to keep questioning, exploring, and pushing the boundaries of what we know, ensuring that the flame of discovery they ignited centuries ago continues to burn brightly into the future.

As you explore the groundbreaking discoveries of the greatest scientists in the 18th century, you might wonder about the tools that made their work possible. Enhance your journey through history by checking out our article, What Are the Oldest Scientific Instruments?, to learn about the devices that paved the way for these scientific breakthroughs.

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