Important People, Important Discoveries, Technology, World-Changing Inventions

The Watt Steam Engine

Developed between 1763 and 1775, the Watt steam engine was an extension and improvement of the Newcomen engine. The Watt was the first steam engine to drive its piston via pressurized steam and a partial vacuum. James Watt’s design is considered a key step in the evolution of modern mechanical engines.

Improving the Newcomen Engine

Developed by Thomas Newcomen, the Newcomen engine was far superior to previous incarnations of the steam engine, offering significant improvements in efficiency. Older steam engine models consistently lost steam, and therefore power, at the end of each stroke.

The Newcomen engine’s “atmospheric” design used a cylinder with a movable piston connected by a chain to one end of a pivoting beam, which operated a mechanical pump at the opposite end. Steam entered the cylinder below the piston with each stroke, followed by water, which condensed the steam. As the upper end of the steam cylinder was open, this created a partial vacuum that drew the piston down and raised the far end of the beam.

After being tasked with repairing a Newcomen engine at the University of Glasgow in Scotland in 1763, Watt noticed its inefficiencies and saw room for improvement. Based on his observations, Watt made several changes to the Newcomen engine’s design.

A separate condenser outside of the steam cylinder itself condensed the steam without the need for water spray, which cooled the piston and cylinder walls, reducing efficiency. The two chambers were connected, allowing for condensation and power transfer without loss of heat—the condenser remained cool, while the steam cylinder stayed hot.

Watt sealed the top of the steam cylinder and devised a method of injecting low-pressure steam into the area above the piston. This boosted the vacuum and increased the power of the down stroke, which in turn improved the speed and efficiency of the engine.

Finally, adjusting the design to produce rotary motion, instead of the previous oscillating movement of the Newcomen, proved more useful for industrial applications.

A preserved/restored Watt steam engine.

A preserved/restored Watt steam engine.

The Boulton Partnership

Though his design was completed and he had built a functioning model (ca. 1774), Watt was unconvinced that a marketable version of his engine could be developed. Watt entering into a partnership with Matthew Boulton, a Birmingham entrepreneur. Boulton funded the development of a full-scale test engine, giving Watt access to the facilities, capital, and craftsmen needed to bring his vision to life.

Boulton and Watt went into business selling and installing the steam engines in mines, ironworks, and other industrial locations. The bulk of their profit, however, came from a licensing fee charged to all owners of the steam engines, based on the fuel savings they generated—a  Watt engine used only about one-quarter the fuel that a similarly-sized Newcomen engine would. Despite the licensing fees, this exceptional fuel efficiency made the Watt steam engine the far more attractive option for most businessmen.

Further Improvements

The first Watt steam engines used hammer iron cylinders, which were out of round and caused leakage in the piston. By 1776, an inventor named John Wilkinson had developed a boring machine that was able to produce cylinders up to 50 inches in diameter with perfect precision. The introduction of bored cylinders further improved the Watt engine’s performance.

With a special arrangement of valves, steam could be admitted to either end of the engine. This allowed the direction of the power stroke to be reversed, creating the world’s first double-acting steam engine. This development also improved the engine’s efficiency and speed, and produced a more regular, stable motion.

Using a unique four-bar linkage, coupled with a pantograph—a development Watt dubbed “parallel motion”—the chain that once connected the piston rod and the engine’s moving beam was replaced. This allowed the piston to both push and pull with equal force.

This, in turn, made it possible for the motion of the beam to turn a wheel. Watt’s first rotary motion solution connected the beam to a wheel by a crank—however, the use of the crank was patented, so another method had to be developed. Using an epicyclic sun and planet gear system, Watt created a unique solution. (Later, after the patent on the crank expired, Watt reverted to this more-effective method.)

To ensure that the turning wheel operated at a consistent speed, a steam regulator valve was attached to a centrifugal governor. Watt based this design on the automatic speed controls used on windmills of his day.


With these improvements, Watt’s steam engine became an effective and reliable replacement for the water wheels and (literal) horsepower that had, until that point, powered British industry. Because it significantly improve efficiency and removed the need for a source of flowing water, the Watt steam engine allowed for vast expansion of industry throughout the country and drove the Industrial Revolution to new heights.


Photo credit: Foter / Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0)

Technology, World-Changing Inventions

A Brief History of Optical Telescopes

The first example of a working telescope was invented in 1608 by Hans Lippershey of Middleburg, The Netherlands. Through others, his arrangement of mirrors and lenses would go through countless evolutions over time, and come to be one of the most useful scientific inventions in history.

Optical Forerunners

The optical properties of convex and concave transparent objects have been known for thousands of years. The first glass lenses were not created until the late 1200s, when techniques for making glass had advanced enough to produce relatively inexpensive, relatively clear glass. Advancements in grinding and polishing glass also contributed significantly.

Before long, small, wearable sets of lenses were used to correct visions—the first eyeglasses. Methods of correcting both farsightedness and nearsightedness were created. These lenses, along with greatly refined glass mirrors, further set the stage for the telescope.

The First Telescopes

Though two others made their own claims to the device’s invention at the same time, Lippershey, spectacle maker, was the first disseminate designs for the telescope, and the first to apply for a patent.

Lippershey’s original telescope was composed of a single convex lens and a single concave lens in a wooden tube, providing 3X magnification. Soon, the “Dutch perspective glass” was being built by lens and spectacle makers throughout the Netherlands, spreading quickly across Europe and evolving rapidly with new technological advancements.

Sir Isaac Newton is credited with creating the first practical reflector in 1668, using a design that included a small, flat, diagonal mirror that reflected light into an eyepiece mounted on the side of the telescope.


The achromatic telescope was invented by Chester Moore Hall in 1733. Using improved lenses, these telescopes reduced color aberrations and could be far shorter and  more functional than previous designs. Hall did not widely publicize his discovery, and the achromatic telescope did not see wide use until John Dollond began producing them in large quantities in the late 1750s.

The Telescope Gets Larger & More Powerful

In 1789, Sir William Herschel built a giant telescope, forty feet long and with a mirror four feet in diameter. This reflector design, with its huge mirror, was capable of gathering hundreds or thousands of times more light than a refractor telescope.

In 1856, a new process of depositing layers of silver on glass telescope mirrors was discovered by Leon Foucault and Karl August von Steinhall. The silver layer provided much greater reflectivity and longevity that the finish on the speculum mirrors used until that time. It also possible to remove and renew the coating without unwanted modification of the glass substrate.

Using improvements to this technique and other technological advancements, the first large, modern research reflectors were built in the early 20th century. These telescopes were designed specifically for high quality photographic imaging and installed in remote high altitude locations. Examples include the Hale telescope at the Mount Wilson Observatory (built in 1908) and the Mount Wilson Hooker telescope (1917), which measured 100 inches in length.

In 1932, a replacement for the telescopes’ silver lens coating was developed. Using thermal vacuum evaporation, a much longer lasting aluminum coating could be applied. An aluminized lens was used in what was then the world’s largest telescope, the 200 inch Hale reflector at Mount Palomar, in 1948.

Photo credit: El Bibliomata / Foter / Creative Commons Attribution 2.0 Generic (CC BY 2.0)

World-Changing Inventions

Brewing Beer: Biotechnology at Its Finest

Did you know that brewing beer is not only an art, but also a science? It’s true! Beer brewing is a form of biotechnology, in that the scientific properties of the base ingredients are carefully manipulated to produce a specific end product.

Like scientists working on a complex chemistry formulation, brewers use four standard ingredients (water, starch [barley, etc.], yeast, and hops) to create the delicious concoction we call beer.


Beer in Ancient History

Beer is among the oldest man-made beverages. Historical evidence suggests that beer brewing dates back to around 6,000 BCE. Various beer “recipes” have been found written in cuneiform (the oldest known form of writing), as has 3,900-year-old Sumerian poetry written in honor of Ninkasi, the patron goddess of brewing.

Early human civilizations including ancient Egypt and Mesopotamia brewed beer extensively. Mesopotamian historical records, found written on clay tablets, suggest that brewing was a highly respected occupation. These ancient brewers used a unique, twice-baked barley bread called bappir that was baked specifically for the brewing process.

In the European Middle Ages, beer became one of the most popular beverages due to the lack of reliable, safe water sources. Because beer was boiled as part of the brewing process, it was guaranteed to be fit for consumption. As it was drunk with every meal (including breakfast), beer also provided a significant portion of daily calories for the lower classes.

Records dating back to 2500 BCE suggest that many different varieties of beer had been developed by that time, some of which were used exclusively in religious ceremonies. Throughout the Middle Ages, brewers’ guilds regularly adopted patron saints—French, Flemish, and Belgian brewers, as well as beer-brewing Christian monks, all shared this practice.

Historical Beer Aficionados

  • Many Egyptian pharaohs made beer part of their everyday diet.
  • Hammurabi’s Code, the ancient law code enacted by the Babylonian king around 2100 BCE, included regulations related to beer and tavern keepers in the kingdom.
  • Sophocles, the great Greek writer of the 5th century BCE, believed that the ideal diet consisted of bread, vegetables, meat, and beer.
  • Charlemagne, the great 8th Century CE king and ruler of the Holy Roman Empire, was a skilled brewer. He considered beer to be an important part of life, and trained many “royal brewers” himself.

The Evolution of Beer: Antiquity to Early Modern Europe

The intentional use of fermentation to produce beer makes brewing perhaps the first-ever application of biological engineering. Because almost any starchy cereal grain will ferment under the right conditions, ancient beers likely varied wildly in their composition and flavor.

The first beers noted in historical records were made with barley, often in large communal vats. These beers were likely thick and almost gruel-like—long reeds were used as straws to drink the liquid from the bottom of the vat and avoid the bitter solids left on top by the fermentation process.

Hops were first used to flavor beer in the 9th century CE. Hopped beer was “perfected”—in that the proper proportion of ingredients was finally discovered—in Bohemia in the 13th century. The use of hops lead to vast improvements in brewing processes and the quality of the finished product. Hops also provided preservative properties that other herbs used for flavoring until that time did not, this allowed beer to be produced in larger batches and sold, traded, and exported.

The oldest commercial brewery still in operation is the Weihenstephan Abbey Brewery in Bavaria, Germany, where beer has been brewed since 1040 CE. Numerous German innovations led to larger kettle sizes for greater production. German purity laws enacted in 1516 (and still used in Germany until 1987) restricted the allowable ingredients in beer to water, barley, and hops—yeast was added after Louis Pasteur’s discovery in 1857.

Thanks to innovations brought about by the Industrial Revolution, the mass production of beer became possible.

Photo credit: i be GINZ / Foter / Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0)

Technology, World-Changing Inventions

Water Treatment Technology Through History

Water Treatment Technology Through History


Civilization has changed in uncountable ways over the course of human history, but one factor remains the same: the need for clean drinking water. Every significant ancient civilization was established near a water source, but the quality of the water from these sources was often suspect. Evidence shows that humankind has been working to clean up their water and water supplies since as early as 4000 BCE.

Cloudiness and particulate contamination were among the factors that drove humanity’s first water treatment efforts; unpleasant taste and foul odors were likely driving forces, as well. Written records show ancient peoples treating their water by filtering it through charcoal, boiling it, straining it, and through other basic means. Egyptians as far back as 1500 BCE used alum to remove suspended particles from drinking water.

By the 1700s CE, filtration of drinking water was a common practice, though the efficacy of this filtration is unknown. More effective slow sand filtration came into regular use throughout Europe during the early 1800s.

As the 19th century progressed, scientists found a link between drinking water contamination and outbreaks of disease. Drs. John Snow and Louis Pasteur made significant scientific finds in regards to the negative effects microbes in drinking water had on public health. Particulates in water were now seen to be not just aesthetic problems, but health risks as well.

Slow sand filtration continued to be the dominant form of water treatment into the early 1900s. in 1908, chlorine was first used as a disinfectant for drinking water in Jersey City, New Jersey. Elsewhere, other disinfectants like ozone were introduced.

The U.S. Public Health Service set federal regulations for drinking water quality starting in 1914, with expanded and revised standards being initiated in 1925, 1946, and 1962. The Safe Drinking Water Act was passed in 1974, and was quickly adopted by all fifty states.

Water treatment technology continues to evolve and improve, even as new contaminants and health hazards in our water present themselves in increasing numbers. Modern water treatment is a multi-step process that involves a combination of multiple technologies. These include, but are not limited to, filtration systems, coagulant (which form larger, easier-to-remove particles call “floc” from smaller particulates) and disinfectant chemicals, and industrial water softeners.

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Planned future articles on Sandy Historical will expand on some of the concepts mentioned here. Please visit this page again soon for links to further reading.