Historical Science & Technology, Technology

I Can See For Miles, Pt. II: A Brief History of Prism Binoculars

Welcome to part two of the Sandy Mountain Historical & Technological Society’s brief history of binoculars. In the gripping cliffhanger finale of part one, we introduced the prism binocular design, which was developed as a method of righting the inverted images presented by the Keplerian optical design. Today, our tale concludes with a closer look at the technology that changed the long-distance viewing game forever.

Go Go Porro Bro Bro

Porro prism binoculars are the kind of field glasses you most likely picture your grandfather using. (Go ahead and conjure up a quick mental image of that. We’ll wait.) Named for the Italian inventor who developed this particular lens configuration in 1854, Ignazio “Big Iggy” Porro, this type of binoculars uses Porro prisms (also developed by Big Iggy) arranged in a Z-pattern to flip the image the right way ‘round. By necessity, Porro prism binoculars are wide, with widely-spaced objective lenses (the ones you point toward what you’re looking at) that are offset from the ocular lenses (the ones you look through, also called eyepiece lenses).

Likely the greatest photo of Porro prism binoculars ever taken.

Likely the greatest photo of Porro prism binoculars ever taken.

One significant benefit of the Porro prism design is that its folding optical path (created by the Z-configuration of lenses and prisms) allows the binoculars to have a focal length that is longer than the physical length, sometimes significantly longer. The wider space of the objective lenses also gives the presented image a better sense of depth.

Cat On A Hot Tin Roof Prism

Developed in the 1870s by noted great-French-name-haver Achille Victor Emile “Big Vic” Daubresse, roof prism binoculars use either the Abbe-Koenig prisms (invented by German engineers Ernst Karl “Big Ern” Abbe and Albert “Big Al” Koenig, and later patented, Thomas Edison-style, by Carl Zeiss in 1905) or Schmidt-Pechan prisms, a.k.a. Pechan prism pairs to invert the image to its proper orientation. In this configuration, the objective lenses are aligned with the eyepiece lenses.

Military-grade roof prism field glasses.

Military-grade roof prism field glasses.

The roof prism design results in field glasses that are narrower and more compact than their Porro prism cousins. And, whereas Porro prism binoculars occasionally need their prisms realigned, the fixed alignment of roof prism models eliminates the need for realignment, except in extreme circumstances. However, due to the silvered surfaces of their lenses and prisms, roof prism binoculars present images that are generally 12-15 percent darker than equivalent Porro prism binocs. Additionally, due to the tighter tolerances required for proper alignment of the optical elements, roof prism binoculars tend to be more expensive than the Porro prism variety.

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Historical Science & Technology, Technology

I Can See for Miles: A Brief History of Field Glasses

Binoculars. Binocs. Field glasses. The ol’ spysie eyesies. Whatever you call them, these popular, (mostly) handheld, binocular telescopes have been around for centuries, essentially since the invention of the boring ol’ monocular telescope (commonly known as the telescope). Which makes sense, since, really, just put two regular telescopes side by side and you’ve pretty much got binoculars.


“Whaddaya see out there, Mildred?”

Galileo Figaro!

The earliest field glasses utilized “Galilean optics”—a convex objective lens (the one you point at what you’re looking at) paired with a concave eyepiece lens (the one you look through, also called the ocular lens). While Galilean optics do present magnified images oriented in the correct direction, unlike the camera obscura and other optical devices that present upside-down images, they provide only a very narrow field of view, and cannot provide particularly high magnification.

The same basic design is still used in modern opera glasses and el cheapo kiddie binoculars, as well as surgical and jewelers’ loupes that don’t require high magnification. The technology remains popular for such applications because they can be very short and produce clear, upright images through a simple design.

Put Some Kepler in Your Step

A significant improvement was made through the use of Keplerian optics, a design used in the first refracting ocular telescopes. Because the image formed by the objective lens is viewed through a positive eyepiece lens, Keplerian optics provide higher magnification and a clearer image. However, this configuration does produce an inverted image, and requires an additional lens or lenses to present a correctly-oriented image.

Erecting Lenses (Oh, Hush…)

Aprismatic field glasses using Keplerian optics have either one or two additional relay lenses betwixt the objective and ocular lenses. By necessity, the design of these binoculars made them too long for practical use. They became obsolete with the invention of prism binoculars (see below) in the late 19th century CE and quickly fell out of use.

Prism Isn’t Just A Disappointing Katy Perry Album

The new-and-improved binoc design, known as prism binoculars, utilize prisms to invert the image so that it is presented right side up. There are two common prism binocular variations: porro prism and roof-prism. Tune in next week to learn about these game-changing field glasses.

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Important People, Important Discoveries, Technology

“Buoying Vessels Over Shoals”: Honest Abe’s Patent

U.S. Patent No. 6,469 begins thusly:

“Be it know that I, Abraham Lincoln, of Springfield, in the county of Sangamon, in the state of Illinois, have invented a new and improved manner of combining adjustable buoyant air chambers with a steam boat or other vessel for the purpose of enabling their draught of water to be readily lessened to enable them to pass over bars, or through shallow water, without discharging their cargoes.”

Yes, that Abraham Lincoln. Patent #6469 is the only patented ever granted to a U.S. President. (Though Lincoln was not president at the time he was granted the patent.)

Waterman, Patent Lawyer, President

Before he became perhaps the GOAT Commander in Chief, Abraham Lincoln worked as a patent lawyer for several years. Before that, he worked a variety of jobs that took him between his home in Illinois and New Orleans via river.

Whilst traveling on the Sangamon River on one such job, the flatboat on which Lincoln was riding got hung up on a milldam and started to sink. Lincoln quickly sprang into action, ditching some of the boat’s cargo into the river to right it, then drilling a hole in the deck to drain the accumulated water. He then plugged the hole, portaged around the milldam with help from the locals, and completed his trip down to New Orleans in the repaired boat.

A few years later, Lincoln made his first foray into politics. One of his first platforms was improving the navigability of the Sangamon River. Another boat he was traveling on during this period became stranded on a shoal, and was only dislodged after a considerable amount of elbow grease was applied by all aboard. This, coupled with the previous incident, inspired Lincoln to create his patented invention.

Scale model of Lincoln's patented invention (see below)

Scale model of Lincoln’s patented invention (see below)

Whatever Floats Your Boat, Abe!

Looking for a way to lift vessels over shoals and other obstructions in waterways, Lincoln invented an inflatable flotation device that could be attached to the hull of a boat. Comprised of a series of waterproof fabric bladders, the device would be inflated when needed to ease a stuck ship over obstacles. In theory, the air chambers would lift the watercraft above the surface of the water, giving it enough clearance to avoid getting stuck.

Lincoln designed and, with the help of Walter Davis, a Springfield, Illinois, mechanic, built a scale model of a ship outfitted with his device. The model is currently on display at the Smithsonian Institution. Lincoln was awarded his patent on 22 May 1849, shortly after the conclusion of his two-year term in the U.S. House of Representatives.

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The Science of Film, Music & Art

A Brief History of Porcelain in China & Japan

We’re just going to assume that you know what porcelain is and get right into the history part. Cool? Cool.

That’s Why It’s Called China

Examples of early, porcelainesque Chinese pottery dating as far back as 1600 BCE still exist, but the it was not until Eastern Han Dynasty (circa 206 BCE-220 CE) that the glazed ceramic material that we now know as porcelain was developed. By the time the Sui Dynasty rolled around (581-618 CE) porcelain was widely produced throughout the country. Soon after, Tang Dynasty (618-907 CE) porcelain made its way to the Middle East, where it was highly valued and sought after.

By the Song Dynasty days (960-1279 CE), porcelain production was widespread, and the artistry involved in making it continued to evolve. Highly organized production, with huge numbers of major kiln sites strewn about the country, was the order of the day.

Within a few hundred years, during the Ming Dynasty (1368-1644 CE), Chinese porcelain was being exported to and traded with Europe. The Silk Road helped the porcelain trade spread throughout Asia and into Africa. By the end of the 15th century CE, Portuguese and Dutch merchants were conducting direct trade with China by sea routes.

A MFin' Ming vase.

A MFin’ Ming vase.

What’s the Plan, Japan?

Japan was a major exporter of Chinese porcelain for centuries. However, they did not learn the secrets of making the material until a number of Korean potters were captured during the Japanese invasions of Korea in the late 1500s, which is hilarious. (The invasions weren’t hilarious—the fact that Japan couldn’t figure out porcelain until they kidnapped some in-the-know dudes is the funny part.)

These Korean potters invented an improved pottery kiln, and found a ready source of porcelain clay near Arita, in far southern Japan. Soon, multiple kiln sites were fired up in the area and were cranking out porcelain that, while not quite as good as the Chinese stuff, was more than sufficient for most purposes. Less expensive, lower quality porcelain goods made with this same process were still being made in Japan well into the 20th century.

Japan’s porcelain game had evolved enough by 1660 or so that they began exporting their wares to Europe via the Dutch East India Company. As civil wars and the collapse of the Ming Dynasty took their toll on Chinese porcelain production, Japan ramped up their production to fill the void. Uniquely Japanese styles of porcelain wares soon began to appear, many of them related to the country’s traditional textile designs.

By the second half of the 19th century, Japan had expanded their porcelain trade routes around the world, and export numbers grew exponentially. However, with higher demand came a significant decline in quality.

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War: What Is It Good For? (Absolutely Nothin'!)

Raiders of the Lost Arquebus

The arquebus—also known/spelled as harquebus, harkbus, or (by far the best alternate) hackbut—is an old-timey muzzle-load firearm. Used from the 15th to 17th century CE, this smoothbore, low velocity, shoulder-fired gun is the predecessor of the more widely-known musket, with which it shares many similarities.

Hungary for Handguns

Admittedly, that header’s a little off, as the arquebus was more like a rifle. It was first used in combat in Hungary during the reign of King Matthias I “Big King Matt” Corvinus in the late 1400s. One in five soldiers in the Hungarian infantry was equipped with an arquebus, though they weren’t used often due to their low rate of fire. By the turn of the 16th century, only about ten percent of soldiers in all the armies of Western Europe were carrying firearms of any kind, underscoring the relative ineffectiveness of the guns of this era.

An extremely ornate arquebus on display in a German museum.

An extremely ornate arquebus on display in a German museum.

However, there is at least one major example of an effective tactical use of the arquebus. The Battle of Cerignola in 1503 pit the French against the Spanish. The Spanish military used the “pike and shot” formation to great effect, and their ensuing victory was the first time in history that a battle had been won through the use of gunpowder-powered, handheld firearms.

Russian to Innovate

In the early 1500s, those crafty Russians developed their own, slightly-modified version of the arquebus, known as the pishchal. One thousand pishchal’niki were so armed during the final annexation of Pskov in 1510, and a thousand more took part in the conquest of Smolensk in 1512. The pishchal’niki divisions were disbanded after their campaigns, but became a permanent addition to the Russian military in 1545, when two thousand soldiers were outfitted, trained, and dispersed throughout the ranks.

During the Battle of Bicocca in 1522, arquebuses were used for the first time to launch volley fire. By the mid-1500s, arquebuses were being issued to Portuguese and Spanish sailors and soldiers headed overseas to foreign lands. The weapons played at least a small part in Hernán “Grande Hern” Cortés’ conquest of Mexico.

A more workaday example of an arquebus on display in a Japanese museum.

A more workaday example of an arquebus on display in a Japanese museum.

In 1543, Portuguese traders introduced the arquebus to Japan. By 1550, the Japanese military was mass-producing their own versions of the firearms, called tanegashima (alternately known as teppō or hinawaju). Within a decade, over 300,000 tanegashima had been manufactured, and it eventually became one of the most important weapons in Japanese military history.

By the middle of the 1700s, however, the arquebus had been more or less replaced the world over by the lighter, faster musket.

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