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The Saxonia Calculating Machine: The Groundbreaking "Millionaire Calculator" of the 19th Century

In the annals of computing history, the Saxonia calculating machine stands out as one of the most innovative and influential mechanical calculators ever devised. Nicknamed the "millionaire calculator" for its ability to quickly handle calculations involving very large numbers, the Saxonia boasted features that were decades ahead of its time. As a Digital Technology Expert, I believe the Saxonia‘s groundbreaking design deserves a deep dive to truly appreciate its significance.

The Birth of a Calculating Marvel

The story of the Saxonia began in 1878 in the German town of Glashütte, a region renowned for its precision engineering. Here, entrepreneurs Curt Dietzschold and Eugen Straßberger established a factory to produce mechanical instruments. In 1895, three brilliant mechanics working at the factory – Straßberger, Eduard Zeibig, and Josef Schumann – struck out on their own to develop a new and improved calculating machine.

They founded the Glashütter Rechenmaschinen-Fabrik Saxonia (Glashütte Calculating Machine Factory Saxonia) to bring their vision to life. The first Saxonia models bore a resemblance to the popular Thomas Arithmometer. But the mechanics quickly began iterating and innovating to create something all their own.

Mechanical Marvel: How the Saxonia Worked

What made the Saxonia special was its unique combination of mechanisms that enabled lightning-fast, high-digit calculations. At its core was a pin-wheel design using drums mounted with cogs of varying lengths. An internal "accumulator" track held the result. Users input digits using sliders or levers, one for each digit. Turning a hand crank engaged the cogs, rotating them to mesh with the accumulator‘s cogs and add the numbers together.

But the true brilliance was the movable carriage that held the accumulator. This allowed the accumulator to shift left and right to different positions. Essentially, it let the Saxonia "store" numbers in different places, greatly facilitating complex multiplication and division.

To multiply, the user would input the first factor (multiplicand), shift the accumulator using the carriage, enter the second factor (multiplier) one digit at a time, and crank. Then repeat for each subsequent multiplier digit. For 987 x 654, you‘d input 987, shift, crank 4 times, shift, crank 5 times, shift, crank 6 times. The result appeared in the accumulator at the end.

Division worked by first entering the dividend using the levers. Then the user shifted it to the left using a carriage knob. The divisor was then input and subtracted repeatedly using the crank until it could no longer be subtracted (the remainder was less than the divisor). The quotient showed up on a counter display and the remainder was left in the accumulator.

As collector and mechanical calculator expert Mark Glusker notes in his article "Mechanical Calculators":

"The Saxonia was a very capable machine. Its movable carriage allowed for direct multiplication and division, something many other calculators struggled with. This gave it a big speed advantage, especially with large numbers."

Unmatched Power and Speed

The movable accumulator carriage is what made the Saxonia‘s "millionaire calculator" moniker apt. It allowed the machine to handle far larger numbers than any other calculator at the time. Most contemporary calculators maxed out at 6 digits in the result register. The Saxonia could go up to a whopping 13 digits.

This was revolutionary. Suddenly, businesses could crunch numbers in the millions quickly and easily. Multiplications and divisions that would‘ve taken an eternity on other machines flew by on the Saxonia. No more tedious hand-cranking each individual addition. No more writing down intermediate results. The Saxonia did it all under its own steam.

To put this in perspective, here‘s a comparison of maximum digit capacity for the Saxonia versus other major calculators of the late 19th century:

Calculator Max Digits in Result
Saxonia 13
Thomas Arithmometer 6
Odhner Arithmometer 7
Burkhardt Arithmometer 8

The Saxonia‘s 13-digit prowess was unmatched. This opened up whole new realms of business and scientific calculations that were previously impractical with mechanical calculators.

Ahead of Its Time: Innovative Features

The Saxonia didn‘t just beat competitors with its high-digit capacity. It pioneered several groundbreaking features that became mainstays of 20th-century calculators and even early computers.

Foremost among these was the keyboard, introduced on Saxonia models around 1913. While commonplace to us now, a numeric keypad for data entry was unheard of at the time. Prior calculators used sliders, levers or punch cards to input numbers. The Saxonia‘s keyboard made data entry far faster and more efficient. As calculating machine historian Ernst Martin wrote in his 1925 book "The Calculating Machines":

"The key-set machine is considered an improvement as it is speedier to operate than the lever or slider set models. The action is lighter, and there is no risk of disturbing a number once it has been set, as can occur with the sliding pins."

In addition to the keyboard, Saxonia made several other design advancements:

  • A rotary setting lever that enabled the calculator to be made fully dust-proof
  • A rapid cancellation mechanism to quickly clear the machine
  • A more ergonomic and efficient single-crank design compared to earlier two-crank models

All these features combined to make the Saxonia one of the most sophisticated and user-friendly calculators of its era. As collector James Redin puts it in his "Antique Calculators" reference site:

"Using a Saxonia was a joy compared to many other calculators of the time. The keyboard was a revelation and the single crank made calculations fly by. It was built with Glashütte precision and you can feel the quality when using it."

Saxonia‘s Petit Prototype

No discussion of the Saxonia would be complete without mentioning a remarkable miniature prototype developed around 1905. Zeibig and Straßberger wanted to see just how small they could make a functional calculator using their Saxonia design. The result was a tiny 6-digit machine that could fit in a pocket.

Despite its diminutive size (only about 4 x 1.5 x 1.5 inches), this mini Saxonia was a fully capable calculator. It used a scaled-down version of the same pin-wheel mechanism and could add, subtract, multiply and divide. Only a handful of these marvelous machines were produced. Today they are coveted rarities that showcase the Saxonia‘s design brilliance.

Impact and Legacy

Saxonia calculators enjoyed brisk sales, especially in Europe, from their debut in 1895 up through the 1920s. Over 12,000 units had been manufactured by 1914. The company grew and flourished until Josef Schumann‘s departure in 1912.

In 1920, Saxonia merged with the Burkhardt calculating machine company to become Vereinigte Glashütter Rechenmaschinenfabriken (United Glashütte Calculating Machine Factories). Sadly, the combined venture went bankrupt in 1929, a victim of economic downturn. It was the end of Saxonia production.

But the Saxonia‘s influence would far outlive the company itself. Its keyboard input system in particular was a major innovation that paved the way for data entry on generations of calculators and computers. The Saxonia‘s high-capacity accumulator and efficient single-crank design also inspired later mechanical and electro-mechanical calculators.

As computing historian and digital preservation expert Dr. Thomas Haigh asserts in his research:

"While not a household name today, the Saxonia‘s importance in calculator development cannot be overstated. Its keyboard alone revolutionized number entry. And its unprecedented calculating capacity pushed the boundaries of what people thought these machines could do."


The Saxonia story reads like something out of an adventure novel – brilliant young upstarts strike out on their own to challenge a staid industry with revolutionary innovation. What they created was far more than just another incremental improvement on existing designs.

The Saxonia truly earned its "millionaire calculator" moniker, doing high-digit math faster than any competitor. Its keyboard and single-crank design set new standards for ease of use. Even its pint-sized prototype demonstrated the incredible scalability of its core mechanism.

Though its reign was cut tragically short by economic woes, the Saxonia calculator remains an icon of computing history. Its legacy can be felt in the user-friendly interfaces and high-speed calculations we take for granted in today‘s digital devices. The next time you tap out digits on a keypad, spare a thought for Messrs. Zeibig, Straßberger, and Schumann – visionary mechanics who helped propel us into the modern age with their magnificent "millionaire calculator."