Curta

The Curta is a hand-held mechanical calculator made by Curt Herzstark. It is very small and fits easily in the palm of your hand. Because of its shape and how it works, people called it the "pepper grinder" or "peppermill."

Curta calculators were thought to be the best portable calculators for many years. They were used until electronic calculators became popular in the 1970s. These tiny machines could do complex math calculations without needing electricity, making them very useful for scientists, engineers, and mathematicians.

History

The Curta was made by Curt Herzstark in the 1930s in Vienna, Austria. He built a small calculator that could add and subtract numbers. This design was simpler than older calculators.

Herzstark’s work stopped when he was taken away during a hard time. While he was away, he could still work on his calculator idea. After he was freed, he made the first working models. With help from a prince, production began in a small country. Even though some people tried to take advantage of him, Herzstark kept working. The Curta became a famous portable calculator until electronic ones took over in the 1970s. Many people still collect these little machines today.

Cost

The Curta Type I cost $125, and the Type II cost $175. Some people tried to take them apart, which made them hard to fix. Today, these calculators are popular with collectors. In 2016, they sold for about US$1,000, and some special ones reached up to US$1,900.

Design

The Curta was inspired by earlier machines created by Gottfried Leibniz and Charles Thomas. It used special wheels and a stepped drum to do calculations.

To put in numbers, you moved slides on the side of the machine. Turning a handle added numbers together. Lifting the handle up a little before turning it let you take numbers away instead. To do more complex math like multiplication or division, you had to move parts of the machine and turn the handle many times.

Models

The Type I Curta calculator could handle eight-digit numbers. It also had a six-digit counter for steps and an eleven-digit counter for results. This model was very light, weighing just 228 grams. A later version made in 1969 weighed a little more, at 245 grams.

The larger Type II Curta came out in 1954. It could handle eleven-digit numbers, with an eight-digit step counter and a fifteen-digit result counter.

Uses

The Curta was a popular tool for people in sports car rallies from the 1960s to the 1980s. Racers used it to figure out times and distances because electronic calculators were not strong enough for the bumps during races.

Pilots also used the Curta before electronic calculators were common. It helped them make exact calculations, like checking the weight and balance of their planes, which are important for safe flying. The Curta let pilots double-check their work easily.

Collections

The Curta calculator is popular with collectors and can be found in many places. A Swiss businessman named Peter Regenass has a big collection of mechanical calculators, including more than 100 Curta calculators. Some of these are shown at the Enter Museum in Solothurn, Switzerland. In 2016, he gave a Curta calculator to the Yad Vashem Museum in Jerusalem.

Popular culture

The Curta is in William Gibson's book Pattern Recognition from 2003. In the story, it is an old computing tool that people trade.

In 2016, Marcus Wu made a design for a Curta that could be printed with a 3D printer. But the technology was not good enough to make it small, so the printed version was about the size of a coffee can and weighed around three pounds.