“The most ingenious
calculating machine ever
to grace an engineer’s hand”
“The most ingenious
calculating machine ever to grace an engineer’s hand”
In 1905, Samual Jacob Herzstark and Marie Amalie Herzstark opened the first calculator factory in Austria.
Their son, Curt Herzstark, grew up with calculators and studied their mechanics. As a boy, he also demonstrated a talent in music. The Austrian composer and virtuoso Fritz Kreisler (a cousin of Samuel Herzstark) insisted on a musical education for Curt but his father prevailed and the technical training was selected.
After graduating the Staatsgewerbeschule in 1922 Curt went back to the family business to continue learning the trade, but soon his father sent him to work in two factories in Chemnitz, Germany in order to gain practical experience.
As a salesman for the family business, Curt heard from customers who needed a smaller, portable calculating machine which could fit in a pocket and be used by one person.
Curt Herzstark conceives the Curta. He begins to draw plans for the smallest handheld mechanical calculator ever invented through breakthrough discovery of the nines’ complement which eliminated the significant mechanical complexity created when "borrowing" during subtraction.
I looked at everything backwards. Let’s pretend that I have already invented everything. What does this machine have to look like so that someone can use it? This machine can’t be a cube or a ruler; it has to be a cylinder so that it can be held in one hand. And holding it in one hand, you would adjust it with the other hand, working the sides, top and bottom. The answer could appear on the top.
Curt is imprisoned in Buchenwald concentration camp in Weimar, Germany
He credited his survival with his idea and the Nazi army’s realization of the potential power of such a device.
The SS Commandant of the camp learnt of Curt’s plans for a mechanical calculator and ordered him to continue work on it on Sundays and after the normal working day was finished.
The head of the department, Mr. Munich said: "I understand you've been working on a new thing. If it is really worth something, then we will give it to the Führer as a present after we win the war."
For me, that was the first time I thought to myself, my God, if you do this, you can extend your life. And then and there I started to draw the CURTA, the way I had imagined it.
In this role, Herzstark saved fellow prisoners by employing them in his department, using his special status to receive food parcels and bring inmates into the sheltering environment of the factory.
After the war, he was awarded the Order of the Luxembourg Brotherhood for rescuing a Luxembourg worker.
Buchenwald was liberated by U.S. troops on 11 April 1945.
By November, Herztark had found a manufacturer in Sommertal, Germany and had three working prototypes.
However Curt became fearful that the Soviets, who controlled East Germany, would forcibly deport skilled workers to Russia. He dismantled the three prototypes and, disguising them as children’s toys, smuggled them to Switzerland.
Herztark fled back to Austria in July 1945, looking for financial backers and filing patents to protect his invention.
Franz Joseph II, Prince of Liechtenstein, took an interest.
It was disclosed to me that the Prince of Liechtenstein wished to build up the country’s industry and was seeking experts in the field, and it had been discovered through thorough enquiries that I was the right man
What about the name?
Originally called "Liliput", the marketing team suggested the name was too exotic. The meeting started to get out of hand. Finally the secretary piped up: ‘Gentlemen, I don’t understand this argument. The inventor’s name is Curt, and this is his daughter. Why don’t we just call her “Curta”?’
The Curta is launched on the market in 1948.
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It was not long before Herzstark's financial backers, thinking they had got from him all they needed, conspired to force him out by reducing the value of all of the company's existing stock to zero, including his one-third interest.
These same financial backers had earlier elected not to have Curt transfer ownership of patents to the company. In this arrangement, any lawsuits would be directed at Curt, rather than the company.
Curt stood by the quality and integrity of his invention
This ploy now backfired: without the patent rights, they could manufacture nothing and Curta kept his company.
An estimated 140,000 Curta calculators were made (80,000 Type I and 60,000 Type II)
For decades, the Curta was the best portable calculator available. Electronic calculators eventually displaced the Curta in the 1970s.
The Curta lives on as a highly popular collectible, with thousands of machines working as smoothly and accurately as they did at the time of manufacture.
The Curta was popular among contestants in sports car rallies during the 1960s, 1970s, and into the 1980s. Even after the introduction of the electronic calculator for other purposes, they were used in time-speed-distance (TSD) rallies to aid in computation of times to checkpoints, distances off-course and so on, since the early electronic calculators did not fare well with the bounces and jolts of rallying.
The Curta enables you to run an entire rally using only one watch and to negotiate any number of speed changes without resetting your odometer. If, for example, you discover that you have changed speed at the wrong point, you can make the necessary
corrections in a few seconds.
The brilliant design of the Curta endures as a testament to Curt Herzstark's technical vision. For pioneering portable computation and exemplifying analog engineering’s heights, Curt Herzstark’s Curta calculator is recognized as an instrument far ahead of its time.
The Curta continues to inspire scientists, engineers, and mathematicians including Curta, a scientifically-focused provider of health economics and outcomes research (HEOR).
Honoring the legacy of the Curta calculator, we help our health technology clients achieve market access and commercial success as a premier research organization that provides tools and customized solutions.