Mechanical calculator

A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically, or a simulation like an analog computer or a slide rule. Most mechanical calculators were comparable in size to small desktop computers and have been rendered obsolete by the advent of the electronic calculator and the digital computer.

In 1642, Blaise Pascal invented the first operational mechanical calculator with better tens-carry. Concerned about his father's exhausting work as tax collector in Rouen, Pascal designed the Pascaline to help with the large amount of tedious arithmetic required.

In 1672, Gottfried Leibniz started designing an entirely new machine called the Stepped Reckoner. It used a stepped drum, built by and named after him, the Leibniz wheel, was the first two-motion design, the first to use cursors (creating a memory of the first operand) and the first to have a movable carriage. Leibniz built two Stepped Reckoners, one in 1694 and one in 1706. The Leibniz wheel was used in many calculating machines for 200 years, and into the 1970s with the Curta hand calculator, until the advent of the electronic calculator in the mid-1970s.

Thomas' arithmometer, the first commercially successful machine, was manufactured in 1851; it was the first mechanical calculator strong enough and reliable enough to be used daily in an office environment. For forty years the arithmometer was the only type of mechanical calculator available for sale until the industrial production of the more successful Odhner Arithmometer in 1890.

Charles Babbage designed two kinds of mechanical calculators, which were too sophisticated to be built in his lifetime, and the dimensions of which required a steam engine to power them. The first was an automatic mechanical calculator, his difference engine, which could automatically compute and print mathematical tables. The second one was a programmable mechanical calculator, his analytical engine, which Babbage started to design in 1834; "in less than two years he had sketched out many of the salient features of the modern computer. A crucial step was the adoption of a punched card system derived from the Jacquard loom" making it infinitely programmable. In 1937, Howard Aiken convinced IBM to design and build the ASCC/Mark I, the first machine of its kind, based on the architecture of the analytical engine; when the machine was finished some hailed it as "Babbage's dream come true".

Ancient history

Further information: Arithmetic and Abacus

People have always wanted to make math easier and faster. Long ago, they used small objects like pebbles to help count. These later became beads on wires, known as an abacus, which was invented by ancient peoples and used all over the world.

After the abacus, the next big idea came from John Napier in 1617 with his numbering rods, called Napier’s Bones. But the first true mechanical calculator was created in 1642 by Blaise Pascal. Before this, there were also machines like odometers and the Antikythera mechanism, which used gears to help with calculations. These early devices showed how people tried to make math work better.

Further information: Pascal's calculator

The 17th century

The 17th century was when mechanical calculators began. In 1642, Blaise Pascal invented the first one. He created a machine that could do basic math automatically. Before this, people had to do all calculations by hand, which was very slow and tiring.

Other tools like Napier's bones, logarithmic tables, and the slide rule were also used to help with math. These tools were easier to use for multiplying and dividing than early mechanical calculators. It wasn’t until the mid-1800s that mechanical calculators became more common.

The 18th century

Further information: Pinwheel calculator and Leibniz wheel

The 18th century was a time when inventors created the first machines that could multiply numbers automatically. In 1709, an Italian inventor named Giovanni Poleni built a wooden calculator that could do multiplication, though division still needed help from the person using it. Other inventors, like Anton Braun from Germany and Hillerin de Boistissandeau from France, also made interesting machines during this time, each trying new ways to make calculations easier. These early machines were important steps before we had modern calculators.

The 19th century

Luigi Torchi created the first machine that could multiply directly in 1834. This was also the second machine where you could press keys to use it, after James White made one in 1822.

The business of making mechanical calculators began in 1851 when Thomas de Colmar introduced his simpler Arithmomètre. This was the first machine people could use every day in an office.

For 40 years, the arithmometer was the only mechanical calculator people could buy, and it was sold all around the world. By 1890, about 2,500 arithmometers had been sold, along with a few more from two other companies that made copies. Another company, Felt and Tarrant, sold 100 comptometers in just three years.

The 19th century also saw the designs of Charles Babbage for calculating machines. First, he worked on his difference engine, starting in 1822. This was the first automatic calculator because it used the results of one operation for the next one. Later, he designed the analytical engine, starting in 1834. This was the first programmable calculator and it showed the ideas that later led to mainframe computers in the middle of the 20th century.

Desktop calculators produced

• In 1851, Thomas de Colmar made his arithmometer simpler by taking out the part that could only multiply or divide by one digit. This made it easier to add, but it could still multiply and divide if you turned a handle. This version was strong and reliable, and people began using it in banks, insurance companies, and government offices.
• In 1878, a company in Germany made a copy of Thomas' arithmometer. Before this, Thomas was the only person making these machines. Eventually, twenty European companies made copies of his arithmometer until World War II.
• Dorr E. Felt in the U.S. created the Comptometer in 1886. It was the first machine where pressing the keys would add numbers without needing to turn a handle. In 1887, he started a company with Robert Tarrant. The comptometer-type calculator later got an all-electronic engine in 1961.
• In 1890, W. T. Odhner started making his calculator again in his workshop in Saint Petersburg. He built and sold 500 machines in 1890. Later, he sold the Berlin part of his factory, and another company made machines under the name Brunsviga. Millions of these were sold until the 1970s.
• In 1892, William S. Burroughs began selling his printing adding calculator. His Burroughs Corporation became very important in making accounting machines and computers.
• The "Millionaire" calculator came out in 1893. It could multiply directly by any digit, and it had a special part to look up products.

Automatic mechanical calculators

• In 1822, Charles Babbage showed a small part of his difference engine. This machine could hold and work with seven numbers that had up to 31 digits each. It was the first machine that could work automatically, using the results from one operation for the next one. It was also the first calculating machine to have a printer. Development of this machine, later called "Difference Engine No. 1," stopped around 1834.
• In 1847, Babbage began working on an improved version called "Difference Engine No. 2." Neither of these designs was fully built by Babbage. In 1991, the London Science Museum built a working version of Difference Engine No. 2 using 19th-century technology.
• In 1855, Per Georg Scheutz finished a working difference engine based on Babbage's design. It was the size of a piano and was shown at the Exposition Universelle in Paris in 1855. It was used to make tables of logarithms.
• In 1875, Martin Wiberg redesigned the Babbage/Scheutz difference engine and built a smaller version the size of a sewing machine.

Programmable mechanical calculators

• In 1834, Babbage began designing his analytical engine, which would become the ancestor of modern mainframe computers. It had separate ways to put in data and programs, printers to show results, a part to process information (mill), memory (store), and the first set of programming instructions. In 1937, when Howard Aiken asked IBM for money to make the Harvard Mark I, he mentioned Babbage's ideas.
• In 1843, while translating a French article about the analytical engine, Ada Lovelace wrote an algorithm to calculate the Bernoulli numbers. This is considered the first computer program.
• From 1872 to 1910, Henry Babbage worked on creating the mill, the "central processing unit" of his father's machine. In 1906, he successfully showed it printing the first 44 multiples of pi with 29 digits.

Cash registers

Further information: Cash registers

The cash register was invented by James Ritty in 1879. It was an adding machine with a printer, a bell, and a display that showed the amount of money for both the customer and the store owner. It was easy to use and became popular in many businesses. By 1900, one company alone had sold 200,000 cash registers, while another company had sold only about 3,300 mechanical calculators.

Prototypes and limited runs

• In 1820, Thomas de Colmar patented the Arithmometer. He spent the next 30 years and a lot of money developing it. In 1851, he made a simpler version that could only add.
• From 1840, Didier Roth made a few calculating machines, including one based on Pascal's calculator.
• In 1842, Timoleon Maurel invented the Arithmaurel, which could multiply two numbers just by entering them.
• In 1845, Izrael Abraham Staffel showed a machine that could add, subtract, divide, multiply, and find square roots.
• Around 1854, Andre-Michel Guerry invented the Ordonnateur Statistique, a cylindrical device to help organize data about things like crime.
• In 1872, Frank S. Baldwin in the U.S. invented a pinwheel calculator.
• In 1877, George B. Grant in Boston began making the Grant mechanical calculating machine. It could add, subtract, multiply, and divide, and it was shown at the 1876 Centennial Exposition in Philadelphia.
• In 1883, Edmondson in the United Kingdom patented a circular stepped drum calculator.

1900s to 1970s

Mechanical calculators improved over time, developing two main types of mechanisms: reciprocating and rotary. Reciprocating mechanisms were usually operated by hand cranks, while rotary mechanisms had shafts that turned continuously.

In the early 1900s, the Dalton adding-listing machine was introduced, and in 1948, the small, handheld Curta calculator was developed. From the 1900s through the 1960s, mechanical calculators were the main tools for desktop computing. Companies like Friden, Monroe, and SCM/Marchant in the USA made popular models. These machines could add, subtract, multiply, and divide by repeating mechanical operations. Some also could find square roots. Mechanical calculators were widely used until electronic calculators took over in the 1970s.

Main article: History of computing hardware