Instant Calculations

Nowadays we do our calculations on our smartphones in the blink of an eye. But between the abacus and digital calculator is a world of complex mechanical calculators.

By NEMO Science Museum

Russia (1941-08) by Margaret Bourke-WhiteLIFE Photo Collection

Calculation tools emerged in countless early cultures. Numbers were ‘saved’ and ‘modified’ by moving beads in an abacus or making knots in ropes. 

Babbage Difference Engine (1837/1871) by Charles BabbageOriginal Source: https://commons.wikimedia.org/wiki/File:Difference_engine.JPG

British mathematician Charles Babbage built a number of what were known as difference engines in the first half of the nineteenth century. He wanted to use them to quickly calculate the outcomes of a mathematical function. 

Part of Babbage Difference Engine (1853) by Charles BabbageOriginal Source: https://commons.wikimedia.org/wiki/File:Difference_engine_plate_1853.jpg

The difference engines used a huge amount of cog wheels to do a series of additions. But Babbage was unable to get his machines working. It was not until the year 1991 that a replica proved that the mechanism did in fact work. 

Mechanical desk calculator (1955) by AntaresNEMO Science Museum

In 1851, arithmometers appeared on the market that were able to add, subtract, multiply and divide.

This machine is called the Antares P2 and appeared later, but works in a comparable way with cog wheels that make a specific number of turns, producing the results.

Entering the settings may take a little while, but after that the sum 255 x 31 is literally done with the flip of a switch. 

Mechanical desk calculator (1943) by BrunsvigaNEMO Science Museum

Calculators were cumbersome and heavy. 

This German-made Brunsviga 20 was sold from the 1930s on and weighed 12 kilos.

Brunsviga calculating machine (1905) by NerenzOriginal Source: https://de.wikipedia.org/w/index.php?title=Datei:Rechenmaschine_Brunsviga_1905.JPG&filetimestamp=20080309194118&

The ad for the Brunsviga calculator claims it ‘never miscalculates’. 

The device was praised as a great option to calculate taxes and wages.

Mechanical desk calculator (1935) by FacitNEMO Science Museum

Manufacturers developed various types of machines. This product by Facit used buttons to enter the numbers, but the mechanical system on the inside looked a lot like the previous calculators. 

Mechanical desk calculator (1930/1940) by BurroughsNEMO Science Museum

A so-called comptometer was able to calculate large numbers quickly. That was its only use too. The sum 123 x 9 could be calculated by pressing the buttons 1, 2 and 3 nine times at the same time. 

Electric calculator by MonroeNEMO Science Museum

To speed up calculations, electric machines were created, such as this one by Monroe. A motor drives the calculation mechanism, that in itself is fully mechanical. 

NASA human computers (1950/1959) by NASAOriginal Source: https://commons.wikimedia.org/wiki/File:NASA_human_computers_-_Mary_Jackson_on_far_right_-_Pressure_Tunnel_staff_taken_in_1950s.jpg

Some institutes – such as the NASA space organization – were in dire need of calculation power and hired human calculators. These hires calculated rocket trajectories for example. This was common practice until the 1970s.

Electric calculator by BurroughsNEMO Science Museum

Over the course of the 1950s, due to innovations of the gears, calculators became smaller and smaller.

These Burrough calculators were able to multiply numbers and print the results on paper immediately.

Scientific electronic pocket calculator by Hewlett PackardNEMO Science Museum

In the 1970s, more compact and fully electronic calculators emerged with a digital display. 

This model issued by Hewlett Packard in 1973 still needed to be plugged in and was intended to make scientific calculations.

Various electronic pocket calculators by UnknownNEMO Science Museum

Nowadays people mostly use their mobile phones or computers for calculations

Abacuses, mechanical and even electronic calculators are now mostly found in museums.

Credits: Story


Object of the Month – October 2021 

Each month, NEMO Science Museum spotlights one item from its collection of 19,000 special objects. These objects, which were once part of people’s everyday lives, show us how technology changes over time. 

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
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