Was there life before computer?

calculating instruments before the digital era

Download my history of the calculating instruments in pdf (English Version)


The modern world, its landscape framed by sky-scrapers and bridges, was designed with calculators conceived in the 17th century, still the youth ignore these instruments that anticipated our technology.

This is my effort to preserve their memory, through exhibits, conferences and lectures where analog and mechanical calculators can be tested by the public.

With my free e-book "Was There Life Before Computer?" and my educational material, the teachers can illustrate the old computing systems in their class.

Everard slide rule, 1663

Everard slide rule, 1663: the first one?

Einstein and Fermi used a simple slide rule, the first nuclear submarine had only an adding machine, the LEM landed on the Moon trusting on a pocket "slipstick".

Pickett 600 ES with Buzz Aldrin on the Apollo 11

The slide rule with Buzz Aldrin on the Gemini 12

The modern computer has been built on these ancient instruments that seem- ed irreplaceable:

Galileo's compass was still useful on board aircraft carriers, the calculating machines of Pascal and Leibniz were the driving force of the financial globali- zation and the slide rule, invented in 1622, served to design everything: from the James Cook's flagship to the Jumbo Jet!

Pickett 600 ES with Buzz Aldrin on the Apollo 11

Pascaline, ca. 1940: patented in 1645 and produced for over 300 years

At the time nobody could imagine a world without them, but in 1972 ...

... appeared the first modern calculator and a whole fascinating world vanished in a flash, and by 1980 was completely forgotten.

It was Leibniz's dream come true:

"It is unworthy of excellent men to lose hours like
slaves in the labor of calculation which could be
relegated to anyone else if machines were used"

A perfect foresight, the modern world has ancient roots and rediscovering these computing instruments ask yourself: what our technology will be tomorrow?

This was the world before computer, designed only with slide rules

I think it's useless to teach math without teaching how calculations were made in the past: it would be like to teach history only from 1970.

It takes just a few minutes to communicate the existence of a world before computers, a world where Man reached the Moon! With my free e-book Was There Life Before Computer? and my educational material, the teachers can after illustrate my program in their classroom.

Was there life before computer? was one of 10 educational projects that
have represented Italy at the Science on Stage Europe Festival 2013

Old Calculators & Democracy

People punch numbers into a calculator and expect the calculator to provide the correct answer, the Art of Numeracy is no longer practiced and the world before computers almost forgotten. Now students learn mathematics while being illiterate about the history of mathematics, which is a false start. With this calculator, modified to give incorrect results, I show how easy one can make and no notice errors.

The operation that appears on the display is correct? Can you detect if there is an error on the fly? Now press CA and solve these operations: 40+55+30, 234*64 or something else of your choice. Are all results right? If you like my calculator visit its page or download the software and try it.

The electronic aids should not blindly be trusted, we need to understand and criticize what we do; software could be buggy and the computer results have to be critically reviewed. In the past, with the old calculating devices, the operators were always aware of their actions and used to check the results.

Today instead many people think "I don't need to check, the computer knows better than me". Sadly, the thinking that "if an expert states it, then it must be true" is the basis of the Authority Principle, which leads to mental slavery.

Teaching the traditional calculating instruments as a school of democracy may seem an overstatement, but nobody can be a free citizen if unaware of what he does or willing to discuss it. Not by chance democracy was born in the same country in which maths and geometry were born, but uncritical use of the computer can lead people to press buttons mindlessly.

Scientific thinking and independence of ideas are not a natural product of intelligence, they must be cultivated steadily. A simple lesson about traditional calculation may help: a rational mind produces better decisions, better citizens and a better world.

We'll believe anythings (if it lets us be lazy ...) Andy Singer

"Old Calculators & Democracy"was one of 10 educational projects that
have representedItaly at the Science on Stage Europe Festival 2015

Let us remember these instruments and those who created the modern world using technology, not dependent on technology for survival. Today, instead, we often use electronic calculator as the alcoholic uses with the street lamp, to lean on not to use the light to read! Fermi and Von Braun had a slide rule less powerful than any smartphone and calculation is now within the reach of everybody, how many will be able to do better?

Welcome back to the analogic era, enjoy my website.


My bio in the International Slide Rule Museum Who's Who

Download my project presentation in English or Spanish

Download this brief and entertaining history of computing

Triumph TR4: the world's  most exciting sport car

About this site

As obvious, I carry out my project in Italy and Italian is the language that I use with students.

This translation, much smaller than the original, is just to show my programs to teachers and specialists, not to students. For teaching I use the Italian version, much more complete and with three times as many contents.

However, here you will find a summary of my text on the history of the calculating instruments and, in the end, all my educational material with its instructions for use. All my publications are distributed free of charge.

I own almost all the instruments that illustrate the various sections, expecial in the Italian part of the website, but since I have not done yet a good photo shoot of my collection, sometimes I use images downloaded from the internet. I always tried to cite the source, which is not always possible, and I would like to be promptly informed of any copyright infringement.


This work is provided under the terms of the Creative Commons license "Attribution - Noncommercial - Share Alike - 3.0 Unported".

Anyone is free to reproduce, distribute, communicate to the public, expose it or modify it under the following conditions:

  • Attribution - you must attribute the work in the manner specified by the author so as not to suggest that it endorses the way it is used.
  • Noncommercial - you can not use this work for commercial purposes.
  • Share alike - who alter or transform this work, or build upon another, it may distribute the resulting work only under a license identical to this one.

The contents were largely produced by myself but there is also material owned by third parties and another was taken in the network, apparently of public domain. In general I applied for authorization to use, which unfortunately is not always possible, and in any case is always shown on the author's name and a link to his personal website: if the name of the owner is not present must be considered the author as unknown to me.

If someone noticed that, unbeknownst to me, there is in this work copyrighted material is encouraged to communicate it, documenting the legitimacy of his rights, to webmaster@nicolamarras.it so I can properly cite the intellectual property or remove it: is my intention to apply all the rules in force on the legal protection of intellectual property.

Ensuring The Future By Preserving The Past

Nicola Marras 2008 - 2017


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