Download my history of the calculating instruments in pdf (English)
Innovative Thinking & Traditional Values
Modern world was designed with slide rule and mechanical calculator.
Still the youth ignore these instruments that anticipated our technology. I believe it's pointless to teach math without explaining how calculations were performed in the past.
With my free e-book "Was There Life Before Computer?" the teachers can effortlessly demonstrate the outdated computing systems.
To maintain the legacy of the slide rule, pascaline, and mechanical calculator, I prepared lectures and exhibits aimed at safeguarding the legacy of antique technologies.
I had also included displays on the history of communications and navigation prior to GPS.
I believe it's essential for an advanced society to preserve the memory of past technologies and the skills needed to manage them: no tree can survive without roots.
The objective is to prevent mental dependency: ignoring the traditional knowledge, people must blindly trust the new one, often overestimating the reliability of results which they are not always able to judge.
A brief history of engineering before the computer era (English)
Boring exhibits leave no trace
Following my concept of reshaping the future by transmitting the past, the exhibits took place from 2007 until 2018 at The Cagliari Festival Scienza and in London, Delft, Berlin, San Francisco, Slubice, Trento etc. My programs has represented Italy twice at the international educational fair Science on Stage.
Every event featured multimedia, and the displayed instruments, whether originals or replicas, were accessible for interactive experience. I think offering tactile experiences is essential; otherwise, the audience will opt for more convenient virtual displays.
A brief history of communications through the posters of my exhibit (Italian)
A brief history of the old navigation and the Melting Factor exhibit (Italian)
Analog & Digital Computing
The antique calculating devices can be classified into two categories: analog slide rules , which handle all scientific computations apart from addition and subtraction, and digital mechanical calculators, able to execute just the four operations.
History of mechanical calculator and slide rule (English). Hackaday`s review
The Slide Rules
In analog calculations, numerical quantities are represented by physical quantities, and the operation is simulated by analogy. The first proportional compasses, such as Galileo's, were equipped with trigonometric scales, and using them required the aid of a standard nautical compass. Highly practical for military applications, the instrument was also used by Giordano Bruno to refute Aristotle's theories.
Transformed over time into the simplified sector rule, it remained in use on ships until the end of the Second World War.
Galileo's Compass, 1597, and modern Sector Rule
The best known analog instrument is the slide rule, invented by the English cleric William Oughtred in 1632, composed of two or more sliding rulers graduated with logharitmic scales.
The sum of logarithmic measurements is, in fact, a product; with appropriate techniques, all the operations of a standard scientific calculator can be performed. The results have an accuracy of about 3 significant figures, with an error of approximately 0.2%, but the slide rule is not intuitive to operate, so please refer to the dedicated page.
This calculator, remained unchanged for 350 years, was used to design all the tecnology before computer, from the first steam machines to the engines of the Saturn-V, the lunar launch vehicle.
For astronomical calculations, logarithmic tables with precision up to 7 decimal places were used, but they were slow to use.
Earth, ca 1819: the inventor Joshua Routledge and his slide rules
Moon, 1969: the Pickett slide rule used in the Apollo program
The Mechanical Calculators
Mechanical digital calculators, the first was invented by Blaise Pascal in 1645, are unable to execute complex calculations and were utilized for accounting tasks.
There are various typologies, divided into sub-categories based on their operating principle.
The concept of a binary calculator was hypothesized by Leibniz in the 17th century. It was realized only 250 years later, but the seed had been planted and modern computers derive from his intuition.
Mechanical calculator: very similar the models of 1645, 1945 and 1975
Pocket adding machines: 1670 - 1890 - 1980
The calculators of Leibniz, 1672 and Odhner, 1895
Comptometer, 1887 and Olvetti Divisumma, 1971
The End of an Era
It was difficult to imagine a world without them, yet in 1972, the arrival of the first modern calculator led to the rapid disappearance of slide rules and mechanical calculators. Leibniz's long-held aspiration materialized:
"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"
The shift occurred quickly but was not without challenges, and in the 80s educators still banned electronic calculators in the classroom, claiming they numbed the intellect.
Washington, 1980s: teachers' protest against the use of calculators
Nowadays, used to constant updates, it is hard to grasp this reluctance to change. New electronic devices were not fully trusted, and numerous manufacturers added a traditional tool alongside the new calculators to ensure they worked properly
Faber TR3 calculator with a sliderule on the back, 1975
By this time, though, the emerging technologies demanded greater computing power, leading Sharp to introduce the first mini computer: the PC era was born.
In 1979, Sharp still kept the verification abacus, but...
...in 1982 it was able to present the pocket computer!
Was there life before computer? educational project has
represented Italy at the Science on Stage Europe Festival 2013
Innovative thinking & traditional values
Nowadays people punch numbers into a keyboard and expect the calculator to provide the correct answer. The Art of Numeracy is no longer practiced and the world before computers almost forgotten.
Mathematics is currently learned without knowledge of its history, a false start. With a calculator, modified to give incorrect results, I demonstrate how easy a student can make errors withoute notice.
Is the operation shown accurate? Check if the result is correct
Electronic should not be unconditionally trusted, we must comprehend and evaluate our actions. Software might contain bugs and the results need to be carefully analyzed.
Previously, with the traditional calculating devices, the operators remained conscious of their actions and routinely verified the outcomes.
Nowadays, numerous individuals believe, "I don't have to verify, the computer understands better than I do". Unfortunately, the belief that "if an expert says it, it has to be true" is the foundation of the Authority Principle, resulting in psychological enslavement.
We'll believe anythings (if it lets us be lazy ...) @ Andy Singer
Promoting the traditional calculating methods as a mean of democracy might seems overstated, but it is impossible to live as a free citizen if we are unaware of our actions or reclutant to discuss them.
It's no coincidence that democracy originated in the same nation where mathematics and geometry emerged: unthinking use of the computer can result in pressing 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.
Let us remember these instruments and those who created the modern world using technology, not depending on it for survival. Today, instead, we often use the electronic aids as a drunk man relies on lamp posts: for support rather than illumination.
Didactics: teach → inspire → delight
Our emblem Dried Roots Do Not Bear Fruits and an exposition table
Little ones are intrigued: if Tom Cat does it, they can do it too!
Best staff = best show!
Download the templates of: E6B, slide rule, nomograms, abaques (English)
About Me
We, the collectors
The power of objects regulates our lives in this faltering era, they become the consolation capable of absorbing all our anxieties about time and death: some thoughts on owning and collecting.
The collectors`nightmare: possessed by possessions! (English)
Essential Library
For those who want to approach the world of analogue calculations, there is nothing better to read than Collecting Slide Rules and All About Slide Rules, both free by the Oughtred Society.
At the International Slide Rule Museum we find a library, where numerous texts and instructions can be downloaded for free. An excellent slide rule seminar is also available at the ISRM.
The Oughtred Society'sannual meetings serve as a key gathering for enthusiasts in the field.
The proceedings, which compile the latest research, can be downloaded from Lovett's website.
To obtain the edition from the 2016 meeting, hosted by Dr. Wolfgang Irler and myself in Trent, click on the cover or visit the dedicated page.
Links
David`s Calculating Sticks - Slide Rule Shop - Nathan Zeldes - Rod`s Slide Rules
© 2004 - 2026 Nicola Marras Manfredi - IS1EH
