The world’s first mechanical calculator, the Pascaline: ‘This is much more than a machine. It embodies an entire chapter of human history’

A widower and father of three, Etienne Pascal quit Paris to settle in the city of Rouen early in 1640. He took up a job as president of Normandy’s Cour des Aides (Board of Excise).

His middle child — a son called Blaise — was struck by the plethora of calculations Etienne had to do when it came to accounting and tax assessment tasks. Blaise wondered if such labour might be relieved by some sort of mechanical device.

Aged 19, he set to work on what has come to be known as the ‘Pascaline’: the world’s first mechanical calculator. Its invention was nothing short of a scientific and technical revolution. Only eight original versions survive, seven of which are held in European museums.

The sole Pascaline in private hands is about to be offered at auction for the first time, in the De la collection Léon Parcé sale on 19 November 2025 at Christie’s in Paris.

Blaise Pascal — a man described by the writer-diplomat François-René de Chateaubriand as an effrayant génie (‘scary genius’) — was born in 1623. He lost his mother aged three, and suffered chronic ill-health throughout his life, some say as a result of contracting tuberculosis in early childhood. His physical struggles, however, were more than offset by his intellectual gifts.

Etienne took personal charge of his offspring’s education (Blaise had two sisters: one older, one younger). The boy was a prodigy, so advanced in physics and mathematics that his father started inviting him to the weekly meetings of the Academia Parisiensis when he was barely a teen. Centred on the polymath Marin Mersenne, this was an informal Parisian circle of scientific and mathematical thinkers, to which Etienne belonged.

At 16, Blaise wrote a highly regarded essay on conics — shortly before the Pascal family moved to Rouen, the capital of Normandy. That region had borne something of the brunt of recent tax rises nationwide, resulting in several revolts, which prompted the secondment there of government officials such as Etienne.

It was in this context that Blaise conceived the Pascaline, in 1642. Aimed principally at lightening his father’s professional load, the invention ended up having far greater significance. For the first time in history, arithmetic went from being a mental activity to a mechanical one.

The abacus had been around since ancient times, but the Pascaline marked a quantum leap: a machine unprecedentedly taking on a job that had hitherto been the task of human reasoning alone.

As Pascal himself put it in a message to prospective buyers: ‘I’m presenting… a small machine of my invention, by means of which you… will be able, without any effort, to perform all the operations of arithmetic, and relieve yourself of the labour that has often wearied your mind when you’ve worked with counters or with the pen.’

Pascal wrote this in a text called Necessary Advice to Those Who Are Curious to See the Said Machine and Use It, which was published in 1645 — the year he completed his first Pascaline. The text served, in part, as a piece of promotional marketing, Pascal having come to realise that his tabletop device might have widespread appeal — and money-making potential. It was, he added, ‘easy, simple, quick and reliable’ to use.

The design of the device, by contrast, was complex, and involved expertise in a combination of physics, mechanics and geometry. Essentially, the Pascaline consisted of an adjacent set of spoked wheels, which turned in connection with a system of gears and springs beneath the surface. The wheels’ movement effected the performance of calculations, whose results were revealed as numbers in a row of windows.

Pascal offered one of his initial devices to Pierre Séguier, the chancellor of France under Louis XIV — a canny move, as one assumes Séguier played no little part in Pascal’s receipt of a royal patent for his machine in 1649, guarding against the activity of potential counterfeiters.

The Pascaline coming to auction appears to have been built some time after he had received that patent, as it is punch-marked with a fleur-de-lis, the symbol of France’s monarchy.

Research suggests that around 20 devices were built. These came in three different types. One was the ‘decimal machine’ (intended for straightforward, base-10 calculations), two examples of which survive.

Another type of Pascaline was the ‘accounting machine’ (intended for monetary calculations, in the currency units of deniers, sous and livres). This type would have been of specific use to Etienne, and five examples survive.

The Pascaline coming to Christie’s is the sole remaining example of the third variant: the ‘surveying machine’. This was designed to perform calculations of distance, in the pre-metric measurement units of lignes, inches, feet and toises. Pascal envisaged that architects would be among its main users.

The machine is composed of two wheels with 12 spokes on each, one wheel with six spokes, and five wheels with 10 spokes. (This is because 12 lignes make one inch, 12 inches make one foot, and six feet make one toise — with the toise count becoming decimal thereafter.)

The early history of the Pascaline being offered is not clear. It was likely made at the start of the 1650s, given that Pascal stopped building his devices around the middle of that decade. They proved expensive to produce — and at a price of 100 livres each, weren’t destined to attract a mass market.

Upon her death in 1733, Pascal’s niece, Marguerite Périer, bequeathed two or three Pascalines in her possession to the Oratory of Clermont (a religious order based in the central French city of Clermont-Ferrand) — and it’s possible that the example coming to Christie’s was one of those.

This possibility is supported by two facts. The oratory’s property is known to have been nationalised and sold off during the French Revolution. What’s more, the device for sale is known to have been acquired by Léon Parcé in 1942, from an antiquarian dealer who himself had bought it in Varennes-sur-Allier, a town 50 miles north of Clermont-Ferrand.

Parcé was a Catalan bibliophile, whose marvellous book collection is being offered — along with his Pascaline — in the De la collection Léon Parcé sale. It contains a number of works by Pascal, whose writings across a range of topics, from mathematics and physics to philosophy and theology, he greatly admired.

Among the standout lots is the earliest known copy of the Frenchman’s landmark book, Pensées. Written in the period shortly before his death (childless, aged 39, in 1662), and published posthumously, it comprises a collection of Pascal’s notes offering an apologia for the Christian faith. Included within is his now-famous argument for believing in God: Pascal’s Wager.

His was a career of stunning achievements, from establishing a key principle of hydraulics, and laying the foundations of probability theory, to devising a five-route coach service through Paris (arguably the world’s first public transportation system).

According to James A. Connor, writing in his 2006 biography, Pascal’s Wager, ‘you cannot walk 10 feet in the 21st century without running into something that Pascal didn’t affect in one way or another’.

In the specific case of the Pascaline, despite being a failure commercially, it was a tremendous triumph otherwise. In introducing the concept of automated calculation, it was a direct precursor to the modern computer. With the transfer to a machine of activities previously carried out only in the human mind, the device also resonates in today’s debates over artificial intelligence.

The impact of the Pascaline is all but impossible to calculate.

The Pascaline will be on view 13-18 November 2025 before the De la collection Léon Parcé sale on 19 November at Christie’s in Paris. On 18 November, an Enigma cipher machine will be offered in The Exceptional Sale in Paris