Alois Salcher

A lazy man is the devil’s handyman.
Austrian proverb

At the beginning of the 20th century, the Austrian engineer and businessman from Innsbruck Alois Salcher devised and put into production a very interesting calculating machine. Despite its original construction, the machine was never much of a success, and it is rare today. The known serial numbers indicate a production run of about 400 machines, and despite production being stopped since 1908, it was still advertised and sold by the end of 1910.

The Adsumudi of Alois Salcher
The Adsumudi calculating machine of Alois Salcher

Salcher got patents for his calculating machine, the so-called ADSUMUDI (after ADdition, SUbtraction, MUltiplication, DIvision), in several countries—Austria (patent AT35115 from 16 Sep 1906), Germany (DE204333 and DE209009), Great Britain (GB190623173 and GB190906657), France (FR370829), and the United States (US974006). Two of the patents Salcher shared with Nikolaus Werle, a merchant from Stuttgart. Some patents (e.g. the American one) are for an improved machine, in which the entire principle of operation has been changed, and that has obviously never been manufactured. ADSUMUDI was produced in Germany by the machine factory of Carl Werner of Villingen (the factory had a branch in Innsbruck), one of the largest watch manufacturers in Germany.  It was a messing device with dimensions 39x30x12 cm, and a weight of 10.8 kg.

The operating principle of this 10-positional calculating machine is quite different from any other mechanical calculator ever manufactured. To move the gears with the result wheels attached to them, it has rectangular plates with a slot in the middle and a gear rack on either side of the slot. Depending on which way the result register moves, the gear engages with the rack on the left or the right of the slot, thus reversing the direction of the result register from addition to subtraction and vice versa. The racks are connected to the spring-loaded setting levers so as soon as they are released, they re-zero themselves and transfer their value to the result. All the rest of the complicated mechanism is designed to engage and disengage the correct side of the rack with the result at the correct time, and to make sure the result register is locked when it is not in engagement with the racks.

Biography of Alois Salcher

Alois Salcher was an engineer and businessman from Innsbruck, Tyrol. He was the owner of Innsbrucker Dampf-Teigwarenfabrik (pasta factory), had a machine workshop, and was engaged in the real estate business. Salcher was a fan of technical novelties and in 1896 he demonstrated the first automobile in Innsbruck.

Alois Salcher married Emilie Hruschka (1870-1930), the daughter of the local dentist Josef Hruschka (1843-1913). The Hruschka family, originally from Moravia, was a famous Austrian family of dentists, and Emilie Hruschka became the first female dentist in Tyrol and Austria. Alois and Emilie had two sons—Alois and Hubert (born 1 Jan 1905), who became doctors and Nazi party members and served in the army during WWII.

Besides the above-mentioned patents for calculating machines, Salcher has one more patent—for Bundle seals for barrels (pat. №DE100118 from 1897).

Josef Uržidil

Pečení holubi nelítají do pusy—Baked pigeons don’t fly into your mouth.
Czech proverb

The patent drawing of Additionsmaschine of Josef Uržidil (DE70752)
The patent drawing of the Additionsmaschine of Josef Uržidil (DE70752)

On 5 February 1893, Josef Uržidil (1854-1922), a railway engineer from Žižkov, a small town in the vicinity of Prague, Austro-Hungarian Empire, received a German patent Nr. 70752 (see DE70752) for Additionsmaschine. The adding machine of Uržidil was a key-operated device with a calculating disc. Besides the granted patent, nothing is known about this device, so most probably it remained only on paper, nevertheless let’s examine the adding machine of Josef Uržidil, using the patent application.

The subject of the invention is an addition machine that is suitable for adding a large number of single-digit numbers. Essentially, this machine consists of a toothed wheel R (see the nearby patent drawing), driven by a spiral spring F, which is held by a pawl i and only rotated when one of the pushbuttons marked with numbers is pressed, the associated pressure lever a connected to this forming a frame b, on which the pawl i is attached, depresses, with which the spiral spring F driving the gear R comes into effect and moves the wheel. A lever e plugged onto pin c through a sleeve d, which can also be rotated about the pin f in the vertical direction, and which has an opening g on the end facing frame b, through which the frame b associated bent rod h is inserted, serves to stop the gear R. It is namely when pressing down the frame b, the lever e is pressed into the teeth of the wheel R, which also takes part in the movement of the wheel. But now this lever e strikes the depressed pressure lever and stops the gear wheel R.

If the pressure lever in question is released, the pawl first jumps into the teeth of the wheel R, and the changed position of the wheel is thus fixed. At the same moment, the lever e comes out of the teeth of the wheel R and is driven back by a leaf spring j mounted on the dial in the direction of arrow 1 (Fig. 2), until it strikes a screw k located in the frame b and is stopped there.

All pressure levers a, each of which only belongs to one digit, can be rotated about the pin l, which forms the pin of the lever; the pushbuttons 1, 2, 3,… (see Fig. 7), which are denoted by the first nine digits, protrude from the upper cover plate m (Fig. 1 and 2) and are screwed into these levers. On the lower side of each pressure lever, a leaf spring n is screwed, which has the purpose of snapping the depressed pressure lever back into its original position when the pressure on the button ceases, these levers being held by a fixed plate 0.

The frame b (see Fig. 5) can be rotated about the pin p and is pressed by the leaf springs qq against the adjusting screws introduced in plate 0 (Fig. 2). The pawl i (see Fig. 4 on an enlarged scale) can be rotated about the pin s in the direction of the arrow. The rotation in the other direction is prevented by an attachment t belonging to the frame b, against which a leaf spring u of the pawl also presses.

Biography of Josef Uržidil

Josef Uržidil and his wife Elise
Josef Uržidil (1854-1922) and his wife Elise (1854-1900)

Josef Uržidil was born on 7 January 1854, in the village of Šipín, part of Konstantinovy Lázně in the Tachov District of Plzeň Region (or in Ošelín, Stříbro), to a German-Bohemian family. His father, Johann Nepomuk Uržidil (1813–1894) was a rural teacher in West Bohemia, who eventually worked as a head teacher in Bor u Tachov, and also wrote textbooks on arithmetic, national studies, and grammar, played the organ and the violin. His mother Barbara Heinl (1814–1900) from Weseritz (Bezdružice), a town in the Tachov District in the Plzeň Region, was born to a German-speaking Czech family. Joseph was named after his paternal grandfather Josef, who was a farmer in Holýšov, while his other grandfather Wenzel Heinl, the father of his mother Barbara, was a surgeon and worked as a doctor and obstetrician in Bezdružice.

Josef Uržidil, his wife Elise and his son Johannes, Prague, 1897
Josef, Elise and Johannes Uržidil, Prague, 1897

In 1895 Josef Uržidil married in Prague to Elisabeth (Elise, Elsa) Metzelesová, a widow of Jewish origin (born 1854 in Prague, she was previously married to Bernhard Steinitz (1850–1892), a merchant and half-brother of the great chess master Wilhelm Steinitz), who from the first marriage had already brought seven children. Their only common son, Johann Nepomuk Josef Adolf, was born on 3 February 1896, in their apartment at Krakovská Street No. 30/3 (Prague II). Johann (Johannes) Uržidil (see the nearby photo from 1897) became a famous German-Bohemian writer, poet, and historian. Elise died on 7 January 1900. On 29 May 1904, Josef married for the second time, to Marie-Anna Mostbeck(ová), a Czech from Nymburk (b. 1864).

Josef Uržidil was an engineer, who worked many years as a clerk and senior inspector of State Railways of West Bohemia and Prague.

In the spring of 1922, Josef’s son Johannes ​​bought a house for his father in Bezdružice near Konstantinovy ​​Lázní, the home district of Josef. On 24 December 1922, Josef Uržidil died there.

Caroline Saruba

An intelligent woman is a woman with whom one can be as stupid as one wants.
Paul Valéry

The adding device of Saruba/Habereder
The adding device of Saruba/Habereder from 1880 (© Dorotheum auction house)

On 22 October 1880, one Caroline Sarúba from Vienna received an Austrian patent Nr. AT4264 (see the patent drawing below) for Calculateur Kolonnen-Addierstift (adding pencil). The machine was put into production by company F. Habereder & Co. of Ferdinand Habereder in Vienna, Griesgasse 26. The adding device of Saruba/Habereder is similar to the earlier Instrument for adding and registering numbers of Charles Corliss from 1868, Adding Pencils of Marshall Smith (patents US175775 and US180949) and John White (US177775) from 1876, and Addirstift of Oskar Leuner from 1877.

The Calculateur of Saruba/Habereder was a portable spiral adder (length 24 cm) with a capacity of up to 329. The input mechanism is based on a (quite a big) wheel. It seems the device was produced in a small series because only several examples survived to the present time (see the nearby picture of an example, sold by Dorotheum auction house in 2017).

The drawing of Austrian patent Nr. AT4264 of Caroline Sarúba
Austrian patent Nr. AT4264 of Caroline Sarúba

We don’t know anything about the inventor of this calculating device—Caroline Sarúba. She certainly used to work for Ferdinand Habereder because there is another patent granted to Caroline Sarúba in Firma Habereder and Co. in Wien—it is German patent №11427 from 1 Feb 1880 for Kaffeemaschine, which was advertised and put into production in the early 1880s.

Jewrem Ugritschitsch

Be humble for you are made of earth. Be noble for you are made of stars.
Serbian proverb

The German businessman and inventor of Serbian origin Jewrem Ugritschitsch (also known as Jevrem Ugrich) was involved in designing, manufacturing, and selling calculating devices for many years. It seems he started in the middle 1890s because his first patent for Additions- und Multiplikationsmashine is from 10 June 1897 (see German patent Nr.99644). Later Ugrich received quite of few other patents for calculating devices and other machines.

German patent Nr.99644 of Jewrem Ugritschitsch
German patent Nr.99644 of Jewrem Ugritschitsch

The first calculating machine of Ugrich (see the nearby patent drawing) was an addition and multiplication machine with a series of partially overlapping number disks with corresponding cutouts. It is similar to the earlier calculators of David Roth, Chaim Slonimski, and John Groesbeck.

The disks of Ugrich’s adding machine overlap: the left one is above the right one so that the disk with the highest point on the far left is clearly raised and this calculator has a comparatively high overall height. Each disc has 2×10 input positions and display numbers. The tens carry is carried out alternately by one of the two pins located on each disc. When the number 9 is exceeded or when the tens are carried over, this engages in the sloping webs attached to the underside of the next disc (see Fig. 3 in Fig. 2) and thereby rotates this next disc by 18° or one position further. With such a direct, simultaneous transfer, such large rotation angle losses arise over several points that it would certainly not have been possible to implement it with more than the 4 digital wheels as shown in the patent.

The adding devices of Ugrich and Hauff - Upper left: Revisor 1902 (©Arithmeum, Bonn); Upper middle: Rechenmedium 1904 (© Norwegian Museum of Science and Technology); Upper right: Autorechner-Union 1905; Lower left: Maxima 1909; Lower middle: Optima 1910; Lower right: RSB Universal 1910 (Image credit: Wilfried Denz, Münster)
The adding devices of Ugrich and Hauff – Upper left: Revisor 1902 (©Arithmeum, Bonn); Upper middle: Rechenmedium 1904 (© Norwegian Museum of Science and Technology); Upper right: Autorechner-Union 1905; Lower left: Maxima 1909; Lower middle: Optima 1910; Lower right: RSB Universal 1910 (Image credit: Wilfried Denz, Münster)

At the beginning of the 20th century, Ugrich designed, patented, and later put into production, several variants of a disk column-adding device (see some of them in the nearby image). These devices were manufactured and sold from 1902/03 and offered until at least 1921 mainly by Ugrich and Dr. Albert Hauff from Berlin, but also by other people and companies. In his initial design Ugrich may have been inspired by Carl Brunner’s patent for a “counting wheel with a spiral” (see patent DE69309 valid from 23 July 1892).

The first variant of Ugrich’s calculator, the model Revisor, is placed on the left hand with the thumb in a ring and the 4 fingers in the grip groove on the input field. Then one can add or subtract single-digit numbers from 1 to 9 in the input area for column addition. The pointer in the slot moves continuously along the spiral path until it reaches the next hundred value with one full revolution. The numerical value of the result up to 99 can be read in the display window at the outer end of the slot. The device is very simple and cheap to make, it only cost 3 marks, about a day’s wages. It consists of only 11 individual parts: 3 punched sheets (2 of which are formed), a sliding slider, a thumb ring with its holder, and 5 rivets. According to advertising, one can enter 10000 items in an hour or 7 numbers in 1 second, quite a brisk operator 🙂 One can also add numbers of any size. This applies to all column adders if you remember or write down the intermediate results of each column to be added and (after deleting the result display) continue the calculation with the next column.

The first patent (in fact, it was a Gebrauchsmuster, German utility model, a patent-like, intellectual property right protecting inventions), DRGM 172544 for his spiral adder Ugrich got on 23 April 1902, for an “adding apparatus with a disc containing a number scale and adjusting a slide indicating the ‘hundreds’ when it rotates.” Later he registered several other improved devices: DRGM 257529 from 16.08.1905, DRGM 269765 from 14.02.1906, DRGM 341153 from 11.06.1908, DRGM 439699 from 09.11.1910, DRGM 452861 from 01.03.1911, DRGM 473847 from 09.08.1911. In 1913 Ugrich patented (DRGM 540480 from 12.02.1913) a key-operated calculator—a small calculating machine with a series of number disks, which are connected by shafts to the buttons, each with ten holes and a pointer. Variants of the spiral adder of Ugrich were made and sold in France, England, Sweden, Russia, Austria, and Norway, and got several gold medals at exhibitions.

Biography of Jewrem Ugritschitsch

Jewrem Ugritschitsch was born as Јеврем Угричић on 12 May 1867 in Belgrade, Serbia. He was the elder son of the civil engineer Dragoljub Ugritschitsch (Драгољуб Јевта Угричић) and his wife Anna Mikhailovich (they had two sons—Јеврем and Јевта, and two daughters—Милица and Ружа). Anna Ugritschitsch, born in 1852, died 6 September 1901 in Berlin and was buried in the Tegel Orthodox cemetery, was probably his mother. Ugritschitsch was a prominent family from Smederevo, as Dragoljub was the eldest son of Јевтимије Угричић (1800-1886)—a famous Serbian magistrate and politician from the middle 19th century.

We don’t know when Jewrem Ugritschitsch moved to Germany, but it must have been early in his life because, in his first patent application of June 1897, he is specified as Dr. Jewrem Ugritschitsch in Charlottenburg. We don’t have information on what kind of doctorate he had. In  1903 Ugritschitsch changed his last name to Ugrich “through ministerial name change approval.” At the same time, he started his own business for manufacturing and selling calculating machines. Ugrich also tried his hand as an inventor and model maker with the “mechanical workshop of J. Ugrich” from at least 1905 to 1910. His entries in the Berlin address books from 1905 to 1909 contain the keywords “Patented Novelties”, “New Products Sales” and “Patented Novelties and Calculating Machines”. It seems Ugrich abandoned this venture in the late 1910s because in 1919 his occupation was specified as “merchant”.

Ugrich married the teacher Luise Helene Minna Margarete Wernaer (born on 1 December 1884 in Berlin) on 21 December 1904. They have one son, Robert, and two daughters (one of them was Heidi Anna Minna, who was born on 13 July 1905).

Besides the above-mentioned patents and utility models related to calculating machines, Ugrich had also: DRGM 225862 dated 15 June 1904 for a Polishing apparatus with two bowls; Patent DE203850 from 14 October 1908 for a Device for folding sheets of paper using two plates. In addition, Ugrich advertised his duplicating machine Ugrograph or AHA from 1911.

Around 1920 Ugrich moved with his family to his home country, Serbia, where he was appointed as a judge. Because of a serious illness (cancer or stomach ulcer), he committed suicide around 1930 in the desire to ease the burden of care for his family.

Emile Grandjean

The difficult is what takes a little time. The impossible is what takes a little longer.
Fridtjof Nansen

On 2 February 1864, Emile Grandjean, a French watchmaker (horlogère) from Fumay (Ardennes), received a 15-year patent (see French patent N°61637) for an adding machine, called Additionneur Grandjean. The Scottish pastor Brown’s Rotula Arithmetica from the 1690s can be seen as the archetype of all of these concentric toothed-disk-adding devices. Besides the patent application, nothing is known about Additionneur Grandjean, so most probably it remained only on paper, but its principle was implemented several decades later in quite a few simple adding devices like French l’Infaillible, German Revisor, Union, Optima, Maxima, Duplo, and Triplo by Jewrem Ugritschitsch and Dr. Albert Hauff from Berlin, English Adal, and others. Let’s examine one of the Grandjean-like devices—the Adal Calculator.

The Adal Calculator of Adal Company, Birmingham, 1910
The Adal Calculator of Adal Company, Birmingham, 1910

The spiral mechanical calculator, called Adal Calculator, was produced in the early 20th century (1907-1915) by Adal Company, Temple Courts, Birmingham (ADAL is formed from the first letters of the names of the company owners—Armand Dreyfus and Alfred Levy, German Jews, who lived in England). It is a single-row adding machine with a diameter of 197 mm, 5 mm thick, 117 gr. weight, which consists of a pair of metal disks and a cursor. The base is a flat aluminum disk with the numbers 00 to 99 around an outer ring which forms a lip. Concentric with this disk, and laid upon it, is a thin brass disk which has one hundred small semi-circular indents and the numbers 00 to 99 in a ring around it. The main part of the upper disk is formed into a spiral of 11 turns. There is a tongue of brass attached to the central bolt, that has a slot in which a steel ball slides as it accumulates turns of the spiral disk. The slot of the tongue has the numbers 1 to 11 marked on it at intervals equivalent to the step between adjacent turns of the spiral. At its further end is a small clamp that holds it at the zero point of the outer ring so that it acts as a stop for the rotation of the accumulating spiral disk.

The whole calculator is held in the flat of the hand. It is a simple adder to 1199 with addends 1-99. The spiral disk is turned by a stylus set into the indent of the number to be added until it reaches the stop. As each number is added the spiral disk rotates and the small steel ball slides in the slot in the tongue indicating the hundreds count of the accumulated result. The total result is thus the number indicated on the tongue (being the hundreds digit) plus the number indicated in the end gap of the stop.

The Adal Calculator was patented in Great Britain (patents GB190705779 and GB190900621), the USA, and Canada (see the first US patent). It seems Dreyfus and Levy bought the rights for the design from Ugritschitsch and were allowed to serve the English and American markets. In 1909, the Addall Co. was incorporated in New York to manufacture the calculating machine.

Eric Arthur Johnson – touch screen

For every problem there is a solution that is simple, clean, and wrong.
Henry Louis Mencken

The touchscreen of Eric Arthur Johnson
The touchscreen of Eric Arthur Johnson

The concept of the finger-driven touchscreen interface was put into words in 1965, by the British engineer Eric Arthur Johnson. He worked at the Royal Radar Establishment in Malvern, England, and was interested in developing a touchscreen for air traffic control, as the UK National Air Defense was in need of a solution that would accelerate response time, minimize workloads, and allow for more accurate decision making for air traffic control operators.

In August 1965 Eric Johnson filed his first patent application, which was amended in 1966, and the complete specification was published on 26 November 1969 (see GB patent No. 1172222). In 1969 Johnson received also a US patent for his invention (see US patent Nr. 3482241).

Eric Arthur Johnson and his touchscreen
Eric Arthur Johnson and his touchscreen in 1965

In October 1965 Johnson described his ideas for a capacitive Touch Sensitive Electronic Data Display in a short 2-page article (Touch Display—A novel input/output device for computers. Electronics Letters, 1(8), 219-220). In 1967, he published another more comprehensive paper on the topic (Touch Displays: A Programmed Man-Machine Interface. Ergonomics, 10(2), 271-277), explaining how the technology worked through diagrams and photographs of a prototype. He also foresaw that the design could work as a keyboard for entering characters.

The touchscreen of Johnson was a device that used wires, sensitive to fingers’ touches, on the face of a cathode-ray tube (CRT) on which the computer could write information. His design consisted of a glass-coated insulator with a transparent conductor made of indium tin oxide. Thin copper wires placed across a computer’s CRT allowed the circuits to sense when they were being touched. Interestingly, although Johnson published the idea in the middle 1960s, it wasn’t made a reality or used by British air traffic controllers until the 1990s.

Bent Stumpe with one the first touch screens developed in 1973
Bent Stumpe with one the first touch screens in 1973

The next step was made in early 1972, by a Danish engineer working in CERN, Bent Stumpe (born 1938). He was asked by Frank Beck, who was in charge of the central control hub in the Super Proton Synchrotron, SPS, control room, to build the hardware for an intelligent system that, in just three console units, would replace all those conventional buttons, switches, etc.

In March 1972, after a few days, Stumpe presented a hand-written proposal to build a touch screen with a fixed number of programmable buttons. It also uses a tracker ball as a computer-controlled pointing device—something like a mouse—and a programmable knob.

“We had very little time to design the new system and demonstrate that both the hardware and the software could really work”, recollected Bent Stumpe. “Thanks to Chick Nichols from the CERN EP workshop, it was possible to evaporate a very thin layer of copper on a flexible and transparent Mylar sheet. This allowed us to produce the very first prototype of a capacitive touch screen.”

The first touchscreens, developed by Bent Stumpe, were installed in CERN in 1973 and remained in operation until 2008.

Christopher Strachey

It is impossible to foresee the consequences of being clever.
Christopher Strachey

Christopher Strachey (1916–1975)
Christopher Strachey (1916–1975)

Christopher Strachey (1916–1975) was a British computer scientist, one of the founders of denotational semantics, and a pioneer in programming language design and computer time-sharing, also been credited as possibly being the first developer of a video game.

Strachey was born to a prominent English family. Stracheys belonged to the Bloomsbury Group whose members included Virginia Woolf, John Maynard Keynes, and Christopher’s uncle Lytton Strachey. At 13, Christopher went to Gresham’s School in Norfolk, where he showed signs of brilliance but in general, performed poorly. Then in 1935, he was admitted to King’s College, Cambridge (just as Alan Turing), where he studied mathematics and then transferred to physics, but continued to neglect his studies. At the end of his third year at Cambridge, Christopher suffered a nervous breakdown, possibly related to coming to terms with his homosexuality. He returned to Cambridge but managed only a “lower second” in the Natural Sciences Tripos.

In 1940, Strachey joined Standard Telephones and Cables (STC) as a research physicist, where he saw a calculating machine—a differential analyzer, which sparked his interest and he began to research the topic. After the war, he became a schoolmaster at St Edmund’s School, Canterbury, and three years later he was able to move to the more prestigious Harrow School in 1949, where he stayed for three years.

Strachey's Draughts on a storage CRT, 1952
Strachey’s Draughts on a storage CRT, 1952

In early 1951, Strachey began his career as a programmer, using a reduced version of Turing’s Automatic Computing Engine (ACE) the concept of which dated from 1945: the Pilot ACE. In his spare time, Strachey developed a program for the game of draughts (also known as “checkers”), which he finished a preliminary version in May 1951. The game completely exhausted the Pilot ACE’s memory. The draughts program tried to run for the first time on 30 July 1951 but was unsuccessful due to program errors. When Strachey heard about the Manchester Mark 1, which had a much bigger memory, he asked his former fellow student Alan Turing for the manual and transcribed his program into the operation codes of that machine by October 1951. By the summer of 1952, the program could “play a complete game of Draughts at a reasonable speed”. It may have been the first video game.

In 1951 Strachey programmed the first computer music in England and the earliest recording of music played by a computer—a rendition of the British National Anthem “God Save the King” on the Ferranti Mark 1 computer. During the summer of 1952, Strachey programmed a love letter generator for the Ferranti Mark 1 which is known as the first example of computer-generated literature.

In 1959 Strachey developed the concept of time-sharing, and filed a patent application in February of that year, and gave a paper “Time Sharing in Large Fast Computers” at the inaugural UNESCO Information Processing Conference in Paris where he passed the concept on to Joseph Licklider.

Joshua Lederberg

The most disastrous thing that you can ever learn is your first programming language.
Alan Kay

Joshua Lederberg in 1962
Joshua Lederberg in 1962

In the early 1960s, the biologist Joshua Lederberg (1925-2008), a 1958 Nobel Prize laureate for his discoveries of genetic transfer in bacteria, started working with computers. Over the summer of 1962, he learned to program on BALGOL (Burroughs Algol) for the Burroughs 220 computer (a 1957 vacuum-tube computer with core memory) and quickly succumbed to the hacker syndrome. Lederberg soon became tremendously interested in creating interactive computers to help him in his exobiology research. Specifically, he was interested in designing computing systems to help him study alien organic compounds.

As he was not an expert in either chemistry or computer programming, Lederberg collaborated with two other prominent Jewish-American scientists from Stanford—chemistry professor Carl Djerassi (1923-2015) to help him with chemistry, and the chairman of Stanford computer science department Edward Feigenbaum (b. 1936) with programming, to automate the process of determining chemical structures from raw mass spectrometry data. Feigenbaum was an expert in programming languages and heuristics (in the late 1950s he developed EPAM, one of the first computer models of how people learn) and helped Lederberg design a system that replicated the way Djerassi solved structure elucidation problems. They devised a system called DENDRitic ALgorithm (Dendral) that was able to generate possible chemical structures corresponding to the mass spectrometry data as an output.

The DENDRAL team in 1991. From left to right: Bruce G. Buchanan, Georgia L. Sutherland, Edward A. Feigenbaum, Joshua Lederberg, and Dennis Smith.
The DENDRAL team in 1991. From left to right: Bruce G. Buchanan, Georgia L. Sutherland, Edward A. Feigenbaum, Joshua Lederberg, and Dennis Smith.

DENDRAL (see a historical note), the first expert system in the world, was written in the Lisp programming language of John McCarthy, which was considered the language of artificial intelligence (AI) because of its flexibility. DENDRAL ran on a computer system called ACME (Advanced Computer for Medical Research), installed at Stanford Medical School in 1965 for use by resident researchers through time-sharing.

The project consisted of research on two main programs Heuristic Dendral (see the description) and Meta-Dendral, and several sub-programs. Heuristic Dendral is a performance system and Meta-Dendral is a learning system. The initial program was coded by the programist Georgia Sutherland, but later the Dendral team recruited Bruce Buchanan to extend the system. Buchanan wanted Dendral to make discoveries on its own, not just help humans make them. Thus he, Lederberg, and Feigenbaum designed “Meta-Dendral”, which was a “hypothesis maker”.

The greatest significance of DENDRAL lies in its theoretical and scientific contribution to the development of knowledge-based computer systems. Many later expert systems were derived from Dendral, including SUMEX, MYCIN, MOLGEN, PROSPECTOR, XCON, and STEAMER.

Gordon Pask

It seems to me that the notion of machine that was current in the course of the Industrial Revolution—and which we might have inherited—is a notion, essentially, of a machine without goal, it had no goal ‘of’, it had a goal ‘for’. And this gradually developed into the notion of machines with goals ‘of’, like thermostats, which I might begin to object to because they might compete with me. Now we’ve got the notion of a machine with an underspecified goal, the system that evolves. This is a new notion, nothing like the notion of machines that was current in the Industrial Revolution, absolutely nothing like it. It is, if you like, a much more biological notion, maybe I’m wrong to call such a thing a machine; I gave that label to it because I like to realize things as artifacts, but you might not call the system a machine, you might call it something else.
Gordon Pask

Gordon Pask (1928-1996)
Gordon Pask (1928-1996)

At the beginning of 1956, two young Cambridge scientists, the psychologist Gordon Pask (1928-1996) and physicist Robin McKinnon-Wood (1931-1995), created a hybrid teaching and learning analog computer, in response to a request by the Solartron Electronic Group for a machine to exhibit at the Physical Society Exhibition in London.

Gordon Pask was an English scientist, designer, researcher, academic, playwright, and one of the early proponents and practitioners of cybernetics, the study of control and communication in goal-driven systems of animals and machines. Originally trained as a mining engineer, he went on to complete his doctorate in psychology. His particular contribution was a formulation of second-order cybernetics as a framework that accounts for observers, conversations, and participants in cybernetic systems.

The operation of the machine, called Eucrates (after the archon of ancient Athens from the 6th century BC, who was famed for neglect and excuses) was based on simulating the functioning of neurons. It was an embodiment of a conversation between machines, where one machine literally “teaches” the other. Let’s see the description of Eucrates, which appeared in the Monday, 4 June 1956, issue of TIME Magazine, London.


A schoolteacher who is tireless, vigilant and indifferent to big red apples was on exhibit at London’s Physical Society. The teacher is electronic and the creation of two young Cambridge scientists, Physicist McKinnon-Wood and Psychologist Gordon Pask, under contract with Solartron Electronic Group Ltd. Designed for teaching such routine skills as typing and running radar equipment, the electronic teacher gives patient, individual attention.

October 1956: British scientist Gordon Pask co-inventor of an electronic brain used as a teaching aid called Eucrates I. (Photo by Harry Kerr/BIPs/Getty Images)
October 1956: British scientist Gordon Pask co-inventor of an electronic brain used as a teaching aid called Eucrates I. (Photo by Harry Kerr/BIPs/Getty Images)

The trouble with human teachers, say Wood and Pask, is that unless they are extremely good, they cannot observe in detail the intimate characteristics of each pupil. Each pupil’s biases, habits and individual eccentricities determine how he should be taught. He may favor his left hand over his right hand, or be able to remember odd numbers better than even ones. An ideal teacher should take all such matters into account and teach accordingly.

Solartron’s electronic teacher is set up to teach how to duplicate patterns of light in a frame containing eight lights. It starts the lessons by showing a single light. In another frame another light appears, telling the pupil which button to press. After a few such easy examples, the lessons get harder. Light patterns can be duplicated only by complicated operations with the buttons. The teacher gives clues, tells the pupil whether he is doing well or badly and makes him repeat over and over if he is making errors. Always understanding, the machine holds back a difficult exercise until the pupil is ready. If set up to teach typing, it can tell the pupil which finger to use and in which direction to move it. If the pupil is a hardened hunt-and-peck typist, the teacher will discover his sloppy habits and set about correcting them at once.

Wood and Pask got so interested in the teaching problem that they created an electronic pupil named Eucrates I, to give the electronic teacher a real workout. Eucrates is electronic but not bright. When not being taught, he is “thinking” in a confused way, and the electronic teacher must take account of his thinking habits. Eucrates follows instructions and observes clues, but is often wrong. If the teacher is too severe or goes too fast, Eucrates shows signs of electronic emotion, equivalent to bursting into tears. Then the electronic teacher is gentle with him until his little dials have stopped quivering.


Solartron EUCRATES II, ca. 1956
Solartron EUCRATES II, ca. 1956

Later in 1956, Park and Wood invented Self-Adaptive Keyboard Instructor (SAKI), a machine, that adapts to the learner’s performance level (it was essentially a system for teaching people how to increase speed and accuracy in typing alphabetic and numeric symbols using a 12-key keyboard.) In late 1956, Park and Wood also created an improved version of Eucrates, called (surprise!) Solartron EUCRATES II.

In his book “An Approach to Cybernetics” (1961) Gordon Pask presents “learning machines”. Pask designates “Eucrates” as “simulating a pupil-teacher system”. The model reconstructs the behavior of “real neurons” and their “absolute refractory period”. The reactions of the “motor-elements” to the input are varying because of a shifting threshold: The threshold increases after the first input with the consequence for learners that they have to wait with further inputs until the threshold falls. “Memory-elements” react to the output of the “motor-elements”. The “memory-elements” are constructed following the example of “the synaptic connections of a neuron”: “Now it is obvious that various modes of activity and various forms of interaction [between a pupil and a teacher or the learning machine] will build up the network.” Pask writes this sentence after a short explanation of possible “interconnections” between “motor-elements” and the learning activities within the “network”. Capable of surviving within the “network” are only the connections that “mediate a favorable behavior”.

Abacus – 2400 BC

‘Can you do Addition?’ the White Queen asked. ‘What’s one and one and one and one and one and one and one and one and one and one?’
‘I don’t know,’ said Alice. ‘I lost count.’
‘She can’t do Addition,’ the Red Queen interrupted…
From Alice’s Adventures in Wonderland

With the complex adding systems that we have today, it can be hard to grasp that people were using small stones or other objects as numerical devices from time immemorial. The word calculate itself comes from the Latin calculus, which means small stone. These methods of calculations introduced some elementary kind of abstraction, but people gradually realized that this method did not go far enough to satisfy their increasing needs. To count up to 1000, for example, they would have had to gather a thousand pebbles, which was enormous work.

That is why, once the principle of the numerical base had been grasped, the usual pebbles were replaced with stones of various sizes to which different orders of units were assigned. For example, if a decimal system was used, the number 1 could be represented by a small stone, 10 by a larger one, 100 by a still larger one, and so on. It was a matter of time before someone thought of arranging some pebbles over a big flat base stone, wire, or something else.

It is unknown when exactly were developed first devices to facilitate calculation, such as the counting board, or abacus. The counting board was invented when someone grasped the idea of placing pebbles or other objects in columns marked on a flat surface and assigning an order of units to the objects in each column. Later, loose objects in columns were replaced with beads that could slide along parallel rods.

Salamis abacus (Salamis tablet)
Salamis abacus (Salamis tablet)

There is unproved information, that a similar to the abacus device was used in Babylonia as early as 2400 BC. The word abacus itself is a Latin word, that comes from Greek άβακασ (board or table). The Greek word probably comes from the Semitic abk, which means sanddust or to wipe the dust, which can suggest to us, that Greeks accepted the idea of an abacus from the Phoenicians (which is the case with the Greek alphabet, inspired by the Phoenician alphabet). Actually, the Romans applied the word abacus (and also the word calculi, which comes from calculus (stone, pebble) to various objects, all with the common characteristic of having a flat surface: tables used in different kinds of games, sideboards and the calculating device still known as the abacus. The Greeks used besides the above-mentioned type of abacus, also so-called dust abacus—a box, full of sand (or dust), divided into columns, over which can be arranged pebbles or other small objects.

The first written information about the abacus that survived to the present, is from the Greek historian Herodotus (480-425 B.C.), who mentioned also, that the ancient Egyptians used abacus. The oldest abacus, which survived to the present day, is the so-called Salamis abacus (see the nearby figure). It was named after the Greek island of Salamis, in the vicinity of which it was found in 1846 and was described later by the Greek archaeologist Alexander Rizo-Rangabe.

The Salamis abacus (kept now in the Epigraphical Museum of Athens) is dated around 300 B.C. and is a large slab of white marble (broken in half now), 149 cm long and 75 cm wide, with five parallel lines engraved into it and, below them, eleven parallel lines divided in half by a perpendicular line. The third, sixth, and ninth of these eleven lines are marked by crosses at their points of intersection with the perpendicular line. Three nearly identical series of Greek characters, which are numerical signs for noting sums of money in the Greek monetary system (the basic unit is drachma, but there are also 2 smaller units—obols and khalkoses, and 2 bigger, which actually were never minted—minas and talents), are engraved on three sides of the slab.

The "abacus" detail from Darius Vase
The “abacus” detail from Darius Vase

The four columns on the top were used for fractions of the drachma, the first one corresponding to khalkoses (1/48 of a drachma), the second to quarter-obols (1/24 of a drachma), the third to half-obols (1/12 of a drachma), and the fourth to obols (1/6 of a drachma). The next five columns were associated with multiples of the drachma: the first on the right corresponded to units, the second to tens, the third to hundreds, and so on. The last five columns (in the bottom part) were respectively associated with talents, tens of talents, hundreds, and so on. Since a talent was equivalent to 6000 drachmas, counters representing 6000 drachmas were replaced with one counter in the talents column. By means of these different divisions, the reckoner could perform addition, subtraction, and multiplication.

There is also another interesting old Greek artifact, the so-called Darius Vase, dated about 500 B.C., in the museum at Naples, which contains a picture of an abacus-like instrument (see the nearby drawing).

Pictures (but not an artifact yet) of a Roman table abacus were found on an Etruscan cameo, on a Roman pier, and on a relief of the Capitoline Museum in Rome.

A modern replica of a Roman hand abacus from 1st century CE
A modern replica of a Roman hand abacus from the 1st century CE

The Roman abacus was similar to the Greek one (see the nearby photo). It consisted of a small metal tablet with parallel grooves, usually nine of them, each corresponding to an order of units, in which spherical counters slid. The abacus in the upper figure has 8 decimal positions (leftmost), for the units, tens, hundreds, and so on to the 100 millions (marked with I, X, C…). When the units of a certain order did not go beyond four, the reckoner indicated them in the corresponding lower groove by pushing up as many counters as necessary. When they reached or went beyond five, he first pushed down the counter in the upper groove (representing five units in the order of that groove), then pushed up as many counters as necessary in the lower groove. The ninth position from the left (marked with O) has an upper part containing one counter and a lower part containing five. It served to indicate multiples of an ounce, each lower counter representing one ounce and the upper counter six ounces. The rightmost groove is divided into 3 parts and is used to indicate a half-ounce, a quarter-ounce, and a duella, or a third of an ounce.

Gerbert d'Aurillac (c. 946-1003)
Gerbert d’Aurillac (c. 946-1003)

During the so-called Dark Ages in Western Europe, the art of counting with the abacus was more or less forgotten. One of the first scientists, who not only popularized the Hindu-Arabic digits but also reintroduced the abacus, was (surprise!) Gerbert d’Aurillac (c. 946-1003), archbishop of Rheims and chancellor of France, well-known as Pope Sylvester II (see the nearby image). Gerbert lived some time in Spain and took the idea of the abacus from Spanish Arabs (in 967, he went to Catalonia to visit the Count of Barcelona, and remained three years in the monastery of Vic, which, like all Catalan Monasteries, contained manuscripts from Muslim Spain and especially from Cordoba, one of the intellectual centers of Europe at that time). The abacus that Gerbert reintroduced into Europe had its length divided into 27 parts with 9 number jetons, so-called apices (this would exclude zero, which was represented by an empty column) and 1000 apices in all, crafted out of animal horn by a shieldmaker of Rheims. For example, with Gerbert’s abacus, the number 308 will be expressed with an apex for 3 in the hundreds column and with an apex for 8 in the column of units. According to his pupil Richer, Gerbert could perform speedy calculations with his abacus, which were extremely difficult for people in his day to think through in using only Roman numerals, that was one of the reasons Gerbert was suspected as a magician and servant of the Devil 🙂 Due to Gerbert’s reintroduction, the abacus became widely used in Western Europe once again during the 11th century.

The first printed book on arithmetic and the operation of the abacus in Europe was the anonymous Arte dell’Abbaco, (Treviso, 1478). The most popular kind of abacus still in use during the Renaissance in Europe was a table on which lines marked off the different decimal orders (so-called reckoning table). The pebbles previously used as counters have been replaced by specially minted coin-like objects (like apices, introduced by Gerbert) that are cast, thrown, or pushed on the abacus table. They are called jetons from jeter (to throw) in France and werpgeld for “thrown money” in Holland. All administrations, merchants, bankers, lords, and rulers had reckoning tables with counters bearing their own marks, made of base metal, gold, or silver, depending on their rank or social position.

Typus Arithmeticae, woodcut from the book Margarita Philosophica, by Gregor Reisch, Freiburg, 1503. The central figure is Dame Arithmetic, watching a competition between Boethius, using pen and Hindu-Arabic numerals, and Pythagoras, using the counting board. She looks toward Boethius, who obviously is in favor.
Typus Arithmeticae, woodcut from the book Margarita Philosophica, by Gregor Reisch, Freiburg, 1503. The central figure is Dame Arithmetic, watching a competition between Boethius, using pen and Hindu-Arabic numerals, and Pythagoras, using the counting board. She looks toward Boethius, who obviously is in favor.

The value of a counter depended on its position. On consecutive lines, going from bottom to top, it was worth 1, 10, 100, 1000, and so on. Between two consecutive lines, it was worth five units of the line immediately below it. Addition was done in the left (or forward) part of the frame, by placing counters corresponding to the numbers involved, then reducing them and taking account of the value assigned to each location. To multiply two numbers, the reckoner began by representing the first one in the left part of the frame, then he eliminated one by one the counters representing this number as he replaced them in the right (or rear) part of the frame with their products by the second number. Computation on the reckoning table was taught till the eighteenth century. The fact that it was discussed in many European arithmetic books in the sixteenth, seventeenth, and eighteenth centuries gives an idea of how common it was. It was so firmly anchored in European tradition, that even when written computation with Hindu-Arabic numerals was becoming general, results obtained in that way were always checked on a reckoning table, just to be sure.

The reckoning table made addition and subtraction easy, but for more complex operations it was slow and required long training. This drawback must have been what prompted the fierce controversy that began early in the sixteenth century between the abacists, who clung to the reckoning table and the archaic Greek and Roman numerations, and the algorists, who advocated a form of written computation (see the nearby figure). Written computation was quickly adopted by scientists (especially by mathematicians and astronomers), while the reckoning table continued to be used in business and finance.

Chinese counting board had 2 ways of representation of digits
Chinese counting board had 2 ways of representing digits

A quite different and much more advanced form and methods for calculation can be seen in the development of the abacus in Asia. The Chinese started to use counting boards, the prototype of the abacus, as early as the 4th century BC. The Chinese counting board was a wooden plate, divided into columns, and calculations were made by means of bamboo or ivory sticks (see the nearby figure for the two ways of representation of digits). In the rightmost column are denoted units, in the next—tens, and so on. Some historians even claim, that this namely was the first use of the decimal numbering system in the world. The most famous Chinese mathematical text—Chiu chang suan shu (Nine Chapters on the Mathematical Art), which dates from the period of the Han Dynasty (206 B.C. to A.D. 220), gives details of algebraic operations on the counting board, including the solution of a system of n equations with n unknowns.

The long and gradual improvement of the Chinese counting board led to the development (sometimes in the 2nd century) of a more convenient type of abacus—the bead abacus, mentioned in the book of Xu Yue, Supplementary Notes on the Art of Figures, written about the year 190 A. D. The Chinese bead abacus (so-called suanpan) has a rectangular wooden frame with thin rods across it. On each rod are placed seven glass or wooden beads: five (the number of fingers of a human) below the strip of wood, that divides the frame into two unequal parts, and two above it (the number of hands).

The Chinese bead abacus (so-called suanpan)
The Chinese bead abacus (so-called suanpan)

The rods correspond to numerical values increasing tenfold from right to left. (Base 10 is not obligatory, of course; another base, such as 12 or 20, could be used if an adequate number of beads were placed on the rods.) If the first rod on the right corresponds to units, the second one corresponds to tens, the third to hundreds, and so on. Users of the suanpan, however, do not always begin with the first rod on the right to represent whole numbers: they sometimes begin with the third from the right, reserving the first two for centesimal and decimal fractions.

Each of the five beads on the lower part of a rod has the value of one unit of the order corresponding to the rod, and each of the two beads on the upper part has the value of five units. Numbers are formed by moving beads toward the crossbar separating the upper and lower parts of the rods. To form the number four, for example, the user simply raises four beads on the lower part of the first rod on the right. For eight, he lowers one upper bead on that rod and raises three lower ones.

The Japanese soroban
The Japanese soroban

As can be seen, there is some kind of redundancy in the notation of numbers in suanpan. Nine units of the order corresponding to a given rod are represented by one upper bead with the value of five units and four lower beads with the value of one unit each. Five beads are thus enough to represent nine units. This raises the question of why each rod has seven beads, which allowed a total value of 15 to be entered. The reason is that in doing division on an abacus, it is often helpful to indicate, temporarily, a number greater than 9 on a single rod. For the three other operations, five beads on each rod are enough. In the case of division, however, the calculation may be simplified if a partial result greater than 9 is temporarily indicated on one rod.

Sometime in the late 16th century, the Chinese suanpan was adopted in Japan, under the name soroban. The soroban however was gradually simplified, and from the middle of the 17th century, the number of beads in the lower part was reduced to 4, while in the upper part remained only 1 bead. This means, that the redundancy of the suanpan was removed, due to the fact, that the older Chinese division method, which makes use of the cumbersome division table, was formerly replaced by the Japanese division method, which makes use of the multiplication table.

The Russian abacus, so called русские счёты
The Russian abacus, so-called русские счёты

Another country, in which the bead abacus was extremely popular, apart from China and Japan, at least in recent times, is Russia. The Russian abacus, so-called русские счёты (russkie schoty) (see the nearby photo) was first mentioned in 1658, in an inventory book. The construction of schoty probably was based on the Chinese suanpan, but was quite different in the design. The main difference between suanpan and schoty is the horizontal position of the rods in the schoty (so the beads are slid right-to-left), and the rods have a slight curvature to prevent the “counted” beads from accidentally sliding back to the home position. The typical schoty has several (usually 8 to 10) decimal positions, and 1 position with 4 beads (which not only acts as a separator or for fractions, but can be also used for calculations in polushki, the Russian monetary system in this time was constituted by polushkikopeiki (1 kopeika equal to 4 polushki), and roubles (1 roubla equal to 100 kopeiki)).

The Russian abacus has some improved variants, like Markov’s abacus (счетьi Маркова), double abacus (двойньiе счетьi), Ezerski’s abacus (счетьi Езерскаго), Kompaneiski’s abacus (счетьi Компанейскаго), etc.

The Russian abacus is still in common use today in shops and markets throughout the former Soviet Union, although it is no longer taught in most schools. Around 1820, the Russkie schoty was brought to Europe (first to France, under the name boulier-compteur), though not as a calculating device, but rather as a didactic tool for beginning course of arithmetic.

Yupana, the counting board of the Incas.
Yupana, the counting board of the Incas.

American Indians also used calculating tools. At the beginning of the 1600s, the Quechua nobleman Felipe Guaman Poma de Ayala wrote a letter to the King of Spain, containing 1179 pages. The letter includes several drawings that show quipus (recording devices used in the region of Andean South America, consisting of colored, spun, and plied thread or strings) and a picture of a counting board in the bottom left-hand corner of one of them (see the nearby picture). This is called the yupana and is presumed to be the counting board of the Incas.