Most histories of computing are dominated by Anglo-Saxon accounts in which devices and practices from elsewhere, continental Europe in particular, are underrepresented and in some cases omitted. However, there is a rich history of such discoveries and the widespread use of computational devices. This article aims to supplement and correct widely accepted accounts, briefly describing examples from European countries in chronological order. Some of these innovations are well known, but, for others, we are no longer aware of them or they are forgotten entirely. Electronic digital computers abruptly replaced digital mechanical calculating machines and analog logarithmic slide rules in the 1970s. The great calculating machines built by Wilhelm Schickard, Blaise Pascal, and Gottfried Wilhelm Leibniz are not included in this survey.
Counting boards. In the early modern period, beautiful counting boards (see Figure 1) were used in many city halls throughout central Europe for addition and subtraction (using counters). Surviving tables (16th to 18th centuries) are today to be found mostly in museums in Switzerland and Germany.16 Counter reckoning, also called "counter casting" and "calculating on the lines," was recommended by the abacists and superseded by "pen reckoning" supported by the algorists.
Sectors. There are uncertainties about the origin of the sector (see Figure 2), which was designed in Italy in the 16th century, meaning Galileo Galilei was not its inventor, as is commonly credited. A similar analog instrument is the versatile proportional compass (such as for multiplication, division, and proportion). Sectors were largely abandoned following widespread use of linear slide rules and circular slide rules (both invented by William Oughtred of England).
Programmable handwriting automaton. Friedrich Knaus of Germany in 1760 constructed a marvelous programmable automatic handwriting machine. His "Alles schreibende Wundermaschine" is today on display at the Technisches Museum in Vienna. The Swiss watchmaker Pierre Jaquet-Droz created in 1772 his famous écrivain, or writer (see Figure 3), now on display at the Musée d'art et d'histoire, Neuchâtel, Switzerland, a machine that is still operational. In both cases the user may input a short text with some limitations on capital letters (Wundermaschine 68 characters, écrivain 37 characters). The complex mechanism is either outside (Vienna) or inside (Neuchâtel). The texts are written in ink with a pen.20,34
The most famous forerunner of Jaquet-Droz was Jacques Vaucanson of France. Unfortunately, his duck-flute-drum player automata were destroyed. Another important maker of automatons was Peter Kintzing of Germany; for details see Bruderer and Meilensteine.6
Early key-driven adder. To my knowledge no book on the history of computing mentions the world-famous watchmaker Jean-Baptiste Schwilgué of France, creator of the astronomical clock in the Strasbourg Cathedral. He received a patent in 1844 for his key-driven adding machine (see Figure 4). One copy (1846) is today in the Musée historique of Strasbourg, the other (1851) at ETH Zürich. The Swiss machine is in much better condition. There was an earlier Italian key-driven calculation machine (1834) developed by Luigi Torchi of Italy, but little is known about it today.
In general, authors writing about the history of computing regard the device (1850) of Du Bois D. Parmelee of the U.S. as the "first" key-driven adder,33 sometimes citing the Schilt machine (1850) by Victor Schilt, a Swiss watchmaker from Solothurn who had worked with Schwilgué. This calculation aid, now in the collection of National Museum of American History in Washington, D.C., was shown in 1851 at the Great Exhibition in London. However, the leading publications on computer history do not mention Schwilgué's key-driven adder. It is not known how many copies of this single-digit adder were built, though many multiple-order key-driven machines were in the U.S. by the end of the 19th century.
Early "process computer." For the construction of his splendid Strasbourg astronomical clock, Schwilgué developed several complicated machines, including a very precise milling machine for producing complex gears (circa 1827) and a large, specialized calculating machine (circa 1830); for dating and technical details, see Bruderer and Meilensteine.6 This device, which is driven by a crank and a weight, helped Schwilgué compute the values needed for the settings of his milling machine. He manually transferred the calculations to a paper tape he would then place in a box beside the milling machine. These numbers controlled the machine. It might thus be considered a simple "process computer" (or precursor). As far as is known, Schwilgué constructed only one such highly specialized machine.
Several books and papers were published by Schwilgué's collaborators and successors (foremost Alfred Ungerer of France) with a short description and picture of the milling machine. The machine is also mentioned in a biography of Schwilgué's son, Charles.
To my surprise I came across Schwilgué's adding machine (see Figure 5) in December 2014 in Strasbourg. Both devices are today in the Musée historique de Strasbourg.
Other historic calculating devices include the common slide adders (see Figure 6). These inexpensive, mass-produced instruments were manufactured in Germany, France, and Switzerland and widely disseminated. Credit is generally attributed to Heinrich Kummer of Germany (1847).
The "planimeter" was invented at the beginning of the 19th century by Johann Martin Herrmann of Germany (1814), Tito Gonnella of Italy (1824), and Johannes Oppikofer of Switzerland (1827). Much more successful were the precise polar planimeters (see Figure 7). The three most influential early designers and manufacturers of these and other integrating instruments were Jakob and Alfred Amsler of Schaffhausen, Switzerland, Gottlieb Coradi of Zürich, and Albert Ott of Kempten, Germany.
The Swiss cylinder musical box (see Figure 8) uses a sophisticated program store (pinned cylinder). Its successor was the German disk musical box with a perforated disk (invented in 1885) that involved much simpler production. The many mechanical musical instruments in Europe at the time were replaced by the phonograph (Emile Berliner of Germany and the U.S.) and the gramophone (Thomas Alva Edison and his Swiss-born engineer Johann Heinrich Krüsi). Another form of storage was music rolls (perforated paper rolls).
Cylindrical slide rule. The world's largest and most precise mass-produced cylindrical slide rule (see Figure 9) was manufactured by Loga Calculator AG in Zürich and Uster, Switzerland. The drum contains 80 sections, each 60 centimeters long; the length of the scale (due to overlapping) is 24 meters. Prior to mid-2013, only three surviving copies were known. Since then, four more have been discovered in Switzerland. Fuller's spiral slide rule has a scale of 12.7 meters; for details see Bruderer and Meilensteine.6
Chess automatons. Playing chess is often regarded as requiring intelligence. Two operational chess automata were created in Spain at the beginning of the 20th century by Spanish engineer Leonardo Torres (y) Quevedo, who also built a cable car for spanning a portion of Niagara Falls.
In 1912, he designed his first electromechanical chess machine (see Figure 10), followed by a second device several years later (see Figure 11). Both machines are today on display at the Museo Leonardo Torres Quevedo in Madrid. Austrian computer pioneer Heinz Zemanek saw the chess automaton demonstrated at the World Exhibition in Brussels in 1958. These devices, which did not play a complete chess game, were restricted to the end gameking and rook against king.
These two sophisticated "intelligent" chess machines were built approximately 30 years before Alan Turing of the U.K. and Konrad Zuse of Germany first thought about computer chess.
Electromechanical "analytical engine." Torres Quevedo also tried to build an analytical engine (see Figure 12) controlled by a remote typewriter and incorporating several notable features of conditional branching, presenting it in Paris in 1920. He also published an important theoretical paper on floating point arithmetic.32
Early commercially available computer. Many historians view the Ferranti Mark 1 (in the U.K.) and the Univac (in the U.S.) as the "first" commercially available computers, both delivered in 1951. However, the German relay calculator Zuse Z4 (see Figure 13) was already operational in 1945, with the ETH Zürich renting it in 1949. It remained in operation in Switzerland from 1950 to 1955 and is today on display at the Deutsches Museum in Munich.
The Zuse Z4 was used in Zürich for scientific and industrial purposes. Two applications were the tension calculations for the Grande Dixence dam (world's highest) in the Canton of Wallis, Switzerland (see Figure 14) and flutter calculations for the jet fighter P-16 of Flug- und Fahrzeugwerke Altenrhein AG, St. Gallen, Switzerand (see Figure 15).5
Relay calculator Bark. Several computer scientists view the tape-controlled Zuse Z4 as the only functioning computer in continental Europe in 1950. Yet there was another relay machine in Stockholm, Sweden, where Bark was controlled via plug board and was in operation until 1955 before being dismantled.27
Early programming language. Plankalkül developed by Zuse (1945) is regarded as one of the earliest programming languages. Zuse also anticipated chess programming.41
Automatic programming. Donald Knuth21 considers mathematician Heinz Rutishauser of Switzerland a father of automatic programming. In 1951, Rutishauser suggested using the computer itself to write programs, publishing "Automatische Rechenplanfertigung" (automatic production of programs) in 1952.30 These efforts later led to the programming language Algol. Though many historians view Grace Hopper as the "mother" of the compiler, Donald Knuth says that Alick Glennie of Manchester, U.K., should share credit for this achievement.21
Calculating punch M9. In the 1950s, Zuse manufactured a series of more than 20 calculating punches for Remington Rand in Zürich. I rediscovered in 2011 one of the M9s (see Figure 16), which is today at the Museum für Kommunikation in Berne, Switzerland.
Böhm's compiler. Pioneer Corrado Böhm of Italy published his doctoral thesis at ETH Zürich in 1954, writing a compiler in its own language.21 He had been, 19491950, a member of Eduard Stiefel's staff at the Institute for Applied Mathematics in Zürich. Along with engineer Harry Laett he tested the legendary relay calculator Zuse Z4 in 1949 prior to its installation in Zürich.5 The "meta-circular compiler" mentioned as part of the Corrado Böhm biography at http://www.corradobohm.it/Corrado_Bohm/Biography.html is the first known example of such a compiler.
Transistorized computer Mailüfterl. One of the earliest European transistorized computers was built by pioneer Heinz Zemanek of Austria in 1958. Called Mailüfterl, or "weak spring wind" (after the large MIT computer Whirlwind),40 it is today on display at the Technisches Museum in Vienna.
Transistorized computer Cora. Researchers at the Ecole polytechnique fédérale Lausanne (EPFL) in 2011 publicly credited Hungarian engineer Peter Tóth with designing the first known Swiss transistorized computer. The only preserved Cora (see Figure 17) is today on display at the EPFL.5,6
Ultimate mechanical pocket calculators/smallest mechanical parallel calculator. From 1949 to 1971 engineer Curt Herzstark of Austria working in Liechtenstein produced two magnificent pocket calculating machines both called "Curta" (see Figure 18). Approximately 130,000 were manufactured and sold worldwide during that time.
In November 2015 I found at Schreibmaschinenmuseum Beck, Pfäffikon, Switzerland, original engineering drawings and patent documents detailing an unknown multiple Curta (see Figure 19),18,19 generally believed to be the world's smallest mechanical parallel calculator. Two, four, or five conventional Curtas are combined, with one single crank needed to operate the combined machines. For more, see the newsletter (Spring 2016) of the Charles Babbage Institute (http://www.cbi.umn.edu/about/nsl/v38n1.pdf) and the journal Resurrection (Autumn 2016) of the Computer Conservation Society (http://www.computerconservationsociety.org/resurrection/pdfs/res75.pdf).
Building an Electronic Digital Computer
After World War II many universities in Europe and elsewhere sought to build their own electronic digital computers. For a number of reasons, including lower cost, independence from foreign countries, education of home-grown mathematicians and engineers, and adaptation to own needs, they often preferred to design the machines themselves rather than buy them on the worldwide market. But how to acquire the necessary knowhow? At the time, the relatively few books and courses on the subject were largely unavailable. Many British and continental European mathematicians and engineers thus spent time in the U.S. at such institutions as the Institute for Advanced Study at Princeton (under the direction of John von Neumann) or at Harvard University (under the direction of Howard Aiken).8
Swiss pioneers Eduard Stiefel, Heinz Rutishauser, and Ambros Speiser in 19491950 spent several months at Harvard and Princeton, as well as in the U.K. The result of their investigations was a fundamental book about computers called Programmgesteuerte digitale Rechengeräte. Stiefel had previously, in 1948, founded the Institute for Applied Mathematics of ETH Zürich.
Book on the Building of Stored Program Computers
As investigated by Arnold Cohen,13 there were, at the beginning of the 1950s, two main books on the construction of stored-program computers: High-speed Computing Devices by Engineering Research Associates (1950)13 and Programmgesteuerte digitale Rechengeräte (Program-Controlled Electronic Digital Computers) by Rutishauser et al.31 This work was published in four parts, 19501951, in the German scientific journal Zeitschrift für angewandte Mathematik und Physik and as a book in 1951 (see Figure 20). It includes a worldwide overview of then-current computing machines and projects. The authors discussed such topics as the advantages and disadvantages of serial and parallel processing, fixed and floating point arithmetic, conditional branching, program storage, and self-modifiable programs.
Heinz Zemanek39 wrote that the report by Rutishauser, Speiser, and Stiefel was "jahrelang die beste Dokumentation über den Computer in deutscher Sprache" ("the best documentation for many years on electronic digital computers in the German language").
Paris Computer Conference of 1951
The conference included 268 participants, among them 10 women, mostly "calculatrices," or female computers, from 10 countries and covered calculating machines and human thinking. This was probably the most important early computer congress in Europe; an earlier meeting had been held in Cambridge, U.K., in 1949.
Many European and American pioneers attended, including Howard Aiken (Cambridge, MA), Ross Ashby (Gloucester, U.K), Andrew Booth (London, U.K.), Bertram Bowden (Manchester, U.K.), Francis Colebrook (Teddington, U.K.), Louis Couffignal (Paris, France), Douglas Hartree (Cambridge, U.K.), Tom Kilburn (Manchester, U.K.), Göran Kjellberg (Stockholm, Sweden), Warren McCulloch (Chicago, IL), Conny Palm (Stockholm, Sweden), Mauro Picone (Rome, Italy), Eduard Stiefel (Zürich, Switzerland), Gonzales Torres Quevedo (Madrid, Spain), Albert Uttley (Great Malvern, U.K.), Willem van der Poel (The Hague, the Netherlands), Adriaan van Wijngaarden (Amsterdam, the Netherlands), Grey Walter (Bristol, U.K.), Alwin Walther (Darmstadt, Germany), Norbert Wiener (Cambridge, MA), Maurice Wilkes (Cambridge, U.K.), Frederic Williams (Manchester, U.K.), and John Womersley (Letchworth, U.K.). Alan Turing did not participate. All papers were translated into French. Norbert Wiener played against the second version of Torres Quevedo's chess automaton (operated by his son Gonzales). In his paper, Francis Colebrook (officer-in-charge, Electronics Section, National Physical Laboratory, Teddington, U.K.) referred to Turing's abstract treatise on the universal machine (1936) but did not mention the concept of a stored program.
The conference is not well known today since its 589-page proceedings27 is still available only in French (see Figure 21). It seems to be one of the earliest large gatherings to explore the themes of human thought and computing machines. In 1956, the Dartmouth summer research project on artificial intelligence took place in Hanover, NH.
Priority and Patriotism
There are still endless debates over such questions as "Who discovered the logarithms?," "Who invented the computer?," "Who created the stored program?," and "Who is the father of artificial intelligence?" Answers can vary depending on nationality of the person answering. Germans are most likely to favor Konrad Zuse and Kurt Gödel, the British Alan Turing, and the Americans and Hungarians John von Neumann.
Gone today, however, are the world's former leading makers of mechanical integrators, including Amsler (Schaffhausen, Switzerland), Coradi (Zürich, Switzerland), and Ott (Kempten, Germany).
As this article focuses on computing history outside the U.K. and the U.S., I do not discuss this matter in detail; for more, see selected contributions by Maston Beard,2 Allan Bromley,4 Maarten Bullynck,10 Jack Copeland,11 Edgar Day-light,12 Thomas Haigh,14,15 Allan Olley,24 Eloína Peláez,26 and Mark Priestley.28
Several independent inventors were also involved in both the mechanical precursors and the electronic digital computer. Who was "first" depends on ones's definition of "computer."37,38 For example, it is likely there were also several creators of the stored program concept. Notably, Presper Eckert, John Mauchly, and John von Neumann (all of the U.S.) had to overcome technical bottlenecks. Konrad Zuse in 1936 wrote in a patent application about the possibility of internal memory.5,11,41 Meanwhile, many terms have since changed meaning; for example, until the 1940s, "computers" were human beings doing calculations, usually with the help of mechanical calculating machines.
The leading scientific journal worldwide in the post-war period was Mathematical Tables and Other Aids to Computation, first published by the American Mathematical Society in 1943. From 1954 to 1957, the Digital Computer Newsletter was published by the Office of Naval Research within the Navy Department in Washington, D.C., and as a supplement to the Journal of the Association for Computing Machinery. Both covered computer developments outside the U.S. and the U.K. Mathematical Tables and Other Aids to Computation included many reviews of non-English works in computing research. Unfortunately, many current U.S. and British books and journals on the history of computing do not adequately acknowledge the contributions of non-English-speaking countries.
For example, there were two co-discoverers of logarithmsJost Bürgi of Switzerland and John Napier of Scotland. Bürgi developed the logarithms first, and Napier published his results first.35 The invention of the pantograph is generally attributed to Christoph Scheiner of Germany (1603), but Heron of Alexandria (first century) should be credited for (a different type of) this drawing instrument.3,17,23
Electronic devices quickly replaced mechanical machines and instruments in the 1970s. Inventions from continental Europe, including sectors, proportional compasses, planimeters, and pantographs disappeared world-wide. Gone today, however, are the world's former leading makers of mechanical integrators, including Amsler (Schaffhausen, Switzerland), Coradi (Zürich, Switzerland), and Ott (Kempten, Germany). Forgotten are the mechanical and electronic analog computers produced in Germany (such as Telefunken) and Switzerland (Amsler, Contraves, and Güttinger). Including these significant achievements in non-English-speaking countries enriches the history of computing for all.
I am very grateful to Thomas J. Misa of the Charles Babbage Institute at the University of Minnesota for copy editing this article and to Thierry Amstutz and Christian Hörack of the Musée d'art et d'histoire, Neuchâtel, Switzerland, for the Jaquet-Droz automata.
This article is based in part on my 2015 book Milestones in Analog and Digital Computing, which includes a comprehensive bibliography.6
4. Bromley, A. The origin of the stored program concept. In The last of the first, Csirac: Australia's First Computer, D. McCann and P. Thorne, Eds. Department of Computer Science and Software Engineering, University of Melbourne, Melbourne, Australia, 2000, 8795.
6. Bruderer, H. Meilensteine der Rechentechnik. Zur Geschichte der Mathematik und der Informatik (Milestones in Analog and Digital Computing. Contributions to the History of Mathematics and Information Technology). De Gruyter Oldenbourg, Berlin/Boston, 2015.
7. Bruderer, H. The birth of artificial intelligence. First conference on artificial intelligence in Paris in 1951? In International Communities of Invention and Innovation. History of Computing 2016, International Federation for Information Processing Advances in Information and Communication Technology 491. A. Tatnall and C. Leslie, Eds. Springer International Publishing AG, Cham, Switzerland, 2016, 181185.
8. Bruderer, H. The world's smallest mechanical parallel calculator. Discovery of original drawings and patent documents from the 1950s in Switzerland. In International Communities of Invention and Innovation. History of Computing 2016, International Federation for Information Processing Advances in Information and Communication Technology 491. A. Tatnall and C. Leslie, Eds. Springer International Publishing AG, Cham, Switzerland, 2016, 186192.
11. Copeland, J. and Sommaruga, G. The stored-program universal computer: Did Zuse anticipate Turing and von Neumann? In Turing's Revolution. The Impact of His Ideas About Computability, G. Sommaruga and T. Strahm, Eds. Birkhäuser/Springer, Cham, Switzerland, 2015, 43101.
16. Hergenhahn, R., Reich, U., and Rochhaus, P. Mache für dich Linihen ... Katalog der erhaltenen originalen Rechentische, Rechenbretter und -tücher der frühen Neuzeit. Adam-Ries-Bund, Annaberg-Buchholz, Germany, 1999.
21. Knuth, D.E. and Trabb P.L. The early development of programming languages. In A History of Computing in the Twentieth Century. A Collection of Essays, N.C. Metropolis, J. Howlett, and G.-C. Rota, Eds. Academic Press, New York, 1980, 197273.
24. Olley, A. Existence precedes essence: Meaning of the stored-program concept. In History of Computing. Learning from the Past. International Federation for Information Processing Working Group 9.7 International Conference, History of Computing 2010, A. Tatnall, Ed. (Brisbane, Australia, Sept. 2023). Springer, Berlin, Germany, 2010, 169178.
27. Pérès, J., Ed. Les machines à calculer et la pensée humaine. Colloques internationaux du Centre national de la recherche scientifique, Nr. 37 (Paris, France, Jan. 813). Editions du Centre national de la recherche scientifique (CNRS), Paris, France, 1953.
33. Turck, J.A.V. Origin of Modern Calculating Machines. A Chronicle of the Evolution of the Principles that Form the Generic Make-Up of the Modern Calculating Machine. The Western Society of Engineers, Chicago, IL, 1921.
37. Williams, M.R. What does it mean to be the first computer? In Proceedings of the IEEE John Vincent Atanasoff 2006 International Symposium on Modern Computing (Sofia, Bulgaria, Oct. 36). IEEE Computer Society, Washington, D.C., 2006, 39.
40. Zemanek, H. Central European prehistory of computing. In A History of Computing in the Twentieth Century. A Collection of Essays, N.C. Metropolis, J. Howlett, and G.-C. Rota, Eds. Academic Press, New York, London, 1980, 587609.
Figure 1. A rare counting board (this one from the 16th century), once very common in the town halls of central Europe; to perform calculations a user would need to put tokens, or rechenpfennige, on the lines (=value 1, 10, 100, 1,000) or between them (=value 5, 50, 500, 5,000) of at most four pieces in the same place. Courtesy of Historisches Museum, Basel, Switzerland.
Figure 2. Sector, a universal calculating instrument developed in the 16th century containing various scales (such as trigonometric) depending on scope; a pair of dividers is necessary for multiplication or division. The sectors are based on the Thales' intercept theorem on intersecting lines.1,25 Courtesy of the Collection of Astronomical Instruments, ETH Library Zürich, Switzerland.
Figure 3. Early programmable handwriting automaton with internal mechanics built by Pierre Jaquet-Droz, 18th century; the text (up to 37 characters) is stored on cam plates. Courtesy of Musée d'Art et d'Histoire, Neuchâtel, Switzerland.
Figure 4. Early key-driven adding machine, or so-called "direct adding machine," developed by Jean-Baptiste Schwilgué of Strasbourg, patented in 1844; pressing a key causes the corresponding number to be stored in the register, making addition very quick. Courtesy of the Collection of Astronomical Instruments, ETH Library Zürich, Switzerland.
Figure 5. Schwilgué's large adding machine that probably facilitated the calculations needed to produce the complex gears of the astronomical clock of Strasbourg Cathedral; the original weight drive is lost. Courtesy of Mathieu Bertola, Musée historique, Strasbourg, France.
Figure 6. Slide adder devised by the French manufacturer Louis Troncet in 1889; the tens carry is semiautomatic, needing a mechanism that looks like a cane. Such an instrument is also able to perform subtractions and is sometimes combined with multiplication tables. Courtesy of Herbert Spühler, Stallikon, Switzerland.
Figure 7. Polar planimeter invented by Jakob Amsler in 1854 was used to calculate surfaces by applying differential and integral calculus. Only one manufacturer remains active today, Gebrüder Haff GmbH, Pfronten, Germany. Courtesy of Amt für Vermessung, Aarau, Switzerland.
Figure 8. Music boxes are still produced by the Swiss firm Reuge and often presented as gifts; the melodies were originally stored on (exchangeable) pegged brass cylinders, though the cylinders were later replaced by (cheaper) perforated disks. Courtesy of Reuge SA, Sainte-Croix, Switzerland.
Figure 9. The world's largest mass-produced cylindrical slide rule from Loga Calculator (circa 1912), Zürich/Uster, Switzerland; length of scale: 24 meters. Multiplication is reduced to addition and division to subtraction in the same way traditional slide rules work. These devices were common in banks and insurance companies worldwide. Courtesy of UBS, Basel, Switzerland.
Figure 10. Early electromechanical chess automaton (1912) by Torres Quevedo; unlike Wolfgang von Kempelen's machine, it is an authentic automaton without hidden human chess player. Courtesy of Museo Leonardo Torres Quevedo, Universidad Politécnica de Madrid, Spain.
Figure 11. Second automatic chess endgame machine by Torres Quevedo, playing with king and rook (automaton) vs. king (human player). Courtesy of Museo Leonardo Torres Quevedo, Universidad Politécnica de Madrid, Spain.
Figure 12. Torres Quevedo's electromechanical arithmometer (1920), typewriter controlled, with conditional branching, based on Charles Babbage's analytical engine. Courtesy of Museo Leonardo Torres Quevedo, Universidad Politécnica de Madrid, Spain.
Figure 13. Zuse's binary relay computer Z4 was first commercially available in 1945; this tape-controlled programmable machine with floating-point arithmetic was in operation in Zürich from 1950 to 1955 and included an innovative mechanical memory without relays. Courtesy of ETH Library Zürich, Switzerland.
Figure 14. Grande Dixence in the Swiss Alps, the world's highest concrete dam, relied on calculations aided by the Zuse Z4 and electromechanical desktop calculators (such as Madas from H. W. Egli AG, Zürich-Wollishofen). Courtesy of Grande Dixence SA, Sion, Switzerland.
Figure 15. Swiss jet fighter P-16 at airport in Flug- und Fahrzeugwerke AG, Altenrhein, Switzerland, on Lake Constance near the German border; flutter calculations were aided by the Zuse Z4 for this supersonic plane in the 1950s. Courtesy of Staatsarchiv, St. Gallen, Switzerland.
Figure 16. Zuse's program-controlled parallel decimal electromechanical "calculating punch" M9 manufactured for Remington Rand, Zürich; combined with punched-card machines, the M9 was used for multiple applications (such as for accountancy and statistics). Courtesy of Max Forrer, Oberhelfenschwil, Switzerland.
Figure 17. Swiss transistorized computer Cora developed and manufactured by Contraves AG, Zürich, in 1963 originally for military purposes as a fire-control calculator. Courtesy of Musée Bolo, Ecole polytechnique fédérale Lausanne, Switzerland.
Figure 18. Curta, the world's smallest mechanical pocket calculator, is a stepped drum machine able to perform all four basic arithmetic operations; Curt Herzstark, deported from Austria by the Nazis in 1943, was compelled to design it while imprisoned in the Buchenwald concentration camp. Courtesy of Sven Beham, Liechtensteinisches Landesmuseum, Vaduz, Liechtenstein.
Figure 19. This engineering drawing of the Double Curta illustrates one of the four arrangements Herzstark proposedhorizontal duplex mechanical pocket calculator. Courtesy of Schreibmaschinenmuseum Beck, Pfäffikon, Switzerland.
Figure 20. One of the most influential early books from continental Europe on the building of electronic stored-program computers includes no mention of the universal Turing machine. Courtesy of ETH Library Zürich, Switzerland.
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