Leonardo Torres Quevedo

Leonardo Torres Quevedo (28 December 1852 – 18 December 1936) was a Spanish civil engineer, mathematician and inventor of the late 19th century and early 20th century. A multifaceted innovator, his fields of interest were extensive and included mechanics, aeronautics and automatics. He was elected member of the Real Academia Española in 1920, and as a foreign associate of the French Academy of Sciences in 1927, among other institutions.

His first groundbreaking work was the patent of a cable car system in 1887 for the safe public transportation of people, an area that culminated in 1916 with the inauguration of the Whirlpool Aero Car located in Niagara Falls. In the early 1890s, Torres focused his research on analogue computation. He published Machines algébriques (1895) and Machines à calculer (1901), technical studies that gave him recognition in France for his construction of machines to solve real and complex roots of polynomials. Between 1902 and 1911 he made significant aeronautical contributions, becoming the inventor of the Astra-Torres airships, a non-rigid trilobed structure that helped the British and French armies to counter the aerial domination by Germany's zeppelins during World War I. These tasks in dirigible engineering led him to be a key figure in the development of radio control systems during 1901–05 with the Telekine, which he created modern wireless remote-control operation principles.

From his Laboratory of Automation founded in 1907, Torres invented and built one of his greatest technological achievements, El Ajedrecista (The Chess Player) of 1912, an electromagnetic device capable of playing a limited form of chess that demonstrated the capability of machines to be programmed to follow specified rules (heuristics) and marked the beginnings of research into the development of artificial intelligence. His pioneering advances included designs for a special-purpose electromechanical calculator in his 1914 paper Essays on Automatics, which has been qualified by British historian Brian Randell as "a fascinating work which well repays reading even today", where he also speculated about thinking machines, introducing concepts still relevant like floating-point arithmetic. Subsequently, he demonstrated the feasibility of an electromechanical analytical engine by successfully producing a typewriter-controlled calculating machine in 1920.

Many other projects were conceived until his retirement in 1930, especially notable in naval architecture, such as the Camp-Vessel (1913), a ship for transporting dirigible balloons attached to a mooring mast of his creation, and the Twin Ship (1916), a multihull steel vessel driven by two propellers powered by marine engines. Beyond his work in engineering, Torres stood out in the field of letters and was a prominent speaker and supporter of Esperanto.

Early years
Torres was born on 28 December 1852, on the Feast of the Holy Innocents, in Santa Cruz de Iguña, Cantabria, Spain. His father, Luis Torres Vildósola y Urquijo, was a civil engineer in Bilbao, where he worked as a railway engineer. His mother was Valentina Quevedo de la Maza. The family resided for the most part in Bilbao, although they also spent long periods in his mother's family home in Cantabria's mountain region. During his childhood, he spent long periods of time separated from his parents due to work trips. Therefore, he was cared by a relatives of his father, the Barrenechea ladies, who declared him heir to their property, which facilitated his future independence.

He studied high school in Bilbao and later went to Paris, to the College of the Christian Brothers, to complete studies for two years (1868 and 1869), where he met French culture, customs, and language and that in later years it would help him in his scientific-technical relationships with personalities, and scientific institutions. In 1870, his father was transferred, bringing his family to Madrid. The following year, Torres began his higher studies in the. He temporarily suspended his studies in 1873 to volunteer for the defense of Bilbao, which had been surrounded by Carlist troops during the Third Carlist War. Once the siege of Bilbao was lifted in 1874, he returned to Madrid and completed his studies in 1876, graduating fourth in his class.

Career
Torres began to work as a civil engineer for a few months on railway projects as his father did, but his curiosity and desire to learn led him to give up joining the Corps to dedicate himself in "thinking about his things". As a young entrepreneur who had inherited a considerable family fortune, he immediately set out on a long trip through Europe in 1877, visiting Italy, France and Switzerland, to know the scientific and technical advances of the day, especially in the incipient area of electricity. Returning to Spain, he settled in Santander, where he continued his self-supported research activities.

Cableways


Torres' experimentation in the field of cableways and cable cars began very early during his residence in the town of his birth, Molledo. There, in 1887, he constructed the first cableway to span a depression of some 40 m. The cableway was about 200 m across and pulled by a pair of cows, with one log seat. This experiment was the basis for his first patent application in Spain, "Un sistema de camino funicular aéreo de alambres múltiples" ("A multi-wire suspended aerial system"), for a cable car with which he obtained a level of safety suitable for the transport of people, not only cargo. The patent was later extended to other countries: United States, Austria, Germany, France, United Kingdom, and Italy. Torres' cable cars used an innovative multi-cable support system, in which one end of a cable is anchored to fixed counterweights and the other (through a system of pulleys) to mobile counterweights. With this system the axial force of the cables via is constant and equal to the weight of the counterweight, regardless of the load in the shuttle. What will vary with this load is the deflection of the via cables, which will increase by raising the counterweight. Thus, the safety coefficient of these cables is perfectly known, and is independent of the shuttle load. The resulting design is very strong and remains safe in case of a support cable failure. Later, he constructed a cableway over the Río León in, Spain, that was faster and motorized, but still used solely for the transport of materials, not of people.

In 1889 Torres presented his cableway in Switzerland, a country very interested in that form of transport owing to its geography, and which was already starting to use cable cars for bulk transport in the Klimsenhorn-Pilatus Kulm line. However, he put his project on hold for a few years due to both rejection by Swiss engineers and comments and caricatures that appeared in the press of that country. On 30 September 1907, Torres put into operation a pioneer cableway suitable for the public transportation of people, the in San Sebastián. The journey was 280 meters, with a drop of 28 meters, lasted for just over three minutes, and the gondola had the capacity to board up to 18 people on each trip. The execution of the project was the responsibility of the Society of Engineering Studies and Works of Bilbao.



The successful result of this type of cable car gave him the opportunity to develop the famous Spanish Aerocar in Niagara Falls in Canada. The cableway of 550 meters in length is an aerial cable car that spans the whirlpool in the Niagara Gorge on the Canadian side. It travels at about 7.2 km/h. The load per cable via is 9 t, with a safety coefficient for the cables of 4.6. and carries 35 standing passengers over a one-kilometre trip. It was constructed between 1914 and 1916. For its construction and assembly, the Niagara Spanish Aerocar Company Limited was set up from the Society of Engineering Studies and Works, both companies promoted by Torres, with a capital of $110,000 (roughly $ million in ), and a planned concession of 20 years. The construction was directed by Torres' son, Gonzalo Torres Polanco. It completed its first tests on 15 February in 1916 and was officially inaugurated on 8 August, opening to the public the following day. The cableway, with small modifications, runs to this day with no accidents worthy of mention, constituting a popular tourist and cinematic attraction.

In 1991, the Niagara Parks Commission received the on the 75th anniversary of the Aero Car, in recognition of its commitment to preserving Torres' design. A plaque, mounted on a boulder in front of Aero Car Gift Shop recalls this fact: ''International Historic Civil Engineering Site. THE NIAGARA SPANISH AEROCAR. A tribute to the distinguished Spanish Engineer who designed the Niagara Spanish Aerocar. This was only one of his many outstanding contributions to the engineering profession. Engineer Leonardo Torres Quevedo (1852–1936). Constructed 1914–1916. CSCE. The Canadian Society for Civil Engineering. 2010. Asociación de Ingenieros de Caminos, Canales y Puertos de España. Spanish aerial ferry of the Niagara''.

Analogue calculating machines


Since the middle of the 19th century, several mechanical devices were known, from integrators, multipliers, to the Analytical engine of Charles Babbage. The work of Torres in this matter is framed within this tradition, which began in 1893 with the presentation of the "Memória sobre las máquinas algébricas" ("Memory about algebraic machines") at the Spanish Royal Academy of Sciences in Madrid. This paper was commented in a report by Eduardo Saavedra in 1894 and published in the. Torres developed a first model of the machine, and Saavedra recommended that the final project of the device be financed.

Torres' calculating machine was considered in its time as an extraordinary event in the course of Spanish scientific production. In 1895 he presented "Machines algébriques", accompanied by his demonstration model, at the Bordeaux Congress of the Association pour l'Avancement des Sciences, and in Paris in the Comptes rendus de l'Académie des Sciences. Later on, in 1900, he presented a more detailed work, "Machines à calculer" ("Calculating machines") at the Paris Academy of Sciences. The commission, informed favorably by Marcel Deprez, Henri Poincaré and Paul Appell, asked the academy for its publication, concluding: "... Mr. Torres has given a theoretical, general and complete solution to the problem of the construction of algebraic and transcendental relations by means of machines..."

These machines examined mathematical and physical analogies that underlay analogue calculation or continuous quantities, and how to establish mechanically the relationships between them, expressed in mathematical formulae. The study included complex variables and used the logarithmic scale. From a practical standpoint, it showed that mechanisms such as turning disks could be used endlessly with precision, so that changes in variables were limited in both directions. On the practical side, Torres built a whole series of analogue calculating machines, all mechanical. These machines used certain elements known as arithmophores which consisted of a moving part and an index that made it possible to read the quantity according to the position shown thereon. The aforesaid moving part was a graduated disk or a drum turning on an axis. The angular movements were proportional to the logarithms of the magnitudes to be represented. Between 1910 and 1920, using a number of such elements, Torres developed a machine that was able to compute the roots of arbitrary polynomials of order eight, including the complex ones, with a precision down to thousandths. The machine calculated the following formula: $$\alpha = \frac{A_1 X^a + A_2 X^b + A_3 X^c + A_4 X^d + A_5 X^e}{A_6 X^f + A_7 X^g + A_8 X^h} \,$$ where X is the variable and A1 ... A8 is the coefficient of each term. Considering the case of α = 1, it becomes the following formula, and the root of the algebraic equation can be obtained: $$A_1 X^a + A_2 X^b + A_3 X^c + A_4 X^d + A_5 X^e - A_6 X^f - A_7 X^g - A_8 X^h = 0 \,$$

By calculated each term on a logarithmic scale, they can be calculated only by sums and products like A1 + a × log(X), which can handle a very wide range of values, and the relative error during calculation is constant regardless of the size of the value. However, to calculate the sum of each term, it is necessary to accurately obtain log(u + v) from the calculated values log(u) and log(v) on a logarithmic scale. For this calculation, Torres invented a mechanism called "endless spindle" ("fusee sans fin"), a complex differential gear with a helical gear, which allowed the mechanical expression of the relation $$y=\log(10^x+1)$$. Putting log(u) – log(v) = log(u/v) = V, and using u/v = 10 V, calculate log(u + v) using the following formula: $$\log (u + v) = \log (v (u / v + 1)) = \log (v) + \log (u / v + 1) = \log (v) + \log(10^V + 1)\,$$, the same technique which is the basis of the modern electronic logarithmic number system.

In addition to this machine, Torres devised other with a small computing using gears and linkages around 1900 to obtain the complex number solution of the quadratic equation X2 – pX + q = 0. The machines are kept in the Torres Quevedo Museum at the School of Civil Engineering of the Technical University of Madrid.

Aerostatics


In 1902, Torres started the project of a new type of dirigible that would solve the serious problem of suspending the gondola, applying for a patent in France for ‘Perfectionnements aux aerostats dirigibles’ ("Improvements in dirigible aerostats"), complemented, with a "Note sur le calcul d’un ballon dirigeable a quille et suspentes interieures" ("Note on the calculus of a dirigible balloon with interior suspension and keel") which was presented together to Madrid and Paris’ Academies of Science.

Opposite to the usual cylindrical envelope, and with the objective of minimizing its stress and subsequent permeability, Torres conceived a trilobed envelope with three longitudinal cables (ropes) placed in the intersection of every two lobes. Inside the envelope, and on the basis of those three cables, a longitudinal frame of triangular cross section was to be completed, made up of non-rigid ropes, permeable fabric curtains, metal cables and longerons. Longitudinal cables and frame would ‘rigidify’ altogether through the excess of pressure level of the gas, so that, when inflated, it would act as an internal rigid structure. A system known as "auto-rigid". By the end of that year the report at Paris's Academy of Science was included in the French journal L’Aerophile, and a summary in English was published in the British The Aeronautical Journal.

In 1904, Torres was appointed director of the Centre for Aeronautical Research in Madrid, "for the technical and experimental study of the air navigation problem and the management of remote engine maneuvers". In 1905, with the collaboration of the Army Engineer Captain Alfredo Kindelán as Technical Assistant, he supervised the construction of the first Spanish dirigible in the Army Military Aerostatics Service, located in Guadalajara, which was finally completed in 1908. The new airship, named Torres Quevedo in his honour, made several successful test flights. Between 1907 and 1909 Torres had requested improved patents for his airship in France, beginning a collaboration with the Société Astra, a new Aeronautical Society integrated in the conglomerate of petroleum businessman Henri Deutsch de la Meurthe and directed by Édouard Surcouf, which managed to buy the patent with a cession of rights extended to all countries except Spain, making the use of said system free in the country. So, in 1911, the construction of dirigibles known as the Astra-Torres airships was begun and Torres would receive royalties of 3 francs for every m³ of each airship sold.

To find a resolution to the slew of problems faced by airship engineers in docking dirigibles, Torres also drew up designs for a ‘docking station’. In 1910, he proposed the idea of attaching an airship's nose to a mooring mast and allowing the airship to weathervane with changes of wind direction. The use of a metal column erected on the ground, the top of which the bow or stem would be directly attached to (by a cable) would allow a dirigible to be moored at any time, in the open, regardless of wind speeds. Additionally, Torres' design called for the improvement and accessibility of temporary landing sites, where airships were to be moored for the purpose of disembarkation of passengers. The patent was presented in February 1911 in Belgium, and later to France and the United Kingdom in 1912, which he named "Improvements in Mooring Arrengements for Airships".



In Issy-les-Moulineaux (south-west of Paris) in February 1911, the trials of ‘Astra-Torres no.1’ were successful and had a capacity of 1600m³. It was faster, more stable and more manoeuvrable than all the systems before it. It won the ‘Deperdussin’ prize and the French Army incorporated it into their operations. In 1913, the handing over of the Astra-Torres XIV (the HMA.No 3 to the Royal Naval Air Service) meant international recognition for the system with this ship beating the world speed record for an airship registering 83.2 km/h during the reception trials, a speed which reached 124 km/h with the wind in its favour. Other Astra-Torres dirigibles followed, including the Pilâtre de Rozier (Astra-Torres XV) named after the aerostier Jean-François Pilâtre de Rozier, which at 23,000 m3 was the same size of the German ‘Zeppelins’ and could reach speeds of around 100 km/h. The distinctive trilobed design was widely used during the First World War (1914–1918) by the Entente powers for diverse tasks, principally convoy protection and anti-submarine warfare. This type of envelope was employed in the United Kingdom in the Coastal, C Star, and North Sea airships.

In 1919, Torres designed, based on a request from engineer Emilio Herrera Linares, a transatlantic dirigible, which was named Hispania, aiming to claim the honor of the first transatlantic flight for Spain. Owing to financial problems, the project was delayed and it was the Britons John Alcock and Arthur Brown who crossed the Atlantic non-stop from Newfoundland to Ireland in a Vickers Vimy twin-engine plane, in sixteen hours and twelve minutes.

The success of the trilobed blimps during the war even drew the attention of the Imperial Japanese Navy, who acquired the Nieuport AT-2 in 1922, with almost 263 ft long, maximum diameter 54 ft and with a hydrogen capacity of 363,950 ft 3. After Torres' patent expired that year, many aerostats of this class continued to be manufactured during the postwar period, including those of the French Zodiac Company, which influenced the design of most later airships.

Radio control: the Telekino
Torres was a pioneer in the field of remote control. He began to develop a system around 1901 or 1902, as a way of testing his airships without risking human lives. For its device, he chose the name Telekino as a combination of two Greek words: tele which means "at distance" and kino which means "movement", resulting both together "movement at distance". Between 1902 and 1903, he applied for patents in France, Spain, and Great Britain, under the title "Systéme dit Télékine pour commander à distance un mouvement mécanique" ("Means or method for directing mechanical movements at or from a distance"). On 3 August 1903, he presented the Telekino at the French Academy of Sciences, together with a detailed memory and making a practical demonstration to its members. For the construction of this initial model, Torres received help from Gabriel Koenigs, director of the Mechanical Laboratory of the Sorbonne, and Octave Rochefort, who collaborated by providing wireless telegraphy devices.



While other radio control proposals were based on a simple technique with a limited set of actions known as 'on/off', Torres established a method for controlling any mechanical or electrical device with different states of operation by using a code based on the number of pulses consecutively sent. In this way, to one pulse corresponded the action number 1, to two pulses corresponded the action number 2, to three pulses the action number 3 and so on. The Telekino has three parts: a wireless telegraph receiver, a multi-position switch unit and two servomotors that can be used to drive a mechanical element. The signal transmitted by electromagnetic waves, is received by the antenna and is transformed into electric pulses by a coherer. Each pulse drives an electromagnet, which closes its secondary circuit causing the multi-position switch unit to go one step forward. This operation is repeated automatically as many times as impulses have got the signal. When the multi-position switch reaches its final position, the battery supplies current to the chosen servomotor terminal. Then, the servomotor is put in motion causing a known and previously defined action. Torres was able to select different positions for the steering engine and different velocities for the propelling engine independently. He was also able to act over other mechanisms such a light, for switching on or off, and a flag, for raising or dropping it, at the same time. Specifically, Torres was able to do up to 19 different actions with his prototypes.

In 1904 Torres chose to conduct initial Telekino testings, first in an electric three-wheeled land vehicle in the Beti Jai fronton of Madrid, with an effective range of just 20 to 30 meters, which has been considered the first known example of a radio-controlled unmanned ground vehicle (UGV). In 1905, Torres tested a second model of the Telekino located in a boat in the pond of the Casa de Campo in Madrid, achieving distances of up to about 250 m. From the terrace of the Club Marítimo del Abra, and with the assistance of the president of the Provincial Council and other authorities, an experiment was carried out with the Telekino remotely controlling the maneuvers of the electrically powered boat Vizcaya. These feats were echoed in the international press.



On 25 September 1906, in the presence of the king Alfonso XIII and before a great crowd, he successfully demonstrated the invention in the port of Bilbao, guiding the boat Vizcaya from the shore with people on board, demonstrating a standoff range of 2 km. Witness to the success of these tests, José Echegaray highlighted how "no one moves" the Telekino, "it moves automatically." He was an automaton of "a certain intelligence, not conscious, but disciplined"; "a material device, without intelligence, interpreting, as if it were intelligent, the instructions communicated to it in a succession of Hertzian waves." The positive results of those experiences encouraged Torres to apply to the Spanish government for the financial aid required to use his Telekino to steer submarine torpedoes, a technological field which was just starting out. His application was denied, which caused him to abandon the development of the Telekino.

In 2007, the prestigious Institute of Electrical and Electronics Engineers (IEEE) dedicated a Milestone in Electrical Engineering and Computing to the Telekino, based on the research work developed at Technical University of Madrid by Prof. Antonio Pérez Yuste, who was the driving force behind the Milestone nomination.

Formal language
In 1907, Torres introduced a formal language for the description of mechanical drawings, and thus for mechanical devices, in Vienna. He previously published "Sobre un sistema de notaciones y símbolos destinados a facilitar la descripción de las máquinas" ("System of notations and symbols intended to facilitate the description of the machines") in the Revista de Obras Públicas. According to the Austrian computer pioneer Heinz Zemanek, this was equivalent to a programming language for the numerical control of machine tools. He defined a table of symbols, a collection of rules and, as usual in his works, applied them to an example. This symbolic language reveals Torres' main capacities, both his ability to detect a problem, in this case a social problem of origin and its technical consequences, as well as his capacity for creation – invention – to give a rational, properly technical response. In the words of Torres: "Babbage and Franz Reuleaux – and I suppose others as well, although I don't have news of them – have tried, without any success, to put remedy to this inconvenience; but although these eminent authors have failed, should not be a sufficient reason to abandon such an important effort". Babbage, Reuleaux and Torres failed. The world of machines continues without any other symbolic language than descriptive geometry.

Laboratory of Automation
As a member of the steering committee of the  (Junta para Ampliación de Estudios e Investigaciones Científicas) established in 1907 to promote research and scientific education in Spain, Torres played a leading and decisive role in the creation of three key state agencies that were the models for the Board support to research, regardless of the discipline: the Laboratory of Automation (1907) — of which he was named director, the construction of instruments –  the Laboratories Association (1910) – the union of state laboratories and workshops – and the Institute of Science Materials (1911)  – the budget allocation.

The Laboratory of Automation produced the most varied instruments; it not only built its own inventions, but also provided services and support to universities and researchers of the Board. Torres, the physicist Blas Cabrera, and Juan Costa, the head of the workshop, jointly designed several scientific instruments (Weiss-type electromagnet, an X-ray spectrometer, a mechanism to handle through remote control a Bunge scale, a reservoir of variable height with micrometer movements for magnetic-chemical measurements, and some on). , head of the Spectroscopy Section of the Laboratory of Physical Research and Miguel A. Catalán’s teacher, ordered Torres’s workshop a spectrographic equipment; requested an interferometer for a variable distance, Michelson- type; Juan Negrín requested a stalagmometer, and Santiago Ramón y Cajal commissioned a microtome and panmicrotome, and a projector for film screenings.

Chess automaton: El Ajedrecista
In early 1910s, Torres began to construct a chess automaton he dubbed El Ajedrecista (The Chess Player). As opposed to The Turk and Ajeeb, El Ajedrecista had a true integrated automation and could automatically play a king and rook endgame against the king from any position, without any human intervention.

The pieces had a metallic mesh at their base, which closed an electric circuit that encoded their position in the board. When the black king was moved by hand, an algorithm calculated and performed the next best move for the white player. If an illegal move was made by the opposite player, the automaton would signal it by turning on a light. If the opposing player made three illegal moves, the automaton would stop playing. The automaton does not deliver checkmate in the minimum number of moves, nor always within the 50 moves allotted by the fifty-move rule, because of the simple algorithm that calculates the moves. It did, however, checkmate the opponent every time. Claude Shannon noted in his work Programming a Computer for Playing Chess (1950) that Torres' machine "was quite advanced for that period". The device has been considered the first computer game in history.

This example recorded in portable game notation shows how White checkmates the black King, following Torres' algorithm: [FEN "8/8/1k6/8/R7/8/5K2/8 w - - 0 1"]

1. Rh4 Kc5 2. Kf3 Kd5 3. Ke3 Kd6 4. Rh5 Kc6 5. Ke4 Kd6 6. Rg5 Kc6 7. Kd4 Kd6 8. Rg6+ Kd7 9. Kd5 Ke7 10. Rh6 Kf7 11. Ra6 Ke7 12. Rb6 Kf7 13. Ke5 Ke7 14. Rb7+ Kd8 15. Ke6 Kc8 16. Rh7 Kb8 17. Rg7 Ka8 18. Kd6 Kb8 19. Kc6 Ka8 20. Kb6 Kb8 21. Rg8#

It created great excitement when it made its debut, at the University of Paris in 1914. Its internal construction was published by Henri Vigneron in the French magazine La Nature. On November 6, 1915 Scientific American magazine in their Supplement 2079 pp. 296-298 published an illustrated article entitled "Torres and His Remarkable Automatic Devices. He Would Substitute Machinery for the Human Mind". It was summarized as follows:

"'The inventor claims that the limits within which thought is really necessary need to be better defined, and that the automaton can do many things that are popularly classed with thought'."



In 1922, Torres completed the construction designs for his second chess player, which he presented in 1923 in Paris. It was more elegant and technically perfected. The mechanical arms to move pieces were replaced for electromagnets located under the board. This version included a gramophone, with a voice recording announcing checkmate when the computer won the game. His son Gonzalo exhibited the advanced machine at several international meetings, introducing it to a wider audience at the 1951 Paris Cybernetic Conference, where it was explained to Norbert Wiener. El Ajedrecista also defeated Savielly Tartakower at the Conference, being the first Grandmaster to lose against a machine. It was later demonstrated at the Brussels World Fair in 1958, Heinz Zemanek described it as "a historical witness of automaton artistry that was far ahead of its time". According to Zemanek, Torres designed a very clever six-part algorithm for the end game, which was implemented using levers, gearwheels, and relays.

Essays on Automatics
"It has been commonly assumed (see Metropolis and Worlton 1980) that Charles Babbage's work on a mechanical digital program-controlled computer, which he started in 1835 and pursued off and on until his death in 1871, had been completely forgotten and was only belatedly recognized as a forerunner to the modern digital computer. Ludgate, Torres y Quevedo, and Bush give the lie to this belief, and all made fascinating contributions that deserve to be better known."

In 1914, Torres published "Ensayos sobre Automática. Su definición. Extensión teórica de sus aplicaciones" (Essays on Automatics. Its Definition – Theoretical Extent of Its Applications) in the Revista de Obras Públicas. It was translated into French with the title "Essais sur l'Automatique" in the Revue Générale des Sciences Pures et Appliquées on November 15, 1915.

This is Torres' major written work on the subject he called Automatics, "another type of automaton of great interest: those that imitate, not the simple gestures, but the thoughtful actions of a man, and which can sometimes replace him". He drew a distinction between the simpler sort of automaton, which has invariable mechanical relationships and the more complicated, interesting kind, whose relationships between operating parts alter "suddenly when necessary circumstances arise". Such an automaton must have sense organs, that is, "thermometers, magnetic compasses, dynamometers, manometers", and limbs, as Torres called them, mechanisms capable of executing the instructions that would come from the sense organs. The automaton postulated by Torres would be able to make decisions so long as "the rules the automaton must follow are known precisely".

The paper provides the main link between Torres and Babbage. He gives a brief history of Babbage's efforts at constructing a mechanical Difference engine and Analytical engine. He described the Analytical Engine as exemplifying his theories as to the potential power of machines, and takes the problem of designing such an engine as a challenge to his skills as an inventor of electromechanical devices. Contains a complete design (albeit one that Torres regarded as theoretical rather than practical) for a machine capable of calculating completely automatically the value of the formula $$a^x(y - z)^2$$, for a sequence of sets of values of the variables involved. It demonstrates cunning electromechanical gadgets for storing decimal digits, for performing arithmetic operations using built-in function tables, and for comparing the values of two quantities. The whole machine was to be controlled from a read-only program (complete with provisions for conditional branching), represented by a pattern of conducting areas mounted around the surface of a rotating cylinder.

The paper also introduced the idea of floating-point arithmetic, which historian Randell says was described "almost casually", apparently without recognizing the significance of the discovery. Torres proposed a format that showed he understood the need for a fixed-size significand as is presently used for floating-point data. He did it in the following way:

"'Very large numbers are as embarrassing in mechanical calculations as in usual calculations (Babbage planned 50 wheels to represent each variable, and even then they would not be sufficient if one does not have recourse to the means that I will indicate later, or to another analogue). In these, they are usually avoided by representing each quantity by a small number of significant figures (six to eight at the most, except in exceptional cases) and by indicating by a comma or zeros, if necessary, the order of magnitude of the units represented by each digit.

Sometimes also, so as not to have to write a lot of zeros, we write the quantities in the form n x 10$^m$.

We could greatly simplify this writing by arbitrarily establishing these three simple rules:

1. n will always have the same number of digits (six for example).

2. The first digit of n will be of order of tenths, the second of hundredths, etc.

3. One will write each quantity in the form: n; m.

Thus, instead of 2435.27 and 0.00000341682, they will be respectively, 243527; 4 and 341862; −5.

I have not indicated a limit for the value of the exponent, but it is obvious that, in all the usual calculations, it will be less than one hundred, so that, in this system, one will write all the quantities which intervene in calculations with eight or ten digits only.'"

The paper ends with a comparison of the advantages of electromechanical devices that were all that were available to Babbage. It establishes that Torres would have been quite capable of building a general-purpose electromechanical computer more than 20 years ahead of its time, had the practical need, motivation, and financing been present.

Analytical machines


Torres went ahead to prove his theories with a series of working prototypes. He demonstrated twice, in 1914 and in 1920, that all of the cogwheel mechanisms of a calculating machine like that of Babbage could be implemented using electromechanical parts. His 1914 analytical machine used a small memory built with electromagnets, capable of evaluating p × q – b.

In 1920, to celebrate the 100th anniversary of the invention of the arithmometer, he presented at a Paris conference the "Arithmomètre Electroméchanique" (Electromechanical Arithmometer), which consisted of an arithmetic unit connected to a (possibly remote) typewriter, on which commands could be typed and the results printed automatically (e.g. "532 × 257" and "= " from the typewriter). This calculator was not programmable, but was able to print the numerical value of the answer. From the user interface point of view, this machine can be regarded as the predecessor of current computers that use a keyboard as an input interface. In terms of usage, it was also assumed that calculations could be performed remotely by extending electric wires, and is considered to be a rudimentary version of today's online systems that use communication lines. Torres had no thought of making such a machine commercially, viewing it instead as a means of demonstrating his ideas and techniques.

Additionally, in his 1920 paper on the electromechanical arithmometer, he pointed out the need for various automatic machines to represent continuous numbers as finite discrete values and perform processing and judgment, which corresponds to current digital data.

Naval projects


In those days when the outbreak of the Great War was anticipated, Torres designed a transport ship intended to accompany fleets. On 30 July 1913, he patented the "Buque campamento" ("Camp-Vessel"), a dirigible balloon carrier with a mooring mast and a hold large enough to house up to two inflated units, and hydrogen cylinders. He had thought of the possibility of combining aeronautics with the navy in this way, offering his patent to Vickers Limited, although the conglomerate did not show interest in the project. Then Torres reached Admiral Reginald Bacon, who, on 17 March 1914, wrote from the Coventry Ordnance Works that "the experience of the Navy has invariably been that any auxiliary craft carried on board ship are of very little real service". A few years later, in 1922, the Spanish Navy would construct a real airship carrier, the Dédalo, to be used in the war against Morocco.

In 1916 Torres patented in Spain a new kind of ship, a multihull steel vessel which received the name of "Binave" ("Twin Ship"). He applied for the patent in the United Kingdom called "Improvements in Ships" in 1917, and it was constructed in Bilbao in 1918, with several test departures such as the successful round trip to Santoña on 28th September. The tests would be resumed in 1919, obtaining the certificate of implementation of the patent on November 12 of that year. He introduced important innovations in this design, including two 30 HP Hispano-Suiza marine engines, and the ability to modify its configuration when sailing, positioning two rudders at the stern of each float, and placing the propellers aft too, making it similar to modern catamarans.

Inventions in other fields
In addition to the aforementioned inventions, Torres patented the "Coordinate Indicator" (1901) to guide people through cities using a mechanical system of signals located on streetlights, which he proposed for Madrid and Paris under the name of "Guide Torres", the "Dianemologo" (1907), a machine to copy, without the need to resort to shorthand, any speech to as it is pronounced, "Deformable Fusiform Balloons" (1914), a fusiform envelope with a variable section depending on the volume of the hydrogen contained, and "Railway Interlocks T.Q." (1918), an interlock of his own design to protect the movement of trains within a certain area.

In the last years of his life, Torres turned his attention to the field of educational disciplines, to investigate those elements or machines that could help educators in their task. From 1922 to 1930 he patented improvements on typewriters, the marginal pagination of books, the "Puntero Proyectable" ("Projectable Pointer"), and the "Proyector Didáctico" ("Didactic Projector"). The Projectable Pointer is based on the shadow produced by an opaque body that moves close to the projected plate, being this shadow used as a pointer. To do this, he designed an articulated system that allowed moving, at the speaker's will, a point or points next to the projection plate, allowing areas of interest to be indicated in the transparency. The Didactic Projector improved the way slides were placed on glass plates for projection.

Esperantist


In the early 1900s, Torres learned the international language Esperanto, and was an advocate of the language throughout his life. Between 1922 and 1926, he participated in the work of the International Committee on Intellectual Cooperation of the League of Nations, proposing the following motion on the first day of the meeting: "The Committee, convinced of the usefulness of an artificial auxiliary language to facilitate scientific relations between different peoples, establishes a subcommittee in charge of studying, with the help of experts, the various solutions that have been proposed". Although almost half of the Committee members were in favor of Esperanto, the motion met with determined opposition from some other participants. In 1925 he participated as the official representative of the Spanish government in the "Conference on the Use of Esperanto in Pure and Applied Sciences" held in Paris, together with and Emilio Herrera Linares. That same year, he joined to the Honorary Committee of the (HEA), founded by Julio Mangada, and defended the language in other forums until his death in 1936.

Spanish-American Technological Dictionary
In 1910 Torres traveled to Argentina with the Infanta Isabel to assist at the International Scientific Congress held in Buenos Aires, one of the events organized to mark the centenary of the independence of Argentina. At the congress, he proposed, along with the Argentinean engineer Santiago Barabino, the constitution of a Spanish-American board of scientific technology, which would eventually become the "Unión Internacional Hispano–Americana de Bibliografía y Terminología Científicas". The first task was the publication of a technological dictionary of the Spanish language to tackle the problems caused by the increasing use of scientific and technological neologisms, as well as the adaptation of words from other languages, confronted with the avalanche of foreign terms. As a result of the work of this board, in 1930 appeared the Volume 1 of the Diccionario Tecnológico Hispanoamericano (Hispanic American Technological Dictionary). and in 1918, he declined the offer of the position of Minister of Development. In 1920, he was admitted to the Real Academia Española, to fill the seat N vacated by the death of Benito Pérez Galdós, declaring in his speech:

"'You were wrong in choosing me as I do not have that minimum culture required of an academic. I will always be a stranger in your wise and learned society. I come from very remote lands. I have not cultivated literature, nor art, nor philosophy, nor even science, at least in its higher degrees… My work is much more modest. I spend my busy life solving practical mechanics problems. My laboratory is a locksmith shop, more complete, better assembled than those usually known by that name; but destined, like all, to project and build mechanisms…'"



That same year he was elected president of the Royal Spanish Mathematical Society, a position he held until 1924 and became a member of the Department of Mechanics of the Paris Academy. From 1921 to 1928 he assumed the presidency of the Spanish section of the International Committee for Weights and Measures, where due to his experience in development of instruments, contributed to the improvement of measurements made in the laboratories of the International Bureau of Weights and Measures (BIPM). In 1923 the Sorbonne named him an Honorary Doctor and became an honorary member of the. In 1925 was appointed a corresponding member of the Hispanic Society of America. In 1927 he was named one of the twelve foreign associate academicians of the French Academy of Sciences with 34 votes for his entry, beating Ernest Rutherford (4 votes) and Santiago Ramón y Cajal (2 votes). Between 1906 and 1934 he also received the following decorations:


 * Grand Cross of the Civil Order of Alfonso XII (1906)
 * Parville Award of the French Academy of Sciences (1916)
 * Grand Cross of the Order of Charles III (1921)
 * Grand Cross of the Military Order of Saint James of the Sword (1921)
 * Commander of the Legion of Honour (1922)
 * Honorary doctorate of the University of Coimbra (1925)
 * Grand-Cross Band of the Order of the Spanish Republic (1934)

Personal life and death
In 1885 Torres married Luz Polanco y Navarro in Portolín (Molledo), with whom he had eight children: Leonardo (died at age 2), Gonzalo (later his collaborator), Luz, Valentina, Luisa, Julia, Leonardo and Fernando. After the death of his first son, in 1889, he moved to Madrid with the firm intention of putting into practice the projects he had devised in previous years. During this time he attended the Athenæum, the literary gatherings at the and the Elipa, but generally without participating in debates and discussions of a political nature. He lived for many years in nº 3.

On 18 December 1936, after a progressive illness, Torres died at the home of his son Gonzalo in Madrid, in the heat of the Spanish Civil War, ten days before his eighty-fourth birthday. He was buried in the monumental Saint Isidore Cemetery.

Legacy and honours
"The wise Spanish engineer Torres Quevedo – today a foreign associate of our Academy of Sciences – who is perhaps the most prodigious inventor of our time, at least in terms of mechanisms, has not afraid to tackle Babbage's problem in turn.

What prospects do such marvels open on the possibilities of the future as regards the reduction to a purely mechanical process of any operation obeying mathematical rules!' In this field, the way was opened, nearly three centuries ago, by the genius of Pascal; in recent times, the genius of Torres Quevedo has managed to enter regions to which he would never have dared to think a priori that he could have access."

After Torres died in 1936, the distressing circumstances that Spain was going during its Civil War meant that his death would go somewhat unnoticed. However, such newspapers as The New York Times and the French mathematician Maurice d'Ocagne published obituaries in 1937 and 1938 praising his engineering and research work, the latter giving some conferences in Paris and Brussels.

Created the Spanish National Research Council (CSIC) in 1939, the architect was commissioned with the project and construction of a large building in Madrid to house the new Institute «Leonardo Torres Quevedo» of Applied Physics, which was completed in 1943. Its dedicated to "designing and manufacturing instruments and investigating mechanical, electrical and electronic problems", and was the germ of the current Institute of Physical and Information Technologies "Leonardo Torres Quevedo" (ITEFI).

In the years following his death, Torres was not forgotten. In 1953 began the commemorative acts of the Centenary of his birth, taking place at the Spanish Royal Academy of Sciences with the intervention of high-ranking academic, scientific and university personalities from the country and abroad, including Louis Couffignal, Charles Lambert Manneback, and.

Two postage stamps were issued in his honour in 1955 and 1983, the last one next to the image of the Niagara cable car.

In 1965, the City Council of Madrid dedicated a commemorative plaque to him in his residence building at Válgame Dios, 3, informing the people of Madrid that "the scientist who brought so much glory to Spain lived in that place."

The (FLTQ) was created in 1981 under his name as a non-profit organization to promote scientific research within the framework of the University of Cantabria and to training professionals in this area. The Foundation had its headquarters at the University of Cantabria School of Civil Engineering.

In 1983, the was established in Spain by the Ministry of Science to recognize the merits of Spanish scientists or researchers in the field of engineering.

A bronze statue on a stone pedestal was erected in 1986 on the occasion of the fiftieth anniversary of his death. The work was commissioned to the sculptor and its located in Santa Cruz de Iguña, Torres' birth town.

On 19 July 2008, commemorated the centenary of the Torres Quevedo airship built in Guadalajara, which was the beginnings of the Spanish Air Force. The same year, the Leonardo Torres Quevedo Centre was opened in Santa Cruz de Iguña, dedicated to his life and work.

On 28 December 2012, Google celebrated his 160th birthday with a Google Doodle. That same year the company had also commemorated the 100th anniversary of "El Ajedrecista", highlighting that it was a marvel of its time and could be considered the "grandfather" of current video games. A conference was organized on November 7 in cooperation with the School of Telecommunication Engineering of the Technical University of Madrid to exhibit the devices devised by the Spanish engineer.

On 8 August 2016, the 100th Anniversary of the Whirlpool Aero Car was celebrated for its uninterrupted operation, without having had any accidents. The ceremony also included members of the Torres Quevedo family, who made a special trip from Spain to attend the anniversary celebrations and, the Spanish Ambassador to Canada. According to Niagara Parks Commission Chair, Janice Thomson, "this morning’s celebrations have allowed us to properly mark an important milestone in the history of the Niagara Parks Commission, all while recognizing the accomplishments and paying tribute to Leonardo Torres Quevedo, who through his work made a lasting impression on both the engineering profession and the tourism industry here in Niagara."

In 2022 was presented in Santander the new turbosail of La Fura dels Baus, La Naumon, a large white structure at the base of which stands out the figure of Leonardo Torres Quevedo, with whose name it was baptized the device. On 4 July, the flag carrier Iberia received the fifth of the six Airbus A320neo planned for that year. This A320neo with registration EC-NTQ bears the name "Leonardo Torres Quevedo", to honoured the Spanish inventor.

On 5 May 2023, the Instituto Cervantes opened the Caja de las Letras to house the "in memoriam" legacy of Leonardo Torres Quevedo. Among the deposited objects, letters and manuscripts; a dozen publications, with books, monographs or catalogues; postcards and a schedule of the Niagara Falls cable car designed by him, and the Milestone awarded by the Institute of Electrical and Electronics Engineers that recognizes the engineer's scoop in the development of remote-control in 1901 with the Telekino. Torres' granddaughter Mercedes Torres Quevedo expressed her gratitude to the institution on behalf of all her descendants for welcoming her grandfather's legacy and the "pride" of all of them for the scientific and humanistic work he carried out throughout of his life. His legacy has been deposited in box number 1275 and the keys in the hands of his descendants and the institution itself.

Selected works

 * "Un sistema de camino funicular aéreo de alambres múltiples" (1887)
 * "Memoria sobre las máquinas algébricas", Revista de Obras Públicas (1895)
 * "Machines algébriques", Comptes rendus de l'Académie des Sciences (1895)
 * "Machines à calculer", Académie des Scienes de l'Institut de France (1901)
 * "Perfectionnements aux aerostats dirigibles", Paris, Academy of Sciences (1902)
 * "Note sur le calcul d’un ballon dirigeable a quille et suspentes interieures" (1902)
 * "Systéme dit Télékine pour commander à distance un mouvement mécanique" (1902)
 * "Sobre un sistema de notaciones y símbolos destinados a facilitar la descripción de las máquinas", Revista de Obras Públicas (1907)
 * "Improvements in Mooring Arrengements for Airships" (1911)
 * "Una nuevo tipo de buque denominado Buque Campamento" (1913)
 * "Ensayos sobre Automática. Su definición. Extensión teórica de sus aplicaciones", Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales (1914)
 * "Una nueva embarcación que se denominará Binave" (1916)
 * "Un nuevo tipo de globo denominado Hispania" (1919)
 * "Arithmometre Electromechanique", Bull. de la Société d'encouragement pour l'industrie nationale (1920)
 * "Puntero proyectable" (1930)
 * "Un proyector didáctico" (1930)

In fiction
Leonardo Torres Quevedo is a main character of the novel Los horrores del escalpelo (The horrors of the scalpel, 2011), written by Daniel Mares. The plot tells how the Spanish engineer travels to London in 1888 to find Maelzel's Chess Player, a mechanical automaton that was believed to have been lost for decades. Together with Raimundo Aguirre, a thief and murderer, who claims to have the clue to the lost automaton, he begins the search through the London underworld and Victorian high society. The search is interrupted due to the streets of the Whitechapel neighborhood dawn with corpses of prostitutes, which causes Torres and his partner Aguirre to become involved in the hunt for Jack the Ripper.

Significant Publications

 * Torres y Quevedo, "Arithmometre Electromechanique," Bull. de la Societe d Encouragement for l'Industrie Nationale, Vol. 119, 1920, pp. 588–99, reprinted in Randell, Brian, Origins of Digital Computers: Selected Papers, Springer-Verlag, Berlin, 1982.