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Carlos Ibáñez e Ibáñez de Ibero

Carlos Ibáñez e Ibáñez de Ibero, 1st Marquis of Mulhacén, (14 April 1825 – 28 or 29 January 1891) was a Spanish divisional general and geodesist.[1][2][3] He represented Spain at the 1875 Conference of the Metre Convention and was the first president of the International Committee for Weights and Measures.[4] As a forerunner geodesist and president of the International Geodetic Association,[5] he played a leading role in the worldwide dissemination of the metric system.[6] His activities resulted in the distribution of a platinum and iridium prototype of the metre to all States parties to the Metre Convention during the first meeting of the General Conference on Weights and Measures in 1889.[4] These prototypes defined the metre right up until 1960.[7]

Carlos Ibáñez e Ibáñez de Ibero
Portrait of Carlos Ibáñez e Ibáñez de Ibero in 1881
Born14 April 1825
Barcelona (Spain)
Died28 or 29 January 1891
Nice (France)
Resting placeCimetière du Château in Nice
NationalitySpanish
Known forPresident of the International Committee for Weights and Measures (1875–1891)
AwardsPoncelet Prize
Scientific career
FieldsGeodesy, Geography, Metrology, Statistics.
InstitutionsInstituto Geográfico Nacional (Spain)

International Association of Geodesy

International Statistical Institute

He was born in Barcelona. According to Spanish tradition, his surname was a combination of his father's first surname, Martín Ibáñez y de Prado and of his mother's first surname, Carmen Ibáñez de Ibero y González del Río.[8][3][9] As his parents' surnames were so similar he was often referred as Ibáñez or Ibáñez de Ibero or as Marquis of Mulhacén. When he died in Nice (France), he was still enrolled in the Engineer Corps of the Spanish Army.[6] As he died around midnight, the date of his death is ambiguous, Spaniards retained 28th, and other Europeans 29 January.[10][11][1][2]

Scientific career Edit

From the Map Commission to the Geographic and Statistical Institute in Spain Edit

 
Swiss baseline measurement with Ibáñez apparatus in 1880.

Spain adopted the metric system in 1849. The Government was urged by the Spanish Royal Academy of Sciences to approve the creation of a large-scale map of Spain in 1852.[9] The following year Ibáñez was appointed to undertake this task.[4] As all the scientific and technical equipment for a vast undertaking of this kind had to be created, Ibáñez, in collaboration with his comrade, Captain Frutos Saavedra Meneses, drew up the project of a new apparatus for measuring bases. He recognized that the end standards with which the most perfect devices of the eighteenth century and those of the first half of the nineteenth century were still equipped, that Jean-Charles de Borda or Friedrich Wilhelm Bessel simply joined measuring the intervals by means of screw tabs or glass wedges, would be replaced advantageously for accuracy by the system, designed by Ferdinand Rudolph Hassler for the Coast Survey of the United States, and which consisted of using a single standard with lines marked on the bar and microscopic measurements. Regarding the two methods by which the effect of temperature was taken into account, Ibáñez used both the bimetallic rulers, in platinum and brass, which he first employed for the central base of Spain, and the simple iron ruler with inlaid mercury thermometers which was used in Switzerland.[4][12]

Ibáñez and Saavedra went to Paris to supervise the production by Jean Brunner of a measuring instrument calibrated against the metre which they had devised and which they later compared with Borda's double-toise N°1 which was the main reference for measuring all geodetic bases in France and whose length was by definition 3.8980732 metres at a specified temperature.[13][6][14][15][16] The four-metre-long Spanish measuring instrument, which became known as the Spanish Standard (French: Règle espagnole), was replicated in order to be used in Egypt.[13][17][18][19] In 1863, Ibáñez and Ismail Effendi Mustafa compared the Spanish Standard with the Egyptian Standard in Madrid.[20][21][22] These comparisons were essential, because of the expansibility of solid materials with raise in temperature. Indeed, one fact had constantly dominated all the fluctuations of ideas on the measurement of geodesic bases: it was the constant concern to accurately assess the temperature of standards in the field; and the determination of this variable, on which depended the length of the instrument of measurement, had always been considered by geodesists as so difficult and so important that one could almost say that the history of measuring instruments is almost identical with that of the precautions taken to avoid temperature errors.[18]

In 1858 Spain's central geodetic base of triangulation was measured in Madridejos (Toledo) with exceptional precision for the time thanks to the Spanish Standard.[4][17] Ibáñez and his colleagues wrote a monograph which was translated into French by Aimé Laussedat.[23] The experiment, in which the results of two methods were compared, was a landmark in the controversy between French and German geodesists about the length of geodesic triangulation bases, and empirically validated the method of General Johann Jacob Bayer, founder of the International Association of Geodesy.[24]

From 1865 to 1868 Ibáñez added the survey of the Balearic Islands with that of the Iberian Peninsula.[17][25] For this work, he devised a new instrument, which allowed much faster measurements.[17] In 1869, Ibáñez brought it along to Southampton where Alexander Ross Clarke was making the necessary measurements to compare the Standards of length used in the World.[4][14][26] Finally, this second version of the appliance, called the Ibáñez apparatus, was used in Switzerland to measure the geodetic bases of Aarberg, Weinfelden and Bellinzona.[4][27]

In 1870 Ibáñez founded the Spanish National Geographic Institute which he then directed until 1889.[28][29] At the time it was the world's biggest geographic institute.[4] It encompassed geodesy, general topography, leveling, cartography, statistics and the general service of weights and measures.[4]

Measurement of the Paris meridian over the Mediterranean Sea Edit

 
The West Europe-Africa Meridian-arc extending from the Shetland Islands, through Great Britain, France and Spain to El Aghuat in Algeria, whose parameters were calculated from surveys carried out in the mid to late 19th century. Greenwich meridian is depicted rather than Paris meridian.[30]

Jean Brunner displayed the Ibáñez-Brunner apparatus at the Exposition Universelle of 1855.[31][32] Copies of the Spanish standard[31] were also made for France[33][34] and Germany.[35] These standards would be used for the most important operations of European geodesy.[18] Indeed, the southward extension of Paris meridian's triangulation by Pierre Méchain (1803–1804), then François Arago and Jean-Baptiste Biot (1806–1809) had not been secured by any baseline measurement in Spain.[36][37]

Moreover Louis Puissant declared in 1836 to the French Academy of Sciences that Jean Baptiste Joseph Delambre and Pierre Méchain had made errors in the triangulation of the meridian arc, which had been used for determining the length of the metre.[37][38] This is why Antoine Yvon Villarceau verified the geodetic operations at eight points of the Paris meridian arc from 1861 to 1866. Some of the errors in the operations of Delambre and Méchain were then corrected.[39]

In 1865 the triangulation of Spain was connected with that of Portugal and France.[23][22] In 1866 at the conference of the Association of Geodesy in Neuchâtel, Ibáñez announced that Spain would collaborate in remeasuring and extending the French meridian arc.[4][40] From 1870 to 1894, François Perrier, then Jean-Antonin-Léon Bassot proceeded to a new survey.[39][33] In 1879 Ibáñez and François Perrier completed the junction between the geodetic networks of Spain and Algeria and thus completed the measurement of a meridian arc which extended from Shetland to the Sahara.[41] This connection was a remarkable enterprise where triangles with a maximum length of 270 km were observed from mountain stations (Mulhacén, Tetica, Filahoussen, M'Sabiha) over the Mediterranean Sea.[42][41][43][33]

This meridian arc was named West Europe-Africa Meridian-arc by Alexander Ross Clarke and Friedrich Robert Helmert. It yielded a value for the equatorial radius of the earth a = 6 377 935 metres, the ellipticity being assumed as 1/299.15 according to Bessel ellipsoid.[44][45] The radius of curvature of this arc is not uniform, being, in the mean, about 600 metres greater in the northern than in the southern part.[30]

According to the calculations made at the central bureau of the International Geodetic Association, the net does not follow the meridian exactly, but deviates both to the west and to the east; actually, the meridian of Greenwich is nearer the mean than that of Paris.[30]

International scientific collaboration in geodesy and calls for an international standard unit of length Edit

In 1866 Spain, represented by Ibáñez, joined the Central European Arc Measurement (German: Mitteleuropäische Gradmessung) at the Permanent Commission meeting in Neuchâtel.[46][40] In 1867 at the second General Conference of the Central European Arc Measurement (see International Association of Geodesy) held in Berlin, the question of an international standard unit of length was discussed to combine the measurements made in different countries to determine the size and shape of the Earth.[47][48][49][4] The Conference recommended the adoption of the metre and the creation of an international metre commission,[46] according to a preliminary discussion between Johann Jacob Baeyer, Adolphe Hirsch and Carlos Ibáñez e Ibáñez de Ibero.[4] Ferdinand Rudolph Hassler's use of the metre in coastal survey, which had been an argument for the introduction of the Metric Act of 1866 allowing the use of the metre in the United States, probably also played a role in the choice of the metre as international scientific unit of length and the proposal by the European Arc Measurement (German: Europäische Gradmessung) to "establish a European international bureau for weights and measures".[50][14][51][46]

The French Academy of Sciences and the Bureau des Longitudes in Paris drew the attention of the French government to this issue. The Academy of St Petersburg and the English Standards Commission were in agreement with the recommendation.[47][52] In November 1869 the French government issued invitations to join the International Metre Commission.[47] Spain accepted and Ibáñez took part in the Committee of preparatory research from the first meeting of this commission in 1870.[53] He was elected president of the Permanent Committee of the International Metre Commission in 1872.[54][55][56] He represented Spain at the 1875 conference of the Metre Convention and at the first General Conference on Weights and Measures in 1889.[4][57][58] At the first meeting of the International Committee for Weights and Measures, he was elected Chairman of the Committee, a position he held from 1875 to 1891.[59][4] He received the Légion d'Honneur in recognition of his efforts to disseminate the metric system among all nations and was awarded the Poncelet Prize for his scientific contribution to metrology.[54][6][60]

As Carlos Ibáñez e Ibáñez de Ibero stated, the International prototype metre would form the basis of the new international system of units, but it would no longer have any relation to the dimensions of the Earth that geodesists were trying to determine. It would be no more than the material representation of the unity of the system.[61]

The European Arc Measurement decided the creation of an international geodetic standard at the General Conference held in Paris in 1875. Thus, the Commission resolved to acquire, at common expense, a measuring instrument which was to be used either to measure new bases in countries which did not have their own device or to repeat previous measurements. The comparisons of the new results with those provided by the old national standards would make it possible to obtain their equation. The apparatus would to be calibrated at the International Bureau of Weights and Measures (BIPM), using the prototype metre. The system with a microscope and bimetallic rulers, which had given such brilliant results in Spain, was proposed.[62]

 
Gravimeter with variant of Repsold-Bessel pendulum.

The 1875 Conference of the International Association of Geodesy also dealt with the best instrument to be used for the determination of gravitational acceleration. After an in-depth discussion in which an American scholar, Charles Sanders Peirce, took part, the association decided in favor of the reversion pendulum, which was used in Switzerland, and it was resolved to redo in Berlin, in the station where Friedrich Wilhelm Bessel made his famous measurements, the determination of gravity by means of devices of various kinds employed in different countries, to compare them and thus to have the equation of their scales.[62]

The reversible pendulum built by the Repsold brothers was used in Switzerland in 1865 by Émile Plantamour for the measurement of gravitational acceleration in six stations of the Swiss geodetic network. Following the example set by this country and under the patronage of the International Geodetic Association, Austria, Bavaria, Prussia, Russia and Saxony undertook gravity determinations on their respective territories. As the figure of the Earth could be inferred from variations of gravitational field, the United States Coast Survey's direction instructed Charles Sanders Peirce in the spring of 1875 to proceed to Europe for the purpose of making pendulum experiments to chief initial stations for operations of this sort, to bring the determinations of gravitational acceleration in America into communication with those of other parts of the world; and also for the purpose of making a careful study of the methods of pursuing these researches in the different countries of Europe.[61][63]

President of the Permanent Commission of the European Arc Measurement from 1874 to 1886, Ibáñez became the first president of the International Geodetic Association (1887–1891) after the death of Johann Jacob Baeyer.[6][5] Under Ibáñez's presidency, the International Geodetic Association acquired a global dimension with the accession of the United States, Mexico, Chile, Argentina and Japan.[42][64][6]

The progresses of metrology combined with those of gravimetry through improvement of Kater's pendulum led to a new era of geodesy. If precision metrology had needed the help of geodesy, it could not continue to prosper without the help of metrology. It was then necessary to define a single unit to express all the measurements of terrestrial arcs, and all determinations of the force of gravity by the mean of pendulum. Metrology had to create a common unit, adopted and respected by all civilized nations. Moreover, at that time, statisticians knew that scientific observations are marred by two distinct types of errors, constant errors on the one hand, and fortuitous errors, on the other hand. The effects of random errors can be mitigated by the least squares method. Constant or systematic errors on the contrary must be carefully avoided, because they arise from one or more causes which constantly act in the same way, and have the effect of always altering the result of the experiment in the same direction. They therefore deprive of any value the observations that they impinge. It was thus crucial to compare at controlled temperatures with great precision and to the same unit all the standards for measuring geodesic bases, and all the pendulum rods. Only when this series of metrological comparisons would be finished with a probable error of a thousandth of a millimetre would geodesy be able to link the works of the different nations with one another, and then proclaim the result of the measurement of the Globe.[61][65] In 1901, Friedrich Robert Helmert found, mainly by gravimetry, parameters of the ellipsoid remarkably close to reality. Although marked by the concern to correct vertical deflections, taking into account the contributions of gravimetry, research between 1910 and 1950 remained practically limited to large continental triangulations. The most significant work would be that by John Fillmore Hayford, which relied mainly on the North American national network. His ellipsoid was adopted in 1924 by the International Union of Geodesy and Geophysics.[66]

In 1889 the General Conference on Weights and Measures met at Sèvres, the seat of the International Bureau. It performed the first great deed dictated by the motto inscribed in the pediment of the splendid edifice that is the metric system: "A tous les temps, à tous les peuples" (For all times, to all peoples); and this deed consisted in the approval and distribution, among the governments of the states supporting the Metre Convention, of prototype standards of hitherto unknown precision intended to propagate the metric unit throughout the whole world. These prototypes were made of a platinum-iridium alloy which combined all the qualities of hardness, permanence, and resistance to chemical agents which rendered it suitable for making into standards required to last for centuries. Yet their high price excluded them from the ordinary field of science.[67] For metrology the matter of expansibility was fundamental; as a matter of fact the temperature measuring error related to the length measurement in proportion to the expansibility of the standard and the constantly renewed efforts of metrologists to protect their measuring instruments against the interfering influence of temperature revealed clearly the importance they attached to the expansion-induced errors. It was common knowledge, for instance, that effective measurements were possible only inside a building, the rooms of which were well protected against the changes in outside temperature, and the very presence of the observer created an interference against which it was often necessary to take strict precautions. Thus, the Contracting States also received a collection of thermometers which accuracy made it possible to ensure that of length measurements.[67][58]

The BIPM's thermometry work led to the discovery of special alloys of iron-nickel, in particular invar, for which its director, the Swiss physicist Charles-Édouard Guillaume, was granted the Nobel Prize for physics in 1920. In 1900, the International Committee for Weights and Measures responded to a request from the International Association of geodesy and included in the work program of the International Bureau of Weights and Measures the study of measurements by invar's wires. Edvard Jäderin, a Swedish geodesist, had invented a method of measuring geodetic bases, based on the use of taut wires under a constant effort. However, before the discovery of invar, this process was much less precise than the classic method. Charles-Édouard Guillaume demonstrated the effectiveness of Jäderin's method, improved by the use of invar's threads. He measured a base in the Simplon Tunnel in 1905. The accuracy of the measurements was equal to that of the old methods, while the speed and ease of the measurements were incomparably higher.[18][68]

Late career, marriages and descent Edit

In 1889, Ibáñez had a stroke and resigned from the management of the Institute of Geography and Statistics, which he had directed for 19 years. His decision seemed to have been precipitated by the publication of a decree which took away economic control of the Institute and handed it over to the Minister of Public Works. Indeed this resignation took effect during a smear campaign orchestrated by Carlist journalist Antonio de Valbuena.[69] The reappearance of the general's first wife after his death in 1891 further discredited him and led to the annulment of his second marriage.[9][8][70]

Carlos Ibáñez e Ibáñez de Ibero was married in 1861 to a Frenchwoman, Jeanne Baboulène Thénié. A daughter was born from this marriage. He remarried in 1878 to a Swiss woman, Cécilia Grandchamp. Carlos Ibáñez de Ibero Grandchamp was born from this second union. After the death of Carlos Ibáñez e Ibáñez de Ibero, his two children and Cécilia Grandchamp settled in Geneva, where the latter was from.[71][72]

Carlos Ibáñez de Ibero Grandchamp, engineer and doctor of philosophy and letters from the University of Paris founded in 1913 the Institute of Hispanic Studies (current Training and Research Unit of Iberian and Latin American Studies of the Faculty of Letters of Sorbonne University).[73] Although it has been argued that the title of Marquis of Mulhacén was granted to him as a reward for the founding of the Institute of Hispanic Studies of the University of Paris, the invalidation of his parents' marriage prevented him from officially obtaining this title.[8][74]

Carlos Ibáñez e Ibáñez de Ibero's eldest daughter, Elena Ibáñez de Ibero, married a Swiss lawyer and politician, Jacques Louis Willemin.[75] The title of Marquis of Mulhacén passed to their son, then to their grandson.[8][71]

Legacy Edit

 
Closeup of National Prototype Meter Bar No. 27, made in 1889 by the International Bureau of Weights and Measures (BIPM) and given to the United States, which served as the standard for American cartography from 1890 replacing the Committee Meter, an authentic copy of the Mètre des Archives produced in 1799 in Paris, which Ferdinand Rudolph Hassler had brought to the United States in 1805.

In 1889, the French Minister of Foreign Affairs, Eugène Spuller introduced the first General Conference on Weights and Measures with these words:

Your task, so useful, so beneficial to mankind, has been traversed by many vicissitudes for a hundred years. Like all the great things in this world, it has cost many pains, efforts, sacrifices, not to mention the difficulties, dangers, fatigue, tribulations of all kinds, which endured the two great French astronomers Delambre and Méchain, whose works are the basis of all yours. I am sure to be your interpreter, paying them supreme tribute on this day. Who does not remember with emotion the dangers to which Méchain so generously exposed his life? General Morin, who has been your worthy colleague for so long, wrote a few lines on this subject that you will be proud to hear: "To brave dangers similar to those which Méchain ran with the necessary calm, it is not enough to be devoted to science and to its duties; you must have an empire over your senses which will protect you from this kind of vertigo, in the shelter of which the most intrepid soldiers are not always. Someone who, without flinching, has faced the bullets a hundred times is, on the contrary, surprised by this insurmountable weakness in the presence of the emptiness that space offers him." It is a soldier speaking, Gentlemen; please listen to him again when he adds: "Science therefore also has its heroes who, happier than those of war, leave behind only works useful to humanity and not ruins and vengeful hatred."

Spuller, Eugène (1889), Compte rendus de la première Conférence générale des poids et mesures (PDF), p. 8

Thanks to the determination and skill of Delambre and Méchain, the Enlightenment of science overcame the Tower of Babel of weights and measures. But it was not without difficulty: Méchain made a mistake which would almost cause him to lose his mind. In his book, The Measure of All Things: the seven year odyssey and hidden error that transformed the world, Ken Alder recalls some errors that crept into the measurement of the two French scientists and that Méchain had even noticed an inaccuracy which he had not dared to admit.[76][77] By measuring the latitude of two stations in Barcelona, Méchain had found that the difference between these latitudes was greater than predicted by direct measurement of distance by triangulation.[36] Indeed, clearance in the central axis of the repeating circle caused wear and consequently the zenith measurements contained significant systematic errors.[78]

 
Repeating circle used for the survey of the meridian arc from Dunkik to Barcelona by Delambre and Méchain

Nevertheless, it was an infavourable vertical deflection which gave an inaccurate determination of Barcelona's latitude and a metre "too short" compared to a more general definition taken from the average of a large number of arcs. The geoid is not a surface of revolution and none of its meridians is identical to another, in other words, the theoretical definition of the metre was inaccessible and misleading at the time of Delambre and Mechain arc measurement, as the geoid is a ball, which on the whole can be assimilated to an ellipsoid of revolution, but which in detail differs from it so as to prohibit any generalization and any extrapolation from the measurement of a single meridian arc.[38][76] Moreover, it was necessary to assume an oblateness of the Earth in order to calculate the length of the metre from the meridian arc measured by Delambre and Méchain. In 1901, Friedrich Robert Helmert determined the values of his ellipsoid of reference taking into account gravimetry work of the International Geodetic Association. He found 1/298,3 for the flattening of the Earth. This was remarkably close to reality compared to the value of 1/344 which had been used to compute the length of the metre a century earlier.[66][79]

Furthermore, until the Hayford ellipsoid was calculated, vertical deflections were considered as random errors.[66] The distinction between systematic and random errors is far from being as sharp as one might think at first glance. In reality, there are no or very few random errors. As science progresses, the causes of certain errors are sought out, studied, their laws discovered. These errors pass from the class of random errors into that of systematic errors. The ability of the observer consists in discovering the greatest possible number of systematic errors to be able, once he has become acquainted with their laws, to free his results from them using a method or appropriate corrections. It is the experimental study of a cause of error that has led to most of the great astronomical discoveries (precession, nutation, aberration).[80]

Since the metre was originally defined, each time a new measurement is made, with more accurate instruments, methods or techniques, it is said that the metre is based on some error, from calculations or measurements. When Ibáñez took part to the measurement of the West Europe-Africa Meridian-arc, mathematicians like Legendre and Gauss had developed new methods for processing data, including the "least squares method" which allowed to compare experimental data tainted with measurement errors to a mathematical model. This method minimized the impact of measurement inaccuracies. The Earth measurements thus underscored the importance of the scientific method at a time when statistics were implemented in geodesy.[81][30][82] As a leading scientist of his time, Ibáñez was one of the 81 initial members of the International Statistical Institute (ISI) and delegate of Spain to the first ISI session (now called World Statistic Congress) in Rome in 1887.[83][84][85]

Among the many reasons why Ibáñez could claim recognition from his country and from science, the geodetic junction of Spain and Algeria has been one of the most remarkable. Therefore the Spanish government chose the name of the peak of Mulhacén to attach forever the memory of this famous scientific achievement to the name of Ibáñez, by conferring on him the title of 1st Marquis of Mulhacén, granted, as it is said in the royal decree, " in recognition of the brilliant services which he rendered during his long career, directing with rare talent the Geographical and Statistical Institute of Spain, and contributing to the prestige of Spain among the other nations of Europe and America ".[4][86][70]

Unfortunately, the extension of the Paris meridian arc over the Mediterranean Sea in 1879 would soon be forgotten due to the adoption of Greenwich meridian as prime meridian at the 1883 International Geodetic Conference in Rome which was confirmed the next year at the International Meridian Conference in Washington, and because of Spain's adoption of Greenwich Mean Time by a decree of 27 July 1900, applicable from 1 January 1901.[87][71] Moreover, it was the Struve Geodetic Arc which would become part of the longest meridian arc of the Old World. In 1954, the connection of the southerly extension of the Struve Arc with an arc running north from South Africa through Egypt would bring the course of a major meridian arc back to land where Eratosthenes had founded geodesy.

France adopted the time of the international meridian of Greenwich with the law of 9 March 1911. However, the text of law did not refer to the meridian of Greenwich, but to the "average time of Paris delayed by 9 minutes and 21 seconds".[88] From a technical and scientific point of view, at this time, the development of wireless telegraphy hinted at the possibility of unifying Universal Time. From 1910, the astronomical clocks of the Paris Observatory sent the time to sea daily through the Eiffel Tower within a radius of 5 000 km. Following a report by Gustave Ferrié, the Bureau des Longitudes organized at the Paris Observatory a Conférence internationale de l'heure radiotélégraphique in 1912. The International Time Bureau was created and installed in the premises of the Paris Observatory. Due to World War I, the International Convention was never ratified. In 1919, the existence of the International Time Bureau was formalized under the authority of an International Time Commission, under the aegis of the International Astronomical Union, created by Benjamin Baillaud. The International Time Bureau was dissolved in 1987 and its tasks were divided between the International Bureau of Weights and Measures and the International Earth Rotation and Reference Systems Service (IERS).[89][90]

Until 1929, the International Time Bureau used exclusively the astronomical determination of Universal Time (or Greenwich mean sidereal time) carried out at the Paris Observatory. This realization of Universal Time was called heure demi-définitive and was published until 1966 by the International Time Bureau. In 1936, irregularities in the speed of Earth's rotation due to the unpredictable movement of air and water masses were discovered through the use of quartz clocks. They implied that the Earth's rotation was an imprecise way of determining time. As a result, the definition of the second, first seen as a fraction of the Earth's rotation, evolved and became a fraction of the Earth's orbit. Finally, in 1967, the second was defined by atomic clocks. The resulting time scale is the International Atomic Time (TAI). Currently, it is established from more than 400 atomic clocks distributed in more than 80 national laboratories by the International Bureau of Weights and Measures. The International Earth Rotation and Reference Systems Service also plays a fundamental role in Coordinated Universal Time (UTC) by deciding whether to insert a leap second so that it is kept in line with the rotation of the Earth which is subject to irregular variations. The Coordinated Universal Time is the current international time scale since 1965.[90][91][92][93]

The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system. It is the only system of measurement with an official status in nearly every country in the world. It comprises a coherent system of units of measurement starting with seven base units, which are the second (the unit of time with the symbol s), metre (length, m), kilogram (mass, kg), ampere (electric current, A), kelvin (thermodynamic temperature, K), mole (amount of substance, mol), and candela (luminous intensity, cd). Since 2019, the magnitudes of all SI units have been defined by declaring exact numerical values for seven defining constants when expressed in terms of their SI units. These defining constants are the hyperfine transition frequency of caesium ΔνCs, the speed of light in vacuum c, the Planck constant h, the elementary charge e, the Boltzmann constant k, the Avogadro constant NA, and the luminous efficacy Kcd.[94]

See also Edit

References Edit

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External links Edit

  • Jaime Nubiola, Carlos Ibáñez e Ibáñez de Ibero (1825–1891). Correspondencia europea de C. S. Peirce: creatividad y cooperación científica. Universidad de Navarra.
  • Clarke, Alexander Ross; Helmert, Friedrich Robert (1911). "Earth, Figure of the" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 08 (11th ed.). Cambridge University Press. pp. 801–813. Better formatted mathematics at Wikisource.
  • Clarke, Alexander Ross; Helmert, Friedrich Robert (1911). "Geodesy" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 11 (11th ed.). Cambridge University Press. pp. 607–615.
  • Miguel Parrilla Nieto, Carlos Ibáñez e Ibáñez de Ibero, Real Academia de la Historia.
  • Excmo. Sr. D. CARLOS IBÁÑEZ E IBÁÑEZ DE IBERO. Académicos Históricos. Real Academia de Ciecias Exactas, Físicas y Naturales.
  • Emilio Prieto Esteban, Rosé Ángel Robles Carbonell, El General Ibáñez e Ibáñez de Ibero, Marqués de Mulhacén, e-medida Revista Española de Metrología, June 2013.
  • Rafael Fraguas, Donde nacen los mapas, Madrid, El País, February 15, 2014.
  • Albert Pérard, Carlos IBAÑEZ DE IBERO (14 avril 1825 – 29 janvier 1891), (inauguration d'un monument élevé à sa mémoire), Madrid, Institut de France Académie des Sciences – Notices et discours., 1957, 7 p., p. 26–31
  • Paul Appell, LE CENTENAIRE DU GÉNÉRAL IBANEZ DE IBERO, Revue internationale de l'enseignement, Juillet-Août 1925, pp. 208–211
  • Adolf Hirsch, LE GENERAL IBANEZ NOTICE NECROLOGIQUE LUE AU COMITE INTERNATIONAL DES POIDS ET MESURE, LE 12 SEPTEMBRE ET DANS LA CONFERENCE GEODESIQUE DE FLORENCE, LE 8 OCTOBRE 1891, Neuchâtel, IMPRIMERIE ATTINGER FRERES, 1891, in COMITÉ INTERNATIONAL DES POIDS ET MESURES, PROCÈS-VERBAUX DES SÉANCES DE 1891, Paris, GAUTHIER-VILLARS ET FILS, IMPRIMEURS-LIBRAIRES, 1892, 197 p., pp. 3–14 or Don Carlos IBANEZ (1825–1891), 1892, 12 p. October 26, 2020, at the Wayback Machine

carlos, ibáñez, ibáñez, ibero, marquis, mulhacén, april, 1825, january, 1891, spanish, divisional, general, geodesist, represented, spain, 1875, conference, metre, convention, first, president, international, committee, weights, measures, forerunner, geodesist. Carlos Ibanez e Ibanez de Ibero 1st Marquis of Mulhacen 14 April 1825 28 or 29 January 1891 was a Spanish divisional general and geodesist 1 2 3 He represented Spain at the 1875 Conference of the Metre Convention and was the first president of the International Committee for Weights and Measures 4 As a forerunner geodesist and president of the International Geodetic Association 5 he played a leading role in the worldwide dissemination of the metric system 6 His activities resulted in the distribution of a platinum and iridium prototype of the metre to all States parties to the Metre Convention during the first meeting of the General Conference on Weights and Measures in 1889 4 These prototypes defined the metre right up until 1960 7 Carlos Ibanez e Ibanez de IberoPortrait of Carlos Ibanez e Ibanez de Ibero in 1881Born14 April 1825Barcelona Spain Died28 or 29 January 1891Nice France Resting placeCimetiere du Chateau in NiceNationalitySpanishKnown forPresident of the International Committee for Weights and Measures 1875 1891 AwardsPoncelet PrizeScientific careerFieldsGeodesy Geography Metrology Statistics InstitutionsInstituto Geografico Nacional Spain International Association of Geodesy International Statistical InstituteHe was born in Barcelona According to Spanish tradition his surname was a combination of his father s first surname Martin Ibanez y de Prado and of his mother s first surname Carmen Ibanez de Ibero y Gonzalez del Rio 8 3 9 As his parents surnames were so similar he was often referred as Ibanez or Ibanez de Ibero or as Marquis of Mulhacen When he died in Nice France he was still enrolled in the Engineer Corps of the Spanish Army 6 As he died around midnight the date of his death is ambiguous Spaniards retained 28th and other Europeans 29 January 10 11 1 2 Contents 1 Scientific career 1 1 From the Map Commission to the Geographic and Statistical Institute in Spain 1 2 Measurement of the Paris meridian over the Mediterranean Sea 1 3 International scientific collaboration in geodesy and calls for an international standard unit of length 2 Late career marriages and descent 3 Legacy 4 See also 5 References 6 External linksScientific career EditFrom the Map Commission to the Geographic and Statistical Institute in Spain Edit nbsp Swiss baseline measurement with Ibanez apparatus in 1880 Spain adopted the metric system in 1849 The Government was urged by the Spanish Royal Academy of Sciences to approve the creation of a large scale map of Spain in 1852 9 The following year Ibanez was appointed to undertake this task 4 As all the scientific and technical equipment for a vast undertaking of this kind had to be created Ibanez in collaboration with his comrade Captain Frutos Saavedra Meneses drew up the project of a new apparatus for measuring bases He recognized that the end standards with which the most perfect devices of the eighteenth century and those of the first half of the nineteenth century were still equipped that Jean Charles de Borda or Friedrich Wilhelm Bessel simply joined measuring the intervals by means of screw tabs or glass wedges would be replaced advantageously for accuracy by the system designed by Ferdinand Rudolph Hassler for the Coast Survey of the United States and which consisted of using a single standard with lines marked on the bar and microscopic measurements Regarding the two methods by which the effect of temperature was taken into account Ibanez used both the bimetallic rulers in platinum and brass which he first employed for the central base of Spain and the simple iron ruler with inlaid mercury thermometers which was used in Switzerland 4 12 Ibanez and Saavedra went to Paris to supervise the production by Jean Brunner of a measuring instrument calibrated against the metre which they had devised and which they later compared with Borda s double toise N 1 which was the main reference for measuring all geodetic bases in France and whose length was by definition 3 8980732 metres at a specified temperature 13 6 14 15 16 The four metre long Spanish measuring instrument which became known as the Spanish Standard French Regle espagnole was replicated in order to be used in Egypt 13 17 18 19 In 1863 Ibanez and Ismail Effendi Mustafa compared the Spanish Standard with the Egyptian Standard in Madrid 20 21 22 These comparisons were essential because of the expansibility of solid materials with raise in temperature Indeed one fact had constantly dominated all the fluctuations of ideas on the measurement of geodesic bases it was the constant concern to accurately assess the temperature of standards in the field and the determination of this variable on which depended the length of the instrument of measurement had always been considered by geodesists as so difficult and so important that one could almost say that the history of measuring instruments is almost identical with that of the precautions taken to avoid temperature errors 18 In 1858 Spain s central geodetic base of triangulation was measured in Madridejos Toledo with exceptional precision for the time thanks to the Spanish Standard 4 17 Ibanez and his colleagues wrote a monograph which was translated into French by Aime Laussedat 23 The experiment in which the results of two methods were compared was a landmark in the controversy between French and German geodesists about the length of geodesic triangulation bases and empirically validated the method of General Johann Jacob Bayer founder of the International Association of Geodesy 24 From 1865 to 1868 Ibanez added the survey of the Balearic Islands with that of the Iberian Peninsula 17 25 For this work he devised a new instrument which allowed much faster measurements 17 In 1869 Ibanez brought it along to Southampton where Alexander Ross Clarke was making the necessary measurements to compare the Standards of length used in the World 4 14 26 Finally this second version of the appliance called the Ibanez apparatus was used in Switzerland to measure the geodetic bases of Aarberg Weinfelden and Bellinzona 4 27 In 1870 Ibanez founded the Spanish National Geographic Institute which he then directed until 1889 28 29 At the time it was the world s biggest geographic institute 4 It encompassed geodesy general topography leveling cartography statistics and the general service of weights and measures 4 Measurement of the Paris meridian over the Mediterranean Sea Edit nbsp The West Europe Africa Meridian arc extending from the Shetland Islands through Great Britain France and Spain to El Aghuat in Algeria whose parameters were calculated from surveys carried out in the mid to late 19th century Greenwich meridian is depicted rather than Paris meridian 30 Jean Brunner displayed the Ibanez Brunner apparatus at the Exposition Universelle of 1855 31 32 Copies of the Spanish standard 31 were also made for France 33 34 and Germany 35 These standards would be used for the most important operations of European geodesy 18 Indeed the southward extension of Paris meridian s triangulation by Pierre Mechain 1803 1804 then Francois Arago and Jean Baptiste Biot 1806 1809 had not been secured by any baseline measurement in Spain 36 37 Moreover Louis Puissant declared in 1836 to the French Academy of Sciences that Jean Baptiste Joseph Delambre and Pierre Mechain had made errors in the triangulation of the meridian arc which had been used for determining the length of the metre 37 38 This is why Antoine Yvon Villarceau verified the geodetic operations at eight points of the Paris meridian arc from 1861 to 1866 Some of the errors in the operations of Delambre and Mechain were then corrected 39 In 1865 the triangulation of Spain was connected with that of Portugal and France 23 22 In 1866 at the conference of the Association of Geodesy in Neuchatel Ibanez announced that Spain would collaborate in remeasuring and extending the French meridian arc 4 40 From 1870 to 1894 Francois Perrier then Jean Antonin Leon Bassot proceeded to a new survey 39 33 In 1879 Ibanez and Francois Perrier completed the junction between the geodetic networks of Spain and Algeria and thus completed the measurement of a meridian arc which extended from Shetland to the Sahara 41 This connection was a remarkable enterprise where triangles with a maximum length of 270 km were observed from mountain stations Mulhacen Tetica Filahoussen M Sabiha over the Mediterranean Sea 42 41 43 33 This meridian arc was named West Europe Africa Meridian arc by Alexander Ross Clarke and Friedrich Robert Helmert It yielded a value for the equatorial radius of the earth a 6 377 935 metres the ellipticity being assumed as 1 299 15 according to Bessel ellipsoid 44 45 The radius of curvature of this arc is not uniform being in the mean about 600 metres greater in the northern than in the southern part 30 According to the calculations made at the central bureau of the International Geodetic Association the net does not follow the meridian exactly but deviates both to the west and to the east actually the meridian of Greenwich is nearer the mean than that of Paris 30 International scientific collaboration in geodesy and calls for an international standard unit of length Edit In 1866 Spain represented by Ibanez joined the Central European Arc Measurement German Mitteleuropaische Gradmessung at the Permanent Commission meeting in Neuchatel 46 40 In 1867 at the second General Conference of the Central European Arc Measurement see International Association of Geodesy held in Berlin the question of an international standard unit of length was discussed to combine the measurements made in different countries to determine the size and shape of the Earth 47 48 49 4 The Conference recommended the adoption of the metre and the creation of an international metre commission 46 according to a preliminary discussion between Johann Jacob Baeyer Adolphe Hirsch and Carlos Ibanez e Ibanez de Ibero 4 Ferdinand Rudolph Hassler s use of the metre in coastal survey which had been an argument for the introduction of the Metric Act of 1866 allowing the use of the metre in the United States probably also played a role in the choice of the metre as international scientific unit of length and the proposal by the European Arc Measurement German Europaische Gradmessung to establish a European international bureau for weights and measures 50 14 51 46 The French Academy of Sciences and the Bureau des Longitudes in Paris drew the attention of the French government to this issue The Academy of St Petersburg and the English Standards Commission were in agreement with the recommendation 47 52 In November 1869 the French government issued invitations to join the International Metre Commission 47 Spain accepted and Ibanez took part in the Committee of preparatory research from the first meeting of this commission in 1870 53 He was elected president of the Permanent Committee of the International Metre Commission in 1872 54 55 56 He represented Spain at the 1875 conference of the Metre Convention and at the first General Conference on Weights and Measures in 1889 4 57 58 At the first meeting of the International Committee for Weights and Measures he was elected Chairman of the Committee a position he held from 1875 to 1891 59 4 He received the Legion d Honneur in recognition of his efforts to disseminate the metric system among all nations and was awarded the Poncelet Prize for his scientific contribution to metrology 54 6 60 As Carlos Ibanez e Ibanez de Ibero stated the International prototype metre would form the basis of the new international system of units but it would no longer have any relation to the dimensions of the Earth that geodesists were trying to determine It would be no more than the material representation of the unity of the system 61 The European Arc Measurement decided the creation of an international geodetic standard at the General Conference held in Paris in 1875 Thus the Commission resolved to acquire at common expense a measuring instrument which was to be used either to measure new bases in countries which did not have their own device or to repeat previous measurements The comparisons of the new results with those provided by the old national standards would make it possible to obtain their equation The apparatus would to be calibrated at the International Bureau of Weights and Measures BIPM using the prototype metre The system with a microscope and bimetallic rulers which had given such brilliant results in Spain was proposed 62 nbsp Gravimeter with variant of Repsold Bessel pendulum The 1875 Conference of the International Association of Geodesy also dealt with the best instrument to be used for the determination of gravitational acceleration After an in depth discussion in which an American scholar Charles Sanders Peirce took part the association decided in favor of the reversion pendulum which was used in Switzerland and it was resolved to redo in Berlin in the station where Friedrich Wilhelm Bessel made his famous measurements the determination of gravity by means of devices of various kinds employed in different countries to compare them and thus to have the equation of their scales 62 The reversible pendulum built by the Repsold brothers was used in Switzerland in 1865 by Emile Plantamour for the measurement of gravitational acceleration in six stations of the Swiss geodetic network Following the example set by this country and under the patronage of the International Geodetic Association Austria Bavaria Prussia Russia and Saxony undertook gravity determinations on their respective territories As the figure of the Earth could be inferred from variations of gravitational field the United States Coast Survey s direction instructed Charles Sanders Peirce in the spring of 1875 to proceed to Europe for the purpose of making pendulum experiments to chief initial stations for operations of this sort to bring the determinations of gravitational acceleration in America into communication with those of other parts of the world and also for the purpose of making a careful study of the methods of pursuing these researches in the different countries of Europe 61 63 President of the Permanent Commission of the European Arc Measurement from 1874 to 1886 Ibanez became the first president of the International Geodetic Association 1887 1891 after the death of Johann Jacob Baeyer 6 5 Under Ibanez s presidency the International Geodetic Association acquired a global dimension with the accession of the United States Mexico Chile Argentina and Japan 42 64 6 The progresses of metrology combined with those of gravimetry through improvement of Kater s pendulum led to a new era of geodesy If precision metrology had needed the help of geodesy it could not continue to prosper without the help of metrology It was then necessary to define a single unit to express all the measurements of terrestrial arcs and all determinations of the force of gravity by the mean of pendulum Metrology had to create a common unit adopted and respected by all civilized nations Moreover at that time statisticians knew that scientific observations are marred by two distinct types of errors constant errors on the one hand and fortuitous errors on the other hand The effects of random errors can be mitigated by the least squares method Constant or systematic errors on the contrary must be carefully avoided because they arise from one or more causes which constantly act in the same way and have the effect of always altering the result of the experiment in the same direction They therefore deprive of any value the observations that they impinge It was thus crucial to compare at controlled temperatures with great precision and to the same unit all the standards for measuring geodesic bases and all the pendulum rods Only when this series of metrological comparisons would be finished with a probable error of a thousandth of a millimetre would geodesy be able to link the works of the different nations with one another and then proclaim the result of the measurement of the Globe 61 65 In 1901 Friedrich Robert Helmert found mainly by gravimetry parameters of the ellipsoid remarkably close to reality Although marked by the concern to correct vertical deflections taking into account the contributions of gravimetry research between 1910 and 1950 remained practically limited to large continental triangulations The most significant work would be that by John Fillmore Hayford which relied mainly on the North American national network His ellipsoid was adopted in 1924 by the International Union of Geodesy and Geophysics 66 In 1889 the General Conference on Weights and Measures met at Sevres the seat of the International Bureau It performed the first great deed dictated by the motto inscribed in the pediment of the splendid edifice that is the metric system A tous les temps a tous les peuples For all times to all peoples and this deed consisted in the approval and distribution among the governments of the states supporting the Metre Convention of prototype standards of hitherto unknown precision intended to propagate the metric unit throughout the whole world These prototypes were made of a platinum iridium alloy which combined all the qualities of hardness permanence and resistance to chemical agents which rendered it suitable for making into standards required to last for centuries Yet their high price excluded them from the ordinary field of science 67 For metrology the matter of expansibility was fundamental as a matter of fact the temperature measuring error related to the length measurement in proportion to the expansibility of the standard and the constantly renewed efforts of metrologists to protect their measuring instruments against the interfering influence of temperature revealed clearly the importance they attached to the expansion induced errors It was common knowledge for instance that effective measurements were possible only inside a building the rooms of which were well protected against the changes in outside temperature and the very presence of the observer created an interference against which it was often necessary to take strict precautions Thus the Contracting States also received a collection of thermometers which accuracy made it possible to ensure that of length measurements 67 58 The BIPM s thermometry work led to the discovery of special alloys of iron nickel in particular invar for which its director the Swiss physicist Charles Edouard Guillaume was granted the Nobel Prize for physics in 1920 In 1900 the International Committee for Weights and Measures responded to a request from the International Association of geodesy and included in the work program of the International Bureau of Weights and Measures the study of measurements by invar s wires Edvard Jaderin a Swedish geodesist had invented a method of measuring geodetic bases based on the use of taut wires under a constant effort However before the discovery of invar this process was much less precise than the classic method Charles Edouard Guillaume demonstrated the effectiveness of Jaderin s method improved by the use of invar s threads He measured a base in the Simplon Tunnel in 1905 The accuracy of the measurements was equal to that of the old methods while the speed and ease of the measurements were incomparably higher 18 68 Late career marriages and descent EditIn 1889 Ibanez had a stroke and resigned from the management of the Institute of Geography and Statistics which he had directed for 19 years His decision seemed to have been precipitated by the publication of a decree which took away economic control of the Institute and handed it over to the Minister of Public Works Indeed this resignation took effect during a smear campaign orchestrated by Carlist journalist Antonio de Valbuena 69 The reappearance of the general s first wife after his death in 1891 further discredited him and led to the annulment of his second marriage 9 8 70 Carlos Ibanez e Ibanez de Ibero was married in 1861 to a Frenchwoman Jeanne Baboulene Thenie A daughter was born from this marriage He remarried in 1878 to a Swiss woman Cecilia Grandchamp Carlos Ibanez de Ibero Grandchamp was born from this second union After the death of Carlos Ibanez e Ibanez de Ibero his two children and Cecilia Grandchamp settled in Geneva where the latter was from 71 72 Carlos Ibanez de Ibero Grandchamp engineer and doctor of philosophy and letters from the University of Paris founded in 1913 the Institute of Hispanic Studies current Training and Research Unit of Iberian and Latin American Studies of the Faculty of Letters of Sorbonne University 73 Although it has been argued that the title of Marquis of Mulhacen was granted to him as a reward for the founding of the Institute of Hispanic Studies of the University of Paris the invalidation of his parents marriage prevented him from officially obtaining this title 8 74 Carlos Ibanez e Ibanez de Ibero s eldest daughter Elena Ibanez de Ibero married a Swiss lawyer and politician Jacques Louis Willemin 75 The title of Marquis of Mulhacen passed to their son then to their grandson 8 71 Legacy Edit nbsp Closeup of National Prototype Meter Bar No 27 made in 1889 by the International Bureau of Weights and Measures BIPM and given to the United States which served as the standard for American cartography from 1890 replacing the Committee Meter an authentic copy of the Metre des Archives produced in 1799 in Paris which Ferdinand Rudolph Hassler had brought to the United States in 1805 In 1889 the French Minister of Foreign Affairs Eugene Spuller introduced the first General Conference on Weights and Measures with these words Your task so useful so beneficial to mankind has been traversed by many vicissitudes for a hundred years Like all the great things in this world it has cost many pains efforts sacrifices not to mention the difficulties dangers fatigue tribulations of all kinds which endured the two great French astronomers Delambre and Mechain whose works are the basis of all yours I am sure to be your interpreter paying them supreme tribute on this day Who does not remember with emotion the dangers to which Mechain so generously exposed his life General Morin who has been your worthy colleague for so long wrote a few lines on this subject that you will be proud to hear To brave dangers similar to those which Mechain ran with the necessary calm it is not enough to be devoted to science and to its duties you must have an empire over your senses which will protect you from this kind of vertigo in the shelter of which the most intrepid soldiers are not always Someone who without flinching has faced the bullets a hundred times is on the contrary surprised by this insurmountable weakness in the presence of the emptiness that space offers him It is a soldier speaking Gentlemen please listen to him again when he adds Science therefore also has its heroes who happier than those of war leave behind only works useful to humanity and not ruins and vengeful hatred Spuller Eugene 1889 Compte rendus de la premiere Conference generale des poids et mesures PDF p 8Thanks to the determination and skill of Delambre and Mechain the Enlightenment of science overcame the Tower of Babel of weights and measures But it was not without difficulty Mechain made a mistake which would almost cause him to lose his mind In his book The Measure of All Things the seven year odyssey and hidden error that transformed the world Ken Alder recalls some errors that crept into the measurement of the two French scientists and that Mechain had even noticed an inaccuracy which he had not dared to admit 76 77 By measuring the latitude of two stations in Barcelona Mechain had found that the difference between these latitudes was greater than predicted by direct measurement of distance by triangulation 36 Indeed clearance in the central axis of the repeating circle caused wear and consequently the zenith measurements contained significant systematic errors 78 nbsp Repeating circle used for the survey of the meridian arc from Dunkik to Barcelona by Delambre and MechainNevertheless it was an infavourable vertical deflection which gave an inaccurate determination of Barcelona s latitude and a metre too short compared to a more general definition taken from the average of a large number of arcs The geoid is not a surface of revolution and none of its meridians is identical to another in other words the theoretical definition of the metre was inaccessible and misleading at the time of Delambre and Mechain arc measurement as the geoid is a ball which on the whole can be assimilated to an ellipsoid of revolution but which in detail differs from it so as to prohibit any generalization and any extrapolation from the measurement of a single meridian arc 38 76 Moreover it was necessary to assume an oblateness of the Earth in order to calculate the length of the metre from the meridian arc measured by Delambre and Mechain In 1901 Friedrich Robert Helmert determined the values of his ellipsoid of reference taking into account gravimetry work of the International Geodetic Association He found 1 298 3 for the flattening of the Earth This was remarkably close to reality compared to the value of 1 344 which had been used to compute the length of the metre a century earlier 66 79 Furthermore until the Hayford ellipsoid was calculated vertical deflections were considered as random errors 66 The distinction between systematic and random errors is far from being as sharp as one might think at first glance In reality there are no or very few random errors As science progresses the causes of certain errors are sought out studied their laws discovered These errors pass from the class of random errors into that of systematic errors The ability of the observer consists in discovering the greatest possible number of systematic errors to be able once he has become acquainted with their laws to free his results from them using a method or appropriate corrections It is the experimental study of a cause of error that has led to most of the great astronomical discoveries precession nutation aberration 80 Since the metre was originally defined each time a new measurement is made with more accurate instruments methods or techniques it is said that the metre is based on some error from calculations or measurements When Ibanez took part to the measurement of the West Europe Africa Meridian arc mathematicians like Legendre and Gauss had developed new methods for processing data including the least squares method which allowed to compare experimental data tainted with measurement errors to a mathematical model This method minimized the impact of measurement inaccuracies The Earth measurements thus underscored the importance of the scientific method at a time when statistics were implemented in geodesy 81 30 82 As a leading scientist of his time Ibanez was one of the 81 initial members of the International Statistical Institute ISI and delegate of Spain to the first ISI session now called World Statistic Congress in Rome in 1887 83 84 85 Among the many reasons why Ibanez could claim recognition from his country and from science the geodetic junction of Spain and Algeria has been one of the most remarkable Therefore the Spanish government chose the name of the peak of Mulhacen to attach forever the memory of this famous scientific achievement to the name of Ibanez by conferring on him the title of 1st Marquis of Mulhacen granted as it is said in the royal decree in recognition of the brilliant services which he rendered during his long career directing with rare talent the Geographical and Statistical Institute of Spain and contributing to the prestige of Spain among the other nations of Europe and America 4 86 70 Unfortunately the extension of the Paris meridian arc over the Mediterranean Sea in 1879 would soon be forgotten due to the adoption of Greenwich meridian as prime meridian at the 1883 International Geodetic Conference in Rome which was confirmed the next year at the International Meridian Conference in Washington and because of Spain s adoption of Greenwich Mean Time by a decree of 27 July 1900 applicable from 1 January 1901 87 71 Moreover it was the Struve Geodetic Arc which would become part of the longest meridian arc of the Old World In 1954 the connection of the southerly extension of the Struve Arc with an arc running north from South Africa through Egypt would bring the course of a major meridian arc back to land where Eratosthenes had founded geodesy France adopted the time of the international meridian of Greenwich with the law of 9 March 1911 However the text of law did not refer to the meridian of Greenwich but to the average time of Paris delayed by 9 minutes and 21 seconds 88 From a technical and scientific point of view at this time the development of wireless telegraphy hinted at the possibility of unifying Universal Time From 1910 the astronomical clocks of the Paris Observatory sent the time to sea daily through the Eiffel Tower within a radius of 5 000 km Following a report by Gustave Ferrie the Bureau des Longitudes organized at the Paris Observatory a Conference internationale de l heure radiotelegraphique in 1912 The International Time Bureau was created and installed in the premises of the Paris Observatory Due to World War I the International Convention was never ratified In 1919 the existence of the International Time Bureau was formalized under the authority of an International Time Commission under the aegis of the International Astronomical Union created by Benjamin Baillaud The International Time Bureau was dissolved in 1987 and its tasks were divided between the International Bureau of Weights and Measures and the International Earth Rotation and Reference Systems Service IERS 89 90 Until 1929 the International Time Bureau used exclusively the astronomical determination of Universal Time or Greenwich mean sidereal time carried out at the Paris Observatory This realization of Universal Time was called heure demi definitive and was published until 1966 by the International Time Bureau In 1936 irregularities in the speed of Earth s rotation due to the unpredictable movement of air and water masses were discovered through the use of quartz clocks They implied that the Earth s rotation was an imprecise way of determining time As a result the definition of the second first seen as a fraction of the Earth s rotation evolved and became a fraction of the Earth s orbit Finally in 1967 the second was defined by atomic clocks The resulting time scale is the International Atomic Time TAI Currently it is established from more than 400 atomic clocks distributed in more than 80 national laboratories by the International Bureau of Weights and Measures The International Earth Rotation and Reference Systems Service also plays a fundamental role in Coordinated Universal Time UTC by deciding whether to insert a leap second so that it is kept in line with the rotation of the Earth which is subject to irregular variations The Coordinated Universal Time is the current international time scale since 1965 90 91 92 93 The International System of Units SI abbreviated from the French Systeme international d unites is the modern form of the metric system It is the only system of measurement with an official status in nearly every country in the world It comprises a coherent system of units of measurement starting with seven base units which are the second the unit of time with the symbol s metre length m kilogram mass kg ampere electric current A kelvin thermodynamic temperature K mole amount of substance mol and candela luminous intensity cd Since 2019 the magnitudes of all SI units have been defined by declaring exact numerical values for seven defining constants when expressed in terms of their SI units These defining constants are the hyperfine transition frequency of caesium DnCs the speed of light in vacuum c the Planck constant h the elementary charge e the Boltzmann constant k the Avogadro constant NA and the luminous efficacy Kcd 94 See also EditHistory of the metre History of geodesyReferences Edit a b Real Academia de Ciencias Exactas Fisicas y Naturales Academicos Excmo Sr D CARLOS IBANEZ E IBANEZ DE IBERO rac es Archived from the original on June 15 2019 Retrieved November 30 2019 a b CARLOS IBANEZ DE IBERO MARQUIS DE MULHACEN academieroyale be in French Retrieved November 30 2019 a b Carlos Ibanez e Ibanez de Ibero Real Academia de la Historia dbe rah es Retrieved November 30 2019 a b c d e f g h i j k l m n o Hirsch Adolphe 1891 Don Carlos IBANEZ 1825 1891 PDF Bureau International des Poids et Mesures pp 9 4 8 5 10 7 8 9 9 Retrieved May 22 2017 nbsp This article incorporates text from this source which is in the public domain a b Drewes Hermann Kuglitsch Franz Adam Jozsef Rozsa Szabolcs October 1 2016 The Geodesist s Handbook 2016 PDF Journal of Geodesy 90 10 907 1205 Table 3 p 914 Bibcode 2016JGeod 90 907D doi 10 1007 s00190 016 0948 z ISSN 1432 1394 S2CID 125925505 a b c d e f Soler T February 1 1997 A profile of General Carlos Ibanez e Ibanez de Ibero first president of the International Geodetic Association Journal of Geodesy 71 3 176 188 pp 178 183 Bibcode 1997JGeod 71 176S CiteSeerX 10 1 1 492 3967 doi 10 1007 s001900050086 ISSN 0949 7714 S2CID 119447198 BIPM former Prototype Metre bipm org Retrieved May 22 2017 a b c d Martin Lopez Jose June 1 2017 Cartografos espanoles 1 ed ES Centro Nacional de Informacion Geografica Mnisterio de Fomento pp 147 7 148 149 doi 10 7419 162 02 2017 a b c Nunez de las Cuevas Rodolfo 2005 Militares y marinos en la Real Sociedad Geografica PDF Universidad de Navarra Retrieved May 22 2017 Carlos Ibanez e Ibanez de Ibero Wikipedia in French 2023 01 06 retrieved 2023 01 06 Paladini Cuadrado Angel 1991 El general Ibanez Su personalidad militar y humana Conmemoracion del centenario del general Ibanez e Ibanez de Ibero in Spanish Madrid Real Academia de Ciencias Exactas Fisicas y Naturales pp 41 46 Cajori Florian 1921 Swiss Geodesy and the United States Coast Survey The Scientific Monthly 13 2 117 129 Bibcode 1921SciMo 13 117C ISSN 0096 3771 a b Brunner Jean January 26 1857 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Geodesie Appareil construit pour les operations au moyen desquelles on prolongera dans toute l etendue de l Espagne le reseau trigonometrique qui couvre la France Paris Gauthier Villars pp 150 152 a b c Clarke A R James Henry January 1 1873 Results of the Comparisons of the Standards of Length of England Austria Spain United States Cape of Good Hope and of a Second Russian Standard Made at the Ordnance Survey Office Southampton Philosophical Transactions of the Royal Society of London 163 445 469 p 16 doi 10 1098 rstl 1873 0014 ISSN 0261 0523 Ibanez e Ibane de Ibero Carlos Saavedra Meneses Carlos 1860 Experiences faites avec l appareil a mesurer les bases appartenant a la commission de la carte d Espagne ouvrage publie par ordre de la reine in French Translated by Laussedat Aime J Dumaine Delambre Jean Baptiste 1749 1822 Auteur du texte Mechain Pierre 1744 1804 Auteur du texte 1806 1810 Base du systeme metrique decimal ou Mesure de l arc du meridien compris entre les paralleles de Dunkerque et Barcelone T 3 executee en 1792 et annees suivantes par MM Mechain et Delambre redigee par M Delambre pp 139 228 a b c d J Bertrand Academie des sciences France Auteur du January 1 1891 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Notice sur le general Ibanez correspondant de l Academie Paris Gauthier Villars pp 266 269 a b c d Guillaume Ch Ed 1906 La mesure rapide des bases geodesiques Journal de Physique Theorique et Appliquee in French 5 1 242 263 doi 10 1051 jphystap 019060050024200 ISSN 0368 3893 Guillaume Charles Edouard 1920 Notice necrologique de F DA PAULA ARRILLAGA Y GARRO PDF BIPM texte Academie des sciences France Auteur du July 1 1864 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Paris Gauthier Villars p 623 Ismail Effendi Moustapha 1864 Recherche des coefficients de dilatation et etalonnage de l appareil a mesurer les bases geodesiques appartenant au gouvernement egyptien Paris V Goupy a b Ibanez e Ibanez de Ibero Carlos 1865 Base centrale de la triangulation geodesique d Espagne Translated by Laussedat Aime Madrid impr de M Rivadeneyra pp Appendice N 9 p CXCIII Appendice N 11 p CCLI a b Laussedat Academie des sciences France Auteur du January 1 1866 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Geodesie Sur les travaux geodesiques executes en Espagne a propos de la publication d une traduction de l ouvrage intitule Base centrale de la triangulation geodesique de l Espagne Paris Gauthier Villars pp 1007 1010 Laussedat Academie des sciences France Auteur du January 1 1864 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Geodesie Sur les operations en cours d execution pour la carte d Espagne d apres les renseignements donnes a l academie de Madrid par M le colonel Ibanez Paris Gauthier Villars pp 70 72 Ibanez e Ibanez de Ibero Carlos 1871 Descripcion geodesica de las islas Baleares Harvard University Madrid Impr de M Rivadeneyra Clarke Alexander Ross James Henry January 1 1867 X Abstract of the results of the comparisons of the standards of length of England France Belgium Prussia Russia India Australia made at the ordnance Survey Office Southampton Philosophical Transactions of the Royal Society of London 157 161 180 doi 10 1098 rstl 1867 0010 S2CID 109333769 A Hirsch et J Dumur Lausanne Commission Geodesique Suisse 1888 116 p Nacional Instituto Geografico Instituto Geografico Nacional Geoportal oficial del Instituto Geografico Nacional de Espana in European Spanish Retrieved December 11 2019 150 aniversario del Instituto Geografico Nacional 1870 2020 150 aniversario del Instituto Geografico Nacional 1870 2020 Retrieved 2023 01 06 a b c d Clarke Alexander Ross Helmert Friedrich Robert 1911 Earth Figure of the In Chisholm Hugh ed Encyclopaedia Britannica Vol 08 11th ed Cambridge University Press pp 801 813 a b Wolf Rudolf 1891 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Gallica pp 370 371 Archived from the original on February 22 2007 Retrieved July 29 2021 Brenni Paolo 1996 19th Century French Scientific Instrument Makers XI The Brunners and Paul Gautier PDF Bulletin of the Scientific Instrument Society 49 3 5 via Universidad de Navarra a b c Tardi Pierre 1897 1972 Auteur du texte 1934 Traite de geodesie par le capitaine P Tardi preface par le general G Perrier pp 25 26 32 Schiavon Martina December 1 2006 Les officiers geodesiens du Service geographique de l armee et la mesure de l arc de meridien de Quito 1901 1906 Histoire amp mesure in French XXI XXI 2 55 94 doi 10 4000 histoiremesure 1746 ISSN 0982 1783 Zuerich ETH Bibliothek 1879 Proces verbaux des seances de la commission geodesique suisse E Periodica in French p 14 Archived from the original on July 29 2021 Retrieved July 29 2021 a b c a Paris vitesse de la lumiere expositions obspm fr Retrieved August 5 2021 a b Puissant Louis 1836 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Gallica pp 428 433 Archived from the original on September 14 2006 Retrieved January 11 2020 a b Levallois J J July 1991 La meridienne de Dunkerque a Barcelone et la determiniation du metre 1792 1799 Vermessung Photogrammetrie Kulturtechnik in French 89 7 377 378 doi 10 5169 seals 234595 a b Lebon Ernest 1846 1922 Auteur du texte 1899 Histoire abregee de l astronomie par Ernest Lebon in French pp 168 169 a b Ibanez e Ibanez de Ibero Carlos 1866 Expose de l etat des Travaux geodesiques poursuivis en Espagne communique a la Commission permanente de la Conference internationale par le Colonel Ibanez membre de l Academie Royale des sciences et delegue du Gouvernement espagnol in General Bericht uber die mitteleuropaische Gradmessung fur das Jahr 1865 Publications IASS publications iass potsdam de pp 56 58 Retrieved December 10 2019 a b Perrier Academie des sciences France Auteur du July 1 1879 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Geodesie Jonction geodesique de l Algerie avec l Espagne operation internationale executee sous la direction de MM le general Ibanez et F Perrier Paris Gauthier Villars pp 885 889 a b Torge Wolfgang 2015 From a Regional Project to an International Organization The Baeyer Helmert Era of the International Association of Geodesy 1862 1916 IAG 150 Years International Association of Geodesy Symposia Vol 143 Springer Cham pp 3 18 doi 10 1007 1345 2015 42 ISBN 978 3 319 24603 1 Ibanez e Ibanez de Ibero Carlos Perrier Francois 1886 Jonction geodesique et astronomique de l Algerie avec l Espagne executee en commun en 1879 par ordre des gouvernements d Espagne et de France sous la direction de M le general Ibanez pour l Espagne M le colonel Perrier pour la France Paris Impr nationale Bessel Friedrich Wilhelm December 1 1841 Uber einen Fehler in der Berechnung der franzosischen Gradmessung und seineh Einfluss auf die Bestimmung der Figur der Erde Von Herrn Geh Rath und Ritter Bessel Astronomische Nachrichten 19 7 97 Bibcode 1841AN 19 97B doi 10 1002 asna 18420190702 ISSN 0004 6337 Viik T 2006 F W BESSEL AND GEODESY Struve Geodetic Arc 2006 International Conference The Struve Arc and Extensions in Space and Time Haparanda and Pajala Sweden 13 15 August 2006 p 10 CiteSeerX 10 1 1 517 9501 a b c Bericht uber die Verhandlungen der vom 30 September bis 7 October 1867 zu BERLIN abgehaltenen allgemeinen Conferenz der Europaischen Gradmessung PDF Berlin Central Bureau der Europaischen Gradmessung 1868 pp 14 123 134 a b c BIPM International Metre Commission bipm org Retrieved May 22 2017 A Note on the History of the IAG IAG Homepage Retrieved May 26 2017 Proces verbaux de la Conference geodesique internationale pour la mesure des degres en Europe reunie a Berlin du 30 septembre au 7 octobre 1867 Neuchatel 1867 pp 21 22 hdl 2027 mdp 39015079998129 Hassler Ferdinand Rudolf 1825 Transactions of the American Philosophical Society p 252 Metric Act of 1866 US Metric Association usma org Retrieved December 24 2020 Bigourdan Guillaume 1901 Le systeme metrique des poids et mesures son etablissement et sa propagation graduelle avec l histoire des operations qui ont servi a determiner le metre et le kilogramme University of Ottawa Paris Gauthier Villars pp 254 258 269 Morin Academie des sciences France Auteur du July 1 1870 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Metrologie Notes sur la premiere session de la Commission internationale du metre tenue a Paris du 8 au 13 aout 1870 Paris Gauthier Villars pp 381 383 a b Perard Albert 1957 Carlos IBANEZ DE IBERO 14 avril 1825 29 janvier 1891 par Albert Perard inauguration d un monument eleve a sa memoire PDF Institut de France Academie des Sciences Archived from the original on May 18 2017 Retrieved May 22 2017 Proces verbaux Commission Internationale du Metre Reunions generales de 1872 in French Imprim Nation 1872 p 155 Ibanez e Ibanez de Ibero Carlos 1872 Resumen de los trabajos preparatorios de la Comision Internacional para la realizacion de los prototipos internacionales y la creacion de la Oficina Internacional de Pesas y Medidas 1871 1872 PDF Centro Espanol de Metrologia in Spanish and English pp 310 311 409 410 Archived PDF from the original on April 12 2021 Retrieved April 12 2021 S N 1875 ETH Bibliothek Documents diplomatiques de la conference du metre Imprimerie Nationale pp 16 8 doi 10 3931 e rara 75532 a b Compte rendu des seances de la premiere conference generale des poids et mesures reunie a Paris en 1889 PDF Bureau International des Poids et Mesures 1890 pp 5 27 Retrieved May 24 2017 BIPM Presidents of the CIPM bipm org Retrieved May 22 2017 texte Academie des sciences France Auteur du July December 1890 Comptes rendus hebdomadaires des seances de l Academie des sciences publies par MM les secretaires perpetuels Gallica in French p 1025 Retrieved June 22 2020 a b c Ibanez e Ibanez de Ibero Carlos 1881 Discursos leidos ante la Real Academia de Ciencias Exactas Fisicas y Naturales en la recepcion publica de Don Joaquin Barraquer y Rovira PDF Madrid Imprenta de la Viuda e Hijo de D E Aguado pp 70 78 a b Hirsch Adolphe 1875 Bulletin de la Societe des Sciences Naturelles de Neuchatel Vol 10 e periodica ch pp 255 256 Retrieved September 18 2020 Report from Charles S Peirce on his second European trip for the Anual Report of the Superintendent of the U S Coast Survey New York 18 05 1877 Retrieved August 25 2019 via Universidad de Navarra Torge W April 1 2005 The International Association of Geodesy 1862 to 1922 from a regional project to an international organization Journal of Geodesy 78 9 558 568 Bibcode 2005JGeod 78 558T doi 10 1007 s00190 004 0423 0 ISSN 1432 1394 S2CID 120943411 Ritter Elie 1858 Manuel theorique et pratique de l application de la methode des moindres carres au calcul des observations in French Mallet Bachelier pp 7 8 a b c Geodesie in Encyclopedia Universalis Encyclopedia Universalis 1996 pp Vol 10 p 302 ISBN 978 2 85229 290 1 OCLC 36747385 a b Guillaume Charles Edouard 1920 The Nobel Prize in Physics 1920 Nobel Foundation pp 1 2 Retrieved September 19 2020 Charles Edouard GUILLAUME 1861 1938 PDF BIPM 1938 Valladares Reguero Aurelio July December 1998 LOS TRABAJOS CARTOGRAFICOS DE FINALES DEL SIGLO XIX ANTE LA CRITICA MORDAZ DE ANTONIO DE VALBUENA PDF Boletin del Instituto de Estudios Gienneses 169 655 661 a b Informacion Huelva December 19 2020 El marques de Mulhacen Huelva Informacion in European Spanish Retrieved February 9 2021 a b c Jacin Luna Jaime Nubiola Carlos Ibanez e Ibanez de Ibero Grupo de Estudios Peirceanos www unav es Retrieved 2023 01 17 Martinez Utesa Carmen 1995 CIENCIA Y MILICIA EN EL XIX EL GENERAL IBANEZ E IBANEZ DE IBERO Madrid UNIVERSIDAD COMPLUTENSE DE MADRID FACULTAD DE GEOGRAFIA E HISTORIA DEPARTAMENTO DE HISTORIA CONTEMPORANEA pp cap 7 El Hombre clairedeprekel 2 January 2017 L Archive du lundi n 32 Le fabuleux destin de Carlos Ibanez de Ibero Grandchamp Cent ans d hispanisme en Sorbonne in French Retrieved December 23 2020 Delgado de Orellana Jose Antonio 1968 La sabiduria fuente de nobleza a href Template Cite book html title Template Cite book cite book a work ignored help Willemin Jacques Louis hls dhs dss ch in French Retrieved December 23 2020 a b Alder Ken Mesurer le monde de Ken Alder Editions Flammarion editions flammarion com in French pp 195 200 449 463 Retrieved December 30 2020 Jouffroy Achille de 1785 1859 Auteur du texte 1852 1853 Dictionnaire des inventions et decouvertes anciennes et modernes dans les sciences les arts et l industrie 2 H Z recueillis et mis en ordre par M le marquis de Jouffroy publie par l abbe Migne pp 419 420 Martina Schiavon La geodesia y la investigacion cientifica en la Francia del siglo XIX la medida del arco de meridiano franco argelino 1870 1895 Revista Colombiana de Sociologia 2004 Estudios sociales de la ciencia y la tecnologia 23 pp 11 30 Quinn T J 2012 From artefacts to atoms the BIPM and the search for ultimate measurement standards Oxford p 13 ISBN 978 0 19 990991 9 OCLC 861693071 a href Template Cite book html title Template Cite book cite book a CS1 maint location missing publisher link Perrier Georges 1872 1946 Auteur du texte 1933 Cours de geodesie et d astronomie par G Perrier pp 17 18 Debarbat Suzanne 2011 FROM OLD WEIGHTS AND MEASURES TO THE SI AS A NUMERICAL STANDARD FOR THE WORLD PDF ui adsabs harvard edu Retrieved December 30 2020 Mesure du 1er metre une erreur qui changea le monde Techniques de l Ingenieur in French Retrieved December 30 2020 Members of the International Statistical Institute a cumulative list for the period 1885 2002 PDF isi web org History of the International Statistical Institute ISI www isi web org Retrieved 2022 12 23 Appell Paul 1925 Le centenaire du general Ibanez de Ibero Revue internationale de l enseignement 79 1 208 211 Canalejas y Mendez Jose February 8 1889 Ministerio de Gracia y Justicia Reales Decretos PDF Gaceta de Madrid Retrieved January 20 2021 Zimmermann Maurice 1901 Espagne Adoption du meridien de Greenwich Projet d irrigation Annales de geographie 10 50 185 Giret A December 1 1964 Quelle heure est il Rappel des textes definissant l heure legale en France L Astronomie 78 465 Bibcode 1964LAstr 78 465G ISSN 0004 6302 Astronomie au fil du temps Observatoire de Paris PSL Centre de recherche en astronomie et astrophysique observatoiredeparis psl eu Retrieved January 12 2021 a b Guinot B 2000 2000ASPC 208 175G Page 175 IAU Colloq 178 Polar Motion Historical and Scientific Problems 208 175 Bibcode 2000ASPC 208 175G Retrieved January 12 2021 Revivre notre histoire Les 350 ans de l Observatoire de Paris 350ans obspm fr Retrieved January 12 2021 BIPM TAI bipm org Retrieved January 12 2021 BIPM IERS bipm org Retrieved January 12 2021 BIPM measurement units bipm org Retrieved January 20 2021 External links EditJaime Nubiola Carlos Ibanez e Ibanez de Ibero 1825 1891 Correspondencia europea de C S Peirce creatividad y cooperacion cientifica Universidad de Navarra Clarke Alexander Ross Helmert Friedrich Robert 1911 Earth Figure of the In Chisholm Hugh ed Encyclopaedia Britannica Vol 08 11th ed Cambridge University Press pp 801 813 Better formatted mathematics at Wikisource Clarke Alexander Ross Helmert Friedrich Robert 1911 Geodesy In Chisholm Hugh ed Encyclopaedia Britannica Vol 11 11th ed Cambridge University Press pp 607 615 Miguel Parrilla Nieto Carlos Ibanez e Ibanez de Ibero Real Academia de la Historia Excmo Sr D CARLOS IBANEZ E IBANEZ DE IBERO Academicos Historicos Real Academia de Ciecias Exactas Fisicas y Naturales Emilio Prieto Esteban Rose Angel Robles Carbonell El General Ibanez e Ibanez de Ibero Marques de Mulhacen e medida Revista Espanola de Metrologia June 2013 Rafael Fraguas Donde nacen los mapas Madrid El Pais February 15 2014 Albert Perard Carlos IBANEZ DE IBERO 14 avril 1825 29 janvier 1891 inauguration d un monument eleve a sa memoire Madrid Institut de France Academie des Sciences Notices et discours 1957 7 p p 26 31 Paul Appell LE CENTENAIRE DU GENERAL IBANEZ DE IBERO Revue internationale de l enseignement Juillet Aout 1925 pp 208 211 Adolf Hirsch LE GENERAL IBANEZ NOTICE NECROLOGIQUE LUE AU COMITE INTERNATIONAL DES POIDS ET MESURE LE 12 SEPTEMBRE ET DANS LA CONFERENCE GEODESIQUE DE FLORENCE LE 8 OCTOBRE 1891 Neuchatel IMPRIMERIE ATTINGER FRERES 1891 in COMITE INTERNATIONAL DES POIDS ET MESURES PROCES VERBAUX DES SEANCES DE 1891 Paris GAUTHIER VILLARS ET FILS IMPRIMEURS LIBRAIRES 1892 197 p pp 3 14 or Don Carlos IBANEZ 1825 1891 1892 12 p Archived October 26 2020 at the Wayback Machine Retrieved from https en wikipedia org w index php title Carlos Ibanez e Ibanez de Ibero amp oldid 1178522833, wikipedia, wiki, book, books, library,

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