Johann Christian Poggendorff

Johann Christian Poggendorff ( born December 29, 1796 in Hamburg, † 24 January 1877 in Berlin) was a German physicist.

Life

He was the son of a wealthy manufacturer, who had benefited from the French siege. At age 16, he went to a pharmacist - administration in Hamburg. He then earned his living as a pharmacy assistant in Itzehoe. Ambition and a strong inclination for science led him to abandon this position and to move to Berlin, where he attended the University from 1820. Here we quickly recognized his abilities, and in 1823 he was appointed by the Academy of Sciences for meteorological observers. His grave was located on the St. Mary's and St. Nicholas Cemetery I in the Berlin district of Prenzlauer Berg.

Poggendorff's services

He built in 1820 the first practical ammeter ( galvanometer, Galvanoskop, even multiplier), and invented in 1826, together with the Gaussian mirror reading for this meter. He developed in 1841 Poggendorffsche compensation circuit or voltage compensation for the precise measurement of electrical voltages, currents and resistances (eg for calibration purposes ) and led by provisions of the electromotive force. He built an electrostatic motor similar to that of Holtz. He also invented in 1840 a ​​practical clamping screw. In 1850 he described the Poggendorff illusion. The Poggendorffsche scale is a named after him experimental arrangement.

Poggendorff's mistakes

JR Mayer in 1841 sent his treatise "On the quantitative and qualitative determination of the forces " for publication in his Annals of Physics at Poggendorff, in which he a law of conservation of energy ( mean energy was ) postulated. He later became known as the first law of thermodynamics or conservation of energy. Also, because the treatise Mayers contained fundamental physical errors, Poggendorff, she refused. Mayer did not even get a reply to its submission. Only after Poggendorff's death 36 years later, the text said to have been recovered from him. However, in 1842 Mayer's essay appeared in "Remarks on the forces of inanimate nature " in edited by Friedrich Wöhler and Justus von Liebig Annalen der Chemie Mayer had yet decades for recognition of his theory wait, . They asserted itself only in his last years.

1847 refused Poggendorff from a work of Helmholtz on the same subject.

On October 26, 1861 Philipp Reis held in the auditorium of the University of Frankfurt to the members of the famous " physical association" a lecture on his invention of the telephone. Poggendorff rejected the announcement of the invention of rice in his annals of physics and chemistry, as he considered them gimmick. He also took Rice 's essay not in his Biographic- Literary Dictionary of the Exact Sciences. So Poggendorff contributed to the fact that rice ' phone does not prevailed.

Poggendorff as editor

Early on, he thought about it, to establish a scientific journal for physics and chemistry. The implementation of this plan has been accelerated by the sudden death of Ludwig Wilhelm Gilbert, editor of Gilbert's Annalen der Physik.

1824 took Poggendorff contact the Publisher Christian Gottlob Barth in Leipzig. The result was that he was in 1829, used as the editor of a scientific journal, Annals of physics and chemistry. It should be an extended continuation of Gilbert's annals. For this item Poggendorff was eminently qualified. He had an exceptionally good memory, which was filled with historic and modern scientific knowledge, well, a cool and objective judgment and he gave facts in preference to speculative theories. So he was able to devote himself fully to the spirit of modern experimental science. In the classification of knowledge and in business life he possessed in abundance on the German virtue of neatness. He also had an uncommonly friendly nature and went with people around very tactful. These characteristics make Poggendorff's Annalen soon become the leading scientific journal in Europe.

During his 52- year tenure as editor of the Annals he learned necessarily the troubles of modern men of science know. This knowledge, together with those which he had acquired in his extensive historical studies, he gave the world in his " Biographic- Literary Handwörterbuch the history of the exact sciences ." It contained reports on the life and work of mathematicians, astronomers, physicists and chemists of all nations and ages. The work contained an amazing collection of facts which are relevant to science biographers and historians invaluable. The first two volumes were published in 1863. A third volume, which covered the period 1858-1883, appeared in 1898. A further, fourth volume, which reached up to the beginning of the 20th century, in 1904 came out.

Poggendorff was a physicist of high, but not highest rank. His mathematical skills left something to be desired, and he never showed that power for scientific generalization that makes up the physical genius. However, he was an able and conscientious experimenter and was very fertile and ingenious in devising physical devices. The largest and most important part of his work was related to electricity and magnetism.

His literary and scientific reputation quickly earned him recognition. In 1830 he was appointed royal professor, 1834, he was associate professor at the University of Berlin and 1839 member of the Academy of Sciences in Berlin. He received numerous offers for the full professor level, but rejected them all off and devoted himself entirely to his scientific research and his duties as editor of the Annals. The Bavarian Academy of Sciences in 1872 took him on as a foreign member.