Beschreibung:

HERTZ, Heinrich Rudolph (1857-1894). Autograph manuscript signed ("Dr. Heinrich Hertz"), Hertz's draft of the announcement of the publication of his Untersuchungen ueber die Ausbreitung der elektrischen Kraft [ Investigations into the Propagation of Electric Force ], [1892]. 1 page, folio, small section pasted at bottom, signed at head and in the text, few emendations and corrections, with German and English typed transcripts . THE THEORY OF WIRELESS TELEGRAPHY: HERTZ ANNOUNCES THE PUBLICATION OF HIS BOOK ON ELECTROMAGNETIC WAVES Hertz was the first to demonstrate experimentally that electromagnetic waves radiate in space at the speed of light, just as Maxwell had predicted in his Treatise on Electricity and Magnetism . He published his discovery in a series of papers printed in Annalen der Physik und Chemie from 1887-1890. In 1892, he issued a reprint of these papers, adding explanatory notes and a 31-page introduction. This autograph manuscript written before the book was published shows that Hertz personally wrote the publisher's "blurb" for the book-the description of the new book and its contents: " Investigations into the Propagation of Electric Force A reprint of the original work along with an introductory overview. Bound with 40 figures in the text. The investigations by which Prof. Hertz demonstrated a few years ago for the first time the propagation in time of a presumed action at a distance, and explained the Maxwell theory regarding the relationship of light and electricity by means of experiments, have appeared in 'Annalen der Physik und Chemie.' Since individual issues of these annals cannot be supplied, the bookstore of the publishing company was in no position to satisfy the frequent requests made for these works. At the suggestion of the publisher of these annals, these works are thus reprinted here as a collection Since the initial publication of this work, many physicists have been active in this area. The experiments have been repeated, extended, and completed. The main results have only been confirmed thereby. However, with regard to some not all insignificant questions, errors have certainly been found at times, and at times they have become probable." Hertz explains that he wishes to take this opportunity to correct some of these errors and answer questions: "In this way, the understanding of the experiments and especially of the theoretical investigations, is not insignificantly simplified." "Hertz had determined that electromagnetic waves were longer than light waves and showed that they were in complete correspondence with the waves of light and heat in the transverse nature of their vibration and their susceptibility to reflection, refraction and polarization" (Norman). Although trained as an engineer, Hertz conducted his experiments for purely theoretical objectives, and did not pursue their practical applications. Marconi and others did, leading to the development of airwave technology. This rich field of research initiated "a technologicial development as momentous as its physical counterpart" (DSB). For the published work, see Norman 1061; PMM 377.