HERTZ, Heinrich Rudolf (1857-94). Untersuchungen ueber die Ausbreitung der Elektrischen Kraft.

HERTZ, Heinrich Rudolf (1857-94).  Untersuchungen ueber die Ausbreitung der Elektrischen Kraft. Leipzig: Johann Ambrosius Barth, 1892. 8vo (217 x 140mm). Illustrations and diagrams (title very lightly browned). Contemporary [?or original publisher’s] black cloth, spine lettered in gilt, blue foliate endpapers, marbled edges. Provenance: from the Collection of Peter and Margarethe Braune. FIRST COLLECTED EDITION of Hertz’s important series of papers on electromagnetic waves, which includes his proof that they travel at the speed of light, and that they can be created and sent through space by means of wireless telegraphy; they have been of profound importance to 20th-century technology. "Experimental proof by Hertz of the Faraday-Maxwell hypothesis that electric waves can be projected through space ... was begun in 1887, eight years after Maxwell's death. The two main requirements were (a) a method of producing the waves, supposing that they existed, and (b) a method of detecting them once they were produced. Hertz found the first problem easy to solve. He used the oscillatory discharge of a condenser. Detection was much more difficult, because there then existed no means of detecting currents alternating at the high speed of these waves. Hertz in fact used an effect as old as the discovery of electricity itself - the electric spark. By inducing the waves to produce an electric spark at a distance, with no apparent connexion between the oscillator and spark gap, and by moving the sparking apparatus so that the length of the spark varied, he proved beyond question the passage of electric waves through space" (PMM). Honeyman 1669; Norman 1061; PMM 377; Sparrow Milestones of Science 101; Waller 1137.