Karl Baedeker

Karl Ludwig Johannes Baedeker, known universally as Karl Baedeker (3 November 1801 - 4 October 1859), was a German publisher whose company, Baedeker, set the standard for authoritative guidebooks for tourists.

Karl Baedeker was descended from a long line of printers, booksellers and publishers. He was the eldest of ten children of Gottschalk Diederich Bädeker (1778–1841), who had inherited the publishing house founded by his own father, Zacharias Gerhard Bädeker (1750–1800). The company also published the local newspaper, the Essendische Zeitung, and the family expected that Karl, too, would eventually join the firm.

Karl changed the spelling of the family name from Bädeker with the umlaut to Baedeker around 1850.

Biography

Karl Baedeker was born in Essen, then in the Kingdom of Prussia, on November 3, 1801.

After his schooling in Hagen, he left home in 1817 to study humanities in Heidelberg where he also worked for a while at the leading local bookseller J.C.B. Mohr. Military service followed, after which he moved to Berlin where he worked as an assistant at Georg Andreas Reimer, one of the leading booksellers in the city, from 1823 to 1825. He then returned home to Essen and worked with his father until 1827 when he left for Coblence (now Koblenz) to start his own bookselling and publishing business. Essen was then a small town with about 4000 inhabitants and he felt that Koblenz, which was not only larger, but was also the capital of the Prussian province of the Rhine and a hub for tourism, had far more to offer.

Karl Baedeker (scientist)

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Karl Wilhelm Sali Baedeker (3 February 1877 – 6 August 1914) was a German physicist, and a professor at the University of Jena. He was the grandson of Karl Baedeker, the founder of the eponymous travel guide publishing house, and the son of Fritz Baedeker (1844 - 1925), who ran the same company from 1869 until his death in 1925 (see Baedeker).

One of his scientific discoveries was that the resistivity of cuprous iodide (CuI) depended on its stoichiometry. Thin films of the material became much more conductive when exposed to iodine vapor; the effect was reversible. This was the first example of doping a semiconductor to change its properties and also the discovery of transparent conductive materials.

He also observed a Hall effect in transparent copper iodide thin films that had the reverse sign to that in copper, an observation of what was later to be known as conduction by electron holes in semiconductors. This observation was critical in developing the theory of electron conduction in solids. Along with his graduate student Karl Steinberg, Baedeker studied the effect of varying concentration of iodine on the electrical properties of copper iodide.