Untersuchungen über die Richtung und Stärke des Erdmagnetismus an verschiedenen Puncten des südwestlichen Europa
Munchen: Hubschmann'schen Buchdruckerei, 1858. First printing. Hardcover. Quarto, plain dark charcoal cloth, with bookplate giving this copy to the Royal Philosophical Society of Edinburgh. 198, CXV pp, 13 lithographed plates at rear. Very good, light foxing to both text and fore-edge of text block. "His most important work was on the magnetism of the Earth. He performed magnetic surveys in Bavaria and northern Germany, France, Spain, and Denmark. He discovered a magnetic decennial period (ten-year cycle) and the electric current in the Earth closing the electric "circuit" creating the magnetic field in 1850. This roughly matched the eleven-year sunspot cycle discovered by Heinrich Schwabe. He calculated the orbits of the moons of Uranus and Saturn, obtaining the first value for Uranus' mass. By chance he observed Neptune in 1845 and twice in 1846, but did not recognize the object as being a new planet." (wiki). Very Good. Item #H18684
Price: $150.00