Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Johann Christian Poggendorff (29 December 1796 - 24 January 1877), was a German physicist born in Hamburg. By far the greater and more important part of his work related to electricity and magnetism. Poggendorff is known for his electrostatic motor which is analogous to Wilhelm Holtz's electrostatic machine. In 1841 he described the use of the potentiometer for measurement of electrical potentials without current draw.