Roggenwolf und Roggenhund; Beitrag zur germanischen Sittenkunde - Softcover

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1865 Excerpt: ...a wire which forms two (rectangular loop) circuits of equal area, in the same plane or in parallel planes, in which (loops) current flows in opposite directions. The object of this arrangement is to get rid of the effects of terrestrial magnetism on the conducting wire....By rigidly connecting two circuits of equal area in parallel planes, in which equal currents run in opposite directions, a combination is formed which is unaffected by terrestrial magnetism (This balance) is therefore called an Astatic Combination (see fig. 1). It is acted upon, however, by forces arising from currents or magnets which are so near to it that they act differently on the two circuits Ampere's theory of the mutual action of electric currents is founded on four experimental facts and one assumption." Ampere's 1820 experiments provided several useful techniques employed in present-day eddy current test systems, including: 1. The methods of shielding leadwire connections to test coils. Figure 1. Maxwell's sketch illustrating Faraday's basic test arrangement with astatic balance coil arrangement 1. (It would be difficult to estimate how many hundreds of 20th century patents are based upon these simple discoveries by Ampere a hundred years earlier. It would also be difficult to estimate the manyears of effort and dollar costs lost during recent developments of eddy current test systems by workers who were not aware of the full significance of Ampere's 1820 work.) 3.1 Ampere's first experiment (505) (Shielding of lead wires)v' In Maxwell's words, "Ampere's first experiment is on the effect of two equal currents close together (flowing) in opposite directions. A wire covered with insulation is doubled upon itself and placed near one of the circuits of the astatic balance (...