The United States Bureau of Mines
๐
Article
๐
1914
๐
Elsevier Science
๐
English
โ 48 KB
tates a return current of more than IOOO amperes; yet not the slightest indication of any such current has so far been found, and no satisfactory explanation for its absence has been given." Much mo.re, of course, might be said on this subject, for it is a big one on which many have labored, but pe