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*THE HISTORY OF OHM'S LAW*

THE HISTORY OF OHM'S LAW |

By Professor JOHN C. SHEDD, olivet college and MAYO D. HERSHEY, u. s. bureau of standards

*Introduction*

IN the historical development of any branch of science three steps may generally be traced. *First,* there is the growth, frequently in disconnected masses, of a body of data. A few of the more readily grasped

facts may find quantitative expression. These formnlæ, whether expressed in words or in mathematical terms, prepare the way for the *second* stage, in which investigation is directed toward the discovery of connecting links between otherwise isolated observations. This inductive process of framing and testing hypotheses ends with that comprehensive generalization in concise mathematical form which constitutes a "fundamental" law. The *third* and final stage comprises the deduc-