| These two standard inducutors, marked 0.1 Henry and 0.01 Henry, were purchased by Professor Almy shortly after legal standards were adopted in 1893. Both were made by Hartman & Braun A.G., Frankfurt A.M. They are numbers 245 and 246. |  |
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| These two standard inducutors, marked 0.1 Henry and 0.01 Henry, were purchased by Professor Almy shortly after legal standards were adopted in 1893. Both were made by Hartman & Braun A.G., Frankfurt A.M. They are numbers 245 and 246. | |