One day a little girl came home from school, and said to her mother, "Mommy, today in school I was punished for something that I didn't do."
The mother exclaimed, "But that's terrible! I'm going to have a talk with your teacher about this! By the way, what was it that you didn't do?"
The little girl replied, "My homework."
Electric motorIn 1904, the first direct current, interpole, electric motor to be patented in the U.S. was issued to Mathias Pfatischer of Phildadelphia, Pennsylvania under the title "Variable Speed Motor" (No.775,310). His improvement was to "effect commutation without sparking, with a variable load as well as at variable speed and which is capable of rotation in either direction." The new design added auxiliary-field pole-pieces which were small as compared to the main pole-pieces.« |
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