Abstract: This paper covers the general switching plan and fundamental plant layout proposed for handling telephone toll messages throughout the United States and Canada using automatic toll switching ...

Abstract: The great diversity of magnetic characteristics demanded by telephone apparatus, and the large number of available magnetic materials propose intricate problems in the choice of materials ...

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The modern world would look very different without these British inventions which have turned out to be some of the greatest Updated: Jun 05, 2025 05:17 AM EST ...