Naomi Pasachoff's Alexander Graham Bell: Making Connections PDF

By Naomi Pasachoff

ISBN-10: 0195099087

ISBN-13: 9780195099089

Examines the character in addition to the concept techniques which led this inventor to his discoveries that have helped our realizing of the flora and fauna.

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It began: "Dear Mr. " Despite the promising breakthrough of early June, the next months were among the most stressful of Bell's life. Tom Watson fell ill, and for many weeks they were unable to make progress on any front. Moreover, Bell was feeling a financial pinch. In his excitement over his electrical experiments, he had given up most of his teaching and now was short of funds. Dean Monroe of Boston University kindly advanced him his salary for the coming academic year, so 47 Alexander Graham Bell there was no need to worry about starving, but the longterm financial picture looked bleak.

He also knew that sound waves from one vibrating object can cause another object with the same natural frequency to vibrate. From singing into the piano in his grandfather's house in London and at his parents' in Canada, he knew that by varying the pitch of his voice he could make different piano strings vibrate in return. He now had the idea of sending many different messages, each at a different pitch, along a single telegraph wire. At the sending end of the wire, tuning forks would be tuned to different frequencies.

What had happened was obvious . . that little strip of magnetized steel I was plucking was generating by its vibration over the electromagnet, that splendid conception of Bell's—a sound-shaped electric current. From the moment the previous summer when he had conceived of the membrane telephone, Bell had worried about a possible flaw in the theory. Perhaps the human voice lacked the power to generate a current strong enough to be heard at the receiver. But now he knew that there was no need to worry.

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Alexander Graham Bell: Making Connections by Naomi Pasachoff

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