When one door closes, another opens; but we often look so long and so regretfully upon the closed door that we do not see the one which has opened for us.

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When one door closes, another one opens.

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The inventor is a man who looks around upon the world and is not contented with things as they are. He wants to improve whatever he sees, he wants to benefit the world; he is haunted by an idea. The spirit of invention possesses him, seeking materialization.

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Before anything else, preparation is the key to success.

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There are two critical points in every aerial flight-its beginning and its end.

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Observe, Remember, Compare.

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The achievement of one goal should be the starting point of another.

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Concentrate all your thoughts upon the work at hand. The sun's rays do not burn until brought to a focus.

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First words on the first telephone - "Mr. Watson - come here - I want to see you.

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One day every major city in America will have a telephone.

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