Thomas Edison tried two thousand different materials in
search of a filament for the light bulb. When none worked satisfactorily, his
assistant complained, “All our work is in vain. We have learned nothing.”
Edison replied very confidently, “Oh, we have come a long
way and we have learned a lot. We know that there are two thousand elements
which we cannot use to make a good light bulb.”
No comments:
Post a Comment