Edison opinion

While working on the electric bulb, Edison and his assistants tried more than 6000 materials for testing as the right material for the filament. He tried a carbonized sewing thread that lasted 45 hours. He found a bamboo fibre that gave a bulb life of 1000 hours.

Many laughed but some sympathized with his problems. In reply to a friend, who sympathized with his trials and tribulations, he smiled and said that he was after all not unsuccessful. Edison said," ¡ discovered hundreds of materials that do not make filament!
story source: world reader