| From Classbrain.com Patents
Before the invention of the electric lightbulb, homes were lit by candle, kerosene-oil lamp, or gaslight. All flickered, were fire hazards, and emitted smoke and heat. Other inventors of the day were experimenting with a glass globe that, if emptied of air, could contain a light that would not burn out. But no one could find a suitable filament, or wire. The filament creates light when an electric current passes through it, but it must neither burn out quickly nor melt. Edison solved this problem by using carbonized cotton. Source: NARA - The Digital Classroom LearningLinksSource DocumentView the original patent for the Edison's electric lamp Source: US Patent and Trademark Office Lesson Plan Teaching With Documents Lesson Plan: Alexander Graham Bell's Patent for the Telephone and Thomas Edison's Patent for the Electric Lamp> Source: NARA - The Digital Classroom Suggested Reading© Copyright 2004 by Classbrain.com |
