How many experiments and materials did Edison use to invent electric lamp?

How many experiments and materials did Edison use to invent electric lamp?


Edison experienced 13 months of hard work, tried more than 6000 kinds of materials, and tested more than 7000 times before he made an electric lamp. The lamp was on for 45 hours



How many experiments did Edison do to invent the electric light?


Edison experienced 13 months of hard work, tried more than 6000 kinds of materials, and tested more than 7000 times before he made an electric lamp. The lamp was on for 45 hours