Edison's Electric-Lamp Invention Dark Gray T-Shirt

Electric lamp - invention of Thomas Alva Edison. Light from electricity was obtained even before Edison invented his electric lamp. Yet all lamps to date shared disqualifying disadvantages. It worked merely minutes up to a few hours. Their low brightness dimmed fast as the internal side of the glass vessel was covered with black deposits from burning filament. The doubt in the possibility of making light out of electricity was common at the time as many recognized inventors failed to meet the challenge. Edison conducted several thousands experiments in his Menlo Park laboratory to develop working construction and find materials meeting the requirements, especially of filament. In contrary to other constructions, which replaced air with gasses expected not to react with filament’s carbon, Edison used vacuum to render the carbon stable and solve the issue of carbon "air washing" - "attrition produced by the rapid passage of the air over [...] highly-heated surface of the carbon". A key novelty of the filament's construction was its spiral shape, which protected it from cracking due to different thermal expansion of the filament and electrodes attached to it. These were made of platinum, whose thermal expansion was close to that of glass. The filament was mostly made of cotton or linen fiber subjected to carbonization and twisted into a spiral. One of the side inventions of the electric-lamp was the process of obtaining platinum from mines' waste. Platinum was significantly difficult to get at the time and its resources were thought to be almost depleted. The process allowed the separation of platinum from gold. It also resulted in obtaining $1400 of gold from waste worth $5. The T-shirt is a part of the Breakthrough invention collection created to commemorate the key discoveries of science and technology. It presents a drawing from the original patent application.