To allow businesses to make exact copies, Edison and his associates developed an electric pen that perforated paper with a series of tiny holes as the pen was drawn across it. Ink was loaded into the holes with one roller and then pressed through them onto a fresh sheet of paper with a clean roller-often several times before re-inking. The pen’s price tag? $35, all supplies included.
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Click here to view Thomas Edison’s 1,093 patent applications.