Thomas Alva Edison was granted US Patent 251,545 for his electrolytic meter, which measured electricity without a coil and requiring no power supply. It allowed those wishing to tax electricity to measure it reliably and inexpensively, thus opening up enormous commercial prospects. Thomas Alva Edison accumulated 80 patents in 1880, 90 in 1881, and 100 in 1882. Edison was enjoying a period of exceptional productivity, averaging a patent every four days. Throughout the decade, he filed one patent a week, combining these activities with his other activities as a builder, engineer, entrepreneur, publicist, conspirator, manager, husband, and father. Some of his companies include the Edison Electric Light Company, the Machine Works, the Edison Company for Isolated Lightning, and the Edison Ore Milling Company.
