7 ene 1839 año - American, Thaddeus Fairbanks invents platform scales.
American, Charles Goodyear invents rubber vulcanization.
Frenchmen, Louis Daguerre and J.N. Niepce co-invent Daguerreotype photography.
Kirkpatrick Macmillan invents a bicycle.
Welshmen, Sir William Robert Grove conceives of the first hydrogen fuel cell.
