That book was bunk. By the time Edison made a light bulb, incandescent light had been initially demonstrated by Davy 70 years beforehand, and shown to practic

That book was bunk. By the time Edison made a light bulb, incandescent light had been initially demonstrated by Davy 70 years beforehand, and shown to practical by Lindsay 35 years after that. Jobard, de la Rue, and de Moleyns had made experimental light bulbs 40 years beforehand, Lodygin had held a patent for 5 years. Most crucially, Swan's lightbulbs had been lighting Mosley Street for six months. Carbon arc lights (also shown by Davy early in the 1800s) having been in commercial use for some time before that. The main invention that made light bulbs practically viable was the improved vacuum pumps of the 1870s, which none of these people lay claim to. This is what led to the rapid development of incandescent light in the 1880s.