Depending on their applied voltage, arc lights can produce between two and four thousand candlepower, compared to the approximately 125 candlepower of a 100-watt incandescent bulb. So the typical ...

He placed the arc at the bottom of the lamp, so that the lamp housing did not cast a shadow and improved the mechanism by which the length of the arc was kept constant. This gave a steadier light.

You can learn more about global energy trends here. 1803 — 1809: First arc lamp created Humphry Davy demonstrated the first incandescent light to the Royal Institute in Great Britain ...