High-intensity mercury-arc lamps

The general relationship between wattage and light output of high-intensity mercury-arc lamps, some of the effects of voltage and pressure on their efficiency, and a tabulation of the actual amount of energy they produce in various portions of the spectrum are discussed in this paper. The practical aspects of these lamps is discussed particularly in the fields of industrial lighting and where very high intensities of light are needed, as in searchlights, locomotive headlights, and, under certain conditions, for projection work.