«A Brief Outline of the History of Stage Lighting»(en inglés). Archivado desde el original el 10 de enero de 2014. Consultado el 30 de agosto de 2013. «The greatest drawbacks to the enjoyment of the theatrical performances are, undoubtedly, the foul air and heat which pervade all theatres. As everyone knows, each gas-burner consumes as much oxygen as many people, and causes great heat beside. The incandescent lamps consume no oxygen, and cause no perceptible heat».
«A Brief Outline of the History of Stage Lighting»(en inglés). Archivado desde el original el 10 de enero de 2014. Consultado el 30 de agosto de 2013. «The greatest drawbacks to the enjoyment of the theatrical performances are, undoubtedly, the foul air and heat which pervade all theatres. As everyone knows, each gas-burner consumes as much oxygen as many people, and causes great heat beside. The incandescent lamps consume no oxygen, and cause no perceptible heat».
