Literary nonsense from a combination of both sources. Though not the first to write this hybrid kind of nonsense, Edward Lear developed and popularized it in his many limericks (starting with "A Book of Nonsense", 1846) and other famous texts such as "The Owl and the Pussycat", "The Dong with a Luminous Nose," "" and "The Story of the Four Little Children Who Went Around the World". Lewis Carroll continued this trend, making literary nonsense a worldwide phenomenon with "Alice's Adventures in Wonderland" (1865) and "Through the Looking-Glass" (1871). Carroll's poem "Jabberwocky", which appears in the latter book, is often considered quintessential
Luminous efficacy a similar curve for dim conditions (scotopic vision). When neither is specified, photopic conditions are generally assumed. Luminous efficacy of radiation measures the fraction of electromagnetic power which is useful for lighting. It is obtained by dividing the luminous flux by the radiant flux. Light with wavelengths outside the visible spectrum reduces luminous efficacy, because it contributes to the radiant flux while the luminous flux of such light is zero. Wavelengths near the peak of the eye's response contribute more strongly than those near the edges. Photopic luminous efficacy of radiation has a maximum possible value of , for the