Kunz made significant contributions to construction of photoelectric cells improving on the methods introduced by Elster and Geitel . During the fall of 1911 , he began a collaboration and friendship with the University of Illinois Observatory director Joel Stebbins that would revolutionize astronomical photometry . Kunz ’s photoelectric cells were many times more sensitive that what was available commercially and therefore able to detect faint star light . Kunz ’s cells would be used at half a dozen observatories all across the nation including Yerkes Observatory , Lick Observatory , and Washburn Observatory . Kunz also accompanied Stebbins and four solar eclipse expeditions beginning with the Solar eclipse of June 8 , 1918 to measure the total light of the solar corona with the photoelectric photometer . The collaboration between Stebbins and Kunz continued until Kunz ’s death in 1938
Solar eclipse of June 8 , 1918
Solar eclipse of June 8, 1918
Jakob Kunz