De la Rue, Warren: Researches on solar physics. Heliographical positions and areas of sun-spots observed with the Kew photoheliograph during the years 1862 and 1863 : received March 31,-read April 30, 1868 ; the positions and areas of the spots observed at Kew during the years 1864, 1865, 1866, also the spotted area [...]. [London] : [Taylor and Francis], 1868-1870