Цит. в: J. Norman Lockyer and W. W. Hunter, «Sunspots and Famine,» Nineteenth Century (1877): 591.
139
Clerke, Popular History, 176. Также см.: Helge Kragh, «The Rise and Fall of Cosmical Physics: Notes for a History, c. 18501920»; , accessed 17 December 2018.
