Letter to Editor of the Times, January 15, 1915
Letter to Editor of the Times, July 18, 1919
Letter to Editor of the Times, November 29, 1918
Letter to Elliott, April 9, 1918
Letter to Fearnside, January 26, 1915
Letter to Fisher, March 16, 1912
Letter to Fotheringham, September 15, 1906
Letter to Hackett (Yale University Press), August 2, 1913
Letter to Hackett (Yale University Press), June 14, 1913
Letter to Hackett (Yale University Press), November 1, 1913