Letter, 16 January 1872
Letter, 1 March 1877
Letter, 28 February 1883
Letter, 7 July 1886
Letter, 28 May 1888
Letter, 25 June 1891
Letter, 12 June 1892
Letter, 13 May 1896
Letter, 2 January 1900
Letter from H. G. Vennor to B.J. Harrington regarding the Geological Survey of Canada.