Letter from H.A. Roebling to B.J. Harrington.
Letter from J.J. Stevenson to B.J. Harrington.
Letter, 19 November 1877
Letter, 4 December 1877
Letter, 12 April 1877
Letter, 27 April 1877
Letter, 12 September 1877
Letter from J.J. Stevenson to B.J. Harrington.
Letter, 14 March 1878
Letter, 30 March 1878