On 19 February 1869, T.H. Huxley delivers “Geological Reform,” his Presidential Address to the Geological Society of London. Image: Photograph of Thomas Henry Huxley (c. 1880). Print by Lock & Whitfield. This image is in the public domain in the United States because its copyright has expired.
The address is a direct, forensic response to William Thomson’s attack on Geology’s temporal vistas and the evolutionary science that depended on its time scale. Thomson replied on April 5 with “On Geological Dynamics,” again addressing the Geological Society of 
Glasgow.
