Conversation so far:
what was Francis Galton known for doing?
Francis Galton was a polymath who made important contributions in many fields of science.
what was one of Francis Galton's contributions?
Francis Galton coined the phrase nature versus nurture. His book Hereditary Genius (1869) was the first social scientific attempt to study genius and greatness.
is there anything interesting that happened during Francis Galton's Middle Years?
Francis Galton became very active in the British Association for the Advancement of Science, presenting many papers on a wide variety of topics at its meetings from 1858 to 1899.

Question: What was a topic of one of the papers he presented?
Self-contained rewrite: What was a topic of one of the papers Francis Galton presented in the British Association for the Advancement of Science?