Title page, 'On the structure and motion of glaciers'

Article published in the Royal Society periodical, The Philosophical Transactions, jointly by two of the most influential scientists of their time, John Tyndall and Thomas Henry Huxley. The paper, which had been presented to the Royal Society a year prior summarises some observations on glaciers they made during a stay in the Alps.
The two scientists proposed that the movement of glaciers relied on fracture and regelation, whereas geologist James David Forbes (1809-1868) had previously published a theory that described the motion as that of a viscous fluid. This disagreement sparked a major controversy in the field which lasted for well over a decade.