<p style='text-align: justify;'>Photograph of etching of Henry Cavendish (1731-1810). Henry Cavendish was a distant relative of William Cavendish (1808-1891), 7th Duke of Devonshire, who provided the money for the building and equipping of the Laboratory. Henry Cavendish discovered hydrogen and also carried out the Cavendish experiment to measure the mass of the Earth (or, equivalently, evaluate the gravitational constant).</p>