James Nasmyth b. 1808, Edinburgh, Scotland; d. 1890, London Photography was but one of James Nasmyth's many interests. He drew prolifically, and many of his works were made into lithographs, circulating mostly among his friends and acquaintances. Nasmyth's greatest historical contribution, however, was in the field of engineering: In 1842, he patented his steam hammer, which radically transformed the practice of casting metal and was a key development in Britain's industrial revolution. Nasmyth retired from engineering in 1856, and spent the last thirty-four years of his life pursuing another great love: astronomy. In 1874, he published The Moon: Considered as a Planet, a World, and a Satellite, which he coauthored with James Carpenter. Back of Hand & Shrivelled Apple. To Illustrate the Origin of Certain Mountain Ranges by Shrinkage of the Globe., 1874 Two Woodburytypes, each 4 1/2 x 3 1/4 inches (11.4 x 8.3 cm) These images appeared in The Moon as illustrations of a theory advanced by Nasmyth and Carpenter to explain its rough surface. They suggested that the moon had once been actively volcanic, but eventually lost energy and began to cool. As this occurred, its core contracted, leaving its crust loose and hanging, much like the skin of an aging body or a desiccated apple. This idea of contraction was a variation of the widely held nineteenth-century view of terrestrial geology—the theory of plate tectonics was devised only in the 1960s—but Nasmyth's and Carpenter's metaphoric leap to the physiology of the hand was entirely their own. —Nat Trotman