This special issue of Notes and Records of the Royal Society addresses important aspects of the new kinds of intensive and ambitious schemes launched by early nineteenth-century British public agencies for worldwide surveys of the phenomena of astronomy and geography, physics and meteorology. Historians and historical geographers of science have already provided separate and increasingly detailed studies of several of these initiatives. Such focused scholarship now invites a comparative and synthetic approach to the development and practice of these surveys. In particular, this nineteenth-century work of surveys and observatories, maritime sciences and global physics, has typically been defined through the deployment of collections of ingenious hardware and material instruments. For this reason, many of the essays gathered here examine the apparatus and the equipment involved in the nineteenth-century surveys; and the means through which they can be understood in historical scholarship, in collections and exhibitions.