This collection of essays discusses the marketing of scientific and medical instruments from the eighteenth century to the First World War. The evidence presented here is derived from sources as diverse as contemporary trade literature, through newspaper advertisements, to rarely-surviving inventories, and from the instruments themselves. The picture may not yet be complete, but it has been acknowledged that it is more complex than sketched out twenty-five or even fifty years ago. Here is a collection of case-studies from the United Kingdom, the Americas and Europe showing instruments moving from maker to market-place, and, to some extent, what happened next.