Practical algebra and hydrostatics: the legacy of Thomas Harriot

This article provides a glimpse of the unpublished work of Harriot’s colleague Walter Warner. The main topic is the use of hydrostatic weighing and algebraic symbolism to determine the constitution of a mixture of metals. This was an important matter in the context of contemporary debates about currency and exchange. Recent discoveries have revealed the extent of Warner’s writings in this field, and the involvement of other notable seventeenth-century figures, such as Charles Thynne, Henry Robinson, John Dury, Samuel Hartlib, Justinian Isham, and David Ramsay. Their work illustrates many facets of scientific enquiry at that time, such as the contemporary concepts of weight and density, and the introduction of the new symbolic algebra in Harriot’s style.