Oughtred vs. Delamain – a dispute over teaching methods and who invented the circular slide rule.

In the last post in this series, I talked about the rapid expansion in the availability and use of mathematical and scientific instruments in England in the Early Modern Period. After describing the areas where these new instruments came into use, I turned to the developing field of mathematical tuition for gentlemen. Here the growing number of private mathematics teachers concentrated on teaching their rich clients the functions and uses of mathematical instruments, not so much that they could use them themselves but more that they could converse intelligently with the expert users. As I expressed it there: To some extent the gentleman was not required or expected to use all of the instruments himself. However, the instruction enabled him to discuss intelligently the work being carried out by his estate surveyors, or follow the bookkeeping accounts of his estate manager, perhaps checking the results of the calculations with one of the numerous multi-scaled calculating rules thrown…