An Introduction to Harriot’s Manuscripts on Motion

Harriot’s notes on projectile motion and the motion of fall are found on roughly two hundred folio pages, the exact number depending very much on what is considered related to these topics. The folios bearing these notes are largely disordered and scattered among the entire corpus of Harriot’s manuscripts comprising about 5,200 sheets, which are preserved partly in the British Library and partly at Petworth House, Sussex, with Lord Egremont.¹ The largest part of the notes on motion is found in the manuscript bundles Add MS 6788 and Add MS 6789 (here designated by the letters G and H) in the British Library.

The overwhelming part of Harriot’s notes on projectile motion and the motion of fall are working notes produced in the process of research. There are only a few possible exceptions, namely notes that Harriot may have prepared in order to communicate certain basic ideas.2 Accordingly, the greatest part of Harriot’s notes on motion consists of drawings, calculations, algebraic transformations, and tables, with only very little text.

It is worth observing that it may well be that the extant Harriot manuscripts on motion are not complete. In particular, the earliest notes appear to be rather fragmentary. The later notes, in contrast, are largely self-contained. In any case, there are no indications that we miss the essential part of Harriot’s notes on motion, or that there would have been treatises on motion neatly written up but now lost, as Shirley speculated.