In the late 1690s and first decades of the eighteenth century, Newton’s works reached a wider public, both inside and outside the universities. They did so due to the rise of the Newtonian textbook, which, as Snobelen (1998) points out, did far more to spread Newtonianism than did the initial editions of Newton’s own works. They were effective not just because they simplified what all were agreed was an incredibly difficult book to understand, but also because they had far more extensive print-runs than Newton’s own texts. Snobelen reminds us that the first edition of the Principia ran to at most 400 copies, whereas William Whiston’s Praelectiones astronomicae had a print run of 1,000, as did his Praelectiones physico-mathematicae. Whiston’s textbooks were not only easier to read and more readily available – they were also cheaper. It is thus likely, as Snobelen concludes, that ‘most would-be natural philosophers first encountered Newton through the poor man’s Principias’.
What Whiston did for his Cambridge undergraduates, and later for the aficionados of Newton attending his popular public experimental lectures at London and Bath, was to explain the Principia (and more usually the Opticks) in ways that made Newton’s ideas accessible to his various audiences. He was not alone in this: much the same process is visible at the universities of Leiden and Dublin where ‘s Gravesande’s Physices Elementa mathematica experimentis confirmatur seu Introductio ad Philosophiam Newtonam (Leiden, 1720), and Richard Helsham’s A course of natural philosophy (Dublin, 1739) performed much the same function. Equally, the audiences attending public experimental lectures at London could not only buy Whiston’s textbooks, but also those of John Theophilus Desaguliers (1683–1744), who did more than anyone to explain Newtonianism to a wider audience.
Snobelen, Stephen D. (1998), ‘On reading Isaac Newton’s Principia in the 18th Century’, Endeavour 22 no. 4, pp 159-163.