Answer: The History of Fish

Among Sir Isaac Newton’s greatest contributions to the field of mathematics is his seminal and incredibly important work Philosophiae Naturalis Principia Mathematica (“Mathematical Principles of Natural Philosophy” or simply known as Principia within the field). The work, published in three parts, lays the foundations for classical mechanics, Newton’s law of universal gravitation, and builds on Kepler’s laws of planetary motion. The Principia is widely regarded as one of the most important works in the history of science.

With that in mind, it is absolutely astounding to learn that the Royal Society failed to publish it. Despite their promise to Newton to fund the publication of his work, they had gone nearly bankrupt the year prior when they financed a huge print run of Francis Willughby’s text De Historia Piscium (“The History of Fish”). The book proved to be very unpopular, and they were unable to even recoup the printing costs and couldn’t print Newton’s book.

Thankfully the clerk of the Society, Edmond Halley (best known for computing the orbit of the eponymous Halley’s Comet) saw the value of Newton’s text and personally financed the first print run. Once the work was in circulation (and receiving the praise and attention it deserved), securing future print runs was no issue.