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Issue 47: the most important publication in science was paid for in fish books
‘It defined how we understand the universe and popularised the ‘scientific method’, which is the bedrock of modern science.’
Welcome to Born Free Press, a fortnightly newsletter delivering a free-range collection of interesting stories for interested people. Currently focusing on quirks and curiosities from the UK’s history.
Let me set the scene: it’s the mid-17th Century, the ‘Scientific Revolution’ is in full swing, and the UK’s prestigious Royal Society (originally dubbed ‘for improving natural knowledge’) has just been founded.
Royal Society Fellows Francis Willughby and John Ray have travelled to Europe to study the natural world with the intention of publishing definitive histories of different animals, insects, and fishes.
Their approach was innovative for the time – defining and classifying species through their external features. As such, detailed illustrations were crucial.
‘De Historia Piscium’ (or ‘The History of Fishes’) was Willughby’s assignment. He was an ichthyologist. (Sadly, he died from pleurisy at 37, and Ray completed the book for him.)
With around 400 pages of text and over 180 illustrations of fishes, it was an expensive book to publish. The Royal Society attempted to finance the upfront costs through subscriptions and ‘sponsorships’ of individual images.

But when it was released in 1686, despite being the first illustrated history of fishes published in England, it was a commercial flop.
Which was bad news for another Royal Society Fellow with a pioneering book of his own in the works.
While all of the above was going on, Isaac Newton – alongside developing calculus and discovering the visible spectrum of light – had been puzzling over celestial mechanics and the forces at play in the universe.
It was another Royal Society Fellow, Edmund Halley (of Halley’s Comet fame), who learned of the work Newton was doing and urged him to publish.
The first of what would eventually become the three-volume ‘Philosophiae Naturalis Principia Mathematica’ (or ‘The Mathematical Principles of Natural Philosophy’) was presented to the Royal Society in 1686. The order to print it was given within a month.
But the Society’s enthusiasm was not reflected in its bank balance. The massive cost and poor sales of ‘De Historia Piscium’ had left it in serious financial strife.
But Halley would not be deterred. With the authorisation of Samuel Pepys – who was President of the Royal Society at the time – Halley offered to put up the money for the Society to publish the book.
And the learned world is forever indebted to him for it. ‘Philosophiae Naturalis Principia Mathematica’, released in 1687, is one of the most important works in the history of science.

It defined how we understand the universe, outlining Newton’s universal law of gravitation and his three laws of motion. And it was produced using the ‘scientific method’ – testing theories with experiments to see if they’re right – which is the bedrock of modern science. The book has become known simply as ‘the Principia’ (or ‘the Principles’).
Poor old, Halley, though.
Despite being instrumental in the publication of this important work, not long after its release, the Royal Society told him it could no longer afford to pay his annual salary (or pay him back for financing ‘the Principia’).
At least, not in cash money. Instead, it paid him in left-over copies of ‘De Historia Piscium’.
Postscript: ‘De Historia Piscium’ is much more widely appreciated today, and worth a lot more, too. On the rare books website, Abe Books, right now there are a couple of first editions on sale for over £7,000 each. For context, Halley’s 17th Century annual salary of £50 is worth about £9,500 today.