Sometimes when you take a volume off the shelf at the Cathedral library what you find in no way reflects the title of the book. What would you expect from a book entitled “The Art of Shadows” written in English in 1635 by John Wells? Certainly not one on a branch of Mathematics so difficult it would task a modern graduate in the field.
The book is a textbook on 3D trigonometry on the surface of a sphere! One can only guess at the number of people who could read, use or understand such a subject. Of course distances and readings taken by explorers and mapmakers were more difficult, and with satellite mapping and location such calculations are now done differently but even so the mind boggles!
When I asked a degreed mathematician from Oxford whether he had ever studied the subject you can guess for yourself his reply. Obviously books in old libraries are important pieces of history and reflect their times, and some like this record fields of study which are now dead ends, but the depth of knowledge occasionally leaves you speechless.
The Art of Shadows was published at London by the printer Thomas Harper. The Cathedral’s copy was donated by Lady Dorothy Berkeley. In the back of the book bound into it, is a copy of Henry Brigg’s Table of Logarithms for numbers from one to 10000. This was published at Gouda by Pierre Rammaseyn in 1626.
In his introduction to the book John Wells explained that the book was originally written thirteen years previously for Wells’ “private delight and exercise”. However, his late friends Henry Briggs, and Henry Gunter, a Lecturer in Astronomy at Gresham College, and more recently by another of his friends, Henry Gellibrand had persuaded him to publish the book.