The Time Two Grammarians Fought a Duel over the Proper Pronunciation of Latin Diphthongs

John Overholt, a rare books curator at the Houghton Library of Harvard University, passes along this enticing image. He recently visited the Bruce McKittrick Rare Books shop in Narberth, Pennsylvania, where he found the marvel photographed above.

I am struggling to find information about this alleged duel fought between 17th Century grammarians Pietro Marverti and Pietro Tesei over the correct way to prounounce certain Latin diphthongs, which is a cominbation of two vowels. But, as the notes indicate, this book is extremely rare.

Though I have no love for bloodshed, I can appreciate such steadfast devotion to a cause that would inspire a man to take up a saber on behalf of it.