 Mohr served in Franco-Dutch War in 1672–1673, and was taken prisoner by the French.By 1673, he had published his second book, "Compendium Euclidis Curiosi".A third book was later mentioned by Mohr's son; for many years this was believed to be the "Gegenübung auf Compendium Euclidis Curiosi" but argue that it must be a different book, and that the "Gegenübung" has a different author.