Boyne
2 of the 7 encyclopedias on this shelf carry an entry for Boyne. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a river of Ireland, rises in the Bog of Allen, County Kildare, and flows N. E. through Meath to Drogheda, below which it enters the Irish Sea. It is navigable for barges up to Navan. The Boyne will ever be memorable in English history for the important victory gained on its banks about 3 miles above Drogheda, July 1, 1690, by the forces under the command of William III., over those of James II. Though James' personal courage was beyond all question, he, on this occasion, allowed the prudence of the sovereign to outweigh the impulses of the soldier. Of his troops 1,500 were killed and wounded, while William lost barely 500 men. In 1736 an obelisk, 150 feet high, was erected at Oldbridge, on the site of the battlefield, in commemoration of this victory.
Aiton's Encyclopedia (1910)
boin, a small river of eastern Ireland. It rises in County Kildare and empties into the Irish Sea about thirty miles north of Dublin. It is memorable in Irish history for a victory gained by the Orangemen under William III, July 1, 1690, over the Stuart forces under James II . Over 1,500 of King James' troops were killed. The battle was final. In 1736 a monument 150 feet high was erected by the Orangemen on the site of the battlefield to commemorate their victory. See Orangemen 2026 Editor's Note: This battle has never become history in Ireland. Its anniversary is still marched every July by the Orange Order — the Twelfth — and remains the most contested date in the Northern Irish calendar. By a quirk of the calendar reform, the July 1 battle is commemorated on July 12. (Ed: BR 2026-06-25)