Zeuthen, Geschichte der Mathematik im 16.
His last publication, which appeared in 1878, was on spherical harmonics (Beitreige zur Theorie der Kugelf unctionen) .
He wrote a large work on the Christian doctrine of justification and atonement, Die Christliche Lehre von der Rechtfertigung and Versohnung, published during the years 1870-74, and in 1880-86 a history of pietism (Die Geschichte des Pietismus).
During this early period was known variously as Ferryhook, Ashley's Ferry and Van der Heyden's Ferry.
After the close of the war there was an influx of settlers from Rhode Island, Connecticut, New Hampshire and Vermont; a town was laid out on the Van der Heyden farm, and in 1789 the name of Troy was selected in town meeting; and in 1791 the town of Troy was formed from part of Rensselaerwyck.