This was his last work, for after a long illness he died at Bonn on the 1st of January 1894.
In particular the remarkable frontier lines which bounded the Roman provinces of Upper (southern) Germany and Raetia, and which at their greatest development stretched from near Bonn on the Rhine to near Regensburg on the Danube, are often called the Limes Germanicus.
These professors formed the " Committee of Bonn," which organized the new Church.
His eldest son, Eilhard Ernst Gustav, born at Berlin on the 1st of August 1852, became professor of physics at Erlangen in 1886, and his younger son, Alfred, born at Berlin on the 18th of July 1856, was appointed to the extraordinary professorship of Egyptology at Bonn in 1892.
Liege, Aix-la-Chapelle, Cologne and Bonn fell into their hands.
