German architect. A pupil of David Gilly, he was one of the first (with T. Allason and C. R. Cockerell) to discover the entasis on Greek columns. With Foster, Jakob Linckh (1786–1841), and Cockerell he discovered the Aegina marbles (1811), and helped to survey the temple of Apollo Epicurius at Bassae. He submitted a design for the Walhalla, near Regensburg (1814–15), consisting of a massive series of battered platforms, a propylaeum with three pylon-towers, and a Greek Revival temple on top, obviously inspired by F. Gilly's monument to Frederick the Great (1797). His unrealized proposals for the Munich Glyptothek (Sculpture Gallery—1814) combined Greek and Egyptian elements. Leo von Klenze built both projects to his own designs, retaining Haller's platform idea at Walhalla.
Colvin (1995);Watkin & Mellinghoff (1987)