Novels
A British 5-year Plan (1905)
The North Sea Mystery (1930)
Red Invader (1931)
The Riddle of the Straits (1931)
The Death Ship (1933)
Wind in the East (1933)
Across the Frontiers (1936)
Red Desert (1936)
The Secret Voyage (1946)
aka The Professor's Last Experiment
The Clockmaker of Heidelberg (1949)
The Rockets (1951)
The Orphans of Brandenburg (1953)
The North Sea Mystery (1930)
Red Invader (1931)
The Riddle of the Straits (1931)
The Death Ship (1933)
Wind in the East (1933)
Across the Frontiers (1936)
Red Desert (1936)
The Secret Voyage (1946)
aka The Professor's Last Experiment
The Clockmaker of Heidelberg (1949)
The Rockets (1951)
The Orphans of Brandenburg (1953)
Visitors also looked at these authors