Factual error: When Dracula is about to bite the neck of his female assistant you can plainly see him in her vanity mirror and as all good horror fans know, you can't see a vampire in a mirror, especially Dracula.
Factual error: After the first encounter with the Apaches, the covered wagon is headed to the Fort at full speed. The camera pans to the Apaches on the ridge and you can see a truck driving at the bottom right corner. (00:32:00)
Factual error: When the riders are watching the wagon train, in the background you can see a communication tower with conical speakers.
Factual error: Based on the lottery poster, the movie is set in 1925. During the scenes in Tampico, numerous newer cars (closer to the 1948 filming) are present in the background.
Factual error: The movie takes place in 1860, yet Ripper wields an 1862 police model Colt revolver.
Factual error: At the start of the film the father (Cedric Hardwicke) alights from a LNER suburban train then walks to his Wimbledon home. The film is set in 1913 but the LNER was not formed until 1923. That apart, LNER suburban services did not serve Wimbledon. A few scenes later the father and mother are sending off their son at Liverpool Street Station on his journey to Osborne Royal Naval College at Dartmouth. Strange since Dartmouth would have been (and still is) reached from Waterloo.