Cabal [Massey]: " ... all the universe or nothing? Which shall it be, Passworthy? Which shall it be?" [the eternal question: progress or stagnation?]
Raymond Massey ties the whole 100-year plot together, playing different characters in the same family line. This film was made with much involvement of H.G. Wells and is based on his story.
The first part showing the war is terribly prescient and was hard to watch knowing what happened in Europe only a few years later.
I enjoy spotting imagined inventions in old sci fi that eventually became realized gadgets: see the dudes on the Segue-like transportation devices in the pics below.