One end was in 1964--the other in 1804. People could go both ways. So could...things. For instance, brand-new "antiques" for the 20th century, and marvels of modern industry for the Napoleonic era.
But you had to be careful--because what would happen to "now" if you did something in 1804 that changed history? It was unthinkable.
Unfortunately, it happened...
NOT to be confused with the later novelizations that were based on the TV show...
This is the original novel which inspired the ABC tv series. The same author later wrote two novelization based on the tv series.
To add to the confusion, the publisher decided to use the same title and basically the same cover art for one of the novelizations.
This edition is the original novel, predating the television series, as originally conceived by the author, Murray Leinster.” DRIVE