Star Trek: The Original Series had titles for each episode. (e.g. - Amok Time, Balance of Terror, The Doomsday Machine, and so forth.)

Doctor Who episodes had titles as far back as 1963. (e.g. - The Daleks, Marco Polo, An Unearthly Child, and so forth.)

The original Twilight Zone episodes from 1959 through 1964 had titles for each episode. (e.g. - It's a Good Life, Escape Clause, The Fever, and so forth.)

What was the original sci-fi TV series to feature specific titles for each episode?