A Series And A One-Off

Whereas "Time Patrol" was written to launch a series, and indeed its first sequel was published later that same year, The Time Machine was designed to be a complete-in-itself one-off narrative with a conclusion explicitly precluding any sequel. The Time Traveller does not return. End of story. Similarly:

the Cavorite sphere is lost at the end of The First Men In The Moon;

the submersible sphere does not return from its second descent in "In the Abyss";

the Invisible Man is killed and his secrets lost.

This kind of sf ends by explaining why the world has remained as it is. Even Wells' The Shape Of Things To Come ends in its author's present. The future described in the text might not "come." Meanwhile, we also value speculative future histories as diverse as Poul Anderson's Technic History and his Genesis.

Could there have been a Time Machine series as there is a Time Patrol series? It would have had to have been designed differently from the outset. As it is, we value The Time Machine as "...that little masterpiece..." (JB Priestley) and the Time Patrol for its length and complexity.