Time Travel Fiction Outputs

HG Wells
"The Chronic Argonauts," an unfinished  9000-word, three-part serial, published in the Science Schools Journal;

"The Time Machine," an unfinished seven-part serial about the Time Traveller and the Eloi but set in 12,203, published in the National Observer by W.R. Henley;

The Time Machine as we know it, a five-part serial published in the New Review by Henley, then published with some alterations as a book by Heinemann, publishers of the New Review, - well over three times as long as the National Observer serial.

Poul Anderson
Three independent novels;

one series complete in two volumes - an omnibus collection containing ten works of different lengths, including short novels, followed by a long novel incorporating three interconnected narratives;

enough non-series short stories for a collection.

Thus:

Wells - bits and pieces/odds and sods, enough to fill a single volume;
Anderson - six volumes, the omnibus collection combining three previous volumes with two newer works.

One of Anderson's independent novels acknowledges, without naming, Wells. Anderson's shorter works could have included a sequel to The Time Machine, which Anderson would have done better than anyone else. Some thoughts on this will follow.