You can think of H.G. Wells' style as a bridge between two different camps of writing "countries."
One the one side we have the literary realists. These guys created a style to write about life "as it is." So, the sentences run like marathon runners, the paragraphs often fill entire pages, and their details can be of such excruciating detail that you'd think you're viewing life through a microscope. George Elliot's Middlemarch is king of this country.
On the other side you have the minimalists. They write sentences quick and clean. They get to the point. They use details, but only a few necessary ones. Ernest Hemingway's "A Clean, Well-Lighted Place" is el presidente here.
Like Goldilocks, Wells desires the nice middle ground between the two extremes. Here's an example:
In a minute or so the trees grew thinner, and I emerged upon a bare low headland running out into the somber water. The night was calm and clear, and the reflection of the growing multitude of stars shivered in the tranquil heaving of the sea (9.32).
The sentences aren't long, but they don't immediately drive the point home either. They meander just enough. They also throw in a few extra details to paint the scene, but our imaginations are still given plenty of room to stretch their muscles. Sure, some of the novel's sentences and paragraphs can get a bit long, but this usually happens when Wells needs a little extra length to give the story an air of realism (not an easy task when your story has Beast Folk scampering through its pages).