While it would be easy to classify The Sinister Researches of C.P. Ransom as sci-fi humour, I wouldn't be so hasty to class it strictly so: it's more of a collection of often humorous short stories that revolve around funny scientific breakthroughs, or at least attempts of a breakthrough, rather than heavy set sci-fi with some humour in it.
The stories themselves are all tied together by this underlying scheme of making the dough that Ransom thinks is going to save him. But all the stories themselves are relatively self-contained, as they all feature their own set of characters and a breakthrough Ransom is trying to use for his own benefit. Only two concurring characters are Ransom and MacTate with the supporting cast of the previous story getting a brief notion in a form or an another.
These schemes of Ransom revolve around different kinds of methods improving art, like teaching a computer to write better poems, or transferring a painting to a canvas straight from the mind of the painter to Ransom inventing a machine that opens a portal to 4th dimension or accidentally coming up with a pill that makes you glow like a light bug. All the things he comes up with, he tests out straight away with a help of faculty members or students, while his friend MacTate is often just trying to pull down the reigns a bit, as Ransom is throwing himself on the situations eager to see what will happen in order to prove his own genius (and to find a way to get his mitts on some hard needed money).
The Sinister Researches of C.P. Ransom is a well-written set of stories. They don't aim to be heavy sci-fi, nor do they aim to be hard science. They are often material what a studio like Disney could use to create a whole series of science influenced movies or series with bumbling main characters and all, but at heart, they are aimed at a bit more mature readers. Nearing's writing style is engaging, often witty and falls in the easy reading category. Each story is short enough to be enjoyed either as a delightful little snack now and then, or just one, nice continuous read. Either way, if you're looking for a bit more humorous light reading, either being a fan or not of sci-fi, you could do a lot worse.
If you want it, you might get a paperback from Amazon or used bookstores.