Jerome K. Jerome's Three Men in a Boat, to Say Nothing of the Dog is incredible. Whimsical in tone, it follows the author and his three chums (counting his irrepressible dog, Montmorency) on a trip up the Thames river. Scenic and picturesque descriptions of the Thames shoreline and river villages are contrasted by elaborate fantastical meanderings through Jerome's imagination (Especially the part where he imagines he is watching Prince John forced to sign the Magna Carta) and by various interactions with and misadventures of the three men and the dog.</p>
I would give this a 10/10 for period humor, and a 9/10 in general. I recommend it to anyone looking for something funny in British classics. Or, to anyone looking for something funny, period.
Also, the book To Say Nothing of the Dog by Connie Willis is one of the best and most charming time-travel stories I've ever read.