"'Good prose is like a windowpane,' wrote George Orwell in his famous essay 'Why I Write,' a rule that would seem to counsel against ever stopping a reader with an unfamiliar word. It’s good advice for beginners, but serious readers are also lovers of language. I find that the occasional obscure word, used correctly, spices prose."
From an essay in The Atlantic by Mark Bowden, titled "In Praise of Fancy Words: The pleasures of reading with a dictionary by one's side."
I usually read on a computer or iPad screen, so the dictionary is built in, but in simpler times, I liked the exercise of getting up and walking over to the dictionary stand to look up any unfamiliar word. I keep a picture of my grandfather on the wall just above that dictionary:
He was a newspaper editor, and in his spare time, he enjoyed reading a dictionary.
And here's the full text of Orwell's "Why I Write."