The spelling ‘surprize’ is used, deliberately, in the novel JONATHAN STRANGE & MR NORRELL. Author Susanna Clarke used certain, isolated but specific alternate spellings to take the story out of our current time, and emulate early 19th century novels. Spelling was less fixed then, and some words were spelled differently depending on who was writing. In extreme cases, they might be different depending on what paragraph or sentence the writer was working on, and what spelling occurred to them at that moment.
John Zakour and Scott Roberts