I have tried to find the Marriage on FMP and can not see it. Unfortunately I do not have the originals we used to transcribe Christ Church Attercliffe.
I can see on the 1851 & 61 census that Thomas Butterworth is a Fork Maker.
I found the marriage at FMP. I agree with Shoemaker.
William's occupation could be Fireman but it is basically an F followed by a choppy sea. It *could* be filecutter. If it is fireman the 'a' is unike the other a's written by the clerk.
If you can send me an email I will send you the image from FMP.