A simple question about Emily

Emily is one important character in the novel. My question is Why it is spelled Em'ly rather than the proper spelling Emily? I have read Through the whole story and guess it has something with British accent. But why in other places it is still spelled Em'ly?

Looking foreward to an early reply.

It is because of the accent of those living in that part of England. Dickens writes those characters as speaking in a lower class manner to accentuate the fact that they are just simple fisherman. Examples 'fur' for 'for' etc