Using the Apostrophe to Mark Possession in Modern English

In writing, it clearly distinguished possession from plurality. So if that apostrophe was marking the letter e that had become silent, it was doing so a couple of centuries after the fact. The printers would have been basing that apostrophe on an historical sound change that had taken place many years earlier. Another theory is that printers introduced the apostrophe to mark possession because it provided a convenient way to distinguish the various ways in which s sounds were added to words in english.