In words of more than two syllables, there is often a second accent given,
but more slight than the principal one, and this is called the secondary
accent; as, em"igra'tion, rep"artee', where the principal accent is marked
('), and the secondary, ("); so, also, this accent is obvious, in
nav"iga'tion, com"prehen'sion, plau"sibil'ity, etc. The whole subject,
however, properly belongs to dictionaries and spelling books.