I was reading the poem "To His Coy Mistress" by Andrew Marvell when something struck me as odd. Let me quote two passages:
Thou by the Indian Ganges' side
Shouldst rubies find: I by the tide
Of Humber would complain. I would
Love you ten years before the Flood,
But at my back I always hear
Time's wingèd chariot hurrying near;
And yonder all before us lie
Deserts of vast eternity.
Thy beauty shall no more be found,
Nor, in thy marble vault, shall sound
My echoing song: then worms shall try
That long preserved virginity,
Now, am I supposed to read flood as [fluːd], eternity as [ɪˌtɜː.nəˈtaɪ̯], and virginity as [vɜː(r)ˌdʒɪ.nəˈtaɪ̯]? Was one supposed to do so back in the 17th century? Or is this, and has always been, some sort of purely "visual" rhyme? The rest of the poem rhymes perfectly in contemporary English.
I guess I could sum it up in one question: What is the term for this type of rhyme?