historical change - Was the pronunciation of “symmetry” different in the past?

First published in Songs of Experience in 1794, the first stanza of the poem “The Tyger” by William Blake is:

Tyger! Tyger! burning bright
In the forests of the night,
What immortal hand or eye
Could frame thy fearful symmetry?

It is easy to guess that in those years that was the way tiger used to be written.

On the other hand, symmetry is not a rhyme for bright, night, eye by today’s usual pronunciation.

Was it ever a rhyme?

Answer

In Shakespeare's time, because of the Great Vowel Shift, symmetry was a much closer rhyme with eye than it is today (if it wasn't exact), and Shakespeare and his contemporaries used rhymes like this all the time.

Shakespeare: Sonnet 1:

From fairest creatures we desire increase,
That thereby beauty's rose might never die,
But as the riper should by time decease,
His tender heir might bear his memory:

Shakespeare: Sonnet 33:

Full many a glorious morning have I seen
Flatter the mountain-tops with sovereign eye,
Kissing with golden face the meadows green,
Gilding pale streams with heavenly alchemy;

By Blake's time, I suspect the Great Vowel Shift had progressed enough that these words no longer rhymed well. Certainly, by the early 19th century, these words were pronounced very much the way they are today. (This can be checked by looking at Walker's Pronouncing Dictionary.) However, Blake (along with some of his contemporaries) seems to have thought that the fact that Elizabethans rhymed these words gave him the license to do so as well.