Thomas Hood - To An Absentee

O'er hill, and dale, and distant sea,
Through all the miles that stretch between,
My thought must fly to rest on thee,
And would, though worlds should intervene.
Nay, thou art now so dear, methinks
The farther we are forced apart,
Affection's firm elastic links
But bind the closer round the heart.
For now we sever each from each,
I learned what I have lost in thee;
Alas, that nothing else could teach
How great indeed my love should be!
Farewell! I did not know thy worth;
But thou art gone, and now 'tis prized:
So angels walk'd unknown on earth,
But when they flew were recognized!

Thomas Hood

http://www.poemhunter.com/poem/to-an-absentee/