Unidentified poem

[odedude]

M'aidez! Help! I am trying to determine the title and author of the following (fragment of a) poem:

Voyager dauntless on Newton's sea,
Year after year still brooding on
His algebraical formulae,
The genius of William Hamilton
Sought the square root of minus one;
In vain; till - all thought of it leagues away -
The problem flowered from a dream one day.

I would appreciate your collective thoughts on this. THANKS in advance.