By reading the text of "London, 1802", the sonnet by Wordsworth addressed to Milton, we can determine the rhyme scheme by looking at the last word in the line. If they rhyme then they are the same letter, if not we add a new letter. So let's do it!
Rhyme Scheme:
Line 1- a
Line 2 - b
Line 3 - b
Line 4 - a
Line 5 - a
Line 6 - b
Line 7 - b
Line 8 - a
Line 9 - c
Line 10 - d
Line 11 - d
Line 12 - e
Line 13 - c
Line 14 - e
Hope this helped! If you have any other questions or would like further explanation just let me know!! :)