He was probably counting on his fingers, trying to ensure that there were exactly 11 syllables in each line.
In the 19th century, counting one's fingers seems to have often meant counting on one's fingers. There are a number of instances in Google books where one can see this. For example, from 1885, less than 20 years after Browning wrote The Ring and the ...
Tree of vices
This is an example of the kind of ‘allegorical woodcut’ that Cook’s friend may have had in mind:
From Boccaccio, De Claris Mulieribus, published by Aegidius van der Heerstraten, Louvain, 1487.
The tree depicted here is simultaneously a tree of vices bearing the seven deadly sins (clockwise from left: wrath, envy, greed, vanity, lust, gluttony,...
TL;DR: No convincing explanation has yet been put forward.
Perhaps nowhere else in Browning scholarship has more critical ink been expended on fewer words than the three of “Hy, Zy, Hine”.
James F. Loucks (1974). ‘“Hy, Zy, Hine” and Peter of Abano’. Victorian Poetry 12:2, p. 165.
A good explanation would meet the following criteria.
The words ‘Lyric Love’ reappear in the third-to-last line of the poem, at the end of book XII:
If the rough ore be rounded to a ring,
Render all duty which good ring should do,
And, failing grace, succeed in guardianship,—
Might mine but lie outside thine, Lyric Love,
Thy rare gold ring of verse (the poet praised)
Linking our England to his ...