What is the structure of the poem "To India My Native Land" by Henry L. V. Derozio?

Henry Louis Vivian Derozio's poem "To My Native Land" is a
sonnet in 14 lines with 3 quatrains and an ending couplet. The rhyme scheme abab abcc
dede ff is a variation on the Shakespearean sonnet (same as English sonnet) rhyme scheme
abab cdcd efef gg.

Derozio varies the rhyme scheme in the second
quatrain. Instead of the Shakespearean cdcd, he uses abcc in which he repeats the ab
opening of the first quatrain then adds a cc couplet.

This variation
is reminiscent of, but not the same thing as, a Spenserian cc couplet concatenating
(i.e., chaining together) the second and third quatrains in the Spenserian rhyme scheme
ababbcbccdcd ee.

Derozio's rhyme scheme variation creates a second
couplet, so there are two couplets cc ff. This is also reminiscent of, but not the same
as, a Spenserian scheme, which actually has three couplets, bb cc
ee.

The variation in the second quatrain allows for two
voltas (i.e., Italian for turn) at lines 5 and
9, as do both the English/Shakespearean and Spenserian sonnets. The first volta is
connected to the topic in the first quatrain, yet presents a different idea on the
overall subject of India. The first quatrain, opening with an apostrophe to "My
Country!",  tells of "glory past" and the "beauteous halo" on the country's personified
brow.

The second quatrain line 5 volta turns and contrasts
India’s past glory with the implied metaphor of an eagle chained "And grovelling in the
lowly dust." The cc couplet refers back to the "reverence" during the days of glory and
proclaims that there is no "minstrel" to sing of India--only of "the sad story of thy
misery."

The second volta at line 9, "Well—let me dive into the depths
of time," is the major turn where the poet declares he will salvage "A few small
fragments of these wrecks sublime." The resolution to the problem of India's lost glory
and present misery comes in the ending couplet. The poet takes upon himself to ease the
pain of "My country!" by writing sonnets to offer "One kind wish for
thee."

This couplet resolution is reminiscent of various love sonnets
written most notably by Shakespeare (Sonnet 18: "So long lives this and this gives life
to thee") and Spenser (Sonnet 75: "My verse your virtues rare shall eternize") that
claim to make their love eternal through their immortal lines of poetry. Similarly,
Derozio's resolution states that the "guerdon" (i.e., reward or recompense) of his
"labour" to salvage from the "depths of time" some glory of old will be that "one kind
wish" is offered for India.