Working on my metre

[Achebe]

I meant "cadence" in a layman's sense.
Let's start with your first line:

MID night SER pent SOUGHT to COR rupt OFF spring

If you're using a combination of a stressed + unstressed syllable ("trochaic meter"), it sounds more natural to use 8 feet rather than 10.  Eg.

MID night SER pent SOUGHT to COR rupt
OFF spring OF a PASSED god NO more
THERE etc. etc.

If you want to retain "longer", you can use 9 feet: 

MID night SER pent SOUGHT to COR rupt THE
OFF spring OF a PASSED god NO lon GER

although in this case, the succession of stressed syllables "THE OFF" necessarily requires you to pause a bit longer at the end of line 1
But the moment you go into 10 feet (pentameter) as in your original line, it sounds weird.
Pentameter works with iambs (unstressed + stressed), not trochees (stressed + unstressed):

the MID night SER pent SOUGHT to COR rupt THE
pale OFF spring OF a PASSED god NO lon GER

Incidentally, "corrupt" sounds more natural as cor RUPT rather than COR rupt
Just follow the metre in this poem (it's iambic) and use your ear:

http://www.poetryfoundation.org/poems-an...tail/44299