PS to my post of 12 Aug 09 - 04:17 PM:
One of my favorite rare stanzas is relevant here:
John Henry said to his Captain,
"Captain, can't you see,
Your hole is choked and your steel is broke
And your hammer can't go down with me?"
These are indeed the main problems faced by steam drills (really compressed-air drills with compressors powered by steam engines).
I have argued, and I maintain, that rare stanzas/couplets/phrases are likely to reflect early versions and therefore actual history. This stanza occurs only once in the books by Guy Johnson and Louis Chappell. I have not found it independently anywhere else.
The reason that something rare is likely to be early is that tradition tends to preserve the things people like to sing and to eliminate the rest. If people liked to sing the stanza above, it wouldn't be rare. It is not something that someone would have been likely to have made up out of whole cloth. Therefore it is probably a leftover from an early version, one that luckily didn't get eliminated entirely.