Mein lieber Doktor, ich glaube ich dem auf den Grund gegangen.

a digger of wells is me

as mad as mad can be

where sod may favor a shovel's lust

there it is that I shall thrust

with handle made from sturdy oak

better for a mighty stroke

head buried down and deep

casts all burdens to the heap

lunge and plunge and twist away

pryin' for a wider splay

heatin' up all coursin' blood

until the strainin' waters flood

from far below the rumble runs

then sure enough a geyser comes

and right away I take a bead

for the next who might my talent need

a digger of wells is me

as mad as mad can be

https://youtu.be/XcATvu5f9vE