I have absolutely no clue who Martha Snow is, and a Google search is not much help, but I sort of stumbled across this one earlier, and thought it worth sharing...here's the link btw...
Spell Chequer - Martha Snow
http://www.davidpbrown.co.uk/poetry/martha-snow.html
And here's the poem...
Spell Chequer
Eye halve a spelling chequer
It came with my pea sea
It plainly marques four my revue
Miss steaks eye kin knot sea.
Eye strike a quay and type a word
And weight four it two say
Weather eye am wrong oar write
It shows me strait a weigh.
As soon as a mist ache is maid
It nose bee fore two long
And eye can put the error rite
It's rare lea ever wrong.
Eye have run this poem threw it
I am shore your pleased two no
It's letter perfect awl the weigh
My chequer tolled me sew.