Tom, this morning I noted your entry about the 1820 census.I was at the libary today looking up a census for my own HALL family in Portage County Ohio, so checked for CLARK in Nelson, of the same county.
There are two Nelson Twp. CLARK families listed next to each other: Wells Clark Birdseye Clark I xeroxed the part of the page where they appear, but I don't have a working scanner at present.I am happy to mail this to you, if you're still searching for this census info.It's not a great copy, but the census taker had pretty legible writing.
From what I can tell, looks like Wells Clark family was: 2 males under 10 1 male 10-16 1 male 16-26 1 male 26-45 2 females under 10 1 female 10-16 1 female 16-26 1 female 26-45 (2 of the people "engaged in agriculture")
Birdseye's family: 1 male over 45 1 female under 10 1 female over 45 (1 person "engaged in agriculture")
Hopefully this is helpful to you. Margaret Jenstad