Whoever did the 1790 census for Cheshire County alphabetized the entire area that he/she covered. (It isn't all of Cheshire County, by the way.) And the grouping of each town's residents by the first letter of the last name is denoted by a number at the beginning of that town's names. Go to the first page of the entire census and you will see how it is organized and broken down:http://search.ancestry.com/Browse/view.aspx?dbid=5058&pa...
You will need to enlarge it at least to 150 percent for easy reading.
For example, Cornish is town number 6. So, go to the census for the names you are researching (by first letter) and look for the letter 6 in front of a name. That name and the subsequent names, up to where the next number appears, are in the town of Cornish. (It doesn't help that the letters sometimes blend in with the name following it!)
Yes, it is horribly awkward for the genealogist, but that wasn't the original point of the census.
And Ancestry.com could help us genealogists by doing a clearer microfilming of this census (page #116, beginning with town Acworth, thru page 131).
Another suggestion for Ancestry.com is that putting a black sheet of paper behind the sheet you are microfilming dramatically cuts down of the "bleed-through" of the images from the back side of the pages. (This also works for photocopying documents that have ink bleed-through!)