Ontario, Canada Voter Lists, 1867-1900 on Ancestry.com
So far no luck. I searched for just the last name Sargent, just the first name Clark and later on I will experiment with additional spellings for the last name. Maybe he is just hiding somewhere. Ancestry.com indicates the areas that are included the Ontario, Canada Voter Lists, 1867-1900 and I should also look to make certain all areas are covered. It is always possible that the entire set of records is not extant. One should not assume.
One of these days, I will hopefully find Clark. In the interim, perhaps readers will have success with this database.