The McGill site says: Between 1874 and 1881, approximately forty county atlases were published in Canada, covering counties in the Maritimes, Ontario and Quebec. Thirty-two of these atlases were produced for Ontario by the following five companies: H. Belden & Co. (17); H.R. Page & Co. (8); Walker & Miles (5); J.H. Meacham & Co. (1); H. Parsell (1). Two types of county atlases exist for Ontario, those which covered a single county or multiple adjacent counties, and those which were published as supplements to Dominion of Canada atlases. In total, 40 Ontario counties were covered by these 32 atlases.