1. The ship was a snow, built in 1839 at Dundee, Scotland and had a tonnage of 300 tons. A snow was a two-masted square-rigged merchant vessel of the eighteenth and nineteenth centuries. The largest ship of her period, with tonnage of up to around 1,000 tons. The mainsail, which was sometimes loose footed, was carried on a snow mast (a light auxiliary mast) which was located immediately abaft the mizzen mast.
The snow mast was a light auxiliary mast for the gaff sail. According to "Lloyd's List" the Cairo sailed from Southampton bound for Quebec (via Plymouth). Captain Treadwell was the Captain. It arrived in Quebec on 7 Sep. (3 May 1996 letter from the Maritime Information Centre, Greenwich, London England)
2. Grosse Ile is located in the upper St. Lawrence estuary, 48 kilometers downstream from Quebec City. From 1832 to 1937, its function was to stop the spread of infectious diseases which might arrive on ships from abroad. Grosse-Ile is now a national historic site, and there are guided tours available. Families, Vol. 35, No. 3, 1996
3. Quebec Mercury 5 Sep 1844: Port of Quebec/ Shipping Intelligence/ Extract of a letter dated Grosse Isle Sept. 3d: "The bark Cairo, Treadwell, from Plymouth, to Atkinson, Usborne & Co., with 5 cabin and 201 steerage passengers, arrived here on Sunday evening last. Eight of her passengers died on the voyage from small pox and scarlet fever. Several have been sent to Hospital here and the others are in the passenger sheds. ...; 10 Sep 1844: Port of Quebec/Arrivals/ Sept 7th / Brig Cairo, Treadwell, 14th July, Plymouth, Atkinson, Usborne & Co., ballast, 191 passengers
4. Quebec Mercury 14 Sep 1844 Port of Quebec/ Entered for loading/ 13 Sept/ Cairo, London; 26 Sep 1844: Port of Quebec/ Cleared/ Brig Cairo, F Treadwell, London, T McCaw & Co.
5. Yonge Street was a military road which was opened in 1796. Besides connecting the Town of York (Muddy York) to the naval base at Penetanguishene, it was the route used by farmers living to the north of York to take their produce to market. Today Yonge Street is Toronto's main street. (Sheila Brown, From Muddy York to World Class City, Ontario Genealogical Society, Toronto Branch, Toronto Tree, Vol.27 #2 p.14)
6. "Grandma's father" would be Ephraim Brewster who lived in Ellisburgh NY.