There is a William Briggs on 1901 census in Collingwood, North Simcoe with parents Thomas & Mary, sibligs Elsie 13 and Lena 10. Birthday is given as 20 May 1900.
Nothing except the births for the other children found on Ancestry.ca
From OCFA on
http://www.islandnet.com/cgi-bin/ms2/jveinot/searchCartwright, Edwin J, Blyth Union Cemetery, Hullett Tp, Huron
Cartwright, Dorothy S [Bryant], same cemetery.
Could be his wife.
Cecil H Cartwright, Clinton Public [Section H], Hullet Tp, Huron.
Harriet Howard Cartwright is in same cemetery.
Mary Elizabeth [Cartwright]Scales , same cemetery, Section C.
This could be [or not] Mary b 1904.
You will have to write to the Huron County Branch, OGS, PO Box 469, Goderich Ontario K7L 5C6 for more information on the headstones.
Did not find any marriages on Ontario Marriages.