Table taken from Les Théâtres du Châtelet by César Daly (no date, about 1872).
Daly reproduces—from Charles Garnier's book: Le Théâtre—various widths of orchestra seats of major theatres and opera houses of Europe to analyze Gabriel Davioud's seats for the Théâtre du Châtelet and the Théâtre Lyrique.
The first column gives the width of the seat (from center of armrest to center of armrest), the second, the row depth.
In comparison:
Average seat width (Daly): 0.535 m (21")
Average seat width (Dolbeau-Mistassini): 0.535 (21")
Average row depth (Daly): 0.828 m (32.6")
Average row depth (Dolbeau-Mistassini): 1.006 m (39.6")
The rows are deeper than standard at Dolbeau-Mistassini because there are more than 16 seats per row, which is not allowed by the Building Code of Canada, unless there are exit doors for every 3 row (which is not the case). To allow rows of up to 32 seats, the Building Authority (Régie du Bâtiment du Québec) accepted an increase in row depth (and clearance), following guidelines of the National Fire Prevention Agency (NFPA-101).
With 16 seats per row, the depth would have been 0.849 m (33.4") instead of 1.006 m (39.6").
