 Among its other uses , in 1880 , measurements from the site were used as part of the effort to develop standard time . The observatory remained the official timekeeper for Canada until 1905 , when that responsibility was transferred to Ottawa 's Dominion Observatory . At exactly 11 : 55 am the clocks in Toronto fire halls were rung by an electrical signal from the Observatory . 
 Among its other uses , in 1880 , measurements from the site <a href='uninflect' title='1'><mark>were</mark></a> used as part of the effort to develop standard time . The observatory remained the official timekeeper for Canada until 1905 , when that responsibility was transferred to Ottawa <a href='null_genetive' title='2'><mark>'s</mark></a>Dominion Observatory . At exactly 11 : 55 am the clocks in Toronto fire halls <a href='uninflect' title='3'><mark>were</mark></a> rung by an electrical signal from the Observatory . 
Among its other uses , in 1880 , measurements from the site was used as part of the effort to develop standard time . The observatory remained da official timekeeper for Canada til 1905 , when that responsibility was transferred to Ottawa  Dominion Observatory . At exactly 11 : 55 am the clocks in Toronto fire halls was rung by an electrical signal from the Observatory .