Scotland's 'other' champions...

There were only 6 seasons between 1891 and 1937 when one or other of the Glasgow 'Old Firm' clubs did not win the Scottish championship.

1891-92: Dumbarton

Jack Bell
Having shared the title with Rangers in the previous season, Dumbarton ended the season 2 points clear of Celtic.  The Sons of The Rock scored 78 goals (13 more than any other side) and had a goal difference of  + 51. Jack Bell was the leagues top scorer for the second season in succession, with 23 goals. He moved to England and played for Everton the following season.
When Scottish Football accepted professionalism in 1893 Dumbarton stuck to their amateur principles, which saw them eclipsed by the clubs who began to import and pay star players.

1894–95: Heart of Midlothian
Edinburgh's Hearts became the only east coast club to join the Scottish Football League on its formation in 1890. They secured their first league championship winning 15, drawing 1 and losing 2. They scored 50 goals and conceded 18, finishing 5 points ahead of Celtic.  

1896–97: Heart of Midlothian
Hearts pipped their neighbours Hibernian to the title by 2 points. Willie Taylor was the league's top scorer with 12 of his side's 47 goals. 

1902–03: Hibernian
Hibernian lost only 1 out of their 22 games and finished the season 6 points clear of Dundee. Welsh International Bobby Atherton was captain, David Reid was top scorer with 14 goals. Hibs first  and longest serving manager, the Irishman Dan McMichael was in charge (his first season).

1903–04: Third Lanark
Glasgow based Third Lanarkshire Rifle Volunteers shortened their name to Third Lanark Athletic Club and severed their ties with the military in 1903. Thirds won the league by a margin of 4 points over Hearts.

1931–32: Motherwell
In manager John 'Sailor' Hunter's 21st season in charge Motherwell lost only 2 of their 38 games and, with a goal difference of +88, they finished 5 points clear of Rangers. Willie McFadyen scored 52 of Motherwell's 119 goals.