John and Isabella emigrated from Scotland and settled in Minto Township, Huron County about 1855. Their son James owned and operated a flour mill at Dunblane in Elderslie Township, Bruce County in 1858. In 1872 James purchased the Valentine Mill and relocated to Pailsey. In 1884 the flour mill burnt down but was replaced the next year by the present mill.
The early mill stones were replaced by a new roller system. The wheat was steamed then crushed by rollers. From there it entered the cups of an elevator belt which carried it to the top of the mill where the separation process began. The crushed grain was fed through five different machines which used silk cloths to separate the bran shorts and low grade flour from the desired finished product.
The by-products, that is, bran, shorts, and low grade flour were sold to the local farmers for feed. The flour was sold locally and exported to England, Scotland, Gibraltar and the middle east, under the trade names of Excelsior, Prairie Rose, and Pure Cream. The local soft wheat was made into pastry flour and the Western wheat brought in by railroad was used in the making of bread flour. This operation continued until 1932.