As all divers should know, ships of the Great Lakes were originally made of wood. Then, around the 1890's, they were made of iron and steel. However, this change did not take place overnight. There was a transition phase, around 1885 to 1890, when some ships were built with a combination of iron and wood in their structures, the approximate 5 year period of the Composite Steamer. The large timbers necessary for the components of the wooden steamers were becoming scarce and therefore expensive.
Steel is stronger than wood.
Therefore less space is wasted with bulky internal support members. More internal volume equals more cargo per trip. This means a greater profit margin, to say nothing of the reduced maintenance costs. After a mediocre career as a canaler she was sent to the Muir Dry Docks of Pt. Dalhousie, now St.