The apathy of the citizens of Detroit in availing themselves of the magnificent advantages possessed by the city for prosecuting manufacturing upon an extensive scale, is wholly inexplicable. There is a mine of unproductive wealth in our midst that might at once be placed at compound interest. It now lies dormant in the sinewy arms of men and the nimble fingers of women and children. There is thus a moral aspect in this question that addresses itself with peculiar earnestness to the philanthropic. But it were a philanthropy that would lay up treasures on earth. Daily, almost hourly, raw material takes its departure from our city destined to be received at eastern manufactories, there to be worked up and returned to us for our consumption, by which we are taxed with the freight both ways, in addition to losing the profit of the manufacture. Every property holder has a direct interest at stake. If a liberal sum were to be subscribed to-morrow for investment in this important branch of enterprise, the direct benefit that would accrue to the real estate of the city would be at least double the amount invested. The Western States look with deep interest to the Grand Trunk Railway, and are hopeful that it may prove a great benefit to them in enabling producers to reach the markets of European consumers at a cheap rate for carriage. Unquestionably great benefits will grow out of the opening up of the great thoroughfare. At the same time there are questions of grave importance to shippers which will soon have to be met, and nothing can be lost, while something may be gained, by meeting them at the outset.