may not be supplied by the quantity within the limited distance. The deficiency will not be great, and we understand that the amount estimated for the two Mackinaw roads will scarcely be less than _two millions of acres_. Of the quantity and value of these lands, we give the estimate made by these roads, as well as the cost of construction. The estimate made by the _Grand Rapids and Indiana Railroad_ is as follows: "The proximity to lake navigation; having several navigable rivers passing through them, the abundance of hydraulic power, the healthfulness of the climate, the fertility of the soil; and lying immediately on the line of this road, are facts which contribute to enhance the value of these lands. "The length of this road from the Straits of Mackinaw to Fort Wayne, will be about three hundred and fifty miles. If the company meet with as good success as the merits of the enterprise deserve, the entire cost of the road should not be over $25,000 per mile, which makes an aggregate sum of $8,759,000." On the supposition that the minimum amount of land is obtained and sold, at half the price above stated, there will yet be broad enough basis to secure the construction of the work. The Amboy and Lansing Company are equally confident of success. They have also located a large quantity of land, and expect their value to be equivalent to the construction of their road. Accordingly, they have put a portion of their road under contract, and have obtained large local subscriptions. Both these lines of railroad will terminate at Mackinaw, on the north, and Cincinnati on the south; hence they will be carried south till they terminate at Norfolk, Charleston, Savannah, and Pensacola, thus forming the grandest and most extensive system of railroads on the continent. Nothing in America equals it--nothing in Europe can compare with it! When all the links shall have been completed, it will stand out the greatest monument to human labor and genius which the world presents. The single line from Mackinaw to Pensacola has been looked upon as one of the most important undertakings of the age. We extract from the "Exposition of its Plan and Prospects," by E. D. Mansfield, Esq., some of the facts, which exhibit its importance, and bearing, and influence on Mackinaw City. "To illustrate," says the Exposition, "the value of this North and South National Line, by its power of producing commerce, mark, in a tabular form, the natural products of each degree of latitude, thus:-- _States._ _Latitude._ _Productions._ Florida, 31 deg. Oranges. " 31 " Sugar. " 31 " Cotton. Alabama, 32 " " " 33 " " " 34 " Cotton, Corn. Tennessee, 35 " " " " 36 " Cotton, corn, tobac., iron. Kentucky, 37 " Corn, tobac., coal, iron. " 38 " Corn, wh't, cat. tob. h'mp. Ohio, 39 " Corn, wh't, cat. h'gs, wine.