Yet however desirable an object the construction of a railroad through our country may be; however high our imaginations may be heated at thoughts of it,--there is always a heart-appalling shock accompanying the account of its cost, which forces us to shrink from our pleasing anticipations. The probable cost of this contemplated railroad is estimated at $290,000; the bare statement of which, in my opinion, is sufficient to justify the belief that the improvement of the Sangamon River is an object much better suited to our infant resources. Respecting this view, I think I may say, without the fear of being contradicted, that its navigation may be rendered completely practicable as high as the mouth of the South Fork, or probably higher, to vessels of from twenty-five to thirty tons' burden, for at least one-half of all common years, and to vessels of much greater burden a part of the time. From my peculiar circumstances, it is probable, that for the last twelve months I have given as particular attention to the stage of the water in this river as any other person in the country. In the month of March, 1831, in company with others, I commenced the building of a flatboat on the Sangamon, and finished and took her out in the course of the spring. Since that time I have been concerned in the mill at New Salem. These circumstances are sufficient evidence that I have not been very inattentive to the stages of the water. The time at which we crossed the mill-dam being in the last days of April, the water was lower than it had been since the breaking of winter in February, or than it was for several weeks after. The principal difficulties we encountered in descending the river were from the drifted timber, which obstructions all know are not difficult to be removed. Knowing almost precisely the height of water at that time, I believe I am safe in saying that it has as often been higher as lower since. From this view of the subject, it appears that my calculations with regard to the navigation of the Sangamon cannot but be founded in reason; but, whatever may be its natural advantages, certain it is, that it never can be practically useful to any great extent, without being greatly improved by art. The drifted timber, as I have before mentioned, is the most formidable barrier to this object. Of all parts of this river, none will require so much labor in proportion to make it navigable, as the last thirty or thirty-five miles; and going with the meanderings of the channel, when we are this distance above its mouth we are only between twelve and eighteen miles above Beardstown, in something near a straight direction; and this route is upon such low ground as to retain water in many places during the season, and in all parts such as to draw two-thirds or three-fourths of the river-water at all high stages.