This article was originally published with the title “ Railway Plant—Sleepers, Ties, and Clips ” in Scientific American Magazine Vol. 21 No. 19 (November 1869), p. 292 doi:10.1038 ...

Final NFL rosters will not be set until August, but the main contributors are in place on teams at this point in the offseason. As such, it is time to look ahead at who could be sleeper candidates ...