The Ford Motor Company held a right of way across certain railroad tracks from a street to its plant, and contracted with B to build an underpass and grade separation from the street and under the tracks. Before full performance, the Ford Company discharged B and completed the work itself. Numerous materialmen claimed mechanics' liens for supplies furnished B. Held, the right of passage was an easement appurtenant to the Ford plant and not lienable as such, because severance from the dominant estate would extinguish the easement. A lien on the underpass as a building on the land of another would also be impossible, because this would defeat the purpose of the easement and its quasi-public use and thus destroy it. McClintic-Marshall Co. v. Ford Motor Co. (Mich. 1931) 236 N.W. 792.