Show Bull Bull- Bullen en Air Lots Lois The Merchandise Mart is built over tracks of the Chicago North Western railway The railroad railroad rail raU road retains ownership of the area on which its tracks operate It sold air lots representing possession possession posses posses- sion of the space above ground occupied by the entire building and numerous miniature ground lots necessary to sink caissons The air was actually subdivided into lots and the diagram of the aerial real estate filed in the office of the recorder of deeds of Cook county Ill |