NORTHERN ILLINOIS UNIVERSITY, 40 MILES TO HARVARD. Unless you're riding Metra, in which case you must go to Elburn, ride a train to Chicago, and ride another train to Harvard. The Chicago Tribune sent its "Ends of the Line" team to Harvard for today's report, which ran sans pictures. The dairies have pretty much gone away, and a Motorola plant the town pinned its economic development hopes on has opened and closed, but Harmilda the Plastic Holstein still taunts arriving Wisconsinites with her "milk center of the world" motto.