A public memorial service celebrating Columbia founder James Wilson Rouse will be held at 4 p.m. tomorrow at Merriweather Post Pavilion in the planned community's Town Center. Mr. Rouse, 81, died Tuesday of amyotrophic lateral sclerosis, commonly known as Lou Gehrig's disease, at his home in Columbia. The public is invited to the Columbia memorial service, where Mr. Rouse's family, friends and colleagues will offer tributes and share experiences they had with him during his varied career. A public reception will follow at the same site. Services for Mr. Rouse will be held at 11: 30 a.m. tomorrow at Brown Memorial Presbyterian Church, 1316 Park Ave., Baltimore. A private burial will follow in Columbia. Viewing will continue today from 3 p.m. to 5 p.m. and 7 p.m. to 9 p.m. at Henry W. Jenkins & Sons, 4905 York Road, Baltimore.