Daniel Knowles Butler, 84, of Gwynedd, formerly of Philadelphia, passed away on June 28, 2013 after a long illness. Dr. Butler was born in New York, New York, on September 12, 1928, to John Ben Butler and Dorothy Cumpson Butler. Raised in Fieldston, New York, Dan graduated from The Fieldston School and received his B.A., M.A. and Ph.D. in Physics from Harvard University. He worked as a nuclear physicist at The Argonne National Laboratory designing nuclear power reactors. He was an early pioneer of the three-dimensional computer modeling of reactor cores. He later taught computer science at Cleveland State University and Rutgers University. An active volunteer, he served as president of the Naperville, Illinois, Board of Education and as chair of building preservation on the Board of The Wyck Association. His lifelong fascination with everything mechanical led him to acquire an extensive collection of antique clocks. A resident of Foulkeways, he was known for his kind and gentle character. Dan summered for eight decades in Marlboro, Vermont, where he met his wife of sixty years, Marigene Harrington Butler. In addition to his wife, he is survived by his children Daniel K. Butler, Jr. (Janice), Paul H. Butler (Christiana), Katherine M. Butler, his five grandsons Daniel K. Butler, III, Andrew R. Butler, Samuel C. Butler, Anand M. Butler and Satya P. Butler, and his sister Mary Butler Williams. He was predeceased by his brothers John Ben Butler, Jr. and Edward R. Butler. Service and interment will be private. Memorial contributions may be made to the Marlboro Meeting House (Preservation Endowment Fund), P.O. Box 64, Marlboro, VT 05344 and to Wyck Association, 6026 Germantown Avenue, Philadelphia, PA 19144.

Huff & Lakjer Funeral Home