Mary Dempsey Flanagan, 92, of East Oak Lane, who had careers as an optical technician at Frankford Arsenal and as a calligrapher, died of complications from surgery Wednesday at Abington Memorial Hospital.

Mrs. Flanagan graduated from John W. Hallahan High School in 1935, and earned a bachelor's degree in math and English from Immaculata College in 1939. She was briefly a substitute teacher in Philadelphia public schools before going to work during World War II at the Frankford Arsenal, where she was one of the first women to make optical devices for gun sights and munitions, said her son, Bill.

After retiring from the arsenal in 1977, Mrs. Flanagan began a career as a calligrapher, a skill that the Sisters of the Holy Child taught her when she was a girl at St. Edward's School in North Philadelphia.

She taught at Temple University's Osher Lifelong Learning Institute and at night schools. Professionally, she addressed wedding invitations; did custom work for Details, a stationery shop near Rittenhouse Square; and was commissioned by Temple Beth Sholom in Elkins Park and by the Wilma Theater in Center City to copy names in elaborate script for their donor books. Her last project was four years ago, when she addressed her son's wedding invitations, he said.

Mrs. Flanagan is also survived by a daughter, Norajean, and three granddaughters. Her husband of 33 years, Charles E., died in 1981.

Friends may call from 7 to 9 p.m. today and from 8 to 9:30 a.m. tomorrow at Geitner Givnish Funeral Home, 6230 N. Fifth St. A Funeral Mass will be said at 10 a.m. tomorrow at St. Helena Church, 6161 N. Fifth St., where Mrs. Flanagan taught religious education for many years. Burial will be in St. Dominic Cemetery.