Burial services will be held Tuesday, December 24 at Mount Auburn Cemetery at 11am.     Elmer J. Frey Ph.D., a 60-yr resident of Lexington, MA, died 17 days before his 96th birthday.  He is survived by his wife, Mary Frey, and children Maria Frey of Lexington, Eric Frey and his wife Betsy of Mendocino, CA.  He is also survived by 3 grandchildren and 3 great-grandchildren.  He was predeceased by his first wife Barbara Ruth Dunnan.     He graduated from CCNY with a B.S. in mathematics and attended the Sorbonne on an academic scholarship.  He later attended NYU and received a Masters in mathematics and physics.  Elmer served during WWII from 1942 to 1946, as a Captain, working in cryptography with the Military Intelligence Division, US Army.  He attended MIT where he received a Ph.D. in 1949 in mathematics.  He pioneered inertial navigation research at MIT as associate director of the MIT Instrumentation Lab.  He was a Masters and Ph.D. thesis advisor to many aspiring scientists over a 20 year period and was invited to teach internationally, often lecturing in the native language of the country.  During the 1960s he taught at Ecole Speciale de Travaux Aeronautique in Paris, France.  In 1987, Elmer was invited to give a series of lectures at Tsinqhua University in Beijing, China, mastering conversational Chinese in the two months before his trip. He was issued two U.S. patents for oil well surveying equipment in 1984 and 1985.  Elmer was a member of the American Mathematical Society, the Society for Instrumentation and Applied Mathematics, the American Rocket Society, and the American Institute of Aeronautics and Astronautics.  In addition to his many scientific achievements, Elmer had a great love for classical music and was an accomplished runner for over 25 years.     An accomplished scientist, Elmer inspired his children with a love for learning, the natural world, and travel.  Elmer's intellectual mindset inspired Maria to become a teacher.  Like her father, she enjoys spreading knowledge to help others.  Elmer, Mary, and Maria traveled extensively, imparting to Maria a love for travel and discovery. Elmer's son Eric applied these lessons with a fly-fishing kit given to him by Elmer as a Christmas gift that inspired a lifelong hobby for both father and son.  Eric still owns to this day a home in Rangeley, Maine near the streams of their past fishing expeditions.     Elmer's nephew, Gregory Katsas, may have put it best: "Elmer was among the most brilliant and intellectually accomplished individuals I have ever met: he was a world-class mathematician and engineer—a rocket scientist quite literally; he was fluent or conversant in at least a dozen languages; and he had encyclopedic knowledge and recall of world history, geography, and decades-old anecdotes from his own remarkable life.  He was endlessly curious; in travelling across the world, whether for pleasure or as an invited guest lecturer, he relished the opportunity to learn about scores of new people, cultures, and events.  His eclectic hobbies included running, fly fishing, and a love of fine food and wines.  Most importantly, he was thoroughly kind, humble and decent: he delighted in teaching and learning from others, and he was equally engaging with and concerned about everyone he encountered, regardless of their rank or station in life."