BRUNSWICK — Louis Ammi Cutter, 89, died April 1, 2017, 51 days after the passing of his wife of 63 years, Ann Hornor Cutter. Louis died in his sleep at Maine Midcoast Hospital of complications following a stroke.

He is survived by his sister, Lady Helen Cutter Noyes Maclennan; his three children, Elizabeth Cutter Evert, Henry Ammi Cutter, and Margaret Cutter Douglas, and their respective spouses: Michael Evert, Victoria Fisher, and Joel Douglas. Also surviving are six grandchildren: Nicholas Evert, Lucy Evert, Benjamin Douglas, Emily Douglas, Louis Cutter, and Alice Cutter.

Louis was born on April 23, 1927, in Boston. He grew up in Cambridge, Mass., where he met Ann as a child in dancing school. Louis spent his summers in what became his true lifelong home: a grouping of family cottages in the town of Randolph, at the foot of Mount Adams, in New Hampshire.

When the time came for Louis to go to college, after serving briefly in the Navy as World War II drew to a close, he walked into the woods below the Randolph house, headed uphill and crossed the Presidential Range to catch a train to Cambridge, where he earned a B.S. from Harvard. Louis went on to the Columbia School of Engineering, in New York, graduating with a doctorate in engineering and a love of learning that continued even after he was diagnosed with Alzheimer’s as an old man. Louis was particularly interested in anthropology, but he could be counted on to come up with accurate historical facts when a conversation called for them.

Louis spent most of his career developing plastics at U.S. Steel in Pittsburgh, winning patents for some of his innovations as he put into practice the idea that if a job is worth doing, it is worth doing properly. He was a member of the American Chemical Society and the American Institute of Chemical Engineers .

Louis also put his chemistry skills to use building a fiberglass canoe that the family called The Blue Sieve for the many leaks it developed on whitewater runs in Western Pennsylvania and New Hampshire. Getting down the river, or hiking to the top of a mountain, didn’t matter much to Louis. He and Ann both loved just being together outside, in Pittsburgh, in the White Mountains, and in Brunswick.

A memorial service will be held at 11 a.m. on Friday, April 7, at St. Paul’s Church, on 27 Pleasant Street, in Brunswick, Maine. A second service is planned for August in Randolph. In lieu of flowers, donations may be sent to The Randolph Mountain Club, at P.O. Box 279, Gorham, N.H., 03581. Arrangements are under the direction and care of Brackett Funeral Home, Brunswick.