Thomas A. Jones knew when he was a red-haired, freckle-faced boy in Warwick, R.I., that he wanted to be a Marine. He enlisted in the Marine Corps Reserve while in high school during the height of the Korean War, but his parents insisted that he graduate before reporting for active duty.

In 1954, he assumed the stern, straight-as-an-arrow demeanor of a Marine. His military discipline, with stoicism and seriousness about getting the job done right, never left him.

So it came as a surprise to his family in the late 1980s when Jones decided to paint his face partially black, cover his nose with a red ball, don a curly wig and take on the bedraggled persona of a hobo clown named Mr. Beans. He performed at area hospitals for five years and occasionally entertained at birthday parties and his wife's school, always donating any proceeds to the Multiple Sclerosis Society or other charities.

Over the years, Jones, who died Aug. 27 at 69 of a pulmonary embolism, wore many faces -- stoic and sober, surprising and silly, serene and steady. But no matter what role he was performing or what job he was doing, he was always the same stand-up, by-the-book guy -- with a little mixture of straightness and fun, said his family and a co-worker.

After multiple sclerosis short-circuited his military career as a master gunnery sergeant in 1980, he worked for eight years in special intelligence assignments with the Department of Energy's Office of International Affairs and with the Department of the Army's Intelligence and Security Command. From 1988 to 1993, he was a naturalist and Civil War historian with the Fairfax County Park Authority.

"He was a marshmallow for children," said his wife of 47 years, Janice P. Jones. "He really enjoyed introducing them to nature." He created a program for blind children, helping them to experience nature by tasting wood and feeling snakes. He enjoyed decorating the bulletin board with three-dimensional figures.

Working at the Walney Visitor Center and Cabell's Mill in Ellanor C. Lawrence Park in Chantilly, he would take the children on hikes in the woods. They looked for signs of animal life and searched the creek for crayfish.

The long hikes could be physically challenging for anyone. For Jones, it was even more so. Because of the multiple sclerosis, his left leg dragged and he wore a brace and carried a cane. Yet he was pretty good at concealing his condition, said his wife.

Karen Waltman, a naturalist who worked with Jones, said her co-worker used his cane to point out flowers as he walked along the paths. "Accidentally, I called it a cane one time," she recalled. "And he said seriously: This is not a cane; it's a walking stick."

When he could no longer walk in the creek with the children because of its uneven bottom, he walked alongside with the children who were afraid of wading through the shallow water, she said.

He took care of the snakes, frogs and toads in tanks at the center and started an animal care program in which teenagers shared the duty. The program, which began with one boy, now has more than 14 youths, Waltman said.

In late 1992, Jones's attention was diverted to caring for his grandson, Tommy, who was born with a life-threatening condition called omphalocele, causing his vital organs to be outside his body. After Tommy's successful surgery at Children's National Medical Center, when it was time for his parents to return to work, Jones volunteered to share nursing duties with Tommy's maternal grandmother. She watched him in the mornings and Jones did so in the afternoons.

His son and daughter-in-law initially were concerned about Jones's ability to hold Tommy and change diapers. But since he so badly wanted to do it, "we let him. We respected that," said his son, Thomas S. Jones.

He tended to his grandson for five years, and later would pick him up from kindergarten. Jones chronicled his time with Tommy in a series of poems, noting "as his grandfather I spent hours at his side and watched the miracle unfold."

Thomas Alfred Jones was born in Boston and grew up in Warwick. He met his future wife, a Washington native, in April 1957. Within 10 days, he proposed at the Iwo Jima Memorial. By September of that year, they married in a full military wedding at Arlington Chapel. In 1976, they settled in Fairfax.

Throughout the years, he drew cartoons, painted landscapes and wrote lots of poetry, including some for his church's newsletter. He also enjoyed playing with his grandsons, Tommy and Nathan, teasing them at the dinner table or regaling them with stories using hand puppets shaped like a raccoon, a skunk and a very realistic-looking rabbit.

Five years ago, his wife said, he made a booklet of his spiritual poems and sold them to support a program called "All God's Children," which sends the children of incarcerated women to summer camp.

Last week, at his gravesite service at Quantico National Cemetery, Jones received a 21-gun salute. One of his poems, "A Warrior Prayer," was read. For all the soldiers who fought and died in wars from Valley Forge to Desert Storm, he prayed in part:

"O Lord! Upon my knees I pray

They'll be remembered judgment day.

Please find a place for men of war

Far ways from cannon's roar.

When that heavenly muster's called

These noble men will stand up tall,

And when that final trumpet sounds

Within His house true peace is found."

Thomas A. Jones, second from left, retired from the Marines as a master gunnery sergeant in 1980. He later worked as a naturalist and Civil War historian. As a hobo clown named Mr. Beans, Thomas A. Jones performed at hospitals, donating the proceeds to charities.