The phone hasn't rung at Ken Fassler's house in 10 years. He hasn't received a single piece of junk mail, been roused from sleep by thr trashmen or had his car fefuse to start.

Fassler doesn't have a phone or a mailbox or a car. He doesn't even have an address.

His home is the Potomac River.

For nine years Fassler was caretaker on Offutt's Island, which lies halfway between Maryland and Virginia about 10 miles upsteam from the Washington Monument. It's connected to the mainland by nothing at all.

Last year soaring property vlaues caught up with him. The owner sold the island for an enormous amount of money and the new people wanted it all to themselves.

Fassler, sho'd grown accustomed to simplicity (no mortgage, no rent, no bills, no hassles) thought about what he should do and then set to work like Noah, building a boat. He scrounged 14 oil drums and hauled them to Silver Spring and welded them together. He scrounged a sink and some siding and some aluminum flashing. He cornered some roofing materials, a wood stove and some glass for big picture windows.

In six months he had a floating house, eight feet wide and 16 feet long.

On April 18, one year ago, he tied a rope to his house and canoed over to the Virginia shore. He got ouyt and started pulling, and before long he had his new digs nestled against Virginia trees, held down by a multitude of stout ropes.

Home. Otal cost, womewhere between $250 and $500. He's been there ever sinmce, through snow, cold, rain and six floods.

Fassler, a gray-bearded Californian who came here in trhe early '50s to studey classical gutar with the redoubtable Sophocles Pappas, is not without a purpose. He spends his days in bushy pursuit of answers to questions he feels the great minds of the world aren't even asking.

The studies he spends the lion's share of each day on are principally physics and biochemistry, he says, "but no the things that other people are measuring. We have plenty of information. We just don't know what the overall questions are. We have too much information and not enough wisdom."

Fassler knows what the speed of light is. He wonders,why its what it is, and whether the numerial figure man gives to it means anything. He has a thousand other fundatmental questions, and in search of them and answers to them he compiles great sheets of numbers alluding toweights of elements, angles or orbit of heavenly bodies, chemical components of the human body . He studies anything with a number, then tries to find where the numbers repeat.

"At the core of everything there are certain mathematical basics, "Fassler says. "If you violate these basics, everything gets oput of whack."

Some would say Fassler himself is out of whack. He certainly doesn't play the game of life by strandard rules. He does have a job. Two or three times a week he does odd jobs for a family in Potomac.

"They've tried to give me a raise four times," he said. I make $2.50 an hour. But I won't take a raise. Idon't believe in inflation. The last time the woman said she was saising my salary to $3 an hour and there was nothing I could do to stop her. 'Fine,' I said. 'Then I quit.' She thought she had me over a barel, but I had her over one."

Fassler takes nothing for granted. Once he wondered whether it was true that vegetables and fruits were required diet factors. So he went on a regfimen of corn muffins and peanut butter for three years, with powdered milk and cocoa for liquid. He held up just fine. For a time he drank nothing but rainwater, but these days he's against water altogther.

As eccentric as Fassler is, he's an active friend and partner to the Canoe Cruisers, Association, whose members often launch near Old Anglers Inn, just across the river from him.

"He keeps an eye on the river and he's always willing to lend a hand," said John Seabury Thomson, a CCA stalwart.

But Fassler doesn't plan to be there forever. "A lot of studies just go on and on, and never end," he said. "But I intend to go ahead with my work and inish it, probably this year. Then I can get along with the rest of my life." CAPTION: Picture, KEN FASSLER: TIME AND THE RIVER AND WHY THINGS ARE AS THEY ARE. By Angus Phillips.