I am going to tell you about my Unidentified Flying Object. I am going to tell you about it with the understanding that I will accept no mail from persons who feel compelled to tell about experiences with three-eyed persons of the Martian persuasion and who underline their words in red ink. Just because I saw a UFO does not mean that I believe such a thing exists.

To begin, as Lewis Carroll once suggested, at the beginning, I first spotted this particluar UFO about 9 one night. This was two weeks ago and what I did was go out the back of the house with my dog, so that he could do what he had to do and which, strictly speaking, has nothing to do with the UFO but somehow I think all the details are important. Anyway, I went down the stairs and looked up and there it was.

It was something like a telephone or utility wire. It was maybe an inch in diameter and it seemed to float in the air, 10 feet long or so and taut as if attached to something, but it was attached on either end to absolutely nothing. aWhere the spotlight from the back of the house hit it, it seemed illuminated, but the rest of it was dark. It was about 20 feet off the ground most of the time and it was not a wire because, simply stated, there is no wire there. Also, it moved up and down.

I went down the stairs and walked under it -- whatever it was. I walked on the other side of it. I studied it. I tried to find where it began and where it ended. I could not. I thought I might be seeing things so I called my son outside. He saw it, too, and enthusiastically helped me with my experiments. He believes in UFOs and was not startled to have one in his back yard. He is 7, I am quite a bit older. Maybe that is why I was startled.

The two of us walked under it. My son saw it move. He was what is called in science a "control" and I thought that if I moved and the UFO moved and yet my son did not move, that proved that I was not somehow imagining it was moving. I did not, after all, take honor bio in high school for nothing.

In the daytime, it was gone. Both my son and I went to look for it and there was nothing there. No wire. No string. No nothing. The next night it was back. We repeated our experiments. This time I looked down on it from the second floor porch. It was still there.

Now, if it were me reading this column, I would stop at this point, or maybe I would have stopped earlier. I would do that because, a long time ago having studied the whole issue, I decided that I did not believe in UFOs and I no longer want to think about them. The issue is closed. Same for my positions on abortion, the existence of God, the meaning of "nothing" and the issue of whether Lee Harvey Oswald acted alone in killing John F. Kenedy. He did.

I mentioned Oswald because he illustrates the sort of thing I'm talking about. When it was announced, for instance, that tape recordings of the rifle shots indicated more than one gunman, I did not flinch. I merely ignored it, dismissed the new evidence as inconsequential and most people, I think, did the same. Once you make up your mind, you make up your mind. This explains, incidentally, everything William F. Buckley has written in defense of Joe Mccarthy and the FBI.

So, I do not believe in UFOs and I believe that what I saw in my backyard can be explained. But not by me. Nor by my wife. She was out of town on business during the original sightings, but she did come back in time to catch the UFO. My son and I mentioned it at dinner and she laughed. Then my son went outside, called "Mother" and my wife laughed no more. She saw it and she, just for the second, is of stolid, Midwestern stock. Nothing flakery there, thank you.

That, though, was the last night we saw it. It never came back. I have mentioned it to some friends who look at me puzzled and if my son is around, people prefer to talk to him about it. It is comforting to pretend this is the fantasy of a child. I understand. I don't want to deal with it either.

Since then, I've talked it over with my either who nonetheless has kept me on the staff of The Washington Post and suggested that I should have called for a photographer from the office. He is a true newspaperman and he believes that if it's not in the paper, it didn't happen. So not it's in the paper, and not I've told it all. Just one thing I didn't mention. The first night we saw it, my son suggested we squirt the UFO with the hose. I ignored him and he went for the hose to do it himself. I ordered him to stop. Understand, I don't believe in UFOs.

But I don't believe in being unfriendly, either.